Unexamined Risks, Unacceptable Consequences

OIL SPILL PREVENTION and RESPONSE 

IN THE U.S. ARCTIC OCEAN
(Photo credits for cover, clockwise from le!: Oil rig, Stockbyte/Getty Images; spectacled eider, U.S. Fish and Wildlife Service; 

children, Burgess Blevins/Getty Images; bearded seal, Brendan Kelly. Background ice photo: Nuka Research and Planning LLC.)
OIL SPILL

PREVENTION and RESPONSE

IN THE U.S. ARCTIC OCEAN:

Unexamined Risks, 

Unacceptable Consequences

November 2010

Report Prepared by:

Nuka Research and Planning Group, LLC

Pearson Consulting, LLC

Commissioned by:

U.S. Arctic Program, Pew Environment Group

Scientific peer review conducted by three experts in oil spill response, oceanography and Arctic marine ecology.
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OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

Acknowledgments 

We wish to thank three individuals for reviewing this report in its !nal draft form: Nancy Bird, Prince William Sound 

Science Center; Rolf Gradinger, University of Alaska Fairbanks; and one anonymous reviewer. These individuals 

were asked to review the draft because of their diverse perspectives and technical expertise. The purpose of 

this independent review was to provide candid and critical comments on the analysis and reasoning contained 

in the report to assist the Pew Environment Group in making it as sound as possible. Although these reviewers 

provided many constructive comments and suggestions, they were not asked to endorse the conclusions or 

recommendations, nor did they see the !nal report before its release.

We also wish to thank the many people who helped make this report possible:

• Nuka Research and Planning Group LLC sta", especially lead authors Elise De Cola and Tim Robertson, and 

designer Kathleen George.

• Leslie Pearson of Pearson Consulting LLC, for her role as a lead author. 

• U.S. Arctic Program sta", who helped write and develop the report and policy recommendations: Raychelle 

Daniel, Mary Engel, Steve Ganey, Marilyn Heiman, Eleanor Hu#nes, Eleanore Humphries, Henry Huntington, 

Melissa Prior and Marlyn Twitchell.

• For additional editing and layout, we thank the Pew Environment Group’s Publications team: Carol Hutchinson, 

Jerry Tyson and Liz Visser.

• And !nally, Susan Harvey, Andrew Hartsig and Eric Jorgensen, who reviewed drafts of the report and provided 

extensive constructive criticism.
ii NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

CONTENTS

Executive Summary 1

Chapter 1: Introduction 3

1.1 Purpose and Scope 3

1.2 Background 4

1.3 Key Concepts 5

1.3.1 The Arctic Ocean Is Different From Other Areas of the U.S. OCS 5

1.3.2 Government and Industry Oil Spill Plans Underestimate Blowout Risks 6

1.3.3 An Oil Spill Could Devastate the Arctic Ecosystem 7

1.3.4 Oil Spill Response Systems Are Unproved in the Arctic Ocean 8

1.3.5 An Oil Spill Response Gap Exists 8

1.4 Policy Recommendations 9

Chapter 2: The U.S. Arctic Ocean 11

2.1 Characteristics of the Arctic OCS Environment 11

2.1.1 Climate 11

2.1.2 Sea Ice 15

2.2 Transportation Infrastructure 20

Chapter 3: Oil Exploration, Infrastructure and Production Operations and Spill Risks in the Arctic Ocean

273.1 Historical Perspective on Oil and Gas in the Arctic Ocean 28

3.1.1 Worldwide 28

3.1.2 United States Arctic Ocean

3.2 Oil Exploration and Production Operations

3.2.1 Exploratory Drilling

3.2.2 Oil Production 

3.3 Challenges to Oil Exploration and Production in the Arctic Ocean

3.3.1 Seasonal Ice

3.3.2 Extreme Storms

3.3.3 Infrastructure and Logistics

3.4 Potential for Blowouts and Oil Spills from Exploration and Production in the U.S. Arctic Ocean

3.4.1 Well Blowouts

3.4.2 Other Spills from Oil Production Operations

Chapter 4: Impact of Oil Spills on Arctic Environment and Ecology

4.1 Fate and Behavior of Oil Spilled in Arctic Waters

4.1.1 Weathering and Emulsification

4.1.2 Oil-Ice Interactions

4.1.3 Predicting the Fate of Oil in Sea Ice

4.1.4 Long-Term Fate of Oil Spilled in Cold-Water Environments
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OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

4.2 Vulnerabilities of the Arctic Ecosystem to Oil Spill Impacts

4.2.1 Oil Toxicity 

4.2.2 Persistence of Oil Spilled in the Arctic

4.3 Impact of Oil Spills on the Arctic Environment, Ecology and People

4.3.1 Lower Trophic Level Species

4.3.2 Fish

4.3.3 Marine Mammals

4.3.4 Birds

4.3.5 People

Chapter 5: Limitations of Existing Oil Spill Response Technologies in the U.S. Arctic Ocean

5.1 Arctic Ocean Challenges

5.2 Stopping a Subsea Well Blowout

5.2.1 Subsea Well Containment and Control

5.2.2 Relief Wells

5.2.3 Challenges to Well Control in the U.S. Arctic Ocean

5.3 Applying Oil Spill Cleanup Methods in the Arctic Ocean

5.3.1 Spill Tracking, Surveillance and Modeling

5.3.2 Mechanical Recovery Methods

5.3.3 In-Situ Burning

5.3.4 Dispersants

5.4 Research and Development to Improve Oil Spill Response in Arctic Waters

5.4.1 Joint Industry Program on Oil Spill Response for Arctic Waters

5.4.2 Field Exercises and Oil Spill Drills in the U.S. Arctic Ocean

Chapter 6: Gaps in Oil Spill Prevention Planning, Response Capacity and Oversight in the U.S. Arctic Ocean

6.1 Arctic Oil Spill Response Gap

6.1.1 Response Limit Estimates for U.S. Arctic Ocean

6.2 Gaps in Oil Spill Response Planning for the U.S. Arctic Ocean 

6.2.1 Oil Spill Contingency Planning for Chukchi Sea Leases

6.2.2 Planning Assumptions in Shell’s Chukchi Sea Oil Spill Contingency Plan

6.2.3 Gaps in Response Capacity for Subsea Well Blowout in the Chukchi Sea

6.2.4 Gaps in Planning and Response Capacity in the Beaufort Sea

Chapter 7: Recommendations

7.1 Improve Arctic Oil Spill Science, Monitoring and Assessment

7.1.1 Close the Knowledge Gaps Regarding Arctic Oil Spill Impacts 

7.1.2 Improve Spatial Data on Environmental Sensitivities

7.1.3 Develop Arctic Oil Spill Trajectory Models

7.1.4 Consider Cumulative Impacts of Oil Exploration and Production in Arctic OCS

7.2 Assess and Plan for Worst-Case Blowout Risks

7.2.1 Conduct Risk Assessment

7.2.2 Require More Realistic Worst-Case Blowout Scenarios

7.2.3 Improve Oil Spill Prevention Technologies for Arctic Exploration and Production
iv NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

7.3 Improve Arctic OCS Oil Spill Response Capacity

7.3.1 Assess Existing Oil Spill Response Capacity for Oil Spills in Arctic OCS

7.3.2 Require Operators to Demonstrate Oil Spill Response Capabilities During Agency-Led 

Field Exercises

7.3.3 Improve On-Water Oil Spill Response Systems and Techniques for Arctic OCS Conditions 

7.4 Conduct an Arctic OCS Oil Spill Response Gap Analysis

References

Appendixes

Appendix A: Acronyms and Abbreviations

Appendix B: Glossary

List of Figures

Figure 1-1. U.S. Arctic OCS Region 

Figure 1-2. Arctic Coastline.

Figure 2-1. Major Arctic Ocean Storm System During October 2004

Figure 2-2. Erosion of the Arctic Ocean Shoreline Area

Figure 2-3. Arctic Ocean Fog

Figure 2-4. Typical Sea Ice Freeze-Up and Breakup Cycle

Figure 2-5. U.S. Arctic Ocean Sea Ice Maps 

Figure 2-6. Shore-Fast Ice Between Barrow and Point Barrow

Figure 2-7. Surface of Pack Ice in the U.S. Arctic Ocean.

Figure 2-8. Satellite Image Showing Ice Zones in the U.S. Arctic Ocean

Figure 2-9. Images from Early July Ice Breakup, Point Barrow, Alaska, 2010

Figure 2-10. Changes to September Ice Coverage in the Arctic, 1979-2009

Figure 2-11. Airstrips, Ports and Roads in the U.S. Arctic

Figure 2-12. Wainwright, Alaska, Aerial Photograph

Figure 2-13. Overland Transportation Options in the U.S. Arctic During Winter

Figure 2-14. Lack of Major Docks or Ports in the U.S. Arctic Ocean

Figure 2-15. Distance from Barrow, Alaska (in U.S. Arctic Ocean), to Nearest Major Port (Dutch Harbor) and 

Nearest Coast Guard Air Station (Kodiak)

Figure 3-1. Arctic Oil and Gas Provinces and Basins, Showing Existing and Pending Production in the Arctic 

Ocean Worldwide

Figure 3-2. Exploration Wells Drilled in the U.S. Arctic Ocean

Figure 3-3. Existing and Near-Future Oil Production in the Beaufort Sea

Figure 3-4. Map of Active Lease Areas in Arctic OCS
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OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

Figure 3-5. Various Exploratory Drilling Configurations

Figure 3-6. The Kulluk Drill Ship

Figure 3-7. Example of Gravel Island-Based Production in Prudhoe Bay

Figure 3-8. The U.S. Coast Guard Launching a Vessel in the Shallow Waters Near Barrow, Alaska

Figure 3-9. Major Well Blowouts

Figure 4-1. Open Lead Near Point Hope, Alaska

Figure 4-2. Oil-Ice Interactions

Figure 4-3. Example of Ice Formations

Figure 4-4. U.S. Arctic Ocean Habitat for Seabirds That Migrate to Other Areas of Alaska

Figure 4-5. The Impact of Oil on Wildlife 

Figure 4-6. Exposure Pathways to Oil Toxicity

Figure 4-7. Typical Arctic Marine Food Web

Figure 4-8. Polar Bear on Ice

Figure 4-9. Lower Trophic Level Species

Figure 4-10. Whales in Ice

Figure 4-11. Bowhead Whale Migration Routes and Concentration.

Figure 4-12. Herd of Pacific Walrus Hauled Out on Sea Ice

Figure 4-13. Arctic Seabirds

Figure 4-14. Culture and Subsistence

Figure 5-1. Subsea Well Containment System Proposed for Use in Gulf of Mexico

Figure 5-2. Oil Spill Tracking and Surveillance Methods in Arctic Ocean

Figure 5-3. Typical On-Water Mechanical Recovery System

Figure 5-4. Skimmers

Figure 5-5. Stationary Deployment of a Weir Skimmer During Training Exercise

Figure 5-6. Ice Interference

Figure 5-7. Typical On-Water In-Situ Burning Operations

Figure 5-8. Smoke Plume from In-Situ Burn Test

Figure 5-9. Typical Dispersant Application and Monitoring Operations

Figure 5-10. Dispersant Application

Figure 5-11. SINTEF JIP Controlled Study with Pre-Positioned Booms and Response

Figure 5-12. Example of Tank Test for Mechanical Recovery of Oil Spilled in Sea Ice 

Figure 5-13. 2000 Broken Ice Exercise in Beaufort Sea

Figure 6-1. Ice Obstacles
vi NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

List of Tables

Table 2-1. Arctic Conditions That May Affect Oil Exploration and Production Activities

Table 3-1. Exploration Wells Drilled in the U.S. Arctic Ocean, 1970s-1990s

Table 3-2. Alphabetical List of Major Well Blowouts Through 2010

Table 4-1. Oil Weathering Processes Affected by Sea Ice

Table 4-2. Threatened and Endangered Species Found in the U.S. Beaufort and Chukchi Seas

Table 5-1. Typical Arctic Conditions and Potential Impacts on Spill Response Options

Table 6-1. Matrix of Approximate Oil Spill Response Limits

Table 6-2. Environmental Factors Affecting Operational Limitations in the U.S. Arctic Ocean

Table 6-3. Resource Requirements and Operating Limitations
1 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

EXECUTIVE SUMMARY

This report examines the risks, challenges and potential consequences of oil spills associated with 

oil and gas exploration and production in the outer continental shelf (OCS) of the United States 

Arctic Ocean. The April 2010 Deepwater Horizon well blowout in the Gulf of Mexico prompted a 

reconsideration of the potential for a major blowout from proposed oil exploration or production in 

the Arctic OCS. This report was developed to contribute to the policy discussion regarding the risks 

and consequences of such spills. 

Several key concepts underlie the technical information and analysis presented in this report:

• The Arctic Ocean is a unique operating environment, and the characteristics of the Arctic 

OCS—its remote location, extreme climate and dynamic sea ice—exacerbate the risks and 

consequences of oil spills while complicating cleanup. 

• Oil spill contingency plans often underestimate the probability and consequence of 

catastrophic blowouts, particularly for frontier o"shore drilling in the U.S. Arctic Ocean.

• The impact of an oil well blowout in the U.S. Arctic Ocean could devastate an already stressed 

ecosystem, and there is very little baseline science upon which to anticipate the impact or 

estimate damage. 

• Oil spill cleanup technologies and systems are unproved in the Arctic Ocean, and recent 

laboratory and !eld trials (including the Joint Industry Program) have evaluated only discrete 

technologies under controlled conditions. 

• Certain environmental and weather conditions would preclude an oil spill response in 

the Arctic Ocean, yet an Arctic spill response gap is not incorporated into existing oil spill 

contingency plans or risk evaluations.

This report recommends several areas in which additional work is needed to reach a level of su#cient 

planning and preparedness to minimize the potentially adverse e"ects of an oil spill resulting from 

o"shore oil and gas exploration or production in the U.S. Arctic Ocean. Federal agencies should:

1. Conduct baseline studies to better understand the marine ecosystem and increase scienti!c 

knowledge regarding the Arctic ecology and sensitivity to oil spills before introduction of 

new o"shore oil spill risks.

(Arctic moon photo: Mike Dunn/National Oceanic and Atmospheric Administration)
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OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

2. Improve spatial data and mapping of Arctic species, habitat and sensitive ecosystems. 

3. Develop oil spill trajectory models with the capability to model oil fate and behavior in the 

presence of a range of sea ice conditions. 

4. Require operators to plan for the possibility of a worst-case well blowout and adopt all 

available engineering and management measures to prevent blowouts.

5. Conduct full-scale deployment exercises under a range of o"shore Arctic conditions to 

determine the limits for safely and e"ectively mounting a large-scale o"shore response in 

the U.S. Arctic Ocean.

6. Conduct an Arctic oil spill response gap analysis to delineate the upper operating limits of 

existing response technologies in the U.S. Arctic Ocean and then estimate the frequency 

and duration of periods when no oil spill response may be feasible.

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OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences
3 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

1.1 Purpose and Scope

The purpose of this report is to examine the risks, challenges and potential consequences of oil 

spills associated with oil and gas exploration and production in the outer continental shelf (OCS) of 

the U.S. Arctic Ocean. 

The Arctic OCS refers to the federal waters1

 in the Beaufort and Chukchi seas o" the northern coast 

of Alaska (Figure 1-1). This remote, extreme northern portion of the OCS has a harsh environment 

with high winds, extended periods of heavy fog, seasonal darkness, subzero temperatures and 

weeklong storms. As a result, the risks, di#culties and unknowns of oil exploration in the Arctic 

OCS are far greater than in any other area of the OCS. Seasonal sea ice, lack of infrastructure, and 

distances from major population centers present challenges that may heighten the risks of a spill 

occurring while also limiting the potential e"ectiveness of spill cleanup technologies. The prospect 

of mounting a response to a catastrophic spill in the Arctic OCS is daunting, and the consequences 

of a major spill in this region could be dire. Scienti!c knowledge of Arctic ecology is based on 

incomplete information about marine mammals, !sheries and the marine ecosystem, and there 

are no computer models that can predict how an oil spill in the Arctic OCS would interact with 

that dynamic sea ice regime. Arctic regions are already under considerable strain from climate 

change, and Arctic species and ecosystems are highly sensitive to pollutants and much slower to 

recover from damage.

Most Americans will never see or visit the U.S. Arctic Ocean, and most are unaware of how the 

remote location and unique conditions of the Arctic OCS could limit the opportunity to contain 

or clean up an oil spill. Likewise, many Americans may be unaware of the potential harm of a 

catastrophic oil spill to the vibrant and iconic Arctic ecosystem. A primary goal of this report is to 

shed light on how and where existing oil exploration and production activities are conducted in 

the U.S. Arctic Ocean, to discuss proposed new activities, and to put into context the oil spill risks 

associated with these existing and new activities so that policymakers and stakeholders can make 

informed decisions regarding future oversight of oil exploration and production in the Arctic OCS. 

1 Subject to important reserved-land exceptions, Alaska has jurisdiction over submerged lands extending three miles 

from the coastline, and the federal government has jurisdiction over submerged lands from the three-mile mark to the 

seaward limit of the U.S. Exclusive Economic Zone, 200 miles from the coastline. 

INTRODUCTION1

(Walrus photo: Sarah Sonsthagen/U.S. Geological Survey)
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OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

1.2 Background

The April 2010 Deepwater Horizon well blowout in the Gulf of Mexico provided a vivid illustration 

of a catastrophic oil spill resulting from exploratory drilling. The worst oil spill in U.S. history, and 

the largest well blowout worldwide, released at least 50,000 barrels per day for three months 

(Lubchenco et al. 2010). The blowout clearly exceeded the limits of existing technologies to 

contain and clean up marine oil spills, even in the temperate and accessible Gulf of Mexico. 

Figure 1-1. U.S. Arctic OCS Region—!e U.S. Arctic Ocean consists of the Chukchi Sea and the Beaufort 

Sea along the northern coastline of Alaska. State waters extend to three miles from the shoreline. Federal 

waters extend from the state water boundary to 200 miles from the shoreline, with the exception of some 

reserved land. 

600 Fathoms

60 Fathoms

ARCTIC OCEAN

Prudhoe Bay

Deadhorse

Kaktovik

Nuiqsut

Barrow

Atqasuk

Wainwright

Point Lay

Anaktuvuk Pass Dalton Highway

Toolik

Wiseman

Arctic Village

Point Hope

Kivalina

Shishmaref

Umiat

CANADA

Chukchi Sea

Beaufort Sea

State Offshore Boundary – 3 miles from shore

Federal Offshore Boundary – 200 miles from shore

Anchorage

While the Deepwater Horizon well blowout continued in the Gulf of Mexico, Shell Oil began to 

prepare for exploratory drilling operations in federal waters of the Beaufort and Chukchi seas. The 

Chukchi Sea drilling sites were located in an area of the U.S. Arctic Ocean where no oil exploration 

or production currently exists, and exploratory drilling was scheduled to begin in July 2010. The 
5 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

drilling was precluded, however, by Interior Secretary Ken Salazar’s decision not to issue the 

required drilling permits in the Arctic OCS (Bureau of Ocean Energy Management, Regulation 

and Enforcement [BOEMRE] 2010).2

 Shortly thereafter, a federal court ruled that the Minerals 

Management Service (MMS)3

 did not comply with federal regulations when it approved Shell’s 

plan to conduct exploratory drilling in that region of the Arctic OCS. This ruling, along with the 

lessons learned from the Deepwater Horizon spill and the increased scrutiny of the regulations 

and statutes governing oil exploration and production, has shed new light on the fact that federal 

oversight of oil exploration and production activities has not been duly diligent and that additional 

safeguards are needed to ensure that operators foresee and prepare for a worst-case oil spill. (U.S. 

Government Accountability O#ce 2010). 

1.3 Key Concepts

This report was developed to contribute to the policy discussion regarding risks and 

consequences of oil spills from oil exploration and production in the Arctic OCS. The report builds 

on several previous studies, including two reports commissioned by WWF, that considered Arctic 

oil spill response technologies and planning concepts (DeCola et al. 2006, Nuka Research and 

Planning Group LLC 2007b, Nuka Research and Planning Group LLC 2007). Several key concepts 

underlie the technical information and analysis presented in this report.

1.3.1 The Arctic Ocean Is Di!erent From Other Areas of the U.S. OCS

The U.S. Arctic Ocean is a unique part of the OCS whose 

characteristics exacerbate oil spill risks and consequences 

and present practical, logistical, technological and 

operational challenges. The Arctic environment, climate 

and weather a"ect all aspects of oil and gas exploration and 

production activities, but they are discussed in this report as 

they relate to potential oil spills.

Chapter 2 of this report provides an overview of the U.S. 

Arctic Ocean physical environment and describes existing 

and proposed oil exploration and production activities in the 

Arctic OCS. Chapter 2 also includes background information 

about drilling operations in the Arctic Ocean to provide a 

broader context for the discussion of how these challenges 

may increase the potential for an oil spill to occur. It details 

2 On May 27, 2010, Interior Secretary Ken Salazar announced that his agency would not consider applications for 

permits to drill (APDs) for Shell’s proposed exploration wells in the Beaufort and Chukchi seas until 2011. In announcing 

the decision to delay, the Interior Department noted “the need for further information-gathering, evaluation of proposed 

drilling technology, and evaluation of oil spill response capabilities for Arctic waters.”

3 On June 18, 2010, Interior Secretary Ken Salazar issued order No. 3302, reorganizing the MMS and renaming the 

agency BOEMRE. All references in this report to activities conducted before June 18, 2010, use the former agency title, 

MMS.

“"e Arctic imposes more than just an 

inhospitable climate. "e remoteness dictates 

a di#erent operating philosophy. Conventional 

road and rail access are unlikely to be available 

to the majority of ports bordering the Arctic 

seas. Beyond a fundamental lack of facilities, 

there is only a sparse resident population. 

Port facilities tend to be shallow (able to 

accommodate only barge and lightering type 

transfers), are only ice-clear and accessible a few 

months a year, and would not be expected to 

have heavy-li! facilities.”

 Keener and Allan 2009
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OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

the challenges associated with containing and cleaning up an oil spill in this environment, and the 

potential harm that a major oil spill could cause to the region.

Figure 1-2. Arctic Coastline (Photo: Mike Dunn/National Oceanic and Atmospheric Administration)—!e 

U.S. Arctic Ocean and its coastline have unique vulnerabilities to oil spills that should be factored into the 

decision-making process for new exploration or production.

1.3.2 Government and Industry Oil Spill Plans Underestimate Blowout Risks

Oil exploration and production create the potential for an accidental oil spill during all phases of 

activity. Chapter 3 of this report describes the spectrum of oil spill risks associated with o"shore 

exploration and production in the Arctic OCS.

“Risk” is a product of probability and consequence. Understanding the risks associated with an 

activity require (1) the ability to predict the likelihood or probability of such an event occurring, 

and (2) the ability to anticipate the potential adverse consequences of such an event. Spill sizes 

and scenarios may range from a catastrophic well blowout to smaller spills from a pipeline, tank or 

vessel. Very large oil spills and well blowouts are low probability events, but the consequences can 

be disastrous. Most of the planning that has been done to date in the U.S. Arctic Ocean expresses 

the risk of oil spills as being extremely low, based on probability estimates that have been derived 

from spill statistics in other regions of the United States. 
7 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

There have been various estimates of oil spill “risks” in the U.S. Arctic Ocean, but none represents a 

comprehensive estimation of these risks. In order to reduce the potentially catastrophic impacts 

associated with uncontrolled oil spills from oil exploration in the Arctic OCS, it is !rst necessary to 

conduct a comprehensive risk assessment that provides a complete picture of the types of oil spills 

that may occur and what those impacts might be. Speci!c measures must then be identi!ed and 

put in place to reduce these risks either by reducing the probability of such events occurring, or 

putting measures in place to 

reduce the potential adverse 

consequence if a spill should 

occur. To do so requires a 

mature understanding of 

how and where spills might 

occur, and how the timing, 

size and location of spills 

could impact the Arctic 

ecosystem in the short and 

long term.

1.3.3 An Oil Spill Could Devastate the Arctic Ecosystem

Although it is generally accepted that oil spills have the potential to cause signi!cant harm to 

Arctic species and ecosystems, signi!cant knowledge and science gaps still exist. Oil exploration 

and production activities have moved forward in the Arctic OCS against a backdrop of uncertainty 

regarding the potential impact of a major oil spill on Arctic wildlife, ecology and traditional 

human use. A 2007 assessment of worldwide oil and gas activities in Arctic regions emphasizes 

that the current state of knowledge regarding the impact of an Arctic oil spill is extremely 

limited. Knowledge is incomplete regarding environmental conditions, species composition and 

ecological interactions, as well as the potential impact on the people who rely on the Arctic Ocean 

for subsistence. 

The impact of an oil spill in the Arctic Ocean would be in$uenced 

by the location and timing of the spill, the ice and weather 

conditions, and the inherent limitations of the spill response. 

Even a moderate-sized spill in an area where sensitive or 

threatened species are concentrated could have devastating 

e"ects. Similarly, oil that is spilled in the fall might become 

entrapped in newly forming sea ice and might not be accessible 

for cleanup and removal for many months. Many of the oil spill 

response plans developed by the industry for Arctic OCS drilling 

propose to concentrate oil spill response activities within open 

water areas that occur when sea ice is present. However, these 

open water areas—referred to as ice leads or polynyas—are a 

major source of nutrients in the Arctic and are considered to be 

“In the event of an unanticipated blowout resulting in an oil spill, it is unlikely to 

have an impact based on the industry-wide standards for using proven equipment 

and technology for such responses.”

Oil Spill Response Plan for BP Deepwater Horizon Drilling

“A large oil spill, such as a crude release from a blowout, is extremely rare and not 

considered a reasonably foreseeable impact.”

Shell Alaska Chukchi Sea Exploration Plan

“Research is required on a wide range 

of the potential biological e#ects of these 

chemicals under conditions and with 

species and life stages appropriate to the 

Arctic, including, among others, studies 

of acute and chronic toxicity, genetic 

e#ects, and combined e#ects with, for 

example, exposure to sunlight. "is 

includes studies of linkages between the 

diverse sub-lethal e#ects and the risks 

they pose to individuals and populations 

of Arctic animals.” 

Arctic Monitoring and Assessment 

Program 2008b
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OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

of vital importance to the entire marine food web, including marine mammals (Stirling 1997). 

Concentrating oil in these open water areas so that it could be burned or removed with skimmers 

would have unforeseen food web impacts and could increase the likelihood that marine mammals 

will contact the oil as they come up to breathe. Understanding and anticipating these potential 

interactions is critical to the spill planning process.

Policymakers and government oversight agencies cannot make informed decisions about oil spill 

risks and consequences without a better understanding of the basic ecological structures and 

populations of key indicator species in the U.S. Arctic Ocean. Chapter 4 of this report discusses the 

vulnerabilities of Arctic species and ecosystems to oil spill impacts, highlighting the gaps in our 

knowledge regarding the e"ects of a catastrophic oil spill on the Arctic ecosystem.

1.3.4 Oil Spill Response Systems Are Unproved in the Arctic Ocean

Even under ideal conditions, cleaning up an oil spill in the open water is a challenging task. 

The response estimates for the Deepwater Horizon spill show that approximately 25 percent of 

the spilled oil was mechanically removed from the environment through direct recovery from 

the wellhead, skimming or burning. Only 3 percent of the oil was mechanically recovered with 

skimmers and booms (Lubchenco et al. 2010). The 25 

percent total is actually a very high success rate for a 

marine oil spill. If a major blowout were to occur in the 

Arctic OCS, the same mechanical cleanup techniques 

(boats with skimmers and booms) would be applied 

at a much less e#cient recovery rate. Although some 

re!nements have been made to adapt certain types of equipment for use in cold or ice-infested 

waters, there have been no breakthroughs in oil spill response technologies to signi!cantly 

enhance the capacity to recover oil when sea ice is present. The National Academy of Sciences 

(NAS) determined that “no current cleanup methods remove more than a small fraction of oil 

spilled in marine waters, especially in the presence of broken ice” (National Research Council-NAS 

2003).

Chapter 5 describes the challenges associated with responding to oil spills in the remote and 

harsh Arctic climate and the limitations posed by the harsh operating environment and lack of 

infrastructure along the U.S. Arctic coast. E"ective oil spill response in the Arctic OCS requires the 

demonstrated capacity to mount a large-scale e"ort using the existing limited infrastructure and 

to safely and e"ectively operate vessels and equipment under the harsh operating conditions 

typical of the Arctic OCS. The cold climate, seasonal sea ice, lack of infrastructure, and distance from 

major population centers add a layer of complexity and challenge to all aspects of the response. 

1.3.5 An Oil Spill Response Gap Exists

The Deepwater Horizon blowout shed new light on the potential for a worst-case subsea well 

blowout. A spill on the scale of the Deepwater Horizon in the U.S. Arctic Ocean would probably 

cripple the existing response technologies and infrastructure. Environmental and weather 

conditions in the Arctic Ocean make on-water oil spill response operations challenging, if not 

“Today there is no proven response method for 

recovery of large-scale oil spills in ice-infested 

waters.” 

Evers et al. 2006
9 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

impossible. Yet the spill plans developed for U.S. Arctic Ocean exploratory drilling and approved 

by the former MMS were built around the assumption that if a blowout occurred in the U.S. Arctic 

Ocean, 95 percent of the oil would be contained or recovered before it hit the shoreline (Shell 

2010). The much more moderate recovery estimates from the Deepwater Horizon spill—3 percent 

recovered through skimming, 17 percent recovered through subsea containment, 5 percent 

burned, in an area with much more favorable operating 

conditions (Lubchenco et al. 2010)—make the 95 percent 

assumption for the Arctic, or any water body, highly 

unrealistic.

Existing spill response systems will encounter limits during 

Arctic operations. There will be times—days, weeks, or months—when environmental conditions 

will preclude any response at all. During such response gaps, an oil spill in the Arctic Ocean will be 

left untreated until weather or ice conditions improve enough that oil spill response systems can 

be operated. More work is needed to quantify the response gap for the Arctic Ocean.

Chapter 6 discusses the need to quantify the response limits to existing oil spill response systems 

in the U.S. Arctic Ocean and to base oil spill contingency planning on realistic assumptions 

regarding the manner in which sea ice, winds, waves and limited visibility may a"ect spill 

response operations. 

1.4 Policy Recommendations

The key concepts presented in Chapters 2 through 6 of this report provide the basis for the policy 

recommendations in Chapter 7. The section presents recommendations for areas where additional 

research, planning, mitigation and oversight are needed to ensure that all future oil exploration 

and production activities in the Arctic OCS are conducted in a manner that minimizes spill risks, 

maximizes response capacity and ultimately prevents adverse impacts on the environment, 

ecology and indigenous people who rely on a healthy and pristine Arctic Ocean.

“Adverse weather conditions sometimes preclude 

any response at all.” 

Oskins and Bradley 2005
10 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

2.1 Characteristics of the Arctic OCS Environment

The Arctic region can be de!ned by latitude (the Arctic Circle at 60 degrees north) or by 

vegetation, temperature or other geographical or political boundaries (Hassol 2004, Arctic 

Monitoring and Assessment Program [AMAP] 1998). This report uses the term “Arctic” as broadly 

inclusive of areas where Arctic characteristics exist for part or all of the year. The term “U.S. Arctic 

Ocean,” as used in this report, refers to the U.S. Beaufort and Chukchi seas.1 The term “Arctic OCS” 

refers speci!cally to federal waters (three to 200 miles from the shoreline, with the exception of 

some reserved land) in the Beaufort and Chukchi seas (see Figure 1-1).

The physical environment of the Arctic Ocean o" Alaska poses many challenges to oil exploration 

and production activities (Table 2-1). The U.S. Beaufort and Chukchi seas can experience moving 

sea ice, subzero temperatures, extended periods of fog, and weeklong storms with extreme 

winds (International Arctic Research Center [IARC] 2005). The brief Arctic summer has nearconstant daylight, but the winter months are dominated by long hours of darkness and six weeks 

during which the sun never rises above the horizon. All of these factors a"ect oil exploration and 

production activities, but the physical characteristic of the Arctic OCS that most directly a"ects oil 

exploration and production is sea ice.

2.1.1 Climate

The U.S. Arctic Ocean and its adjacent coastline in northern Alaska have an Arctic climate. The 

high-latitude marine region is situated o" Russia’s East Siberian coast and the northwestern and 

northern coasts of Alaska (Figure 1-1), where Paci!c waters meet the Arctic Ocean via the Bering 

Strait. The region is characterized by major seasonal and annual changes in ocean climate and by 

the annual formation and deformation of sea ice (Section 2.1.2). Local winds strongly in$uence ice 

conditions near the coast. The warmest month in Barrow, Alaska, on the U.S. Arctic coast, typically 

is July, when the average temperature is around 39 degrees Fahrenheit. The days in Barrow with 

temperatures below the freezing point total 321 each year. The average temperature is near 30 

degrees in September and near 13 degrees in October. Wind chill is a serious concern 

1 The Northern Bering Sea meets the broadly inclusive de!nition of the Arctic region; however, the Northern Bering 

Sea is not discussed in this report because there are no existing or pending OCS drilling activities in that region.

THE U.S. ARCTIC OCEAN 2

(Arctic icicle photo: Mike Dunn/NOAA)
11

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

for people and equipment operating in the U.S. Arctic, where the average annual wind speed is 12 

mph. When the temperature is 30 degrees, a 12-mph wind creates a wind chill of 20 degrees; at 13 

degrees, a 12-mph wind creates a wind chill of minus 1 degree (Western Regional Climate Center 

2009a and 2009b). 

Table 2-1. Arctic Conditions That May Affect Oil Exploration and Production Activities (AMAP 

2008a, MMS 2007b and Grebmeier et al. 2010).

Characteristics Relevance

Physical

Environment

Cold Di#cult work conditions, particularly in winter; slow weathering of oil compounds.

Light/dark regime Limited visibility and di#cult work conditions in winter; extreme seasonality of 

biological production.

Sea ice Di#cult site access and di#cult operating conditions for vessels. Oil spill response 

systems may be ine"ective. Spilled oil di#cult to locate and track; may migrate with 

ice $oes or become trapped/frozen.

Wind and sea state Hurricane-force storms in fall. Sea states producing up to 20-foot waves.

Biological

Environment

Seasonal aggregation of 

animals

Major impacts possible even from localized spills or other disturbances.

Migration Impacts in the Arctic a"ect other parts of the world, and impacts elsewhere a"ect the 

Arctic.

Short and efficient food webs Disruption to key species may have cascading e"ects for other species.

Human

Environment

Remote, limited access Di#cult to reach by air, water or land during emergency or oil spill, with limited 

capacity to transport equipment and personnel.

Limited infrastructure Lack of resources to support major spill response or other sudden in$ux of personnel 

and equipment.

Small population Signi!cant demographic changes from industrial activities; in$ux of people from 

other places to support activities.

Indigenous people Impacts to subsistence food supply with potential for entire communities to 

face starvation conditions; impacts on local livelihood, culture, environment and 

indigenous rights and interests, including landownership.

The predominant summer winds in the U.S. Arctic Ocean are from the east and northeast, with 

speeds of 10 to 25 mph, but the major storm winds blow from the southwest, a direction that 

gives them maximum fetch (open-water distance over which to blow uninterrupted) for the 

southwest-facing coastline of the Chukchi Sea. The Beaufort Sea is more protected. The higher 

wind speeds progress northward beginning in the Bering Strait in June and continuing into the 

U.S. Arctic Ocean from July to October. In November and December, the maximum winds in 

the area start to decrease with a southward migration into the Chukchi Sea and eventually back 

through the Bering Strait into the Bering Sea, coincident with the sea ice retreat and advance in 

the area. The maximum daily average wind speed2 for Barrow is highest in October (44 mph), 

November (40 mph) and December (35 mph). The yearly variance of wind speeds follows a similar 

2 The maximum daily wind speed is the maximum speed measured over a 24-hour period.
12 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

northward and southward migration, and the highest variance happens in October. Wind data 

collected over the past 10 years from communities along the Chukchi and Beaufort seacoast show 

a substantial increase in the maximum wind speeds in September and October (Western Regional 

Climate Center 2009a and 2009b).

The Arctic climate has been a"ected by global climate change in several ways. One obvious 

impact has been changes to polar ice coverage, with a general decrease in multiyear sea ice 

(Section 2.1.2). Climate change has also resulted in an increased occurrence of “extreme events” 

in the Arctic region (IARC 2005). Atmospheric scientists use this term to describe a variety of 

weather occurrences, from single events to unusual climate variability lasting days or weeks. 

Examples of extreme events include heavy rains, dry spells, strong storms and winds, and extreme 

temperatures. During extreme events (Figure 2-1), atmospheric pressure at sea level, which is 

normally about 1,000 milibars, can drop to 30 to 70 milibars, creating enormous storm systems 

with hurricane-force winds (IARC 2005). 

Figure 2-1. Major Arctic 

Ocean Storm System 

During October 2004

(Source: IARC 2005)—!is 

satellite image shows a 

major storm forming over 

the Bering Sea in October 

2004. !e extreme event 

pounded the northwest 

Arctic with 50- to 80-mph 

winds and caused coastal 

"ooding and major wind 

damage. Extreme storm 

events have become more 

common in the U.S. Arctic 

Ocean, particularly the 

Chukchi Sea, as part of 

global climate change.

Storm surges often 

accompany major Arctic 

Ocean storm events, causing serious local $ooding. The area most susceptible to storm surge 

$ooding is north from Point Lay. Nearshore surface currents $ow primarily northeast, parallel to the 

coast. Storms moving from the west or southwest can develop su#cient fetch for surges up to 10 

feet during the ice-free period from July to October (Fontneau 1990). Many coastal communities 

along the U.S. Arctic Ocean are facing signi!cant erosion because of these increasingly strong 

storm events (Figure 2-2).

Fog is also a major component of the Arctic Ocean climate (Figure 2-3). Low stratus clouds and 

advection fog are relatively common in the warmer months because of the passage of warmer 
13

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

air masses over the cold ice surfaces. Point Barrow averages 12 days of fog per month from May 

through September. During the winter, visibility can be limited by a combination of a short 

solar day, low sun angle, very light snowfall, occasional windblown snow, and low clinging fog 

over leads and other open-water areas. Air over open water in cold winter conditions becomes 

saturated almost immediately because of the low water-vapor capacity of cold air (Fontneau 1990).

Figure 2-2. Erosion of the Arctic Ocean Shoreline Area (Photos: Le! - Benjamin Jones/USGS, 

Right - Shishmaref Erosion and Relocation Commission) (See Figure 1-1 for the location of Kivalina and 

Shishmaref)—Extreme storms are occurring more frequently in the Arctic Ocean, in part because of 

changes in sea ice coverage. Coastal erosion is causing a signi#cant problem for several Alaska villages, 

including Kivalina (le$) and Shishmaref (right).

Figure 2-3. Arctic Ocean 

Fog (Photo: Dr. Pablo 

Clemente-Colon, chief 

scientist, National Ice 

Center)—Sea ice melt pools 

provide some contrast for 

a vessel plying the Arctic 

Ocean in August 2009. 
14 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

2.1.2 Sea Ice

Sea ice coverage varies by season and location. In the U.S. Arctic Ocean, sea ice is typically present 

eight months of the year, from October to June. During the summer, the Beaufort and Chukchi 

seas experience a period of open water (predominantly ice-free, though scattered sea ice may 

be present) lasting approximately three months in the Beaufort and four months in the Chukchi. 

The brief ice-free summer ranges from late June to late October, depending upon location, 

distance from shore, and the conditions of each year. The Chukchi Sea tends to break up before 

the Beaufort and freeze up afterward. Sea ice formation and melting are cyclical, with ice taking 

on di"erent forms (Figure 2-4). Freeze-up begins with “frazil” ice forming !rst as small pieces in 

open water. As frazil ice gradually thickens, it forms “grease” ice and “pancake” ice. Sheets of pack ice 

typically form by late October and persist until spring (late May into June). Breakup begins in June 

or July.

Figure 2-4. Typical Sea Ice Freeze-Up and Breakup Cycle—Sea ice formation and deformation are 

cyclic. !e process through which sea ice begins to form on open water is dynamic and gradual, and ice 

conditions may vary and change considerably within a relatively small geographic area. Ice less than 10 cm 

thick constitutes new ice and includes “frazil,” “grease” and 

“pancake” ice formations that build layers to form 

the pack ice. As solar radiation increases, melt 

ponds appear, melting accelerates, and 

cracks form, and eventually the ice 

disintegrates.

Throughout the eight- to 

nine-month ice season, solid 

or “fast” ice extends from 

the surface to the seabed 

at shallow depths and may 

continue out to water depths 

of 50 to 100 feet, where it 

transitions into what is known as a 

shear zone. The shear zone is a highly 

variable area where ridging and rubble 

occur (Eicken et al. 2006). Seaward of the shear 

zone is pack ice, which may encompass many types of 

sea ice. Pack ice contains young ice (newly formed and typically less than 30 cm thick), !rst-year 

ice and multiyear ice that has survived the previous summer melt season and can measure up 

to 10 meters thick (Arctic Council 2009). Figure 2-5 shows typical ice coverage for the U.S. Arctic 

Ocean based on satellite ice observations from four dates during 2007. Figures 2-6 and 2-7 show 

examples of Beaufort and Chukchi sea ice coverage.

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15

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

Figure 2-5. U.S. Arctic Ocean Sea Ice Maps—!is series of maps shows the progression of U.S. Arctic 

Ocean ice represented by the ice coverage from four days in 2007, the year with the lowest ice concentration 

in recorded history. !ese maps are generally representative of Arctic ice conditions in March, June, 

September and December. September typically has the most open (ice-free) water, and March typically has 

the most solid (pack) ice. June and December are transitional ice periods: June shows the spring breakup, 

and December shows the fall freeze-up. Note that in December 2007, ice coverage was exceptionally low. In 

some years, there will be more land-fast ice in the Beaufort Sea by December. (Adapted from satellite images 

acquired from SIZONET 2010).

Ice-Free Ocean

Mixed Sea Ice

Multiyear Ice

Recent Melt

Anchorage

Ice Coverage in the U.S. Arctic Ocean on June 1, 2007

Melt on Sea 

Ice Surface

ARCTIC OCEAN

Prudhoe Bay

Deadhorse

Kaktovik

Nuiqsut

Barrow

Atqasuk

Wainwright

Point Lay

Anaktuvuk Pass Dalton Highway

Toolik

Wiseman

Point Hope Umiat

CANADA

Chukchi Sea

Beaufort Sea

Ice-Free Ocean

Mixed Sea Ice

Multiyear Ice

Recent Melt

Anchorage

Ice Coverage in the U.S. Arctic Ocean on December 1, 2007

Melt on Sea 

Ice Surface

ARCTIC OCEAN

Prudhoe Bay

Deadhorse

Kaktovik

Nuiqsut

Barrow

Atqasuk

Wainwright

Point Lay

Anaktuvuk Pass Dalton Highway

Toolik

Wiseman

Point Hope Umiat

CANADA

Chukchi Sea

Beaufort Sea

Ice Coverage in the U.S. Arctic Ocean on March 1, 2007

Ice-Free Ocean

Mixed Sea Ice

Multiyear Ice

Recent Melt

Anchorage

Melt on Sea 

Ice Surface

ARCTIC OCEAN

Prudhoe Bay

Deadhorse

Kaktovik

Nuiqsut

Barrow

Atqasuk

Wainwright

Point Lay

Anaktuvuk Pass Dalton Highway

Toolik

Wiseman

Point Hope Umiat

CANADA

Chukchi Sea

Beaufort Sea

Ice-Free Ocean

Mixed Sea Ice

Multiyear Ice

Recent Melt

Anchorage

Ice Coverage in the U.S. Arctic Ocean on September 1, 2007

Melt on Sea 

Ice Surface

ARCTIC OCEAN

Prudhoe Bay

Deadhorse

Kaktovik

Nuiqsut

Barrow

Atqasuk

Wainwright

Point Lay

Anaktuvuk Pass Dalton Highway

Toolik

Wiseman

Point Hope Umiat

CANADA

Chukchi Sea

Beaufort Sea
16 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

Sea ice is variable and complex, and the pack ice is constantly moving and shifting, with variability 

in a single season as well as from year to year. Shoreline ice is typically composed of large rubble 

and boulders, and the surface of the pack ice is highly textured (Figure 2-6 and 2-7). Several 

unique structures or formations may exist within and among the ice zones. For example, leads and 

polynyas3 are openings that can occur in sea ice. Polynyas are caused by o"shore wind conditions 

or warm water upwelling and are biologically rich areas with high rates of phytoplankton 

production. Polynyas are variable features and may open and close depending on conditions 

(AMAP 1998). Leads are openings in ice that are navigable by a vessel (WMO 2005). These, too, are 

variable, and they may occur naturally 

or be created using icebreaking vessels. 

Note that the satellite image in Figure 2-8 

shows a large polynya present between 

the land-fast and pack ice. This large 

open-water area is important to biological 

productivity and is used by marine 

mammals for breathing (Chapter 4). 

Figure 2-6. Shore-Fast Ice Between Barrow 

and Point Barrow (Source: University of 

Alaska Fairbanks Geophyscial Institute 

2010)—A photograph shows shore-fast ice between Barrow and Point Barrow, Alaska, at the convergence 

of the Beaufort and Chukchi seas. Shore-fast ice is present from October to June, with some variability. !e 

photo was taken in June, just before the spring breakup. Note that more ice was present in June 2009 than 

in the June 2007 satellite image in Figure 2-5. Annual variations in sea ice coverage are particularly evident 

during the transitional ice seasons.

Figure 2-7. (Photo: 

Henry Huntington) 

—Surface of Pack 

Ice in the U.S. 

Arctic Ocean

3 Alternative spelling: polynia
17

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

Figure 2-8. Satellite Image Showing Ice Zones in the U.S. Arctic Ocean (Source: University of Alaska 

Fairbanks Geophysical Institute 2010)—Ice covers most of the U.S. Arctic Ocean from October to June. 

Openings known as polynyas (polynias) 

may occur. Some polynyas occur seasonally 

in the same location year a$er year, and 

others may be temporary. Multiyear 

recurring polynyas are ecologically 

signi#cant to a number of Arctic species. 

During the spring, melt ponds will form 

in the pack ice as it starts to break up 

and retreat, beginning with the inshore 

land-fast ice and moving seaward. 

Nearshore ice (shear zone) is the next 

to clear, typically by mid-July (Figure 

2-9). The pack ice (typically in 70 feet or 

more of water) is the last to clear and is 

typically gone by early August (Eicken 

et al. 2006). The multiyear ice pack, 

which is located much farther o"shore, has the potential to advance into ice-free areas during 

the open-water period, but this advancement has not occurred in the Beaufort or Chukchi in the 

past decade. During freeze-up and breakup, ice conditions can vary considerably by location and 

change rapidly over a short period (Eicken et al. 2006).

Sea ice conditions are in a state of $ux because of global climate change. Minimum sea ice 

coverage (and thus maximum extent of open water) typically occurs in September. Observations 

from three decades of satellite imagery (1979-2008) suggest that the lowest sea ice coverage 

occurred during September 2007. Maximum sea ice coverage occurs in March, and observations 

from the past 30 years indicate that this coverage has decreased at a rate of approximately 2 

percent per decade. The most signi!cant declines to the thick multiyear sea ice occurred in the 

central Arctic Ocean, which was observed to decline at a rate of 7 percent per decade from 1978 

to 1998 (Arctic Council 2009). Figure 2-10 illustrates historical changes in Arctic Sea ice coverage, 

with projections to 2040.

Global climate models developed as part of the Arctic Climate Impact Assessment (ACIA) indicate 

that summer ice-free areas in the Arctic Ocean are expected to expand considerably over the next 

century (Hassol 2004). However, there is no indication that winter sea ice coverage will completely 

disappear, meaning that the Arctic OCS will probably continue to have sea ice present in winter 

through at least the next century. Sea ice conditions may become more dynamic in coastal seas, 

with shorter periods of fast ice. These changes to Arctic sea ice are predicted to lead to an increase 

in Arctic shipping, which may increase the risk of oil spills or other accidents. (Arctic Council 2009). 
18 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

Figure 2-9. Images from 

Early July Ice Breakup, 

Point Barrow, Alaska, 

2010 (Source: University 

of Alaska Fairbanks 

Geophysical Institute 

2010)—Satellite image 

taken near Point Barrow, 

between the Chukchi 

Sea (to the west) and the 

Beaufort Sea (to the east). 

!e image shows the #nal 

retreat of land-fast ice and 

the initiation of open water 

in the nearshore Chukchi 

Sea during July 2010.

Naval Arctic Research 

Laboratory (NARL)
19

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

Figure 2-10. Changes to September Ice Coverage in the Arctic, 1979-2009 (Adapted from Arctic Council 

2009 and National Snow and Ice Development Center 2010)—Projected reductions in sea ice coverage 

suggest an increased area available to o%shore development and shipping tra&c through the Arctic Ocean. 

Ice Coverage September 1979

Ice Coverage September 2009

Projected Ice Coverage for Septembers 2040-2060

Arctic Circle

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2.2 Transportation Infrastructure

The Arctic OCS lies north and west of Alaska’s North Slope, which is a remote and largely 

inaccessible region. The Dalton Highway (known as the “Haul Road”) is the sole overland route to 

the U.S. Arctic Coast; it runs 415 miles from Livengood, near Fairbanks, to Deadhorse, which is in 

Prudhoe Bay adjacent to the Beaufort Sea. No roads link the Chukchi seacoast to the rest of Alaska 

or the continental United States (Figure 2-11). 
20 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

Figure 2-11. Airstrips, Ports and Roads in the U.S. Arctic—!e U.S. Arctic coastline in northern Alaska 

is sparsely populated with no major port or dock facilities and only a single road connecting Deadhorse, in 

the eastern part of the U.S. Arctic region, with the city of Fairbanks in central Alaska. !ere are no roads 

connecting the widely scattered communities.

Airports > 5,000 ft

Airports 4,000 to 5,000 ft

Airstrips < 4,000 ft

Dock/Pier

Small Boat Anchorage

Dalton Highway

Trans Alaska Pipeline

Anchorage

LEGEND

0 15 30 60 90 120 Miles

ARCTIC OCEAN

Prudhoe Bay

Deadhorse

Kaktovik

Nuiqsut

Barrow

Atqasuk

Wainwright

Point Lay

Anaktuvuk Pass Dalton Highway

Toolik

Wiseman

Arctic Village

Point Hope Umiat

CANADA

Chukchi Sea

Beaufort Sea
21

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

The North Slope region includes eight main communities (Anaktuvuk Pass, Atqasuk, Barrow, 

Kaktovik, Nuiqsut, Point Hope, Point Lay and Wainwright), and they are not connected to 

each other by road or to the rest of the state by highway. (Figure 2-12 shows an aerial view of 

Wainwright.) 

The regionwide population is approximately 7,400 people (2000 census data). Most of these 

communities have airstrips or small airports and small docks or boat ramps that provide the 

primary transportation link into the communities. People and materials coming into these small 

airports are then moved around via snow machine in the winter, and with ATVs or other vehicles 

along unpaved roads or by vessels over water in the summer. Travel over land is particularly 

challenging in the Arctic summertime, because the thawed tundra is easily damaged by tire 

tracks or even footprints. In the winter, overland travel is easier because the frozen tundra may be 

traversed by snow machine or ATV, and ice roads may be constructed to support larger vehicles 

(Figure 2-13). However, ice roads require time and a large supply of water to construct. An ice 

road six inches thick and 30 to 35 feet wide would require approximately 1 million to 1.5 million 

gallons of water per mile and could cost $200,000 to $250,000 per mile to construct and maintain 

(Department of Energy/National Energy Technology Laboratory 2007).

Figure 2-12. Wainwright, 

Alaska (Photo: Henry 

Huntington)—Wainwright 

is the second-largest 

town in Alaska’s North 

Slope Borough. !e total 

population as of the 2000 

census was 546 people. 

Temperatures in Wainwright 

range from 56 degrees 

below zero to 80 degrees F. 

A 4,500-foot-long gravel 

runway allows plane access, 

but Wainwright is not 

connected to a road system 

and has no port facilities. 

!e coastline is frozen from 

late October through 

early July.
22 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

Figure 2-13. Overland Transportation 

Options in the U.S. Arctic During 

Winter (Photo: U.S. Army)—Overland 

travel is extremely challenging during 

the brief Arctic summer because of the 

lack of a road system. Ice roads (right) 

may also be constructed during the 

winter, but one mile of ice road may 

require as much as 1.5 million gallons of 

water and can cost up to $250,000 

to construct.

Docks are limited along the U.S. 

Arctic coast, and shallow water 

depths along the shoreline make 

vessel access challenging (Figure 

2-14). The nearest major port 

(Unalaska’s Dutch Harbor, in the 

Aleutian Islands) is 1,300 nautical 

miles from Point Barrow. There are limited airstrips, a few with the ability to accommodate larger 

cargo planes, but these are not connected to a road system. The nearest U.S. Coast Guard air 

station is 950 air miles away in Kodiak, Alaska, and no Coast Guard vessels reside in the Beaufort or 

Chukchi seas (Figure 2-15).

Figure 2-14. Lack of Major Docks or Ports in the U.S. Arctic Ocean (Photo: Petty O$cer 1st Class David 

Mosley/USCG)—With no major docks available, shallow dra$ barges and landing cra$ pull right onto the 

beach during ice-free months. Large vessels cannot navigate close to shore and must remain in deeper water, 

transferring their supplies or passengers to smaller boats capable of beach landings. To launch small boats, 

the Coast Guard crews must uncover a boat ramp at Barrow.
23

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

Figure 2-15. Distance from Barrow, Alaska (in U.S. Arctic Ocean), to Nearest Major Port (Dutch 

Harbor) and Nearest Coast Guard Air Station (Kodiak)—Barrow, Alaska, is the northernmost community 

in the United States, located adjacent to the Arctic Ocean at the con"uence of the Beaufort and Chukchi 

seas. !ere are no major docks or port facilities in Barrow or anywhere on the U.S. Arctic coast, nor are 

there U.S. Coast Guard cutters or aircra$. !e nearest major port is 1,300 miles away in Dutch Harbor. !e 

nearest U.S. Coast Guard air station is 950 air miles away in Kodiak, Alaska. !e map below illustrates the 

distances relative to the U.S. mainland.

1,300 Miles

USCG Base

Kodiak

Dutch Harbor

Anchorage

Barrow 950 Miles

725 Miles
24 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

The process of extracting oil and gas from reservoirs in the Arctic OCS region is conducted in 

two broad phases: exploration, during which oil companies conduct studies to determine where 

oil and gas reservoirs are located and how the oil may be extracted from them and production, 

during which more permanent operations are established to extract the oil. Exploration involves 

drilling wells into oil reservoirs under the ocean, and production of oil from wells in the Arctic 

Ocean involves pumping oil from the subsea wells using a range of technologies. (Section 3.2 

describes the basic mechanics of drilling.)

Before an oil company can commence with exploratory drilling in the United States, it must 

purchase a lease. Leasing for oil exploration and production from subsea reservoirs in federal 

waters is managed by the Bureau of Ocean Energy Management, Regulation and Enforcement 

(BOEMRE, formerly the Minerals Management Service) under a !ve-year planning program. 

Once a lease has been secured and the Interior Department has approved the exploration plan, 

exploration can begin, typically starting with seismic studies and other surveys to assess the oil 

and gas production potential, then moving to exploratory drilling in areas considered to have the 

highest potential. If viable reservoirs are discovered through exploratory drilling, the operator will 

move on to oil production. This process takes several years, and a range of permits and plans 

are required.

This section describes the basic mechanics of oil exploration and production operations and 

provides a brief history of oil exploration in state and federal waters of the U.S. Beaufort and 

Chukchi seas. The challenges of oil exploration and production in the Arctic Ocean are discussed, 

and the risks of spills from various phases of exploration and production are considered. 

Because there is currently no o"shore oil production in water deeper than 100 feet in the U.S. 

Arctic Ocean, the oil production technologies discussed here are based on current or proposed 

technologies in other Arctic countries.1

1 The description of oil production in waters deeper than 100 feet is presented for discussion purposes only; the 

authors do not suggest that these operations are feasible in the U.S. Arctic Ocean.

OIL EXPLORATION, INFRASTRUCTURE AND PRODUCTION

OPERATIONS AND SPILL RISKS INTHE ARCTIC OCEAN 3

(Oil rig photo: Stockbyte/Getty Images)
25

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

3.1 Historical Perspective on Oil and Gas in the Arctic Ocean

3.1.1 Worldwide

O"shore exploratory drilling and oil production have taken place in several Arctic regions, 

including the Canadian Beaufort Sea, West Greenland, the Norwegian Sea, the Barents Sea, the 

West Siberian Basin and the Far East Siberian Basins. The Arctic currently produces about a 10th 

of the world’s oil and a quarter of its gas, and Russia is by far the highest-producing Arctic nation, 

contributing 80 percent of total Arctic oil production and 99 percent of Arctic gas (AMAP 2008a). 

Most of this Arctic activity has been concentrated onshore, particularly in the United States. (Figure 

3-1). 

Figure 3-1. Arctic Oil and Gas Provinces and Basins, Showing Existing and Pending Production in the 

Arctic Ocean Worldwide (adapted from AMAP 2008a and Anderson 2010)—Although there are a number 

of major oil and gas provinces and basins in the Arctic region, oil production in the worldwide Arctic has 

been concentrated primarily on land. Increased exploration and production in the Arctic Ocean is expected 

as a result of new drilling technologies and reductions in sea ice coverage.

Far East Siberian Basins

East Siberian Basins

West Siberian Basins

Timan-Pechora Basin

East Barents Sea Basin

Barents Sea

Svalbard

Norwegian Sea

Faroese Shelf

East Greenland

West Greenland

Labrador Shelf

Eastern Arctic

Hudson Platform

Arctic Islands

Central Mackenzie Valley

(mainland NWT and Yukon)

Mackenzie Delta/Beaufort Basin

Beaufort Sea (U.S. OCS)

Northern Alaska (North Slope)

Chukchi Sea (U.S. OCS)

Bering Sea (U.S. Outer Continental Shelf)

$ODVND

&DQDGD

*UHHQODQG

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1RUZD\

8QLWHG

.LQJGRP

,UHODQG

)LQODQG

(VWRQLD

/DWYLD

/LWKXDQLD %HODUXV 8NUDLQH

'HQPDUN

*HUPDQ\ 1HWKHUODQGV 3RODQG

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6ZHGHQ

Chukchi Sea

Disko Bay

Norman Wells

Lofoten Islands

Prudhoe Bay Fields

Yamal (gas only)

Prirazlomnoye

Shtokman (gas only)

Goliat

Snohvit (gas only)

Nenets !elds

Beaufort Sea

Canadian Beaufort Sea
26 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

A combination of factors, including decreasing production from existing reservoirs, new oil 

exploration technologies and reductions in Arctic ice coverage, have led to recent increases in oil 

activities in the Arctic Ocean. Exploration and production from marine facilities farther o"shore in 

the Arctic Ocean create challenges for operators (Arctic Council 2009 and AMAP 2008a).

3.1.2 United States Arctic Ocean

In the U.S. Arctic, oil exploration began in the 1960s and production began in 1977, 10 years after 

the discovery of the Prudhoe Bay oil !eld. That year, the Trans-Alaska Pipeline System (TAPS) was 

completed, connecting Prudhoe Bay production units with a major oil terminal in Valdez, Alaska. 

The majority of the existing oil production infrastructure and oil !elds in northern Alaska are on 

land and in state waters of Prudhoe Bay in the Beaufort Sea. 

Although oil production in the U.S. Arctic Ocean remains clustered in state and nearshore federal 

waters in Prudhoe Bay, some exploration drilling has taken place in federal waters farther o"shore 

in the Beaufort and Chukchi seas. Exploratory drilling in the Arctic OCS was most prevalent 

from the mid-1970s to the mid-1980s. Figure 3-2 shows sites where exploratory drilling has 

been conducted in the U.S. Arctic Ocean. A few of those exploratory drilling projects resulted 

in production from state and federal waters in the U.S. Beaufort Sea from arti!cial islands near 

Prudhoe Bay (Figure 3-3). There are no production operations in the Chukchi Sea. 

Exploration activities in the Arctic OCS declined during the 1990s and into the 2000s. Although 

lease sales continued during this period, little exploratory drilling resulted. There is no concise 

explanation for this trend, but it is reasonable to assume that declining oil prices contributed to an 

economic disincentive to continue exploration in these frontier seas. 

No new exploratory drilling has taken place in the Chukchi Sea since the early 1990s. In 2008, the 

MMS held Lease Sale 193, and as a result of that sale, oil companies leased 2.75 million acres in 

the Chukchi Sea. Several active leases exist in the Beaufort Sea from past lease sales (Figure 3-4). 

Exploratory drilling was planned for the Chukchi and Beaufort seas in 2010 but was put on hold 

because of Interior Secretary Ken Salazar’s decision not to approve !nal drilling permits in the 

wake of the Deepwater Horizon disaster.2

2 Several conditions probably must be met before Shell can proceed with exploratory drilling in the Chukchi Sea: 

(1) the Interior Department must !nalize its revised !ve-year leasing program for 2007-2012; (2) Interior must complete 

additional analysis of Lease Sale 193 to comply with a federal district court order; (3) Interior must approve Shell’s application for a permit to drill; and (4) the Environmental Appeals Board (an independent body within the Environmental 

Protection Agency) must issue a decision on Shell’s air permit under the Clean Air Act. 
27

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

Figure 3-2. Exploration Wells Drilled in the U.S. Arctic Ocean—From 1983 to 1991, exploration wells 

were drilled at 65 sites in the U.S. Arctic Ocean. Sixty of these were drilled in the Beaufort Sea in state and 

federal waters. Five exploration wells were drilled in the Chukchi Sea, all in federal waters farther from 

shore. A few of the Beaufort Sea exploration sites have resulted in production operations (see Figure 3-3), 

but there is no existing or planned production in the Chukchi Sea.

Anchorage

Past Exploration Wells in the Chukchi Sea

(drilled 1983-1991)

Past Exploration Wells in the Beaufort Sea

(drilled 1983-1991)

Trans-Alaska Pipeline

LEGEND

2

3

4 5

1

22 PAA Rig #5, Sandpiper Gravel Island

23 PAA Rig #5, Sandpiper Gravel Island

24 PAA Rig #5, Sandpiper Gravel Island

25 PAA Rig #5, Sandpiper Gravel Island

26 P.N.J.V. Rig #1 Seal Gravel Island

27 P.N.J.V. Rig #1 Seal Gravel Island

28 P.N.J.V. Rig #1 Seal Gravel Island

29 P.N.J.V. Rig #1 Seal Gravel Island

30 SDC/MATT

31 SDC/MATT

32 Nabors 27-E, BF-37 Gravel Island

33 Nabors 27-E, BF-37 Gravel Island

34 Nabors 27-E, BF-37 Gravel Island

35 Nabors 27-E, BF-37 Gravel Island

36 Pool Arctic #5, Tern Gravel Island

37 Pool Arctic #5, Tern Gravel Island

38 Brinkerhoff #84, Tern Gravel Island

39 Brinkerhoff #84, Tern Gravel Island

40 Brinkerhoff #84, Tern Gravel Island

41 Brinkerhoff #84, Tern Gravel Island

42 PAA #4 Tern Gravel/Ice Island

43 PAA #4 Tern Gravel/Ice Island

44 Explorer II Drillship

45 Explorer II Drillship 

46 Canmar Explorer II

47 Canmar Explorer II

48 Beaudril Kulluk

49 Beaudril Kulluk

50 Beaudril Kulluk

51 Beaudril Kulluk

52 Canmar Kulluk

53 Canmar Kulluk

54 Canmar Kulluk

55 Canmar Kulluk

56 Canmar Explorer II

57 Canmar Explorer II

58 Canmar Explorer II

59 Canmar Explorer II

60 GLOMAR Beaufort Sea #1

61 GLOMAR Beaufort Sea #1

62 SSDC/MAT

63 SSDC/MAT

64 Beaudrill Kulluk

65 Beaudrill Kulluk

Exploration Wells

# Name

1 Shell-Popcorn

2 Shell-Crackerjack

3 Chevron-Diamond

4 Shell-Klondike

5 Shell-Burger

6 SSDC

7 SSDC

8 SSDC/MAT

9 SSDC/MAT

10 Beaufort Sea #1, CIDS

11 Beaufort Sea #1, CIDS

12 Beaufort Sea #1, CIDS

13 Beaufort Sea #1, CIDS

14 GLOMAR Beaufort Sea #1 CIDS

15 GLOMAR Beaufort Sea #1 CIDS

16 Spray Ice Island

17 Spray Ice Island

18 United Rig #2, Mukluk Gravel Island

19 United Rig #2, Mukluk Gravel Island

20 SSDC/MAT

21 SSDC/MAT

ARCTIC OCEAN

Prudhoe Bay

Deadhorse

Kaktovik

Nuiqsut

Barrow

Atqasuk

Wainwright

Point Lay

Anaktuvuk Pass Dalton Highway

Toolik

Wiseman

Arctic Village

Point Hope Umiat

CANADA

Chukchi Sea

Beaufort Sea
28 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

Figure 3-3. Existing and Near-Future Oil Production in the Beaufort Sea—Although there are a number 

of oil production operations on land in the U.S. Arctic (not shown on this map), there are only six existing 

or near-future oil production operations from subsea reservoirs in the U.S. Arctic Ocean, all in the Beaufort 

Sea. All production is conducted from arti#cial gravel islands.

Trans-Alaska Pipeline

Pump 

Station 1 Location Operator Oil Field State/Federal Status

#1 Oooguruk – 

Artifi cial Drilling 

Island

Pioneer Oooguruk State In Production

#2 Near Spy Island – 

Artifi cial Drilling 

Island

ENI Nikaitchuq State In Planning for 

2011 Start-Up

#3 Northstar – 

Artifi cial Drilling 

Island

BP Northstar State/Federal In Production

#4 Endicott Main

Production Island

(MPI)

BP Duck Island State In Production

#5 Endicott Satellite

Drilling Island 

(SDI) 

BP

BP

Duck Island State In Production

#6 Endicott SDI

Expansion 

Liberty Federal In Construction

ARCTIC OCEAN

Beaufort Sea

Anchorage Existing and Near-Term Oil Production Sites

Trans-Alaska Pipeline

Federal/State Offshore Boundary

LEGEND
29

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

Figure 3-4. Map of Active Lease Areas in Arctic OCS (Chukchi and Beaufort seas)

Active Beaufort Sea Leases

2008 Chukchi Sale 193 Boundary

Federal/State 

Offshore Boundary Anchorage

ARCTIC OCEAN

Prudhoe Bay

Deadhorse

Kaktovik

Nuiqsut

Barrow

Atqasuk

Wainwright

Point Lay

Anaktuvuk Pass Dalton Highway

Toolik

Wiseman

Arctic Village

Point Hope Umiat

CANADA

Chukchi Sea

Beaufort Sea

Trans-Alaska

Pipeline
30 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

3.2 Oil Exploration and Production Operations

This section describes the basic mechanics of oil exploration (test drilling into a formation 

to determine whether the petroleum resources in that formation are viable to extract) and 

production (drilling into a previously tested or explored reservoir to bring oil to the surface for 

processing, storage and transport). 

Exploratory drilling and subsequent oil production may be conducted from land, concrete drilling 

islands or water. Drilling con!gurations di"er depending upon their location. For drilling in Arctic 

waters, the water depth, seasonal ice conditions and distance from land are all considerations. 

The discussion here focuses on drilling technologies for use in Arctic waters and explains how the 

Arctic marine environment can limit or impair drilling operations.

3.2.1 Exploratory Drilling

Exploratory drilling rigs use diesel engines to generate power to turn a drill bit, which cuts through 

the surface and the rock beneath with the help of hydraulic nozzles that spray large volumes of 

drill $uids pumped down from the surface. As the well bore is extended, the hole is periodically 

cased with metal pipe (known as casing) inserted into the borehole and cemented into place. 

Drilling $uids, known as drilling mud, are pumped down the center of the drill string, which 

refers to sections of pipe that are added as the bit descends. The drilling $uid, which lubricates 

the drill string, removes the cuttings and holds back formation pressure, returns to the surface in 

the annular space between the drill string and the casing or borehole for cleaning and reuse. The 

hydrostatic weight of the drilling mud is the !rst barrier to prevent any oil or gas in the formation 

from intruding into the well. 

Drilling engineers design drilling mud systems with su#cient weight to control the subsurface 

pressure expected for the oil reservoir, but it is not always possible to predict the exact magnitude 

of the subsurface pressure, especially when drilling an exploration well in a previously unexplored 

area (National Research Council [NRC] 2003b). 

If the subsurface pressure exceeds the pressure imposed by the column of drilling mud in the well 

bore, the reservoir formation $uids (e.g., oil and gas) will $ow into the well bore in what is known 

as a kick. A kick can eventually $ow to the surface, potentially causing a blowout (an uncontrolled 

$ow of oil and gas from the well). To prevent a kick from becoming a blowout, drilling rigs are 

equipped with heavy-duty valve assemblies called blowout preventers (BOPs) attached to metal 

casing cemented into the well bore. Properly designed blowout prevention systems should 

control excess pressure at the wellhead, but underdesigned or malfunctioning systems may fail to 

contain the excess pressure, resulting in a release of drilling mud and hydrocarbons. 

Three types of structures have been used to support Arctic exploratory drilling in the United States 

and other countries: (1) arti!cial islands constructed of gravel or spray ice (winter only); (2) bottomfounded or gravity-based platforms such as the Concrete Island Drilling Structure (CIDS); and (3) 
31

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

$oating drill ships (Masterson et al. 1991).3 Arti!cial islands and bottom-founded drill structures 

are generally used in shallow water (less than 75 feet). Bottom-founded or gravity-based platforms 

are massive, dense structures anchored to the ocean bottom by a concrete base with wells drilled 

through it. Bottom-founded drilling is usually limited to water depths of 100 feet or less, but work 

is under way to engineer deeper structures. Drill ships can work in water thousands of feet deep 

(Paulin et al. 2010, Matskevitch 2007). Figure 3-5 shows examples of drilling con!gurations.

One important di"erence between bottom-founded drilling structures and $oating drill ships 

is the location of the BOPs. In the bottom-founded structures, BOPs are located above water in 

an accessible location. In $oating drilling operations, the subsea BOP is located on the sea$oor 

and can be accessed only with divers or remotely operated vehicles. Subsea BOPs are more 

complicated to activate and harder to inspect and test. In the event of a blowout, subsea BOPs are 

more di#cult to access and control. 

Figure 3-5. Various Exploratory Drilling Configurations—!e blowout preventer sitting on the sea"oor 

was the type used with the Deepwater Horizon.

3 Note that Masterson et al. (1991) also discuss jack-up rigs, which are mobile rigs that balance on the sea$oor by 

resting on support legs and can be used in water depths of up to 500 feet but are not generally suited for ice-infested 

waters. Masterson notes that jack-up rigs may be ice-reinforced and adapted for Arctic use in the future, but this has not 

occurred.

Drilling from 

Floating Platform

Gravel Island Drilling Bottom-Founded Drilling Onshore Drilling

O!shore – Deep Water Nearshore – Shallow Water Onshore

Drill ShipWell Casing

Well CasingWell Casing

Land-Based 

Drilling Rig

Well Casing

Onshore 

Drilling Rig

On-Bottom 

Drilling Platform

= Blowout Preventer

Typically < 100 ft

Typically > 100 ft
32 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

From the late 1970s to the early 1990s, 65 exploration wells were drilled in the U.S. Arctic 

Ocean—53 in federal waters and 12 in state waters—most in water depths of less than 72 feet and 

most conducted using bottom-founded drilling structures. Fifteen exploration wells were drilled 

in the U.S. Arctic OCS during this period, at depths of 60 to 220 feet (Table 3-1, Keener and Allan 

2009). 

Drilling was restricted to ice-free periods, which in the Beaufort is typically August to October and 

in the Chukchi is July to October. During the 1985 drilling season, Unocal, Shell and other minor 

partners drilled the !rst well in the U.S. Arctic from a $oating drill ship, the Kulluk (Figure 3-6). This 

operation involved towing the Kulluk to the site in the fall and leaving the drill ship and its support 

$eet, unmanned, at an anchorage over the winter ice season so they would be on site when the 

spring breakup occurred (Gaida et al. 1983, Keener and Allan 2009). 

As interest in Arctic oil exploration has increased, some work has been done to develop models 

for new drill ships built for Arctic service. Although no new drill ships have been constructed, naval 

engineers have proposed an Arctic class of drill ships with hull standards and propulsion design 

similar to other Arctic icebreaking vessels, combined with enhanced blowout prevention systems 

and a higher degree of self-su#ciency so that less-frequent resupply would be required (Allan et al.

2009, Keener and Allan 2009, Masterson et al. 1991, Regg and Kuranel 1992).

Table 3-1. Exploration Wells Drilled in the U.S. Arctic Ocean, 1970s-1990s (Keener and Allan 2009)

Drill Ship Beaufort Sea Chukchi Sea Totals

Kulluk 5 0 5

Canmar/Dome Drill Ships 4 5 9

Barges 1 0 1

Totals 10 5 15

Figure 3-6. e Kulluk Drill Ship—!e Kulluk, built in 1983, 

was the #rst "oating drilling unit constructed for Arctic waters. 

!e Kulluk drilled 12 wells in the U.S. and Canadian Arctic Ocean 

in the 1980s and 1990s. !e Kulluk was purchased by Shell in 2005 

and refurbished to support planned OCS drilling in the U.S. Arctic 

Ocean beginning in 2010. A major alteration of the Kulluk was 

the addition of thrusters, changing the drill ship from a barge that 

required towing to a self-propelled vessel. 

3.2.2 Oil Production

Once an oil well has been drilled, it must be completed so it can be placed in production. 

Additional metal casing is placed in the well bore and cemented in place, a process that stabilizes 

the well bore, prevents collapse and provides pressure control. Inside the casing, valves and 
33

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

piping are installed to control the well pressure and provide a conduit for hydrocarbons to $ow 

to the surface. Production wells are often equipped with emergency shuto" valves (subsurface 

safety valves), which are installed down in the well bore; these valves close in a fail-safe position 

when excessive pressure is encountered in the well bore. Wellhead valves (surface safety valves) 

are also placed atop the well to control the well pressure and route the hydrocarbons from the 

wellhead into a nearby piping transportation or tank storage system. Surface wellhead systems 

are commonly referred to as the “Christmas tree” assembly on a production wellhead, because the 

piping and valve assembly required to control the wellhead pressure is shaped like a tree and is 

adorned with valves and gauges to monitor and control the pressure. The surface safety valve is 

also designed to close if excessive pressure is observed at the wellhead or if a surface leak occurs, 

causing a sudden drop in pressure. 

Oil production begins at the well. Each well produces oil, gas and water in varying proportions. 

Flow lines carry this three-phase mixture to a processing center, which contains a variety 

of equipment, including machines that separate the oil from produced water and gas, and 

equipment to condition the gas. Oil is !ltered to remove sediment and is then considered to be 

sales grade and ready for transport to market. In the U.S. Arctic, oil produced from North Slope 

wells is routed through a crude oil transmission pipeline that carries it to the Trans-Alaska Pipeline 

System (TAPS), which transports the crude oil 800 miles south to the Valdez Marine Terminal for 

shipment to re!neries in the United States and, occasionally, Asia. Natural gas is processed to 

remove liquids, then compressed and reinjected into the reservoir or used as a fuel supply for 

production operations. Produced water (water that is extracted from the well along with the oil 

and gas) is chemically treated and also injected into the reservoir. The reinjected gas and water 

help to maintain reservoir pressure (NRC 2003b).

All oil production in the U.S. Arctic Ocean takes place in state and federal waters of the Beaufort 

Sea (Figure 3-3) from bottom-founded structures based on arti!cial islands (Figure 3-7). As with 

exploratory drilling, production from bottom-founded structures typically occurs in areas where 

the water depth is less than 75 feet. 

Figure 3-7. Example of 

Gravel Island-Based 

Production in Prudhoe 

Bay (Photos: BP)—!e 

Northstar Unit (near le$), 

operated by BP, produces 

from state and federal 

waters in the Beaufort Sea. 

!e drilling operations are 

conducted from a #ve-acre 

man-made gravel island about six miles o%shore. Endicott Island (far le$) is also a man-made island, 45 

acres in size, and is in state waters 2.5 miles o%shore. Northstar operates under seasonal drilling restrictions. 

Drilling is allowed during winter months, when the island is engulfed in shore-fast ice, and is prohibited 

during broken-ice periods. However, production from existing wells continues year-round.

 
34 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

Until recently, bottom-founded production was not considered feasible when water depth 

exceeded 75 to 80 feet (Masterson et al. 1991), although new gravity-based designs allow 

production in water depths of up to 250 feet (Ho" et al. 1994, Matskevitch 2007). If oil production 

were to commence in the U.S. Arctic Ocean in areas where water depths were above the 75- to 80-

foot threshold, the production operations would require some adaptation of those typically used 

for o"shore production in temperate regions: 1) a subsea completion and tieback to a shore-based 

processing center; 2) a gravity-based (bottom-founded) structure; or 3) a $oating production, 

storage and o"-loading facility. None of these types of structures have been constructed or tested 

in the deeper areas of the U.S. Arctic Ocean.

In a subsea completion, wellheads are located on the sea$oor, manifolded together, and the 

produced oil/water/gas is piped directly to an onshore processing center. Subsea completions are 

not easily accessed to test or repair once the drilling rig has moved from the location.

Gravity-based production operations produce oil from subsea wells through the bottom-founded 

concrete structure, and oil is processed and stored onboard. Produced oil would probably be 

transported from the structure via subsea pipeline. A gravity-based structure in the U.S. Arctic 

Ocean would have to be constructed to withstand millions of tons of moving ice. 

3.3 Challenges to Oil Exploration and Production in the Arctic Ocean

Exploration or production from $oating structures in the Arctic Ocean, which would be conducted 

during the brief Arctic summer, must still overcome a number of obstacles.

3.3.1 Seasonal Ice

The short open-water season compresses the exploratory drilling season for operators using a 

drill ship. Even during the summer, ice $oes may be encountered, making it necessary for $oating 

operations to have some contingency for dealing with unexpected or encroaching ice. Ice 

management strategies must be able to handle !rst-year ice and must be prepared to deal with 

multiyear ice, should it encroach on drilling or production sites (Keener and Allan 2009, Hinkel 

et al. 1988).

During the frozen winter, the drill ship and associated support vessels must either be moved o"

site or closed in and left on site. Any equipment left over the winter must be ice class and able to 

withstand severe icing and tolerate temperatures to minus 40 degrees Fahrenheit. Ice can scour4

subsea wellheads or pipelines in shallower water, requiring an extra level of precaution to prevent 

ice scours from damaging wells. Drill ships, $oating processors and associated vessels will need to 

be able to overwinter in an emergency, in case ice conditions cause them to be iced in before they 

can be moved out of the region (Keener and Allan 2009).

4 Ice scouring, sometimes referred to as ice gouging, occurs when collisions between fast (moving) ice and pack ice 

create physical abrasions along the sea$oor. 
35

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

During exploratory drilling in the Arctic OCS in the 1980s and 1990s, several wells took two 

seasons to complete. Reasons for the delays included ice conditions in the Beaufort and heavy 

weather in the Chukchi. Whale migration also caused a suspension of drilling activities because 

of permit requirements imposed on the drilling companies. In an article documenting past 

exploration activities in the Arctic OCS, Regg and Kuranel (1992) describe challenges encountered 

during the 1991 drilling season:

“In 1991, severe ice was responsible for delaying the start of drilling operations in the 

eastern Beaufort Sea until mid-September. This shortened the already limited drilling 

season to roughly 30 days. Chukchi Sea operations were initiated earlier (mid-July), 

but were continuously plagued by hazardous ice !oes moving through the area and 

occasional heavy weather causing excessive vessel motion.”

3.3.2 Extreme Storms

Severe storms are common in the fall and early winter in the U.S. Arctic Ocean and may overlap 

with the end of drilling season for $oating o"shore production; global climate change may 

exacerbate the frequency or intensity of these storms (IARC 2015). During the months when the 

Arctic Ocean is ice-free, high winds and storms may drive higher sea states, with wave heights 

approaching 30 feet. 

3.3.3 Infrastructure and Logistics

Logistical challenges of the U.S. Arctic Ocean necessitate self-su#ciency because of limited 

support and infrastructure in many areas. All of the equipment required for exploratory drilling and 

production—well casings, drill strings, mud, cement, diesel fuel and associated drilling equipment, 

as well as the people required to operate this equipment—must be transported to the drilling 

site by air, land or sea. In the Arctic OCS, the basic logistics associated with supporting $oating 

production are complicated by a lack of transportation infrastructure (NRC 2003b).

A shift from exploration to production in the OCS will require development of waste-disposal and 

water-treatment programs (and possibly facilities), transportation of power generation sources, 

construction of additional infrastructure, and establishment of residential facilities for production 

workers. Logistical support requirements for the life cycle of an oil production facility are 

substantial, including on- and o"-road vehicles, aircraft (!xed and rotary wing), vessels of various 

types and sizes, and trained personnel. The ecological footprint of all these activities is signi!cant, 

and in addition to the risk from oil spills, exploration and production activities also a"ect air and 

water quality (NRC 2003b). 

Oil exploration activities in the Beaufort Sea are concentrated during the winter season, because 

the logistical requirements of drilling activities are more easily met during the winter by building 

ice roads, pads and ice airstrips. A shift to $oating exploration or production operations, which 

would be focused during the summer months, will require the development of new transportation 

methods and corridors and has the potential to be more environmentally damaging (NRC 2003b). 
36 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

In either season, transportation of the 

equipment and personnel required to 

undertake exploratory drilling operations 

farther from shore or in new regions of the 

Chukchi Sea will require signi!cant e"ort 

and planning (e.g., Figure 3-8).

Figure 3-8. (Photo: U.S. Coast Guard)—!e U.S. 

Coast Guard Launching a Vessel in the Shallow 

Waters Near Barrow, Alaska

3.4 Potential for Blowouts and Oil Spills from Exploration and Production in the 

U.S. Arctic Ocean

Oil spills may occur during any phase of oil exploration, production, storage or transportation. 

Potential sources of marine oil spills include well blowouts during subsea exploration or 

production, leaks from subsea pipelines, spills from on-land storage tanks or pipelines that travel to 

water, or vessels carrying oil either as fuel or cargo. Oil spills may be caused by a variety of factors, 

such as human error, structural or mechanical failures or sabotage. Arctic conditions such as sea 

ice, low temperatures, reduced visibility or complete darkness, high winds and seas, and extreme 

storms add to the probability of an accident or error that might cause a spill (Anderson and Talley 

1995, MMS 2007b). 

3.4.1 Well Blowouts

An oil well blowout may occur at the surface or on the sea$oor. Surface blowouts deposit oil on 

the surface of the water, sea ice, drilling platform or other adjacent features. A subsea oil well 

blowout, such as the Deepwater Horizon incident, involves an underwater release in which oil 

and gas travel upward through the water column before reaching the ocean’s surface. Depending 

upon the sea ice formations present when a blowout occurs, the oil may be trapped below the ice, 

may be incorporated into newly forming ice or may spread between ice $oes.

 An uncontrolled oil well blowout creates the largest possible oil spill risk if the oil reservoir 

pressure is high enough to force the oil to $ow to the surface. Unlike a spill from a tank or pipeline, 

a well blowout has a much larger potential volume, depending upon the size and pressure of the 

oil reservoir. Blowouts that occur during exploratory operations may be particularly high in volume 

because the pressures within subsurface reservoirs may not be known. The Deepwater Horizon 

blowout, the largest well blowout worldwide, occurred during exploration drilling, as did the 2009 

Montara well blowout in Australia’s East Timor Sea (Figure 3-9).
37

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

Figure 3-9. Major Well Blowouts (Top photo: Chris Twomey/Environs Kimberley; bottom photo: NOAA)—

In August 2009, the Montara platform (top) experienced a blowout during exploratory drilling in the East 

Timor Sea, Australia. !irty years earlier, the second-largest well blowout (a$er the Deepwater Horizon) 

occurred from the Ixtoc I in Mexico, also from an exploratory well (bottom). Both blowouts were controlled 

by drilling relief wells; the Montara relief well required 10 weeks to complete, and the Ixtoc I required 

nine months. 

Despite their infrequency, 

blowouts are still a threat during 

both exploration and production. 

Although most blowouts do 

not lead to a major oil spill, they 

occur every year. From 1992 

to 2006, the rate in the United 

States was one blowout for 

every 387 wells drilled, for 39 

total blowouts through the end 

of the 1990s (Fairweather 2000). 

The Deepwater Horizon spill 

occurred in unusually deep water, 

but a 2007 MMS study showed 

that most blowouts occur in 

water depths of less than 500 

feet (Fairweather 2000). Several 

other major oil well blowouts 

worldwide illustrate this risk 

(Table 3-2). In addition to the 

environmental damage, Table 3-2 

shows that more than 230 lives 

have been lost because of well 

blowouts.

Data on oil well blowouts in 

the Arctic Ocean are limited 

because oil exploration and 

production have been limited 

in the Arctic OCS. In Alaska’s 

Arctic, 11 well control incidents 

were documented from 1977 to 

2000 in which natural gas and/or 

drilling muds were released to the 

environment (Fairweather 2000). 
38 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

Table 3-2. Alphabetical List of Major Well Blowouts Through 2010 (Source: Oil Rig Disasters 2010, 

ADN 2008)—Though infrequent, well blowouts do occur. A review of major well blowouts worldwide 

shows that at least one blowout has occurred in most years since the mid-1970s. In the past decade 

alone, 16 well blowouts have been documented worldwide, two of which resulted in a major oil spill. 

Well blowouts resulting in reported oil spills are shaded in gray; blowouts that occurred in the United 

States are shown in bold text. *Key: DS—Drill Ship, JU—Jack-Up Rig, LR—Land Rig, P—Platform, SS—

Semisubmersible, S—Ship 

Rig Name / Well Name Year Location Spill Size Rig Type* Comments

Actinia 1993 Vietnam SS Major release

Adriatic IV 2004 Mediterranean Sea, 

Egypt JU Fire destroyed rig and platform; gas blowout

Al Baz 1989 Nigeria JU Burned and sank, !ve fatalities

Arabdrill 19 2002 Saudi Arabia JU Fire destroyed rig and platform

Atlantic No. 3 1948 Alberta, Canada LR Major release, !re; blowout lasted six 

months

Banjar Panji-1 2006 Java, Indonesia LR Mud volcano, major release

Beaver Creek 1A 1967 Cook Inlet n/a Gas to surface

Beluga River 212-35 1962 Cook Inlet n/a Gas to surface

Blake IV/Greenhill 1992 Gulf of Mexico 72,000 to 

112,000 gal. JU Major release, !re

Bohai 3 1980 — JU Fire, 70 fatalities

Cerveza 1983 — P Abandon

Cirque No. 1 1992 North Slope n/a Gas to surface during exploratory 

drilling

Cook Inlet State No. 1 1962 Cook Inlet n/a Gas to surface, exploration well

C.P. Baker 1964 Gulf of Mexico DS Catamaran type, explosion and !re, 22 

fatalities

CPF1-23 1979 Kuparuk Field n/a Gas to surface

Deepwater Horizon 2010 Gulf of Mexico 4.9 million 

barrels (bbl)

Three months required to control 

blowout; five months to complete relief 

well 

Drake Point L-67 1969 Canadian Arctic LR Ice volcano

Eko!sk B 1977 Norwegian CS 202,000 bbl P Major release 

Enchova Central 1984 Enchova Field, Brazil P Fire, lifeboat fell to sea, 37 fatalities

Enchova Central 1988 Enchova Field, Brazil P Destroyed by !re

Ensco 51 2001 Gulf of Mexico JU Setting casing string, !re

F-20 1986 Prudhoe Bay n/a Gas to surface

Funiwa Platform 1980 Nigeria 200,000 bbl P Major release; 14 days to control blowout

Glomar Baltic I 2001 Gulf of Mexico JU —

Glomar Grand Isle 1983 Indonesia DS Fire

Grayling Platform 

(Trading Bay Unit) 1985 Cook Inlet, Alaska P Gas to surface

Gubik #2 1951 Umita, Alaska n/a Gas to surface during exploration drilling

Hasbah Platform 1980 Persian Gulf 100,000 bbl P Major release, 19 fatalities
39

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

Rig Name / Well Name Year Location Spill Size Rig Type* Comments

I-23/Q-20 1994 Endicott, North 

Slope n/a Gas to surface

Ixtoc-I 1979 Mexico 3.5 million 

bbl JU Nine months to cap well

Jim Cunningham 2004 Egypt SS Fire

J-23 1987 Prudhoe Bay n/a Gas to surface

Kavik #1 1969 North Slope n/a Gas to surface during exploration drilling

Keyes Marine 303 1990 Gulf of Mexico JU —

King Christian D18 1970 Canadian Arctic LR Ice volcano

Little Bob 1968 — JU Fire o" La. Coral Drilling, seven fatalities

Lodgepole 1982 Alberta, Canada LR Amoco, major H2S release, two fatalities

Lusi Mud Volcano 2006 Java, Indonesia LR Mud volcano, major release

Maersk Endurer 1980 Gulf of Suez JU Derrick collapse, renamed EDC Setty, estimated three fatalities

Maersk Giant 2006 Norwegian CS JU Shallow gas

Marine IV 2001 Gulf of Mexico JU —

MGS State 17595 No. 1 1962 Cook Inlet n/a Gas to surface, exploration well

Mississippi Canyon 

311A 1987 Gulf of Mexico P Platform tilted

Mobil Moquawkie No. 1 1965 Cook Inlet n/a Gas to surface, exploration well

Moquawkie No. 4 2008 Cook Inlet n/a Gas to surface

Mr. Louie 1963 German CS JU Crater

Montara/West Atlas 2009 Timor Sea, Australia 30,000-

220,000 bbl JU Major spill; size estimates vary greatly; 74 days to drill relief well

NFX Platform A 1999 Gulf of Mexico P Fire

NGI-7 1976 Prudhoe Bay n/a Gas to surface

Ocean King 2002 Gulf of Mexico JU Fire

Ocean Odyssey 1988 UK CS SS Fire, one fatality

Penrod 52 1983 Gulf of Mexico JU Collapsed during blowout

Petrobras P7 2001 Bicudo Field, Brazil P Fire

Petromar V 1981 South China Sea DS Sank after blowout

Placid L10a 1983 SNS, NL P Corrosion

Pride 1001E 1997 Gulf of Mexico P Fire

Ron Tappmeyer 1980 Saudi Arabia JU Hasbah platform blowout, 19 fatalities

Saipem Paguro 1965 O" Ravena, Italy JU Destroyed by !re

Sea Quest 1980 Nigeria SS Sedco 135C, !re, scuttled o" Nigeria

Sedco 135F 1979 Mexico JU Ixtoc-I—Capped 1980 Mar 23

Sedco 252 1989 Indian Coast JU Fire, three fatalities

Ship Shoal 246b 1980 Gulf of Mexico P Killed after one day

Simpson Core Test #16 1948 North Slope n/a Gas to surface while drilling exploration 

well

Simpson Core Test #26 1950 North Slope n/a n/a Oil release to surface while drilling 

exploration well
40 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

Rig Name / Well Name Year Location Spill Size Rig Type* Comments

Snorre A 2004 Norwegian CS P Seabed gas blowout

South Timbalier 26 1970 Gulf of Mexico P Platform lost, four fatalities

Steelhead Platform 1987 Cook Inlet, Alaska P Fire. Unocal, Penrod rig also lost, nine 

months to complete relief well

Sundowner 15 1996 Gulf of Mexico P Fire

Teledyne Movible 16 1989 Gulf of Mexico JU Total loss

Treasure Seeker 1984 Norwegian CS SS Shallow gas

Trinimar Marine W327 1973 Venezuela P Major release

Union Oil Platform A 1969 Dos Cuadras F, 

U.S. OCS

80,000 to 

100,000 bbl P

Major release, 11 days to control 

blowout; spill estimated at 80,000 to 

100,000 bbl

Usumacinta 2007 Gulf of Mexico JU Storm, major release, 22 fatalities

Viking Explorer 1988 SE Borneo DS Explosion and sinking. Total Oil, four fatalities

Vinland 1984 Sable Island, 

N. Atlantic SS Shell, Uniacke G-72

West Vanguard 1985 Haltenbanken, 

Norway SS One fatality

Zacateca 1986 Mexico JU Sank. Perforadora Co

Yum II / Zapoteca 1987 Gulf of Mexico JU PEMEX

Zapata Enterprize 1985 Javan coast JU Fire

Zapata Lexington 1984 Gulf of Mexico JU Fire, four fatalities

Zapata Topper III 1975 Gulf of Mexico JU Sank off La.

The potential oil spill volume from a blowout is equal to the volume of the reservoir that can $ow 

to the surface until the well is controlled. Oil reservoirs may contain billions of barrels of oil and 

may continue to spill into the environment until the well naturally bridges on its own (plugs with 

sand or debris); until the well is controlled by human or mechanical intervention (e.g., capping the 

well, igniting the well, drilling a relief well); or until the subsurface reservoir pressure !nally drops to 

such a level that the oil stops $owing out. Although blowouts are very infrequent, they can last for 

days, weeks or months.

Engineers design drilling operations and manage drilling $uids to reduce the risk of a blowout. 

Drilling $uid systems and blowout prevention systems are critical safety factors, particularly during 

exploratory drilling, when unexpected reservoir pressures may be encountered.

3.4.2 Other Spillsfrom Oil Production Operations

Oil spill risks from production operations tend to increase with the age of the equipment. As oil 

reservoirs age, the balance of $uids extracted may change, with a higher ratio of produced water 

to produced oil, a combination that is typically more corrosive. Valves and piping may eventually 

corrode or erode and face a higher risk of failure or leakage. Saltwater can also corrode pipelines 

and oil production equipment from the outside in. Routine maintenance, inspection, repair and 

replacement programs help to reduce the risk of oil spills from production operations, but they 

never eliminate the risks. There may also be a tendency toward complacency in older production 

operations, a factor that can contribute to the risk of an accident or oil spill.
41

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

As discussed in Section 3.4.1, a catastrophic blowout from a producing well would be the worstcase discharge during production, but several other sources could also cause a damaging spill. Any 

subsea pipeline used to transport oil from production wells to onshore facilities could experience 

a sudden breach that results in a rapid discharge of the pipeline contents. Small, undetected leaks 

from subsea pipelines can also be extremely damaging if they are undetected for long periods. 

Signi!cant amounts of undetected oil can be spilled from pipeline leaks, as occurred in the largest 

oil spill from Alaska’s North Slope production operations in March 2006. In that incident, more than 

200,000 gallons of crude oil were released to the environment onshore through a leak that went 

undetected for several days (Alaska Department of Environmental Conservation [ADEC] 2006).

A release from a subsea pipeline that occurs when sea ice is present may spread under the ice or 

within ice $oes or become incorporated into newly forming ice. A pipeline release at or above the 

waterline or a spill on land that travels to the water would discharge oil to the sea surface. 

It is critical that pipelines are designed with materials that are appropriate for the environment 

and length of expected service. O"shore pipelines experience higher external corrosion rates 

(saltwater exposure), have higher potential to harm the fragile o"shore environment, are typically 

hard to access during most of the year (e.g., buried subsea or under ice) and are more di#cult 

to inspect and repair. Pipelines installed in ice-laden waters must be properly designed and 

constructed with double walls, and in some cases it is necessary to bury the pipeline well below 

the seabed or protect the pipeline with a thick cement casing to avoid ice scouring. Pipelines must 

be protected from internal and external corrosion and erosive forces and should undergo routine 

maintenance, inspection, repair and replacement programs to ensure their integrity. 

In addition to spillage from transmission pipelines, oil may be spilled from storage tanks, facility 

piping or manifold valve systems on o"shore platforms, or from onshore storage tanks required 

along the pipeline route. The potential worst-case oil spill volume would be the volume of the tank 

or tanks or the volume of oil in the piping. The amount of oil discharged into the water depends 

on how much escapes secondary containment around the tanks and piping, and how quickly 

the leak is controlled. Spills from tanks associated with o"shore platforms may $ow directly to the 

water or sea ice surface because these tanks typically have no additional containment around 

them. Prevention systems for o"shore storage tanks and piping may include use of double-walled 

piping, double-walled storage tanks and improved containment structures to capture and pump 

recovered $uids before they reach water. 

Increased vessel tra#c associated with oil production may also present additional spill risks. Oil 

tankers or barges pose a spill risk during oil transfer operations and while in transit. The potential 

spill volume from a tanker or other vessel ranges from a small spill during oil transfer to a complete 

cargo loss. Vessel spills pose an additional response challenge because they can occur anywhere 

along the vessel route. A vessel spill may release hydrocarbons above or below the sea surface, 

depending upon where the tank breach is located.

Spill prevention measures for tankers and other vessels may include structural features such as 

double hulls or double bottoms. Engineered systems that detect leaks or ice or monitor weather 

can also increase onboard safety. Navigational safety programs such as vessel tra#c systems, 

navigational restrictions during periods of adverse weather, and monitoring of vessel tra#c 
42 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

may help to prevent accidents. Prevention measures that target human factors—the human 

or organizational errors that are estimated to cause as much as 85 percent of marine vessel 

accidents—are also important. These may include personnel training, drug and alcohol testing, 

medical monitoring and watch-standing procedures that ensure adequate crew rest (U.S. Coast 

Guard 1998).
43 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

A 2007 Arctic Council study of potential e"ects of oil and gas in the Arctic found that oil and gas 

activities in this sensitive region were likely to increase, including expansion into new areas and 

extension of transportation systems (AMAP 2008b). The U.S. Arctic Research Commission (2010) 

echoed these concerns in its white paper with recommendations for research on oil spills. As this 

expansion progresses, oil spills “have the greatest potential to impact aquatic environments,” the 

commission said (AMAP 2008b). 

To avoid harm to the ecosystem and its many threatened and endangered species (Table 4-2), oil 

and gas operations in the Alaskan Arctic Ocean must be carefully designed to take into account 

both the behavior of spilled oil in regions with sea ice present during part or all of the year, and 

the unique vulnerabilities of the Arctic 

ecosystem to spilled oil (Figure 4-1). This 

chapter describes the fate and e"ect of oil 

spilled in the Arctic marine environment and 

describes the vulnerabilities of Arctic species 

and ecosystems to the spilled oil, and the 

potential short- and long-term impact of oil 

spilled in the o"shore Arctic.

Figure 4-1. Open Lead Near Point Hope, 

Alaska (Photo: Henry Huntington)—!e U.S. 

Arctic Ocean and its coastline have unique 

vulnerabilities to oil spills that should be factored 

into the decision-making process for new 

exploration or production.

4.1 Fate and Behavior of Oil Spilled in Arctic Waters

4.1.1 Weathering and Emulsi"cation

When oil is spilled on water, it begins to weather and change. The presence and formation of sea 

ice can a"ect oil weathering in many ways. Observations from actual spills, laboratory experiments 

IMPACT OF OIL SPILLS ON ARCTIC

ENVIRONMENT AND ECOLOGY 4

(Photo of North Slope: Ground Truth Trekking, 2010)
44

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

and !eld studies provide some insight into oil and ice interactions. This interaction is heavily 

in$uenced by where the oil is released: above or below the ice (Dickins and Fleet Technology 

1992). 

Oil behavior and movement in ice conditions may di"er from those exhibited in ice-free waters. 

For example, spilled oil may not spread as far in the presence of ice $oes or irregularities on the ice 

surface, because the ice may create natural barricades to oil movement (Evers et al. 2004). Oil can 

move hundreds of miles from the spill site, however, if it is trapped under or within a piece of ice 

(Wilson and Mackay 1987, NRC 2003a).

The behavior, fate and weathering of oil spilled in Arctic waters are a"ected by multiple factors, 

including the type of oil; the temperature of the oil and water; and the wind, current, tides and 

weather. The presence of sea ice and low ambient temperatures will slow the weathering process 

and also a"ect spreading and other physical processes (Table 4-1). If the oil is frozen or trapped 

in ice, the weathering process may stall until the oil is thawed and exposed to air and water. Sea 

ice slows the process of water uptake and evaporation (Dickins and Fleet Technology 1992, Evers 

et al. 2004). Evaporation will be slowed by cold weather and may be completely arrested if the 

oil is buried in snow or ice (Singsaas 2005). If the type of oil and the presence of waves lead to 

emulsi!cation, the volume of the oil-water mixture will increase the size of the slick, and other 

weathering processes will slow (NRC 2003a). 

Table 4-1. Oil Weathering Processes Affected by Sea Ice (adapted from Evers et al. 2004)

Process Open Water Extreme Cold or Ice 

Spreading and 

Dispersion

A thick layer of oil grows thinner 

and covers a larger area of water 

(depending on the oil).

Ice acts as a physical barrier (broken ice) or retardant (grease 

ice); oil does not spread or disperse as far and ends up in a 

thicker layer. 

Drift Oil moves with wind/current. Oil will drift separately from the ice at less than 30 percent 

ice coverage, and with the ice at 60 to 70 percent (or greater) 

coverage. Unpredictable in broken-ice conditions.

Evaporation Relatively fast (thin oil !lms). Slower where oil spills are thickened.

Emulsi!cation Higher in areas with breaking 

waves. Rate of emulsi!cation, 

total water uptake, and stability of 

emulsion depend on type of oil.

Total water uptake and rate of uptake may be lower as a 

result of reduced wave activity because of the presence of 

ice.

4.1.2 Oil-Ice Interactions

The fate and behavior of oil spilled into ice-infested waters depends to a large extent on the type 

of ice present and the timing of the release relevant to the ice formation and breakup cycle (Figure 

2-4). Oil may move above or below the ice or become trapped within it (Figure 4-2).

If oil is released underneath a solid sheet of ice (e.g., from a subsea blowout or pipeline rupture), 

it will rise until it reaches the ice cover, then spread laterally and accumulate in crevices under the 
45 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

ice. The rate of spreading is in$uenced by several factors, including the proportionate amount of 

gas, which tends to increase the spreading rate. The velocity of currents under the ice will also 

a"ect the spreading rate (Dickins and Fleet Technology 1992). The rough underside of the ice will 

cause the oil to pool in some places unless the current is strong enough to keep the oil moving 

(AMAP 1998). Late-winter ice tends to be rougher in texture and able to hold more oil pooling 

under its uneven surface. It is estimated that 1.5 million liters of oil per square kilometer (km2

) 

could be stored under late-winter fast ice along the Alaska North Slope (Dickins and Buist 1999). 

Oil spilled on top of a continuous ice sheet will tend to move based on the wind direction and 

velocity (Dickins and Fleet Technology 1992).

Figure 4-2. Oil-Ice Interactions (Bobra and Fingas in AMAP 1998).

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The actual behavior of oil spilled to newly frozen ice (e.g., grease or slush ice, Figure 4-3) has been 

widely variable. Oil has been trapped at the edges of ice pancakes, frozen in place, caught within 

the structure of the grease ice, observed moving under the ice and dispersing as leads open, and 

carried underneath brash ice (Fingas and Hollebone 2003). Ice $oes may transport oil hundreds 

of miles from the spill source. The slick can also move underneath ice $oes (e.g., pancake ice in 

Figure 4-3) or be tossed on top of them in wave action, causing bumping and moving of the $oes 

(Wilson and Mackay 1987). Some studies suggest that oil will move at the same rate and in the 

same direction as ice (Dickins and Buist 1999). Oil movement is more strongly in$uenced by the 

movement of ice at higher ice concentrations (Dickins and Fleet Technology 1992).

Oil trapped under multiyear ice could remain in the marine environment for many years (AMAP 

1998) and may not be released until it slowly migrates to the surface. Some scientists estimate that 

oil could be trapped under multiyear ice for up to a decade (NRC 2003a). Oil spilled on the surface 
46

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

of an ice sheet tends to pool in ice depressions and may be trapped under snow cover. However, 

oil spilled on top of the ice surface will be exposed to the air and subject to evaporation (Owens et 

al. 2005). 

Figure 4-3. Example of Ice Formations (Photos: Mike 

Dunn/NOAA)—Sea ice formation is a highly dynamic 

process, and the type of ice present when an oil spill occurs 

will a%ect the fate and behavior of the spilled oil. Oil spilled 

to newly frozen ice such as grease ice (le$) may move 

under the ice, migrate into openings in the ice or become 

encapsulated in the growing sheet. Oil released when ice 

has begun to form pancakes (below) may move under the 

ice pack or be tossed on top of it by wave action. As the 

ice sheet melts and breaks up, oil will be released back to 

the water. !e level of emulsi#cation will not change much 

while the oil is encapsulated. 

Oil released during freeze-up or breakup will be impeded by grease or slush ice between the 

$oes (Dickins and Fleet Technology 1992). Because of the density di"erence between oil and 

water, spilled oil probably will rise to the surface of a slushy oil and ice mix (Martin et al. in Fingas 

and Hollebone 2003). If a spill occurs during freeze-up when the ice sheet is still forming, oil may 

become encapsulated in the ice. A review of !eld tests and laboratory experiments !nds that oil 

can be partially encapsulated within four hours and fully encapsulated in as little as 24 hours after 

contact with the ice (Fingas and Hollebone 2003). The oil essentially becomes part of the ice sheet 

and will move with the sheet. 
47 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

Conversely, the oil can a"ect ice formation by acting as an insulator to slow ice formation or can 

speed it by reducing wave activity. The presence of oil will typically slow early ice development 

(Ross in Wilson and Mackay 1987). When oil and gas are released together, as in a well blowout, the 

gas may also a"ect the oil by causing fractures or heaving (Dome’s Petroleum Ltd. in Fingas and 

Hollebone 2003).

Areas of open water such as ice leads and polynyas can change oil behavior as well. Polynyas 

and leads will allow oil to spread more rapidly than it would on the ice surface or below the 

ice, causing the oil to pool in those areas (Arctec in Wilson and Mackay 1987). The weathering 

process will resume once the oil is exposed to open water, air and wind in the polynyas and 

leads, unless it is encapsulated by freezing water conditions. Water moving in or out of a lead can 

cause a pumping action, which moves oil out from under ice and into the lead. This is particularly 

common in the early hours of the spill when the oil !rst encounters the ice (Reed et al. 1999).

Oil that is frozen in ice or transported with ice $oes has the potential to end up on the shoreline, 

where the oil can mix with the sediment, form emulsions or cover beaches, depending on the 

type and amount of oil and how much it has weathered. Oil released under ice or encapsulated 

within it could reach the shoreline but be invisible until the ice begins to break up or melt 

(AMAP 1998).

When the spring melt starts, oil tends to move upward through the ice and form pools that will 

begin to weather and eventually be released to the water (AMAP 1998). As ice begins to melt, 

brine channels open up and may allow oil trapped in or under the ice to travel to the surface 

(Dickins and Fleet Technology 1992).

This process of releasing oil from within the ice will accelerate as spring temperatures rise, forming 

increasingly thicker pools. Fine droplets of oil, such as the spray released from an oil well blowout, 

may take more time to reach the surface than a thicker slick (Dickins and Buist 1999). The release 

of encapsulated oil during spring melt has been correlated to the time at which it becomes frozen 

into the ice. In general, the earlier the oil was encapsulated in the ice formation, the earlier the oil 

will be released in the spring. One study found that 85 percent of oil encapsulated into the ice 

sheet early in the fall was released to the surface before spring breakup. Encapsulated oil that has 

not emulsi!ed tends to remain non-emulsi!ed, and emulsi!ed oil entrapped in ice tends to remain 

in its emulsi!ed form (Dickins and Fleet Techonology 1992).

Microorganisms such as bacteria and some fungi slowly degrade petroleum hydrocarbons spilled 

in the marine environment (AMAP 1998). However, degradation is slower in coldwater areas than 

in temperate regions, because the oil tends to be more viscous and does not evaporate as quickly, 

making it less accessible to bacteria (Atlas 1985 in AMAP 1998). 

4.1.3 Predicting the Fate of Oil in Sea Ice

Predicting the fate of oil in sea ice requires new and improved algorithms to take into account 

the seasonal variation, weathering and other factors, described above, that a"ect the behavior of 
48

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

oil spilled on, in or under ice. Standard models used to predict the fate of oil spilled in temperate 

marine waters are inadequate for modeling the fate of oil in dynamic sea ice conditions. Despite 

considerable research into the fate and behavior of oil in sea ice, little progress has been made in 

integrating this information into existing oil spill models.

A 2010 study considering the state of oil spill modeling in ice found:

“Modeling oil spills in ice-infested water is much less developed than oil spill modeling 

in open water. This is not necessarily due to the lack of quantitative understanding 

of the fate and behavior side. ... Overall, it appears that there is a lag between the 

advancement of understanding the fate and behavior and the integration of the 

results into operational oil spill models.” (Khelifa 2010)

The 2010 study, conducted by researchers at Environment Canada, found that existing modeling 

approaches that do include oil-in-ice interactions are more than two decades old and essentially 

use the same parameters as open-water oil spill models, with a correction factor that is meant to 

account for the presence of ice but is oversimpli!ed and not technically accurate (Khelifa 2010). 

Upon reviewing theoretical models of oil behavior in ice conditions, Fingas and Hollebone (2003) 

conclude that the existing models are inadequate because most are tested only against laboratory 

or very small-scale !eld experiments and are unable to adequately replicate the complexity or 

uniqueness of di"erent ice-ridden marine environments. Reed et al. (1999) concluded that the 

ice leads play a dominant role in oil behavior but are not incorporated into most models. It is 

especially challenging to develop accurate modeling algorithms to predict the behavior of oil 

in ice over time, because the characteristics of the oil are constantly changing, as are the ice 

conditions. 

Predicting the fate of oil in the speci!c circumstances surrounding any incident, especially in an ice 

environment, is beyond the capacity of existing models. In fact, in current oil trajectory studies that 

have been completed for the o"shore Alaska Arctic, ice conditions have been excluded entirely 

because of the inability of NOAA models to account for oil-ice interactions. To improve oil spill 

modeling capabilities in sea ice, models must be validated against data from Arctic oil spills or 

large-scale !eld trials. Because of the high variability of oil behavior in sea ice conditions, models 

developed for one region of the Arctic may require some adjustment before being applied to 

other Arctic regions. Data are available for only a limited range of oil and ice types (Singsaas and 

Reed 2006). 

Understanding and predicting how oil and ice may interact in the o"shore Arctic is only one 

component of assessing the potential impact of a major Arctic oil spill. Another equally important 

consideration is how oil spilled in di"erent regions at di"erent times of the year may a"ect the 

Arctic ecosystem.

4.1.4 Long-Term Fate of Oil Spilled in Cold-Water Environments

Follow-up studies of past oil spills, including the Exxon Valdez incident, have increased our 
49 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

understanding of the long-term consequences of oil spills in cold-water regions (AMAP 2008b). 

A 2003 study on impacts of the Exxon Valdez spill found that although most of the oil on the 

beaches was removed in the !rst few years, oil remaining beyond that time was generally found 

in areas that were protected from physical weathering, and further degradation was very slow 

(Peterson et al. 2003). In 2005, Exxon Valdez oil was found only slightly weathered under beaches 

across the spill impact area (Integral Consulting Inc. 2006). The lingering oil remains toxic and 

biologically available, and scientists predict that this subsurface oil may persist for decades (Short 

et al. 2004). 

A series of intentional oil spills was conducted during 1982 and 1983 on Canada’s Ba#n Island 

to study the impact of oil spilled in Arctic environments, focused primarily on shoreline cleanup 

technologies and shoreline impacts. Much of the oil weathering documented on Ba#n Island and 

in Prince William Sound was due to physical processes. Low temperatures, lack of sunlight and ice 

cover slow all forms of oil weathering—in addition to the slowing of bacterial degradation by cold 

weather—causing oil to linger in cold-water environments longer than in more temperate regions 

(AMAP 2002).

The long-term e"ects of oil spills have also been documented in Cape Cod, Mass., where recent 

studies published by the Woods Hole Oceanographic Institution found that oil remains in the 

sediment layer of some coastal marshes from a 1969 oil spill. The lingering oil continues to a"ect the 

behavior of burrowing !ddler crabs, which avoided digging burrows into this oiled sediment layer. 

The crabs have also shown signs of toxic e"ects from the 38-year-old oil (Culbertson et al. 2007).

4.2 Vulnerabilities of the Arctic Ecosystem to Oil Spill Impacts

The U.S. Arctic Ocean hosts a productive ecosystem and provides vital habitat to walrus, polar 

bears, ice-associated seals and whales, along with seabirds, !sh and myriad smaller organisms that 

support a complex food web (Figure 4-4). Arctic species are well adapted to the area’s conditions 

and are found nowhere else in the United States. Millions of birds and various species of whales 

migrate great distances to the Arctic each year. More than 100 species of !sh—including Arctic 

cod, capelin, herring and sa"ron cod—underpin the region’s marine food chain.

Ice is present in the Arctic Ocean for much of the year, and the interface between ice and water is 

the heart of the Arctic ecosystem. A spring bloom of phytoplankton at the sea ice margin forms 

the base of the food chain. Cracks in the ice provide spaces for marine mammals and birds to 

surface to breathe, and ice provides a platform for animals to rest, hunt and give birth (Smith and 

Barber 2007).

The Arctic Ocean is not a homogeneous environment, and certain areas are especially important 

to the ecosystem. Among the most important are the openings in the ice, both at recurring 

polynyas (patches of open water within the sea ice) and at the edge of the primary ice pack. 

This edge moves hundreds of miles as the ice expands and retreats with the seasons. Additional 

important ecological areas are likely to be found in areas where the sea$oor community is 

especially diverse or productive. Other important areas include the migration corridors of whales 
50

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

and other marine mammals, the areas under ice where some northern !sh species spawn and 

leave their eggs to incubate over winter and hatch in the spring, as well as the sea bottom areas 

where some birds and marine mammals are known to feed (AMAP 2008b). 

Figure 4-4. (Photo: Henry Huntington)—e U.S. Arctic Ocean Habitat for Seabirds at Migrate to 

Other Areas of Alaska

4.2.1 Oil Toxicity

Oil comprises thousands of chemical compounds, with varying levels of toxicity to wildlife and 

habitat, based on a number of factors. Generally speaking, the water-soluble fractions (WSFs) and 

volatile organic compounds (VOCs) of oil are the most acutely toxic components, because they 

are the components of oil that evaporate into the air or mix into marine waters and often cause 

direct harm to organisms. These components—which include benzene, naphthalene, xylene and 

toluene—are toxic to wildlife and to humans. As oil remains in the environment and weathers, the 

WSFs and VOCs are typically lost, and the remaining oil tends to have proportionately higher levels 

of polycyclic aromatic hydrocarbons (PAHs). These are also toxic to humans and wildlife and have 

the potential to linger in the environment for years (AMAP 2008b).
51 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

Impacts on wildlife from oil toxicity occur at the individual and the group level. Individual impacts 

include death, disease, impaired reproduction, genetic alterations, changes to endocrine or 

immune functions, hypothermia and a range of other biological disorders. Group-level impacts 

include changes to local population sizes, community structures and overall biomass (Albers 2003 

in AMAP 2008b).

 The most obvious toxic impact of spilled oil is direct contact with wildlife and habitat. Images of 

oiled animals and shorelines dominate typical media coverage of major oil spills. Yet toxic impacts 

from spilled oil persist beyond direct oiling, and the long-term toxicities and complex interactions 

between spilled oil and ecological processes are still the subject of considerable research and 

debate (AMAP 2008b, Bu"agni et al. 2010). Although oiled wildlife provides the most vivid 

images of a spill’s impact (Figure 4-5), the level of ecosystem harm is much greater than the acute 

mortality would suggest. Long-term ecosystem impacts come from chronic exposure to oil in 

sediments and beaches, reduced !tness of animals exposed to sublethal doses of oil, and impacts 

through the food web (AMAP 2008b). 

Figure 4-5. e Impact of Oil on Wildlife (Photos: below le!, Exxon Valdez Oil Spill Trustee Council; right, 

Paul Flint/U.S. Fish and Wildlife Service [USFWS])—Direct oiling is only one way that spilled oil may harm 

animals; other less-visible impacts include loss of fertility, interruption to feeding activity, and metabolic 

disorder. 

Plants and animals are exposed to oil toxicity through a 

number of pathways. Typically, mammals are exposed 

primarily through ingestion of contaminated food and water, 

inhalation of VOCs, or dermal absorption of hydrocarbons 

through the skin or fur. In mammals, oil is metabolized in the 

liver, reducing the overall concentration of PAHs and other 

toxic compounds in the organs and tissues. The byproducts 

of hydrocarbon metabolism may also have toxic e"ects in 

mammals. Oil toxicity exposure pathways and metabolism 

in birds are similar to those in mammals, with the additional 

exposure pathway of transferring oil through the surface of 

incubating eggs. Fish and aquatic species can be exposed to 

waterborne 

hydrocarbons 

through the 

gills, through 

ingestion or 

by physical 

contact. Plant 

species (both 

terrestrial and 

marine) can 
52

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

be exposed through direct contact (deposition) on the plant structure or absorption through the 

stomata or roots (Albers 2003 in AMAP 2008b). Figure 4-6 depicts typical exposure pathways for 

mammals, !sh, birds and plants.

Figure 4-6. Exposure Pathways to Oil Toxicity (AMAP 2008b)

Translocation of 

hydrocarbon 

by-products 

within plant

Absorption 

through stomata

Absorption by 

root

DEPOSITION ON PLANT SURFACE

Transfer of oil 

to eggs during 

incubation

Inhalation of 

volatile fractions

Ingestion 

through diet

Ingestion 

through 

grooming

Liver

(major site of 

hydrocarbonmetabolism)

Lungs

(major site of 

exposure for 

inhaled 

components)

Dermal 

absorption

Inhalation of 

volatile 

fractions

Ingestion 

through diet

Ingestion 

through 

grooming

TARGET ORGANS

Ingestion 

through diet

Absorption 

through gills

LIVER

(major site of hydrocarbon metabolism)

ROUTES OF EXPOSURE

4.2.2 Persistence of Oil Spilled in the Arctic

The persistence of oil is particularly problematic in cold environments, where biological 

degradation is greatly slowed. In an experimental oil spill on Ba#n Island in Arctic Canada, the 

biological degradation was determined to be negligible after two years (Humphrey et al. 1987). 

Twenty years later, although most of the original hydrocarbons had degraded, some samples had 

not degraded, and they contained toxic oil similar in composition to freshly spilled oil (Prince et 

al. 2002). Metabolic rates of bacteria are slowed in cold waters, and oil-degrading bacteria are 

relatively rare in the Arctic (AMAP 2008b). A study of bacterial oil degradation showed a latitudinal 

gradient, with water from Barrow, Alaska, showing slower degradation than water from Valdez, 

Alaska, and water from the Fletcher T3 ice island (a $oating island in the Arctic Ocean north of 

Barrow) showing the slowest degradation of all (Arhelger et al. 1977 in AMAP 2008b). Bacteria from 

sediments in the Beaufort and Chukchi seas were also shown to be very limited in their ability to 

metabolize hydrocarbons (Braddock et al. 2004 in AMAP 2008b). 

Life phase is also a consideration in evaluating the potential toxicity of spilled oil; the larval or 

young stages of many organisms are particularly sensitive to oil, and the impact of exposure may 

not be obvious until years later and will a"ect future generations (Peterson et al. 2003). One lesson 

from the Exxon Valdez spill was that !sh embryos and larvae are far more sensitive to oil than 

are adult !sh, making previous toxicity calculations a drastic underestimate. Chronic exposure 

to weathered oil was toxic to young pink salmon and herring at concentrations 1,000 times 

lower than the level required to have acute e"ects on adult !sh, showing substantial impacts at 

concentrations as low as 1 part per billion (Peterson et al. 2003). Some of the e"ects did not show 
53 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

up until much later in the life of these !sh. Hydrocarbons are rapidly taken up from the water 

by !lter-feeding invertebrates such as clams and mussels (Majewski and Scherer 1985 in AMAP 

2008b) and are consumed with contaminated sediments by bottom-feeding invertebrates. The 

contaminants are known to bioaccumulate in their organs. Invertebrates metabolize hydrocarbons 

more slowly than do vertebrates, and in areas with contaminated sediments, they can be 

continually reexposed (AMAP 2008b). After the Exxon Valdez spill, clams and other invertebrates 

living in subtidal and intertidal areas with contaminated sediments remained contaminated for 

more than a decade, a"ecting animals that fed on them (Peterson et al. 2003). Studies in Prince 

William Sound from 1999 to 2003 showed that some species, including harlequin ducks and sea 

otters, were still ingesting toxic oil compounds from their food sources and had not recovered as 

expected (Peterson et al. 2003). 

Exposure to sunlight can greatly increase the toxicity of PAHs, complicating the determination 

of risk levels. Photo-enhanced toxicity can occur when PAHs are exposed to sunlight before 

organisms encounter them, when exposure is simultaneous or when small translucent organisms 

(such as larvae, eggs or plankton) are exposed to PAHs and then to sunlight. For some compounds, 

the toxicity can be increased up to 400 times (Landrum et al. 1987 in AMAP 2008b). Arctic species 

have not been speci!cally studied, but the increased toxicity has been shown for sub-Arctic 

species of copepods and herring (Barron et al. 2003). This e"ect could have a signi!cant impact 

in the Chukchi or Beaufort Sea if organisms were exposed to an oil spill during the near-constant 

daylight of the summer open-water season, either from a spill at that time or from a spill under or 

into ice that melted out in the spring.

4.3 Impact of Oil Spills on the Arctic Environment, Ecology and People

Oil can persist in the Arctic environment for decades, continuing to have toxic e"ects long after 

the initial spill. Most of the published data on oil spill impacts are based on research from past 

spills in Arctic and other cold-water regions. Based on this relatively small data set, we have a 

limited understanding of the actual and potential negative e"ects of spilled oil on the natural 

environment and the human populations that depend upon this environment (AMAP 2008b).

Characteristics of many Arctic species put them at a heightened risk for impacts from oil spills. 

Many Arctic animals have long life spans and slow reproductive rates, potentially prolonging 

population level impacts. Some animals that are high on the food chain already experience the 

e"ects of bioaccumulation of persistent organic pollutants. As a predator consumes its prey, the 

toxins in the body of the lower-level organism are incorporated into the predator’s body in what is 

known as bio-magni!cation. This continues in each predator-prey interaction, and animals at the 

top of the food chain (or food web, as shown in Figure 4-7), such as polar bears and humans, can 

accumulate high levels of these toxins (AMAP 2002). 
54

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

Figure 4-7. Typical Arctic Marine Food Web (Source: Arctic Climate Impact Assessment 2004)

The behavior of Arctic animals can in$uence their vulnerability to the e"ects of oil. Arctic species 

often aggregate in large numbers and are sometimes con!ned to open-water leads where oil may 

concentrate, increasing the chances that a spill will a"ect a large number of individual animals. 

Several species that spend all or part of the year in the U.S. Arctic Ocean are already protected 

under the Endangered Species Act and are facing ongoing and increasing stresses because of 

global climate change (Table 4-2 and Figure 4-8). All marine mammals also are protected under 

the Marine Mammal Protection Act. 

One of the principal challenges confronting Arctic managers and decision-makers is the lack of 

integrated and comprehensive information about the composition, structure and functioning 

of Arctic marine ecosystems (e.g., Richter-Menge et al. 2008, North Paci!c Fishery Management 

Council [NPFMC] 2009). Even basic information, such as knowledge of the species that inhabit the 

U.S. Arctic Ocean permanently or seasonally, is substantially incomplete, resulting in an incomplete 

understanding of marine ecosystem structure and functioning. Without adequate scienti!c 

information about the Arctic marine species, we do not have the ability to determine whether impacts 

of oil spills on marine species will be signi!cant (MMS 2007a). 

The NPFMC has set an example of how to sustainably manage natural resources in the Arctic 

by taking a science-based and precautionary approach toward !shery management (2009). 

The council adopted a !shery management plan that prohibits commercial !shing unless new 

information demonstrates that it can be conducted sustainably, without harming the ecosystems 

or peoples of the Chukchi and Beaufort seas. The council acknowledged that current scienti!c 

information is insu#cient to accurately predict the impact of commercial !shing on ecosystems 

and subsistence activities in the Arctic and decided to take a proactive and precautionary 

approach.
55 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

Table 4-2. reatened and Endangered Species Found in the U.S. Beaufort and Chukchi Seas

(Source: USFWS 2010a)

Common Name (Species Name) Threatened or Endangered Location Within U.S. Arctic Ocean 

(Beaufort and Chukchi Seas)

Bowhead whale (Balaena mysticetus) Endangered Beaufort and Chukchi seas

Fin whale (Balaenoptera physalus) Endangered Chukchi Sea (occasional)

Polar bear (Ursus maritimus) Threatened On sea ice and coastlines of Chukchi 

and Beaufort seas

Spectacled eider (Somateria "scheri) Threatened Chukchi Sea

Bearded seal (Erignathus barbatus) Candidate for listing Beaufort and Chukchi seas

Ringed seal (Phoca hispida) Candidate for listing Beaufort and Chukchi seas

Paci!c walrus 

(Odobenus rosmarus divergens)

Candidate for listing Chukchi Sea

Figure 4-8. Polar Bear on Ice (Photo: Canadian Coast Guard)—!e polar bear was declared a threatened 

species under the Endangered Species Act in 2008. Changes to polar ice coverage are putting pressures on 

polar bear populations. A major oil spill in the U.S. Arctic Ocean could harm or kill polar bears that are 

exposed to spilled oil.
56

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

4.3.1 Lower Trophic Level Species

Lower trophic level species refer to those at the bottom of the typical food web. An experimental 

exposure of Arctic phytoplankton to oil caused signi!cant and di"erential mortality, with some 

types of phytoplankton, such as diatoms, proving far more sensitive than others (AMAP 2008b, 

citing Hsiao 1978). Even if plankton numbers recovered, a large oil spill could cause a substantial 

shift in species composition at the bottom of the food chain that would have reverberating 

impacts across the food web. 

Benthic invertebrates are important food sources for Arctic species such as the walrus and gray 

whale. Amphipods (Figure 4-9), which are bottom-dwelling invertebrates that scavenge detritus 

(dead food particles) on the sea$oor, are particularly sensitive to certain toxic components of oil 

(NRC 1985 in AMAP 2008b). Amphipods grow more slowly in the Arctic, and populations that are 

negatively a"ected by a spill may be slow to recover and may also cause a shift in the food web. 

For example, during the !rst !ve years after the 1996 Sea Empress spill in the United Kingdom, 

amphipod populations virtually disappeared and were replaced by polychaetes, a type of marine 

worm (Edwards and White 1999 in AMAP 2008b). Ten years after the 1978 Amoco Cadiz spill o"

the coast of France, populations of amphipods had recovered to only 39 percent of pre-spill levels 

(Dauvin 1989 in Highsmith and Coyle 1992). 

Although there are limited data on recolonization of sea$oor areas a"ected by oil contamination, 

other natural processes, such as ice scours, have been shown to disrupt Arctic bottom-dwelling 

communities. A study on recolonization of bottom-dwelling organisms after ice scours showed 

that recolonization is a slow process in the Arctic, and only about 65 percent of the organisms 

disrupted by an ice scour had returned nine years after the disturbance (Conlan et al. 1998). Large 

mollusks (snails and mussels) are typically among the last organisms to recolonize disturbed areas. 

Figure 4-9. Lower Trophic Level 

Species (Photos: NOAA)—Lower 

trophic level organisms, such as 

amphipods (far le$) and diatoms 

(le$, with amphipod), provide a 

link between lower- and upper-level 

trophic organisms within the short, 

e&cient Arctic food web. 

4.3.2 Fish

Larvae, eggs and young are generally more sensitive to PAHs than are adult !sh (Peterson et al.

2003). In the U.S. Arctic Ocean, the life histories of pink salmon and capelin put these two !sh 

species at an elevated risk of being a"ected by oil spill toxins. Salmon and capelin spawn during 

the open-water season (when drilling activity would be likely to take place) in large concentrations 

in nearshore areas (MMS 2008). Capelin are highly speci!c with regard to their spawning habitat, 
57 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

and salmon generally return to their birth streams, putting both at risk if their spawning habitat 

were exposed to an oil spill (MMS 2008). 

As seen in the aftermath of the Exxon Valdez spill, contamination of nearshore spawning habitats 

can persist for many years, a"ecting multiple generations of young !sh. Paci!c herring populations 

in Prince William Sound su"ered a dramatic decline after the 1989 spill, which occurred a few 

weeks before the spawning season. It is estimated that 40 to 50 percent of the egg biomass was 

exposed to oil from the spill, as was a signi!cant proportion of the adult herring. Lesions and 

elevated hydrocarbon levels were documented in some adult Paci!c herring from the oiled areas. 

Laboratory studies showed abnormalities and possible depressed immune functions in Paci!c 

herring exposed to oil. Four years after the spill, there was a major collapse of the herring !shery, 

which has yet to recover to pre-spill levels (Brown and Carls 1998).

Arctic cod is a key species in Arctic food webs. This abundant !sh is the primary connection 

between plankton and larger animals, and impacts on them would be likely to a"ect many of 

their predators, such as the ringed seal. Arctic cod spawn under sea ice in winter, and the eggs 

hatch during the plankton bloom that occurs with spring breakup of the sea ice (AMAP 2008b). 

They would be vulnerable to an under-ice spill during the spawning period, or to a spill that 

concentrated in the lead system during breakup. 

4.3.3 Marine Mammals

Impacts on marine mammals could include the ingestion of oil and the inhalation of vapor from 

crude oil, loss of insulation by oiling, and e"ects from contaminated prey (NRC 2003b). Inhalation 

of volatile compounds from fresh crude oil is known to damage the respiratory system, nervous 

system and liver of marine animals surfacing to breathe (AMAP 2008b, NRC 2003b). However, there 

are few data supporting a link with mortality (NRC 2003b). An estimated 302 harbor seals were 

killed in the Exxon Valdez spill, probably from inhalation of toxic fumes (Frost and Lowry 1994). 

PAHs from weathered oil are toxic to developing fetuses in at least some mammals and probably 

have other health consequences. However, the long-term health impact of sublethal oil exposure 

on marine mammals is generally not known. 

Some marine mammals are dependent on fur for insulation, and oiling of their fur causes 

substantial acute mortality. Direct oiling of fur killed 1,000 to 2,800 sea otters in the Exxon Valdez 

spill (Peterson et al. 2003). In the Arctic, this could a"ect ice seal pups, polar bears and Arctic foxes. 

A 1969 spill o" the coast of Canada during harp seal breeding season oiled 10,000 to 15,000 seals, 

causing signi!cant mortality to the pups (AMAP 2008b). Polar bears and Arctic foxes, both present 

in the Beaufort and Chukchi Sea regions, would also be vulnerable to oil ingestion from grooming 

their fur.

Predatory mammals such as toothed whales (e.g., beluga whales), seals and polar bears are 

vulnerable to bio-magni!cation of contaminants from their food sources (Figure 4-10). Even when 

marine mammals have the potential to escape the oil spill, they may not do so. Although some 

whale species, such as the !lter-feeding bowhead whales, have been observed to avoid oilcontaminated areas, other species have shown no avoidance behavior. After the Exxon Valdez spill, 
58

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

killer whales were observed swimming through slicks with no obvious attempts to avoid them 

(Matkin et al. 2008). After this exposure, high mortality rates (20 to 40 percent) were observed in 

subsequent years in both a resident and transient pod of killer whales in Prince William Sound 

(Peterson et al. 2003). Because the e"ects from an oil spill for long-lived species such as toothed 

whales are not immediately detectable, assessing the impact of a spill may be di#cult without 

adequate information about populations, such as trends, population size and reproductive rate 

(NRC 2003b).

Endangered bowhead whales are vulnerable to oil spill impacts because of their concentration 

at ice edges and leads where spilled oil may concentrate (Engelhardt 1987 in MMS 2008). During 

spring migration (Figure 4-11), the entire population of bowhead whales in the Bering, Chukchi 

and Beaufort seas (BCB population) travels north through the U.S. Arctic Ocean ice lead and 

polynya system, and their path is relatively constrained (AMAP 2008b). This migration path is also 

the primary calving area for this population of whales. 

A spill into ice leads or polynyas in the spring could have potentially devastating e"ects, trapping 

the whales where they may encounter fresh crude oil. Calves would be even more vulnerable 

than adults, because they need to surface more often to breathe and have less ability to travel 

under ice or to break ice to breathe. Filter-feeding bowhead whales are also sometimes observed 

aggregating in large numbers during the summer open-water season, when they could also be 

vulnerable to a spill. Like the bowheads, beluga whales use the spring lead system to migrate and 

would be exposed to a spill that concentrates in these leads.

Figure 4-10. Whales in Ice (Photo: 

Brad Benter/USFWS)—Beluga whales 

(le$) are an important Arctic species 

that feed higher in the food web and 

may be exposed to toxic compounds 

that are accumulated in lower trophic 

species. Bowhead whales (below) are an 

endangered species. 
59 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

Paci!c walrus distribution varies seasonally and is limited by water depth and ice conditions. 

Walrus have historically followed the receding sea ice, from which they have easy access to feeding 

grounds in shallow water on the continental shelf (USFWS 2010), Jay and Fishback 2008, Burns et 

al. 1980, Fay et al. 1984, Fay 1982, Fay 1985). Most of the population spends the summer months 

in the pack ice of the Chukchi Sea while the (predominantly) male portion of the population 

hauls out onto land in the Bering Sea (Fay 1981). Walrus are considered an ice-associated species 

because they use $oating sea ice for giving birth, nursing calves and resting and as passive 

transport to feeding areas (Figure 4-12). In the Chukchi Sea, they also concentrate at coastal 

haul-outs, particularly when the ice edge has shrunk away from their feeding grounds on the 

continental shelf. This is becoming more frequent as global climate change leads to a shrinking of 

the summer ice cover (USFWS 2010b, Jay and Fishback 2008, USGS 2010, Hassol 2004). 

Although Paci!c walrus are not listed as threatened or endangered under the Endangered Species 

Act, several petitions have been made to the USFWS to o#cially list this species (USFWS 2009). An 

oil spill that contacts an aggregation of walrus or displaces them from this important habitat may 

have a severe impact on the population, exacerbated by their low natural rate of reproduction. 

They would also be sensitive to impacts on their food supply. Information is scarce on the large 

mollusks that form the walrus’s primary food source, but they are slow-growing and would be 

expected to recover slowly after an oil spill (MMS 2008). Suspension-feeding invertebrates such 

as mollusks metabolize hydrocarbons slowly, so walrus would be exposed to contamination by 

eating them. Walrus also stir up sediment when feeding and could be exposed to oil residue. 

Because of their long life span, walrus could su"er severe e"ects from this bioaccumulation of oilderived contaminants.

4.3.4 Birds

Seabirds are very vulnerable to oil, particularly in cold environments. A square-inch spot of oil can 

compromise the water repellency of the feathers, potentially causing hypothermia (MMS 2008). A 

large spill can cause a massive acute die-o" of oiled birds. Seabird deaths from the Exxon Valdez 

spill were estimated at 250,000 (Peterson et al. 2003). Many Arctic bird species have characteristics 

that make them especially vulnerable to oil spills. These birds make long-range migrations, 

aggregate in colonies and have low reproductive rates and long life spans (Figure 4-13). Birds 

nesting in dense colonies are especially vulnerable to spills a"ecting their breeding sites. Many 

seabirds congregate to feed at ice edges, polynyas and open leads, where their prey species 

congregate and where oil may concentrate (AMAP 2008b). 

A number of studies have shown that seabird colonies can be wiped out by oil spills. A pu#n 

colony crashed after the Amoco Cadiz spill in 1978 (Clark 1984 in AMAP 2008b), and a guillemot 

colony in Southern California was wiped out because of a number of oil spills in the 1980s 

(Parker et al. 2007 in AMAP 2008b). Oil spills from sinking ships were probably responsible for the 

disappearance of pu#ns and guillemots from the English Channel during World War II (Gaston and 

Jones 1998 in AMAP 2008b). 
60

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

Figure 4-11. Bowhead Whale Migration Routes and Concentrations
61 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

Figure 4-12. (Photos: le!, Brad Benter/USFWS; right, Sarah Sonsthagen/USGS)—Herd of Pacific Walrus 

Hauled Out on Sea Ice

Figure 4-13. Arctic Seabirds (Photos: le!, Ground Truth Trekking; right, Mike Dunn/NOAA)—Ivory gulls 

(bottom right) concentrate at the ice edge and polynyas to feed. Northern fulmar (below right) live as long 

as 30 to 40 years and produce one egg per year, starting between the ages of 6 and 12. Seabird colonies along 

the Arctic shoreline o$en provide nesting habitat for multiple species, such as these on Cape Lisburne, 

below le$.
62

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

4.3.5 People

A large oil spill could signi!cantly a"ect the people and communities along the Chukchi and 

Beaufort seacoasts. The most signi!cant impact to the approximately 8,000 people living in 

this region would be on the subsistence resources that provide much of their diet and form 

the basis for their culture and social well-being. In the short term, both the spilled oil and the 

response activities could lead to disturbance or displacement of species important to subsistence 

!shers and hunters. Concerns over tainting or contamination of subsistence foods could lead to 

avoidance, both in the short term and into the future. If the oil spill caused signi!cant populationlevel impacts to these species, their availability to hunters would be a"ected for a long time after 

the spill (Figure 4-14). A reduction in the availability or safety of subsistence foods could have 

a profound impact on the economy and culture of Arctic communities on the U.S. and Russian 

coastlines (AMAP 2008b and MMS 2008). Reductions in the overall caloric input from subsistence 

food have also been documented to have negative impacts on the physical and mental health of 

Arctic indigenous communities (Wernham 2007). 

Bowhead whales are an important subsistence resource for native communities in the U.S. Arctic. 

Depending on the timing, a spill could stop the spring or fall hunt because of displacement of 

the whales or concerns about tainting of the meat. Also, local hunters could be pulled into spill 

response e"orts, preventing them from hunting (MMS 2008). Even if the oil spill has no long-term 

impact on whale populations, bowheads are known to avoid contaminated areas, making them 

more di#cult for hunters to access. In 1944, Barrow elder Thomas Brower Sr. observed an oil spill 

from a U.S. Navy vessel in the Plover Islands east of Barrow, where about 25,000 gallons spilled. 

“In 1944, I saw the e#ects of an oil spill on Arctic wildlife, including the bowhead. ... The 

"rst year... I observed how seals and birds who swam in the water would be blinded and 

su#ocated by contact with the oil. It took approximately four years for the oil to "nally 

disappear. I have observed that the bowhead whale normally migrates close to these 

islands in the fall migration. ... But I observed that for four years after that oil spill, the 

whales made a wide detour out to sea from these islands. ... If there were a major blowout, 

all the Inupiat could be faced with the end of their marine hunting.” (Brower, 1978)

In addition to bowhead whales, many other subsistence resources of the Arctic Ocean are 

causes for concern, including birds, !sh and other marine mammals. On the Arctic coast, marine 

mammals and !sh often make up 60 percent of a community’s diet (MMS 2008). An oil spill could 

cause these foods to be less abundant, more di#cult to access, or tainted by contaminants or 

perceived to be tainted. Loss of these subsistence resources could have economic impacts as 

people are forced to buy more of their food. Such a loss could also have negative social impacts 

from the loss of culturally important foods and activities, as well as adverse e"ects on physical and 

mental health. Psychological impacts of oil spills have been documented in other areas, especially 

among indigenous peoples (AMAP 2008b). 

Although the impact of oil spills on local communities is an obvious concern, the broader impact 

of oil and gas activities adjacent to human populations is not well understood. An Arctic Council 
63 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

study recommends additional research into these potentially negative impacts, noting: 

“In general, there is no good characterization of contamination sites in the Arctic region 

and a complete lack of exposure information for Arctic populations living near to oil 

and gas activities.” (AMAP 2008b)

Public health is not generally included in the National Environmental Policy Act (NEPA), 

from which the environmental impact statement process evolved in the United States. In a 

congressionally commissioned review of the impacts of oil and gas development in Alaska’s 

Arctic, the National Academy of Sciences concluded that the e"ect on human health was 

an area in great need of additional study and attention in the planning process (NRC 2003b). 

Despite the recommendations in that report, the impact on the local population is still strikingly 

underemphasized in the planning process. Few NEPA documents contain any explicit analysis of 

baseline public health conditions in the region, nor do they assess the potential direct, indirect and 

cumulative impacts on the human population (Wernham 2007). This shortage of attention to the 

people who live, work and subsist in the region means that decisions are made without a full and 

fair consideration of local populations, that the local population may be exposed to potentially 

preventable risks and harm, and that the bene!ts of well-planned development go unrealized. 

This is of particular concern because the baseline prevalence of some health problems that can 

be a"ected by oil and gas activities are markedly elevated in the North Slope region compared 

with the general U.S. population. Health information should be used in the NEPA process to help 

in$uence decisions about development. 

Figure 4-14. Culture and Subsistence (right, bowhead 

whale muktuk photo: Henry Huntington; far right, bowhead 

whale bones, Barrow, 

Alaska: Raychelle Daniel; 

below, drums, Henry 

Huntington)—Marine 

mammals are important 

in Inupiat culture and as 

subsistence food items.
64 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

Oil spill response is a labor- and resource-intensive activity that typically results in the removal of 

only a small fraction of the released oil. The Arctic marine environment poses unique challenges to 

oil spill response technologies and tactics that may reduce the e#ciency of response equipment 

or, in some cases, prevent response operations entirely because of technological limits, logistical 

challenges and safety concerns.

As the Deepwater Horizon spill illustrated, it is a major challenge to control a well blowout while 

simultaneously attempting to clean up the oil. Of the 4.9 million barrels spilled during the threemonth Deepwater Horizon incident, an estimated 25 percent was recovered through skimming, 

burning or direct recovery. Most of the oil recovery—17 percent of the total spill—occurred at 

the wellhead. On-water skimming operations removed only 3 percent of the total spill amount, 

or 147,000 of the 4.9 million barrels spilled. In-situ burning treated 5 percent of the oil (245,000 

barrels), and chemical dispersants treated 8 percent, or 392,000 barrels (Lubchenco et al. 2010). 

At the height of the response, more than 6,500 vessels worked on that spill, with more than 3 

million feet of containment booms and nearly 900 skimmers (Joint Information Center 2010). Yet 

75 percent of the oil (3.67 million barrels) was left in the Gulf of Mexico to evaporate or dissolve 

naturally, chemically disperse, or remain in the environment as residual oil (Lubchenco et al. 2010).

The response estimates from the Deepwater Horizon spill are relevant to the discussion of oil 

spills in the Arctic Ocean because they demonstrate that existing oil spill response technologies 

cannot remove all the oil spilled in the marine environment. The Deepwater Horizon spill occurred 

in temperate waters during the spring and summer. The Gulf of Mexico coastline has signi!cant 

infrastructure in place to support a major response, and every available resource was enlisted, 

yet 75 percent of the oil could not be treated or recovered. In the Arctic Ocean, where sea ice, 

fog, wind, rough seas, darkness and lack of infrastructure make spill cleanup even more di#cult 

and probably less e"ective, how much of the oil spilled during a well blowout would escape 

containment and cleanup?

Experts agree that oil spill response systems do not function as e"ectively in Arctic waters, but 

their opinions vary as to how those limits a"ect the overall capacity to respond to spills (Fingas 

2001). Even if the U.S. Arctic had equipment stockpiles equivalent to those used during the 

Deepwater Horizon response, would that arsenal of equipment make a di"erence in terms of 

reducing the environmental consequences of a well blowout in the U.S. Arctic? 

LIMITATIONS OF EXISTING OIL SPILL RESPONSE

TECHNOLOGIES IN THE U.S. ARCTIC OCEAN 5

(Skimmer photo: BOEMRE)
65

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

This chapter reviews the major technologies in use for stopping a well blowout and cleaning up 

an oil spill and examines how each may be limited in the Arctic Ocean environment.

5.1 Arctic Ocean Challenges

Arctic conditions—sea ice, low visibility, high winds, rough seas and cold temperatures (discussed 

in Section 2.1)—would complicate all aspects of a spill response, from stopping a well blowout 

to predicting or tracking the movement of an oil spill trapped in sea ice (Table 5-1). All of the 

major spill cleanup technologies face operating limits that are tied to wind speed, wave height, 

ice conditions and visibility (Potter 2004). Once the limit is reached for any one or combination of 

these factors, spill response operations may be slowed or shut down for days, weeks or months. 

Table 5-1. Typical Arctic Conditions and Potential Impacts on Spill Response Options (Adapted 

from Nuka Research 2007b)

1 Sea ice is a prominent feature of the Arctic marine environment. The generic term “sea ice” encompasses a wide 

range of ice conditions. Sea ice may be present year-round, or it may follow an annual freeze-melt cycle. Ice conditions 

may be described in terms of the formation of the ice or the percent coverage. The World Meteorological Organization 

ice classi!cation system and terminology are used in this report (WMO 2005).

ARCTIC

CONDITIONS

POTENTIAL IMPACTS TO SPILL RESPONSE

All Response Options Mechanical Recovery In-Situ Burning Dispersants

Sea Ice 1 Challenges:

Di#cult for vessels to access spill site.

Di#cult to sense, track or model 

movement of oil in, on or under 

sea ice.

Ice-class vessels required in higher 

ice concentrations.

Slush ice can clog water intakes.

Ice scouts may be needed.

Ice-management vessels may be 

needed in addition to primary 

response vessels.

Experienced vessel operators must 

be familiar with ice.

Ice conditions may change suddenly 

and create dangerous conditions.

Benefits:

Oil may weather and spread more 

slowly.

Challenges:

Ice may tear, lift or move 

containment boom.

Reduced encounter rates for 

skimmers.

Ice may clog skimmers or reduce 

e#ciency.

Ice may clog pumps or cause them 

to fail. 

De$ection of ice away from 

skimmers may inadvertently de$ect 

oil.

Limited maneuverability may 

prevent or delay accurate skimmer 

or boom deployment.

Attempts to de$ect the ice from 

recovery areas may also de$ect the 

oil.

Ice must be separated from 

recovered oil.

Benefits:

Ice may contain oil in pools for smallbatch recovery.

Challenges:

Certain ice conditions (i.e. slush ice) 

may reduce burn e"ectiveness or 

impede ignition.

Di#cult to deploy !re boom.

Di#cult to track and recover burn 

residue.

Impact of smoke plume and soot to 

ice unknown.

Benefits:

Ice may provide containment for 

burning.

Challenges:

Cannot access oil under ice.

Ice reduces mixing energy.

Dispersants generally less e"ective at 

lower salinities.

In most regions, dispersants are 

not considered an operational 

technology for use in sea ice.

Little information about dispersant 

toxicity to Arctic organisms.

Benefits:

None apparent.
66 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

ARCTIC

CONDITIONS

POTENTIAL IMPACTS TO SPILL RESPONSE

All Response Options Mechanical Recovery In-Situ Burning Dispersants

High Winds Challenges:

Unsafe to operate vessels and 

deploy on-water equipment during 

high winds.

Aircraft cannot $y above certain 

wind thresholds.

High winds drive sea state, may 

enhance wave height or create 

choppy seas.

High winds may combine with low 

temperatures to create dangerous 

wind chill.

Benefits:

Strong directional winds may drive 

oil away from sensitive areas.

Challenges:

High winds can move boom or tear 

it from anchor.

Di#cult to keep vessels and 

equipment on station.

Benefits:

None apparent. Increasing winds 

make all aspects of on-water 

recovery more challenging and 

eventually create safety issues.

Challenges:

Di#cult to ignite oil in high winds.

Aircraft cannot deploy heli-torches in 

high wind.

High winds may drive plume.

Benefits:

None apparent. In-situ burning is 

not generally safe or feasible in high 

winds.

Challenges:

Di#cult to accurately spray 

dispersants.

Aerial spraying not safe during high 

winds.

Cannot conduct application 

monitoring from aircraft.

Benefits:

Wind-driven sea state will provide 

mixing energy for dispersants and 

oil if the dispersants can be safely 

applied.

Cold 

Temperature

Challenges:

Potential for hypothermia among 

responders.

More frequent breaks (every 10 to 15 

minutes in some cases) needed to 

warm up.

Unsafe to work at extreme low 

temperatures.

Cold may cause brittle failure in 

some metals. 

Cold air may freeze sea spray, 

creating slick surfaces. 

Icing conditions may make vessels 

unstable. 

Natural bio-degradation of oil 

slowed.

Benefits:

Oil may weather more slowly, 

increasing window of opportunity 

for response.

Challenges:

Skimmers freeze up.

Sea spray may freeze on boom, 

causing it to fail.

Pumps may freeze up.

Increased oil viscosity makes oil 

di#cult to recover and pump.

Benefits:

None apparent. Cold temperatures 

will slow or limit nearly all aspects of 

spill response.

Challenges:

Ignition more di#cult.

Oil may burn more slowly or less 

completely.

Benefits:

No speci!c bene!ts. 

Challenges:

Increased oil viscosity may reduce 

dispersant e"ectiveness.

Some studies have shown reduced 

e#ciency in cold waters.

Benefits:

None apparent.

Limited 

visibility 

(including 

darkness)

Challenges:

Limit or preclude safe vessel 

operations.

Aerial operations typically not 

conducted during darkness, heavy 

fog or low ceiling.

Di#cult to see, track or locate oil 

spill.

Challenges:

Cannot conduct mechanical 

recovery in darkness or low visibility 

unless work lights can be used.

Benefits:

No apparent bene!ts.

Challenges:

Cannot conduct in-situ burning 

during darkness.

Fog or low visibility may limit aerial 

operations.

Benefits::

No apparent bene!ts.

Challenges:

Darkness or low visibility that limits 

aerial operations will preclude aerial 

application and observation.

Vessel application requires visual 

con!rmation of slick location.

Benefits:

No apparent bene!ts.

Sea state (high 

waves, strong 

tides)

Challenges: 

High waves limit small boat 

operations.

Strong currents challenge vessel 

operations.

Benefits:

Calmer, low current sea states are 

typically more favorable than high 

sea state.

Challenges: 

Booms and skimmers do not 

function well at high sea states. 

Short, choppy waves may be more 

limiting than longer period waves.

Moderate to high currents cause 

boom to fail.

Benefits:

None apparent. Increases in wave 

height and period and moderate to 

high currents all make mechanical 

recovery more di#cult.

Challenges: 

High sea states make containment 

and ignition di#cult and potentially 

unsafe.

Benefits:

None apparent. Increases in wave 

height and period and moderate 

to high currents all make in-situ 

burning more di#cult.

Challenges: 

Vessel-based application limited by 

sea state based on vessel size.

Benefits: 

Sea state should not inhibit aerial 

application (assuming no high 

winds).

High sea states typically enhance 

the e"ectiveness of chemical 

dispersants.
67

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

Other characteristics of the Arctic Ocean and the Arctic region—lack of infrastructure, limited 

transportation options, and distance from major ports (Section 2.2)—also a"ect the ability to meet 

the basic requirements for implementing a major oil spill response. 

Oil spill response equipment and systems face many limits, including the overall e#ciency of the 

technique or equipment. E#ciency is a measurement or estimate of how well the equipment or 

technique might function under ideal conditions to clean up or treat spilled oil. No oil spill cleanup 

technique is 100 percent e#cient, and even spill cleanup measures that are shown to have very 

high e#ciencies under test conditions face signi!cant limits in real-world situations. 

There are several basic requirements for on-water oil spill cleanup operations that also apply 

in the Arctic, and failure to meet any of these requirements can reduce the response e#ciency 

signi!cantly or halt operations altogether. 

• Spill managers must be able to locate and track the movement of the oil spill. 

• Response equipment and trained responders must be transported to the spill site.

• Available response equipment must be able to access the spilled oil.

• The response equipment and technologies must be appropriate for the type of oil spilled 

and the conditions under which the equipment is used. 

• Su#cient storage devices and disposal plans must be in place to deal with oil, oily liquid 

and other contaminated materials recovered during the response. 

• Communications networks must be in place so that responders can communicate among 

themselves and with response managers in the incident command post. Ground-to-air, 

vessel-to-air, vessel-to-vessel and ground-to-vessel communication networks must be in 

place. 

• Vessels or aircraft that provide the basis for response operations must be able to safely 

operate in the weather and environmental conditions. 

• Food, water and housing must be provided for response personnel. 

• All operations must meet basic safety parameters to prevent injury to responders.

5.2 Stopping a Subsea Well Blowout

There are a number of well control measures that can be taken to mitigate the intrusion of oil and 

gas into the well bore, but if those measures fail for any reason, an open ori!ce blowout can occur. 

In this case, the !rst and most important task in any oil spill is stopping the $ow of oil into the 

environment. Subsea blowouts are especially di#cult to stop because the blowout preventer and 

wellhead are located underwater. Controlling a subsea well blowout may require months, as was 

the case with the Deepwater Horizon spill. 
68 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

The options for controlling a subsea well blowout are limited and time-consuming. The two 

options most often discussed are subsea well control or containment measures (sometimes 

described as capping) and drilling of a relief well (Grace 2003). 

5.2.1 Subsea Well Containment and Control

Once the well has bypassed the blowout prevention (BOP) system and achieved an uncontrolled 

blowout state, the wellhead control equipment may su"er considerable damage. In this case, one 

option to reestablish control of the well would be to install some kind of containment barrier. It is 

di#cult to install a containment barrier to control a subsea well blowout because of the di#culty of 

accessing the underwater wellhead. The Deepwater Horizon blowout provided the opportunity for 

responders to test and re!ne several di"erent approaches to subsea well containment and control, 

and resulted in some novel approaches that have the potential to substantially improve existing 

technologies in this area (Joint Industry Subsea Well Containment and Control Task Force 2010). 

Before the Deepwater Horizon well blowout, no prefabricated subsea well containment devices 

were available for immediate use. Several devices were constructed after the Deepwater Horizon 

blowout, and ultimately one of those devices was successful in sealing in the oil. A joint industry 

task force is working on a long-term plan to develop tools and equipment to establish a standing 

capability to use prefabricated structures or equipment to quickly control subsea well blowouts. 

Areas of new research include well containment devices for use on the sea$oor (Figure 5-1), 

equipment and technologies for use within the subsea well, and devices for subsea collection and 

processing of oil recovered from the blowout plume (Joint Industry Subsea Well Containment and 

Control Task Force 2010).

Figure 5-1. Subsea Well 

Containment System 

Proposed for Use in Gulf 

of Mexico—During the 

Deepwater Horizon well 

blowout, a subsea containment 

system was proposed to stop 

the uncontrolled "ow from the 

well. Research is ongoing into 

other potential subsea well 

control structures; however, 

at present there have been 

no technologies proposed or 

developed to control subsea 

well blowouts in the Arctic.
69

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

The transfer of technologies from the Deepwater Horizon blowout and the ongoing work of the 

Subsea Well Control and Containment (SWCC) Task Force are likely to improve the techniques 

available for subsea well blowout control. An action plan for the SWCC Task Force is scheduled for 

completion Dec. 31, 2010. Preliminary documents from the task force do not indicate whether the 

research and development activities will include an Arctic component. 

The introduction of new techniques and technologies for subsea well containment and control is 

likely to improve future options for reducing the amount of oil released during a subsea blowout. 

If operators are able to develop and demonstrate the ability to quickly and e"ectively contain 

subsea wells, the risks would be signi!cantly reduced. However, like all engineered systems, subsea 

well containment and control measures would require certain adaptations or enhancement for 

use in the Arctic Ocean. Equipment installed on the sea$oor in shallow water would risk damage 

or destruction from ice scouring if left in place over the winter. The specialized equipment and 

trained personnel required to install subsea well control or containment devices would need to 

be transported to the well site, because no subsea well containment equipment or personnel 

are located in Alaska nor has anything been fabricated and demonstrated to withstand Arctic 

conditions.

5.2.2 Relief Wells

A relief well intercepts the subsurface well bore of the out-of-control well. Drilling a relief well is 

often not the !rst or only well control option selected because of the time it takes to move a rig 

into the area of the blowout and drill a relief well. However, a relief well is the most reliable method 

for stopping a blowout. If a rig is on location or nearby, it may be possible to shut down its drilling 

operations to aid the blowout response. If no rigs are available nearby, then substantial time will be 

required to move a rig into the area. In the interim, other well control operations may be initiated, 

as was the case in the Deepwater Horizon blowout in the gulf, where a subsea containment 

structure was successfully installed while relief well drilling continued to completion. 

5.2.3 Challengesto Well Control in the U.S. Arctic Ocean

The ability to control a blowout in the U.S. Arctic Ocean will vary, based on the ice season and the 

location of the well. Even if Arctic Ocean drilling is limited to open-water season, it is possible that 

a blowout that occurs late in that season could continue during the freeze-up, and the blowout 

control and response could be a"ected by encroaching sea ice. 

Data are sparse and poorly compiled on the international experience with Arctic subsea oil well 

blowout control. Some conclusions can be drawn, however, by considering the known challenges 

of well control technologies and relief well drilling in temperate or sub-Arctic conditions, and then 

factoring in Arctic conditions. 

All blowout control measures require time to mobilize and deploy the required equipment, 

and a period of weeks or months may pass before well control is achieved. For example, it took 

several months to mobilize a rig and drill the relief well in a gas well blowout at the Steelhead 

platform in Cook Inlet, Alaska. The blowout occurred in December 1987, but the relief well was 
70 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

not completed until June 1988 (Petterson and Glazier 2004). In the U.S. Arctic Ocean, if a relief well 

cannot be completed before pack ice encroaches on a drill site, it is possible that a blowout could 

continue uncontrolled through the eight- to nine-month ice season. If subsea containment or 

control measures controlled the blowout, the containment system would have to be engineered 

to withstand the Arctic winter. Ultimately, a relief well would probably be required to completely 

control an Arctic subsea well blowout, unless the well were to naturally seal itself with rock 

fragments from the collapsing formation. 

5.3 Applying Oil Spill Cleanup Methods in the Arctic Ocean

The challenges associated with controlling a well blowout in the Arctic Ocean are only the !rst 

part of the equation. Cleaning up spilled oil in the marine environment—whether from a blowout 

or another spill source—is a tedious and labor-intensive process that, even under the best of 

circumstances, may result in the recovery or removal of only a small fraction of the total spill 

volume. In the Arctic, every step of that process may be more di#cult or even impossible under 

certain conditions. Most technologies used in response to oil spills in sea ice have been adapted 

from those typically used on open water and land. Although on-water response technologies may 

transfer to open-water Arctic conditions, sea ice has been demonstrated to reduce the e#ciency 

of many response methods and to preclude the use of others (AMAP 1998).

Oil spill response methods are generally divided into three main categories: mechanical recovery, 

in which oil is corralled using natural or man-made barriers and removed using skimmers and 

pumps; nonmechanical recovery, in which an oil slick is treated with chemicals, burning or 

bioremediation; and manual recovery, in which oil is removed with hand tools or machines. 

Most operations in Arctic waters rely on a combination of mechanical recovery and two types 

of nonmechanical treatment—in-situ burning and dispersant application—to clean up or treat 

spilled oil. All of these options face limits from environmental and weather conditions (Table 5-1).

All three response technologies require surveillance and spill tracking to identify the location, 

extent and condition of the spilled oil so that the appropriate response equipment and tactics may 

be selected. All three also require logistical support to transport equipment and trained personnel 

to the spill site, deploy and operate the equipment, and decontaminate the equipment when 

response operations are complete. Spill responders must be able to safely access the spill site—

often one of the biggest challenges, particularly in remote areas. With all three oil spill response 

options, time is critical. As soon as oil is spilled in water, it begins to spread, evaporate and emulsify, 

and as time passes, it generally becomes more di#cult to track, contain, recover and treat. The 

quick mobilization and deployment of response equipment and trained personnel are important 

to the overall response e"ectiveness. 
71

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

5.3.1 Spill Tracking, Surveillance and Modeling

Several technologies are available to detect and track oil spills on open water and ice. These 

include tracking buoys, satellite imagery, aerial surveillance, visual observations, on-ice surveys, 

and trajectory models. All have their strengths and weaknesses, and many are limited by Arctic 

conditions. Figure 5-2 shows examples of these technologies (Glover and Dickins 1999, Dickins and 

Buist 1999, Owens et al. 1998).

Tracking buoys may be used to follow an oil slick as it moves with winds, surface currents and 

ice movements. The buoys are released into an oil slick, where they move with the oil and ice, 

transmitting data on the location and movement of the slick. 

Satellite imagery may be available to provide real-time images of ice conditions and possibly oil 

slicks. Satellite images may lack the resolution necessary to detect small oil slicks directly, but in 

combination with tracking buoys, satellite imagery can be used to develop a picture of the ice 

conditions in the vicinity of the oil. After the Deepwater Horizon blowout, satellite imagery of the 

spill was used to estimate the spill size and track the movement of major oil slicks (SkyTruth 2010). 

Airborne reconnaissance may be conducted using a range of technologies, including visual 

observations and still and video cameras or remote sensing using infrared and ultraviolet sensors, 

laser $uorosensors and radar (Fingas 2001). Trained visual observers can be teamed with remote 

sensing technologies to identify oil slicks, although it is often di#cult to distinguish between 

oil slicks and other factors such as silt on ice, cloud shadows on water, and wind patches, which 

may appear similar to oil. Visual observations may also be used to track oil and ice position 

and movement. Still and video cameras may be deployed from a response vessel or dedicated 

surveillance vessel and can record overall spill locations and slick boundaries in reasonable light 

conditions. The accuracy of visual observations from vessels may be limited by visibility factors. 

Figure 5-2. Oil Spill Tracking and Surveillance Methods in Arctic Ocean—Tracking and surveillance 

methods in use or proposed for use in the Arctic include surveillance from aircra$ or vessels using remote 

sensing or visual observation methods (below le$), using specially trained dogs to sni% oil under solid ice 

(opposite page), or deploying tracking buoys into oil that is "oating on the surface or amid sea ice (below right). 

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72 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

A 2010 study found that detecting isolated patches of oil 

amid sea ice is a major challenge to all existing technologies 

and that darkness, low clouds and fog limit tracking and 

surveillance methods regardless of ice conditions (Dickins et 

al. 2010). (Photo: SINTEF)

On-ice surveys may be used on solid ice that is 

thick enough to support personnel and equipment. 

Handheld GPS units may be used during on-ice 

surveys to document the location and extent of spills 

in conjunction with spill survey activities, but these are 

limited by ice thickness and are typically ine#cient, 

requiring signi!cant time and manpower. Underice lights, slots, trenches, boreholes (holes that are 

bored or drilled into the ice to see whether there is 

oil underneath) and other techniques may be used to 

identify and track ice location and movement. All of 

these techniques are time-consuming and are best 

applied when responders have a basic idea about where under-ice oil may be located. Remote 

sensing technologies have also been tested to track oil under ice, and researchers have used 

specially trained dogs to detect oil under ice using their olfactory senses. Under-ice tracking with 

equipment or dogs can be time-consuming, and the logistics of transporting them by air and over 

icy terrain may cause stress (Dickins et al. 2010).

Trajectory models may also be used to map or predict the movement of oil if it cannot be tracked 

using other surveillance techniques. In open water, surface oil trajectories are developed based on 

the wind speed and direction and the current. Predicting the movement of oil under ice or within 

ice $ows can be more complicated. As discussed in Section 4.1.3, existing oil spill trajectory models 

cannot accurately predict how oil and ice interactions will a"ect oil movement when sea ice is 

present (Khelifa 2010).

A 2010 study that compared various technologies for remote sensing of oil in ice found that a 

$exible combination of sensing methods that can be operated from a variety of platforms should 

be available for oil spill tracking in Arctic seas (Dickins et al. 2010). All airborne sensing systems 

were a"ected by clouds, fog or darkness, with the exception of side-looking airborne radar (SLAR). 

Although SLAR showed the most promise for slicks in very low ice concentrations, the presence of 

grease ice made oil indistinguishable from ice. In close pack-ice conditions (above 60 percent ice 

coverage), GPS tracking buoys were found to be the most e"ective tool. For oil trapped under solid 

ice, ice-sni#ng dogs and ground-penetrating radar (GPR) were the most promising options. The 

study found that detecting isolated patches of oil among tightly packed $oes of sea ice is a major 

challenge to all existing technologies, and that the presence of darkness, low clouds and fog limits 

most tracking and surveillance methods, regardless of ice conditions (Dickins et al. 2010).
73

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

5.3.2 Mechanical Recovery Methods

Mechanical recovery of oil spilled on water involves the physical containment of the oil and the 

subsequent removal of the oil from the surface. Mechanical recovery of oil spilled in the Arctic 

Ocean can be conducted only during open-water or broken-ice conditions. Once oil is trapped 

under pack ice, the on-water mechanical recovery methods discussed here are no longer a viable 

option until the ice breaks up. The objective of mechanical recovery is to concentrate oil to a 

thickness that will permit recovery.

Mechanical recovery systems have three major components: containment barriers, recovery 

systems, and storage for recovered oil and water. Mechanical recovery systems are supported 

by additional equipment and resources such as vessels, pumps, anchors, decanting (oil/water 

separation) systems and trained personnel (Figure 5-3).

Figure 5-3. Typical On-Water Mechanical Recovery System—On-water mechanical recovery operations 

involve containing oil to an appropriate thickness and then removing it from the water surface using 

skimmers. On-water mechanical recovery is viable in open water and in some low ice concentrations and 

would be applicable in the Arctic Ocean only a few months of the year.

A boom is the most 

common type of 

on-water barrier used 

to intercept, contain 

and concentrate 

spreading oil. 

Booms come in a 

variety of forms and 

may be deployed 

in a number of 

con!gurations. Sea 

ice may act as a 

natural containment 

barrier under 

certain conditions, 

but typically the presence of sea ice is an impediment to response. Recovery of oil contained or 

concentrated with booms or natural barriers is accomplished using a skimming or recovery system 

that removes oil and water from the surface and transfers the recovered liquids to temporary 

storage, where the oil and water can eventually be separated for disposal. As with booms, there are 

many models of skimmers (Figure 5-4). 
74 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

Figure 5-4. Skimmers—!ere are three main types of skimmer design. Weir skimmers (le$) draw liquid 

from the surface by creating a depression in the water into which oil and water pour and are then pumped 

to storage. Oleophilic (oil-attracting) skimmers (right) use surfaces such as rotating discs, brushes or drums 

to pick up oil adhered to a collection surface, and the oil is then scraped from the collection surface and 

pumped to a storage device. Suction skimmers (bottom) use a vacuum to li$ oil from the surface of the 

water. Weir and suction skimmers may collect a large proportion of water with the recovered oil. Most 

suction skimmers are mounted on trucks and work best on land.

Skimmers operating in the marine environment may be stationary, meaning they are dropped into 

a pool of oil to recover it (Figure 5-6). They may also operate in an advancing mode, in which they 

are slowly moved through an oil slick. In either mode, the e"ectiveness of the skimmer relies on 

its ability to encounter oil at su#cient thickness to remove it. Mechanical recovery may be limited 

if the encounter rate—the rate at which a skimmer comes into contact with pooled oil—is not 

su#cient to allow for e"ective skimming. Factors that may 

limit the encounter rate include the speed of the skimmer 

through the water (above very low speeds, the skimmer 

may not work) and failure to contain and concentrate the 

oil to the required thickness, which would happen if the 

boom was not e"ective. Ice and other debris can clog the 

skimmer or prevent it from encountering and recovering 

oil. They also can cause the boom to tear or at higher 

concentrations can prevent some vessels from safely 

deploying booms or skimmers.

Figure 5-5. Stationary Deployment of a Weir Skimmer 

During Training Exercise (Photo: Sr. Airman Jonathan Ste#en/

U.S. Air Force)—Sea ice complicates skimming operations, 

including positioning of the skimmer. Skimmers typically work 

best in open-water conditions where there is no ice. Skimmers 

work poorly during fall freeze-up conditions when ice is #rst 

beginning to form and is more slushy. 

Vacuum or 

Suction 

Skimmers

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75

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

On-water mechanical recovery technologies are signi!cantly less e#cient when sea ice is present 

(Abdelnour and Comfort 2001). Sea ice in its various forms a"ects the functionality of booms, 

skimmers and vessel operations and may limit or preclude the ability to operate certain classes of 

vessels. Cold-weather conditions can further complicate mechanical recovery. 

The presence of sea ice interferes with containment of oil in su#cient thickness to recover it. Oil 

tends to disperse and mix into the ice, creating an additional step for responders trying to separate 

the oil from the ice. Sea ice may reduce the e"ectiveness of containment booms by interfering 

with the boom position, allowing oil to entrain or travel under the boom or causing the boom to 

tear or separate. Sea ice may also reduce a skimmer’s e#ciency in recovering oil by lowering the 

encounter rate and increasing the time needed to position the skimmer for optimum recovery 

among ice $oes (Abdelnour and Comfort 2001, Fingas 2004). Marine operations in sea ice are 

vulnerable to rapid changes in weather and ice conditions, and signi!cant down time often occurs 

because of the movement of ice in response to wind conditions and sea state (Dickens and 

Buist 1999).

Although sea ice coverage generally complicates on-water mechanical recovery, increasing ice 

concentrations may help contain oil under certain conditions. Dickins and Buist (1999) found 

that ice concentrations of 60 percent or higher provide “an e"ective means of reducing oil spill 

spreading.” Although the spreading rate is diminished, the recovery rate can be severely a"ected 

by responders’ inability to access the oil because of weather, visibility, or vessel, mechanical 

and human limitations. Higher ice concentrations make recovery operations extremely di#cult 

because of limits to vessel operations. 

In ice concentrations below 60 percent, additional containment is usually required to concentrate 

the oil so that it can be recovered by mechanical skimming devices. Dickins and Buist (1999) found 

that most containment booms can be used in light brash ice conditions and ice concentrations 

up to about 30 percent. Based on these estimates, ice conditions ranging from 30 percent to 

70 percent coverage may present the biggest challenge to mechanical response, because 

conventional booms are likely to be ine"ective and ice conditions are not su#cient to contain the 

oil (Evers et al. 2006, Glover and Dickens 1999).
76 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

Figure 5-6. Ice Interference 

(Photo: Kirsten Ballard, ADEC)—

Ice interferes with mechanical 

recovery equipment during sea 

ice response trials in the Beaufort 

Sea in 2000. A series of #eld trials 

conducted in the Beaufort Sea 

during the spring and fall ice 

seasons in 2000 demonstrated that 

the maximum operation of the 

barge-based recovery system in sea 

ice conditions was zero to 1 percent 

in fall ice, 10 percent in spring ice 

without ice management, and 30 

percent in spring ice with extensive 

ice management (NRC 2003b). 

!e images at right, in which ice 

conditions were estimated at 10 

percent coverage or less, show how 

relatively low ice concentrations can interrupt mechanical recovery because of sea ice interfering with the 

skimmer (top le$) or boom (bottom le$), or causing the boom to fail (right).

5.3.3 In-Situ Burning

Like mechanical recovery, in-situ burning is a response option that is available only when oil is 

$oating on the surface of open water or amid broken ice. Oil that has pooled on the surface of 

pack ice may be available for in-situ burning during spring melting, but oil trapped below pack ice 

through the winter cannot be accessed for burning.

In-situ burning of spilled oil on the water’s surface involves a controlled burn of $oating oil that 

is contained to the appropriate thickness (1 to 3 mm for fresh crude, more than 3 mm thick 

for weathered crude oil). The oil is ignited by releasing a burning, gelled fuel from a helicopter 

onto the oil or by releasing an ignition device from a vessel or other access point. If successfully 

ignited, some of the oil will burn o" the surface of the water or ice, but some residual nonvolatile 

compounds will remain. This residue may $oat, sink or be neutrally buoyant, depending upon the 

type of oil spilled and the conditions of the burn (Brandvik et al. 2010a). 

As in mechanical recovery, oil containment for in-situ burning can be accomplished with natural 

barriers (topographic features on land, snow berms, sea ice) or man-made booms. However, !re 

booms used for in-situ burning must be constructed of !re-resistant materials. Response vessels 

may tow !re booms in a U-shaped con!guration that is also commonly used during mechanical 

response (Figure 5-7). Alternatively, oil may be encircled in a stationary !re boom or pooled in ice 

leads and burned.
77

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

Figure 5-7. Typical On-Water In-Situ 

Burning Operations

Successful ignition and burning require 

adequate slick thickness for ignition, 

minimal wind and waves, and oil that 

has not emulsi!ed (incorporated water) 

too much. The more weathered the oil, 

the thicker it must be to burn (Brandvik 

et al. 2010a). If a burn is ine#cient, a 

mixture of unburned oil, burn residue 

and soot will form (NOAA 2005). 

Downwind emissions must be below 

threshold levels for sensitive populations 

(NRT 1997). Chemical herders, currently 

under development, may thicken a slick 

to allow for ignition (Buist et al. 2006, 

Buist et al. 2010a and 2010b).

The in-situ residues that remain after a 

burn have characteristics and behavior that depend on the chemical composition and physical 

properties of the parent oil, the state of weathering and the oil slick thickness (Buist et al. 1997).

The results of in-situ burning di"er from mechanical recovery in that the oil is not completely 

removed from the environment. The by-products of in-situ burning include air emissions (Figure 

5-8) and burn residues, and the process of burning creates heat at the air-water interface. All of 

these factors have potential environmental and ecological consequences. 

The smoke plume presents a number of response challenges, from predicting the contents and 

movement of the plume to assessing and communicating the human health and environmental 

toxicity risks posed by the emissions. Soot from an in-situ burn plume may coat sea ice and snow 

cover.

Although a number of scienti!c studies have con!rmed that the residues that remain after in-situ

burning are less toxic than the original oil, burn residues are not completely benign and should 

be removed from the marine environment whenever possible (API 2004). Burn residues may $oat 

or sink, and they sink only after they have cooled. Residues from burns of thicker slicks of heavier 

crude oils (both fresh and weathered) are more likely to sink than are burn residues from lighter 

oils (S.L. Ross 1998). Research also indicates that crude oil burn residues are generally denser than 

their parent oils and that residue density is related to the density of the parent oil, the state of 

weathering, and the slick thickness (Buist et al. 1997).

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78 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

Figure 5-8. (Photo: MMS)—Smoke 

Plume from In-Situ Burn Test

Floating burn residue may be 

picked up with large strainers, 

nets or hand tools, with viscous-oil 

sorbents, or with standard viscousoil skimmers; however, this is a very 

time- and labor-intensive process. 

Floating residues can be stranded, 

much as $oating oil slicks can, 

along shorelines or other coastal 

features, but because of their thick 

consistency, they can be di#cult to 

remove using conventional shoreline 

response technologies. Floating 

residues may be ingested by !sh, 

birds and marine mammals and may also foul gills, feathers, fur or baleen (Shigenaka and Barnea 

1993). The presence of sea ice makes tracking and recovering burn residues more challenging. 

There are no published accounts of in-situ burning operations in broken ice during an oil spill.

Burn residues that sink to the bottom are far more di#cult to recover. In 2002, the American 

Petroleum Institute (API) published a study that investigated the potential for residues to sink 

after an in-situ burn of spilled oil. The researchers identi!ed the need for recovery of sinking burn 

residues and recommended suspending a net along the bottom of the containment boom across 

the apex of the burn area to catch the residues as they begin to cool and sink. To date, no new 

technologies for recovering sunken in-situ burn residues have been reported in the literature. The 

recovery of sunken in-situ burn residues in broken ice conditions has not been well studied.

Sunken residues can threaten benthic communities, adversely a"ecting resources that would not 

otherwise be a"ected by an oil spill at the water surface. They may be ingested by benthic feeding 

organisms, including !sh, shell!sh or marine mammals. During the Haven spill in Italy in 1991, 

approximately 3 million gallons of oil was burned, and the residues sank and were distributed over 

an area of the seabed approximately 55 square miles in size. These residues adversely a"ected 

local trawl !sheries because the !shermen feared they would foul their gear (Martinelli et al. 1995). 

Although trawling !sheries do not exist in the U.S. Arctic Ocean, many species live on the seabed 

and would be negatively a"ected by sunken oil residues. Publicly available documentation from 

the Deepwater Horizon spill does not specify whether in-situ burning residue recovery operations 

were undertaken to remove the oily residues left behind from the multiple burns. 

In-situ burning can also a"ect the surface micro-layer, which is approximately the upper fewhundredths of an inch of the water surface. The surface micro-layer is an important ecological 

niche that provides habitat for many sensitive life stages of marine organisms. Eggs and larval 
79

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

stages of !sh and crustaceans and reproductive stages of other plants and animals develop in this 

layer, which often contains dense populations of micro-algae with distinct species compositions 

from the phytoplankton in the layers below (Shigenaka and Barnea 1993). 

Surface micro-layer organisms are vulnerable to oil slicks, but the e"ects do not seem to 

be intensi!ed by burning. Experimental data from a large o"shore burn showed that water 

temperature did not increase during burning, despite the intense heat generated by the burn 

(Fingas et al. 1994). To date, no published studies address the potential impact of in-situ burning 

on the surface micro-layer in polynyas. 

Numerous published articles and reports refer to the potential use of in-situ burning in sea ice 

conditions. The reduced e#ciencies of mechanical recovery are frequently cited as a rationale for 

in-situ burning in ice leads. In-situ burning is also considered a viable option for treating oil on 

top of solid ice or oil that pools on top of melting ice in the spring (Solsberg 2008). The general 

consensus is that leads in broken and pack ice provide an opportunity for in-situ burning, because 

the ice acts as a natural containment barrier to the slick and the open water in the lead provides 

the necessary access. However, responders must also have access to ice class vessels and/or air 

support to carry out these operations. 

Before the Deepwater Horizon oil spill, in-situ burning had not been widely used, particularly in 

cold climate on-water spill response, so the body of information regarding in-situ burning in Arctic 

regions is based primarily on experimental data. The presence of sea ice appears to slow the rate 

of in-situ burning and create slightly larger quantities of residue than occur in open water (Fingas 

2004, Buist et al. 2003). However, in-situ burning studies in slush ice showed e#ciencies as high as 

50 percent for weathered crude oils and 80 percent for fresh oil (Buist et al. 2003). 

Burn e#ciencies cited in laboratory studies (e.g., the 50 percent cited in Buist et al. 2003) may 

not be duplicated in most !eld conditions, because burn studies involve pouring oil into a 

containment area to the required thickness, rather than having to corral the oil under !eld 

conditions in which vessels and !re booms must be able to operate. It is also important to 

recognize that burn e#ciency rates describe the percentage of the corralled oil that is burned 

o", rather than the percentage of the total spill amount that is treated. For example, the in-situ 

burning operations after the Deepwater Horizon blowout reportedly included some highly 

e#cient burns, yet burning was estimated to treat only 5 percent of the total spill amount. In the 

Arctic Ocean, even if individual burns removed 50 percent of oil present in a burn area, they might 

treat only a very small percentage of the oil spilled, leaving most of the total spill volume in the 

environment.

As with mechanical recovery, the e"ectiveness of in-situ burning is related to the percentage of 

ice coverage. Both techniques face particular challenges in slush or grease ice; burn e#ciencies 

in the presence of slush ice are lower than in open water and leave behind more residue (Buist 

et al. 2003). The major di"erence between mechanical recovery and in-situ burning in ice is that 

the natural containment provided by ice $oes at higher ice concentrations may be conducive to 

in-situ burning if ignition can be attained. At ice coverage up to about 30 percent, in-situ burning 
80 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

generally requires the use of man-made !re booms to contain the oil to the desired thickness. 

Because of this, in-situ burn operations face many of the same constraints as mechanical recovery. 

Boom-towing vessels must be able to maneuver and position booms to contain the oil to the 

desired thickness, and an ignition source must be deployed from a vessel or aircraft.

When ice coverage is above 60 or 70 percent, in-situ burning may be accomplished using the 

ice $oes as natural containment. In this case, the ignition source will probably be from an aircraft, 

unless icebreaking or ice-reinforced vessels are available and capable of maneuvering in the 

vicinity of the spill. Ice conditions in the 30 percent to 70 percent range are considered to be 

the “most di#cult from an in-situ burning perspective” (Evers et al. 2006). In this range, natural 

containment by the ice is less likely, and containment boom deployment is generally not possible. 

Research into the use of herding agents—chemicals used to improve slick thickness—is ongoing, 

with a focus on use of herding agents in the presence of sea ice (Evers et al. 2006, Buist et al. 2010a 

and 2010b). 

In-situ burning relies on good visibility and weather. In-situ burns cannot be ignited when visibility 

conditions or darkness preclude $ight operations. 

5.3.4 Dispersants

Dispersants are typically selected as a response technique because, although they do not 

physically remove the oil from the water, they may break up oil slicks and reduce the amount of 

oil that reaches and contaminates shoreline areas. Chemical dispersants have been the subject of 

signi!cant research over the past decade, much of it focused on cold-water and Arctic applications 

(Evers et al. 2006). However, substantial scienti!c and technical work still must be done before 

dispersants can be considered a practical response tool for the Arctic. Under the spill response 

framework established by the joint state/federal Alaska Regional Response Team, there is no preapproval for dispersant use in the U.S. Arctic Ocean. Therefore, most discussion of dispersant use in 

the U.S. Arctic Ocean is theoretical.

Many questions remain about the e#cacy of dispersants in Arctic waters, the potential toxicities, 

and the operational feasibility of applying dispersants in ice-infested waters.

Dispersants are chemicals sprayed or applied onto oil slicks to accelerate the dispersion of oil 

into the water column. The chemical mixtures contain three components: surfactants, solvents 

and additives. Surfactants are molecules with an a#nity for two distinct liquids that do not mix, 

acting as an interface between them. One part of the surfactant molecule used in dispersants 

has an attraction to oil (i.e. it is oleophilic) while another part has an attraction for water (i.e. it 

is hydrophilic). Dispersants promote the formation of tiny oil droplets in the water column and 

prevent the re-coalescence of droplets into slicks.

Dispersants do not actually remove oil from the water but are intended to limit the amount of 

oil forming a slick on the water surface or shoreline by breaking the oil into smaller droplets. 

Dispersants are applied using spray nozzles, pumps and hoses and can be applied from a vessel 
81

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

or aircraft (Figure 5-9). Dispersant operations are usually monitored from aircraft to make sure that 

the application is on target. They have a limited time frame for e"ective application, requiring a 

prompt, accurate application of the chemicals, with the oil type, emulsi!cation, salinity, weather 

conditions and sea state all aligned. Recently, there has been research into new dispersant 

application systems designed for use in Arctic conditions (Daling et al. 2010)

Figure 5-9. Typical Dispersant Application and Monitoring Operations

After the Deepwater Horizon blowout in the Gulf of Mexico, substantial amounts of dispersants 

were applied underwater to the oil as it escaped from the well. This type of application appears 

to have been a novel approach, because no published studies or spill response plans for U.S. 

oil exploration or production operations discuss subsea dispersant application. Current U.S. 

dispersant application monitoring protocols address above-water application only (U.S. Coast 

Guard et al. 2006).

The use of dispersants in Arctic waters presents a special set of considerations and concerns 

(Figure 5-10). Reduced water temperatures, variations in salinity, and the presence of sea ice can all 

a"ect dispersant e"ectiveness. However, the slowed weathering of oil under Arctic conditions may 

be viewed as extending the window of opportunity for dispersant use (Daling et al. 2010).

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82 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

Figure 5-10. Dispersant 

Application (Photos: USGS)—

Chemical dispersants are 

applied from the air, le$. 

!e U.S. Arctic presents 

many challenges, such as the 

presence of sea ice, below.

Researchers at the National Marine Fisheries Service Auke Bay Laboratory in Juneau, Alaska, 

reported on laboratory e"ectiveness tests that examined the dispersibility of Alaska North Slope 

crude oil under a combination of sub-Arctic salinities and temperatures. Their results showed 

that the dispersants tested, Corexit 9500 and Corexit 9527, had an e"ectiveness of less than 40 

percent for fresh oil and less than 10 percent for weathered oil. The researchers concluded that “at 

the combinations of temperature and salinity most common in the estuaries and marine waters 

of Alaska, e"ectiveness of dispersants was less than 10 percent.” They cautioned, however, that 

these results are based on laboratory studies performed at low mixing energy (Moles et al. 2002). 

The results contradict an earlier study by S.L. Ross (1998), which concluded that “if used properly, 

Corexit 9527 should be reasonably e"ective on spills of Alaska North Slope crude in Prince William 

Sound or the Gulf of Alaska.” 

Dispersant toxicity is also an issue that weighs into response decision-making, particularly in Arctic 

environments, which may be slower to recover from exposure to toxic chemicals. Chemically 

dispersed oil has been demonstrated to be more toxic to some marine organisms than untreated 

oil (Fuller and Bonner 2001, Singer et al. 1998, Gulec and Holdway 1997). Researchers have also 

found that the undispersed oil residue after a dispersant application may be more toxic than the 

untreated oil (Lindstrom et al. 1999).

The toxicity of chemically dispersed oil may be enhanced by exposure to sunlight (Barron 2000). 

Chemical dispersion of oil has been shown to enhance oil uptake and bioaccumulation (Wolfe et 

al. 1997). Direct exposure to misapplied dispersant can harm birds and mammals (NRC 1989). No 

studies to date consider the toxicity of dispersed oil to marine mammals, either directly or through 

uptake of contaminated food. 

Despite ongoing studies, the general consensus in the spill response community is that 

dispersants are not a proven technology for use in most sea ice conditions (Evers et al. 2006). 
83

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

A review of dispersant use in oil spill response conducted by the National Academy of Science 

recommends additional studies on the physical and chemical interactions of oil, dispersants and 

ice before dispersants can be considered a mature technology for use in sea ice (OSB 2005). A 

report on oil spill response technology in ice-covered waters recommends additional study into 

the potential use of dispersants in sea ice, including the potential use of icebreaking vessels to add 

mixing energy, which is the energy required to mix dispersants with surface oil so that they work 

as intended (D.F. Dickins Associates 2004). 

More dispersants were used in the Deepwater Horizon spill response than on any previous spill. 

Unlike most spills and published studies, in which a single dispersant is used, the Deepwater 

Horizon response involved combinations of several dispersant chemicals. Studies are ongoing 

on the impacts of dispersant use on species and the synergistic e"ects of multiple dispersant 

formulations mixed together and with oil in the marine ecosystem. The subsea application of 

dispersants during the Deepwater Horizon spill also represented a signi!cant variance from typical 

dispersant use. Additional study is needed to determine whether subsea dispersant use is in fact 

a viable response tactic and to consider the e#cacy and the environmental impacts of applying 

dispersant chemicals to a subsea release.

Use of dispersants is also limited by environmental conditions and weather. Aerial application 

of dispersants requires low winds and good visibility, and dispersants cannot be applied during 

periods of darkness. The damping e"ect of sea ice reduces the mixing energy necessary for 

dispersants to work as intended.

5.4 Research and Development to Improve Oil Spill Response in Arctic Waters

The need to improve mechanical recovery capabilities in sea ice is cited repeatedly in the 

published literature (Abdelnour and Comfort 2001, Dickens and Buist 1999, Fingas 2004). This 

poses a signi!cant research and development challenge, because oil leasing, exploration and 

production in the Arctic are outpacing oil spill response technologies, particularly in sea ice. A 

2004 report prepared for the Prince William Sound Oil Spill Recovery Institute and the U.S. Arctic 

Research Commission (D.F. Dickins Associates 2004) identi!es a need to “expand the operational 

capability of existing spill response equipment to enable oil recovery in ice.” The same document 

indicates a “low” con!dence in the ability to improve mechanical response in ice, noting 

“improvements likely to be incremental, resulting in modest increases in recovery e"ectiveness.” 

Recent research and development focused on improving oil spill response in ice has considered 

the use of oil de$ection systems, which apply technologies such as air jet blowers, propeller wash, 

booms, belts, plates or small “curtains” of water bubbles to redirect the $ow of oil into a collection 

area while moving ice in a di"erent direction (D.F. Dickins Associates 2004). Researchers in Finland 

have developed oil spill response devices for sea ice conditions that may be attached to the bow 

of a vessel and include a combination of ice-processing belts and skimming systems (Rytkonen et 

al. 2003). 

Although there have been incremental improvements in individual skimming technologies, 

there have been no breakthrough technologies reported in the literature that would signi!cantly 
84 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

improve mechanical recovery in sea ice. One skimming technology that has shown some promise 

is a brush drum skimmer that can be deployed from a hydraulic arm on a response vessel, because 

of its ability to recover oil from pools in ice. In general, the use of skimmers in ice is considered 

more appropriate for “batch” removals, focusing on small pockets of oil, than for recovery of oil 

from a major blowout (BPXA 2003). 

5.4.1 Joint Industry Program on Oil Spill Response for Arctic Waters

In 2006, a Joint Industry Program (JIP) on Oil Spill Response for Arctic and Ice-covered Waters was 

initiated with funding from several major international oil companies and research by consultants, 

academicians and a few national agencies. A team of researchers from SINTEF, a large Norwegian 

research organization that is active in oil spill response technologies research and development, 

led the JIP e"orts. The purpose of the JIP, which was completed in 2009, was to improve “oil 

spill response techniques for Arctic waters” through a combination of laboratory and !eld trials, 

and to gather more knowledge about the fate and behavior of oil spills in ice and cold water 

temperatures (Sorstrom et al. 2010). JIP was funded jointly by SINTEF, the Norwegian Research 

Council, and seven major oil companies; there was no public participation in or review of the JIP 

published !ndings. 

The JIP experiments focused on aspects of in-situ burning, dispersant use, and mechanical 

recovery in various sea ice conditions and also looked at remote sensing and tracking technologies 

and physical and chemical processes associated with oil weathering in Arctic waters. The program 

culminated in a series of !eld experiments during 2008 and 2009 in the Norwegian Barents Sea. 

Results from the JIP are summarized in a synthesis report (Sorstrom et al. 2010) and in a series of 

technical reports presented at technical conferences.

The reported !ndings from the JIP paint an optimistic picture of the potential applicability of 

several technologies to Arctic oil spills. The overwhelming emphasis of the program appears to 

have been on nonmechanical technologies. Of the eight papers presented on JIP studies during 

the 2010 Arctic Marine Oil Pollution (AMOP) Technical Seminar sponsored by Environment Canada, 

four dealt with in-situ burning technologies (Buist et al. 2010b, Potter and Buist 2010, Brandvik 

et al. 2010b, Brandvik et al. 2010c), one with dispersant application (Daling et al. 2010), two with 

oil-water interactions and weathering (Faksness et al. 2010, Brandvik et al. 2010a), and one with 

remote sensing (Dickins et al. 2010). No papers were presented on mechanical recovery, which is 

the only preapproved oil spill response technique for the U.S. Arctic. The JIP !nal report presents 

a brief discussion of the mechanical recovery testing program, which focused only on skimmer 

technologies and resulted in the identi!cation of two skimmer designs, modi!cations of typical 

open water-skimmers with the addition of ice processing mechanisms that show “promise” for 

Arctic application (Sorstrom et al. 2010).

The JIP was a !rst step toward more rigorous study of oil spill response technologies under Arctic 

conditions, and the inclusion of !eld testing, in which small oil spills were released among sea 

ice for the purpose of experimentation, adds a !eld element to the experiments. However, the 

studies were conducted under controlled conditions, at preselected times and locations where 
85

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

researchers had ready access to the area and were able to pre-position the needed resources to 

conduct the experiments as planned (Figure 5-11). This distinction is relevant to any attempts to 

draw real-world planning assumptions based on the reported study results, because application of 

these technologies, should they become market-ready, will be subject to a wide array of potential 

logistical and operational constraints that could signi!cantly reduce or preclude their applicability.

Figure 5-11. (Photo: SINTEF)—SINTEF JIP Controlled Study with Pre-Positioned Booms and Response

Several JIP studies considered oil-ice weathering as it a"ects the window of opportunity to use 

nonmechanical response technologies (in-situ burning and dispersants). They found generally that 

the slower weathering and degradation of oil spilled in ice-infested waters may extend the period 

during which the oil is ignitable and/or dispersible. 

The chemical herder studies focused on the use of chemical herding agents to thicken oil spills 

when sea ice is present in order to facilitate in-situ burning. This concept has been a subject of 

substantial research over the past several years, indicating a strong interest on the part of the oil 

industry to develop in-situ burning for use in Arctic oil spills. Chemical herders are sprayed onto 

the water surrounding an oil slick to form a thin layer of surfactants on the water surface, reducing 
86 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

the surface tension of the surrounding water. When the surfactant layer reaches the edge of a thin 

oil slick, it changes the chemical balance that caused the oil to contract and fold against itself and 

serves to form thicker layers over a smaller area. The application to response involves thickening 

the slick to the point where it will support ignition and burning. 

During the JIP !eld study, two experimental burns were conducted on chemically herded oil slicks 

in pack ice. The researchers report that 80 percent of the oil was burned in the !rst application, 

a 26-gallon oil slick, and 90 percent in the second experiment, a164-gallon oil slick (Buist et al.

2010b). Although these results con!rm that chemically herded oil slicks are indeed combustible, a 

number of considerations must be made when these results are extrapolated to the real world. For 

example, in the second application, in which 90 percent of the oil was burned, chemical herders 

were applied 15 minutes after the slick (fresh crude oil) had been released to the pack ice. Boats 

were standing by to surround and spray the slick. The fresh oil was easily accessed because there 

was no need to track it, travel to it, or mobilize the equipment needed to apply the herder and 

ignite the oil. The experiment demonstrated that chemical herders work, but to jump from such a 

small, controlled !eld exercise to assumptions about real-world spill response may be premature.

The JIP dispersant tests report focuses on new application technologies to apply chemical 

dispersants to small pockets of oil in sea ice, reporting that the application system resulted in 

highly e#cient dispersant application. Because sea ice dampens wave activity, which is required 

for dispersants to mix with oil and work properly, propeller wash from boat engines was used to 

add mixing energy. Interpretation of the results is subject to the same types of considerations 

discussed for the chemical herder studies; real-world logistical and operational constraints were 

not present during the !eld trials. 

The JIP program was an important step forward in researching oil spill response technologies for 

use in Arctic waters. The results, however, are subject to interpretation before assumptions can 

be made about the applicability of the technologies to spill response in the Arctic. For example, 

the two skimmer models looked at the recovery e#ciencies of these skimmers deployed under 

controlled ice conditions, with ready access to pooled oil. The other components of an on-water 

recovery system—the booms required to contain the oil, the vessels required to operate the 

booms and skimmers, the on-water storage for recovered oil, and the overarching spill response 

system required to support major on-water response operations—would still prove daunting. 

Even if the skimmer e#ciencies are extremely high, there may be days or weeks during which 

the skimmers cannot be deployed because conditions are too rough, windy, foggy or dark (See 

Chapter 6 of this report).

5.4.2 Field Exercises and Oil Spill Drillsin the U.S. Arctic Ocean

Most of the published studies on oil spill response in Arctic waters focus on the use of speci!c 

techniques or technologies under a range of ice conditions (Figure 5-12). These studies are often 

conducted in a laboratory or small test tank. Field testing is less common, and most !eld trials 

involve arti!cial controls of weather or ice conditions, or use only one or two components of a 
87

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

spill response system. Although such studies are valuable to improve empiric knowledge of how 

response technologies function, their results must be viewed with caution when applied to a fullblown spill response in the Arctic Ocean. 

Figure 5-12. Example of Tank Test for Mechanical Recovery of Oil 

Spilled in Sea Ice (Photo: Nuka Research)—During wave tank tests, ice 

is typically frozen under controlled conditions to the desired thickness 

and concentration, and various technologies are tested. !e ice is then 

combined with oil in tanks of various sizes to test equipment. At le$, 

ice was created in tanks at the U.S. Army Cold Regions Research and 

Engineering Laboratory and used in a series of skimmer tests. 

The terms trial, exercise and drill are often used interchangeably, 

yet they are di"erent types of !eld tests. Field trials, such as the 

JIP, are experiments that, though conducted in the !eld, involve 

controlled conditions and signi!cant pre-planning and are typically research and development 

e"orts focused on getting detailed data on a few components of a spill response system, rather 

than exercising the entire system. Field exercises are planned !eld tests in which actual responders 

practice the deployment of spill response equipment under real-world conditions. Exercises are 

valuable for training and practice and may generate information about the functions of response 

equipment and the limits to response systems posed by real-world conditions. But exercises, like 

!eld trials, have an inherent arti!ciality in that the equipment, vessels and personnel are prenoti!ed and often pre-positioned. A true spill response drill, on the other hand, tests the ability to 

put the response system together in the !rst place. During an announced drill, an operator will be 

required to demonstrate the response capacity that is described in its oil spill contingency plan by 

contacting, mobilizing and deploying all or part of the spill response system. 

The primary di"erence between the !eld trials conducted during the JIP and other types of 

!eld exercises or drills is typically one of scale—drills and exercises are practical endeavors that 

test the entire system to various degrees and may involve mobilizing, deploying, operating 

and demobilizing sets of equipment and personnel that would carry out one of more response 

functions. Field trials typically evaluate the performance of an isolated technology or piece of 

equipment under various conditions. A !eld trial is more akin to a laboratory study than to a true 

drill or exercise. The JIP included a series of !eld tests conducted in the Barents Sea in 2009, during 

which a variety of tactics and techniques were tested in the !eld under controlled conditions. The 

results of these studies provide important empirical data that contribute to rules of thumb for 

using these techniques under a range of ice conditions, oil weathering and other factors. However, 

these trials were not full-scale !eld deployments, because they tested only certain components of 

a response system. 
88 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

Drills and exercises typically occur well after a !eld trial or research and development program 

has been completed. For example, while the JIP !eld trials looked at two speci!c skimmer designs 

and tested those skimmers in a controlled area to measure their recovery capacity, the 2000 

Beaufort Sea !eld exercise in Alaska deployed skimmers, boom, multiple vessels, ice scouts and ice 

management and assessed the operating limits of the entire system. Both types of research and 

testing are important to furthering our understanding of oil spill response capabilities and limits in 

the Arctic, yet there have been few !eld exercises in the Alaskan Arctic Ocean. 

A review of State of Alaska records shows that over the past decade, there have been four 

!eld exercises in which spill response equipment has been deployed in sea ice conditions 

and evaluated by state regulators. The !rst such exercise was the 2000 broken ice trials in the 

Alaska Beaufort Sea (Figure 5-13), where it was demonstrated that the actual operating limits for 

mechanical recovery systems—which are typically de!ned in the literature as being operable in up 

to 30 percent ice coverage—were closer to 10 percent. During fall freeze-up, ice conditions as low 

as 1 percent constituted the operating limit for a barge-based mechanical recovery system using 

conventional booms and skimmers (Robertson and DeCola 2001, NRC 2003a). A follow-up !eld 

trial testing the barge-based tactic, conducted in 2002, showed no major improvements (State of 

Alaska Senate Natural Resources Committee Hearing 2010)2

 and was followed shortly thereafter 

by the removal of that barge (the Endeavor) from the Alaska North Slope spill response equipment 

inventory. Two other !eld trials were conducted on the North Slope during open-water or brokenice season, one in 2003 and one in 2009, but no reports were published documenting the lessons 

learned there.

Once the distinction between drills, exercises and !eld trials is understood, it becomes clear that 

it is not appropriate to extrapolate results from isolated !eld trials into expectations for a spill 

response. For example, in-situ burning tests conducted as part of the JIP showed that 98 percent 

of pooled oil can be burned in three-tenths ice coverage (Potter and Buist 2010). However, the 

oil was introduced into a pre-contained area at the desired thickness, then immediately ignited, 

and all vessels were on site and standing by. In the real world, the oil would have to be contained 

using !re booms or other barriers, and vessels would have to be able to navigate in and around 

the burn area, all before the oil became signi!cantly weathered or emulsi!ed. And even if the burn 

were extremely e#cient and removed 98 percent of the oil within the containment area, the oil 

contained within that single burn might represent only a fraction of a percent of the total 

amount spilled. 

2 There is little written documentation from !eld trials in the U.S. Arctic Ocean since the 2000 broken ice exercises. A 

Freedom of Information Act request to the State of Alaska from Oceana yielded documentation that did not show that 

any subsequent tests had successfully deployed equipment under broken ice conditions.
89

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

Figure 5-13. 2000 Broken Ice Exercise in Beaufort Sea (Photo: Kirsten Ballard/ADEC)—Broken ice 

exercises were conducted in the U.S. Beaufort Sea during the spring and fall transitional ice periods in 2000. 

!e exercises involved deployment of all vessels, booms, skimmers and ice management tactics that would 

be used for barge-based oil spill recovery in sea ice. !e exercises tested the operating limits of the response 

system and found that skimmers clogged and booms failed at ice concentrations much lower than expected. 

!is type of real-world deployment is critical to establish the operating limits of the components needed to 

clean up oil in ice-infested waters.
90 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

In the best of conditions, recovering spilled oil is di#cult. Spill response experts typically consider 

a response to be successful if 20 percent of the oil is recovered, and the cold and icy Arctic 

environment hampers the best technology available for spill response. 

During the planning and permitting process for exploratory drilling in the Chukchi Sea in the 

summer of 2010, Shell Oil developed an oil spill plan and scenarios that contemplated how oil 

spill response operations in the U.S. Arctic Ocean might be conducted. The Minerals Management 

Service determined the proposed spill response system to be su#cient to clean up a well blowout 

of 5,500 barrels per day over 30 days. The scenarios submitted by Shell Oil showed that most of this 

165,000-barrel volume could be contained and recovered. Missing from Shell’s oil spill contingency 

plan for the U.S. Arctic Ocean, and from the MMS (now BOEMRE) review of spill planning capacity, 

is a realistic estimate of how Arctic conditions might limit spill response operations. 

This section highlights areas where U.S. oversight of oil spill response planning in the Arctic OCS 

may not be taking into account the realistic limits to containing and cleaning up an oil spill. The 

concept of an oil spill response gap is introduced, and the need for additional response gap 

analysis is explained. A review of oil spill planning assumptions and oil spill response capacity in 

the U.S. Arctic Ocean is presented to demonstrate that additional planning and preparedness are 

necessary to minimize the potential for a catastrophic blowout while also ensuring that if a major 

spill should occur, it would be contained and cleaned up as quickly and e"ectively as possible. 

6.1 Arctic Oil Spill Response Gap

A response gap exists whenever environmental conditions exceed the operating limits of oil spill 

cleanup equipment, meaning that if a spill occurred during this time, it could not be contained 

or cleaned up (Nuka Research 2006 and 2008). The term “response gap” is relatively new to the 

published literature, and there has been some confusion about what the term means and how it 

relates to other oil spill planning and response concepts. 

A response gap estimate, which is typically expressed as a percentage, has nothing to do with 

the percentage of oil that could be recovered. It is an estimate of how frequently conditions on 

the scene would exceed the limits of all available technologies to safely and e"ectively operate, 

meaning that during those times, either no spill response would be attempted, or attempts to 

GAPS IN OIL SPILL PREVENTION PLANNING, RESPONSE

CAPACITY AND OVERSIGHT IN THE U.S. ARCTIC OCEAN 6

(Coast Guard response boat photo: Kurt Fredrickson/U.S. Coast Guard)
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OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

recover oil would be unsuccessful. When a response gap exists 65 percent of the time at a given 

oil spill location, it means that on 65 out of 100 days, no response would be conducted and no 

oil would be recovered, for reasons that may vary from logistical to practical to safety. Recovery 

percentages and response e"ectiveness would come into play during the other 35 days, when it 

would be possible to send out oil spill response equipment. Although it has not been described as 

such, a response gap occurred several times during the Deepwater Horizon response, when high 

winds and storm conditions prompted managers to cease on-water operations for a period of 

hours or days.

6.1.1 Response Limit Estimatesfor U.S. Arctic Ocean

In considering the response gap for the U.S. Arctic Ocean, it is necessary !rst to identify the upper 

limits of the response systems in place. A response gap exists during periods when at least one 

of these upper limits is realized. Upper limits may include ice conditions, visibility, wind, sea state, 

temperature or other physical or environmental parameters. (Table 5-1 summarizes how each of 

these parameters limits oil spill response.) The upper limits of a spill response system involve a 

dynamic interplay among multiple factors and the individual components of a response system. 

However, once the upper limit is reached for one component of a system, it has been reached for 

the entire system. 

Establishing response limits for oil spills in the Arctic Ocean is a challenge, especially given the 

limited data available from actual spills in Arctic waters. The degradation of spill response capability 

does not occur at a single point, nor is it necessarily linear in nature. For instance, if 30 percent ice 

coverage is considered to be the operating limit for mechanical recovery, this does not mean that 

mechanical response e#ciency would plummet to zero as ice coverage increases from 29 percent 

to 30 percent. Likewise, ice coverage of 15 percent does not indicate that the response e#ciency 

is twice as high as it would be at 30 percent. The degradation curve is probably di"erent for each 

environmental factor that a"ects spill response. This further complicates the task of setting discrete 

operational limits for any one factor.

In considering operating limits for the Arctic Ocean, it is also important to recognize that these 

limits are just as likely to be realized because of limits to the vessels or aircraft required to carry 

out the response as they are because of limits to the spill recovery or treatment technology. If 

helicopters or vessels cannot access an area to initiate in-situ burning because of ice conditions or 

visibility limits, then the response is not feasible, even if experiments have shown that oil can be 

ignited under similar conditions.

In addition to ice coverage, the type of ice has a documented impact on spill response limits. 

Each of the di"erent ice regimes (solid ice, open water, fall freeze-up, spring breakup) will limit the 

safety, e"ectiveness or operational feasibility of oil spill response systems. During the transitional 

ice seasons in the U.S. Arctic Ocean (freeze-up and breakup), ice conditions are so dynamic that a 

technique that may be appropriate for use one day could be useless the next (Evers et al. 2006).

During times when ice conditions may be favorable for response, other conditions, such as wind 

and waves, may create a response gap. For example, the “Field Guide for Oil Spill Response in Arctic 
92 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

Waters” recommends that wind speeds above 30 mph and wave heights above six feet be the 

maximum operating limit for in-situ burning and mechanical recovery (Owens et al. 1998). Waves 

that are considerably smaller than six feet in height may limit response if the wave period (distance 

and time between waves) is short. 

Rules of thumb have been developed to estimate whether oil spill response techniques or 

equipment may be used under a range of ice conditions. It is important to recognize that these 

are theoretical estimates only; little real-world data are available to corroborate these !gures. 

Several published sources estimate the operating limits to oil spill response techniques posed by 

ice coverage, wind, waves and visibility (Owens et al. 1998, Fingas 2004, Evers et al. 2006, Robertson 

and DeCola 2001). 

The response gap for oil spill response in the U.S. Arctic could be quanti!ed by comparing 

historical climatic data against a set of upper limit parameters, such as those listed in Table 6-1.

Table 6-1. Matrix of Approximate Oil Spill Response Limits—This matrix summarizes the generally 

accepted response limits to mechanical recovery (with and without ice management) and in-situ burning as they correlate to a range of ice coverage, wind, wave height and visibility conditions. Green blocks 

indicate conditions generally considered to be favorable for the response technique. Yellow blocks indicate that conditions may impede response operations. Red blocks indicate that response would not be 

possible under these conditions. Note that any single red factor could shut down a response. Similarly, 

a combination of yellow factors may have an aggregate impact on response. More work is needed to 

understand these limits and their impact on oil spill response capability in the U.S. Arctic Ocean. Green 

indicates only that the technique may be feasible; the effectiveness of that technique in removing or 

treating oil may still be limited. Dispersants are not included in this table because they are not a mature 

technology and have not been pre-authorized for use in the U.S. Arctic Ocean.

LIMITING 

FACTOR ICE COVERAGE WIND WAVE HEIGHT VISIBILITY

Conditions <10%

11% 

to 

30%

31% 

to 

70%

>70% Solid 

Ice

0-20 

mph

21-35 

mph

>35

mph <3 ft 3-6 ft >6ft High Moderate* Low*

Mechanical 

recovery with no 

ice management

Mechanical 

recovery with ice 

management

n/a

In-situ burning

*Moderate visibility = light fog or <1 mile visibility; low visibility = heavy fog, <1⁄4 mile visibility, or darkness

Response limits may also be driven by a combination of factors that individually would not a"ect 

the response. The cumulative e"ect of two or more environmental factors is not necessarily 

equal to the sum of the two factors individually, and the interaction of the factors could cause 
93

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

more extreme impacts. For example, the combination of wind and cold can cause the wind chill 

factor to make air temperatures dangerous to responders, or cause ice to form on vessels and 

equipment, making them unsafe or unstable (Figure 6-1). The combination of sea ice and low 

visibility might make vessel operations too dangerous. Waves of a certain height or period present 

a greater obstacle to response operations when there is a strong wind or low visibility.

Figure 6-1. Ice Obstacles (Photo: USCG)—Ice can form on vessels, making it more di&cult to operate 

machinery and equipment.

Table 6-2 provides a general seasonal listing of environmental factors that can a"ect and limit 

response operations in the U.S. Arctic, resulting in response gaps. The data are limited and based 

on climatological history for the communities of Barrow and Wainwright. Weather parameters may 

di"er at the actual location of an incident. Information associated with sea state and wave height is 

not available because of the lack of weather buoys in the U.S. Arctic region.
94 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

Table 6-2. Environmental Factors Affecting Operational Limitations in the U.S. Arctic Ocean

(adapted from data at Western Regional Climate Center 2009a & 2009b)

Environmental Factors and Response Gaps

(Estimated Percentage of Time When Operating Limits Are Impaired or Exceeded in U.S. Arctic)

Winter

(Jan-March)

Spring

(April-June)

Summer

(July-Sept)

Fall

(Oct-Dec)

 Ice Condition: Solid (100%)

Approx. Daylight Hrs 4.5

Avg. # Days Peak Gust >30: 20 

(22%)

Avg. # Days of Fog: 51 (57%)

Avg. Ext Min Temp: -49F

 Ice Condition: Solid (80%), Broken 

Ice (20%)

Approx. Daylight Hrs 19

Avg. # Days Peak Gust >30: 12 (1%) 

Avg. # Days of Fog: 53 (58%)

Avg. Ext Min Temp: -9F

Ice Condition: Broken Ice (60%) 

Open Water (40%)

Approx. Daylight Hrs 21

Avg. # Days Peak Gust >30: 19 

(21%)

Avg. # Days of Fog: 44 (49%)

Avg. Ext Min Temp: 20F

 Ice Condition: Open Water (20%), 

Broken Ice (60%), Solid (20%)

Approx. Daylight Hrs- 5.5

Avg. # Days Peak Gust >30: 30 

(34%)

Avg. # Days of Fog: 51 (57%)

Avg. Ext Min Temp: -32F

6.2 Gaps in Oil Spill Response Planning for the U.S. Arctic Ocean 

Plans to drill exploratory wells up to 200 miles o"shore in the Chukchi Sea would have created the 

potential for a subsea well blowout in an area of the U.S. Arctic Ocean where there is no ongoing 

oil exploration or production, and where the capacity to clean up an oil spill in the presence of 

seasonal sea ice is unproved. 

6.2.1 Oil Spill Contingency Planning for Chukchi Sea Leases

Under existing U.S. regulations, once an o"shore lease sale is completed, the lessees begin the 

process of developing an exploration oil discharge prevention and contingency plan1

 (ODPCP or 

“C-plan”), which is an important link between operational risks and response capabilities. The plan 

describes how available resources would be applied to a release of oil under a range of potential 

circumstances. A C-plan for OCS exploration and production operations is required under 30 CFR 

Part 254 and must be submitted to the BOEMRE (formerly MMS) for review and approval. 

A lessee’s C-plan must include a worst-case discharge scenario. Section 311 of the Clean Water 

Act (33 USC § 1321 (a)(24)) de!nes “worst-case discharge” as “the largest foreseeable discharge in 

adverse weather conditions.”2

 Under the MMS regulations (30 CFR 254.47(b)), an operator’s worstcase discharge scenario is the daily volume possible from an uncontrolled blowout. In determining 

the daily discharge rate, the operator must consider any known reservoir characteristics. If 

reservoir characteristics are unknown, the operator must consider the characteristics of any 

analog reservoirs from the area and give an explanation for the selection of the reservoir(s) 

used. The scenario must discuss how to respond to a well $owing for 30 days (30 CFR 254.26(d)

(1)). The adverse weather conditions that must be addressed include, but are not limited to, fog, 

inhospitable water and air temperatures, wind, sea ice, current and sea states (30 CFR 254.6). It 

1 Also referred to as a response plan.

2 Adverse weather conditions are conditions found in the operating area that make it di#cult for response equipment 

and personnel to clean up or remove spilled oil or hazardous substances (30 CFR 254.6).
95

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

does not refer to conditions such as a hurricane under which it would be dangerous or impossible 

to respond to a spill (30 CFR 254.6). 

Shell, the largest leaseholder in the Chukchi Sea, submitted exploration plans and a C-plan to 

the MMS, which were approved in December 2009 and !nalized in March 2010 (Shell 2010). The 

Shell C-plan includes blowout scenarios, but the scenarios presented do not re$ect a true worstcase discharge or response. They fall short of the regulatory requirement to plan for a “worst case 

discharge under adverse conditions” and thus do not provide any real assurance, should a major 

well blowout occur from drilling in the o"shore Arctic. 

6.2.2 Planning Assumptionsin Shell’s Chukchi Sea Oil Spill Contingency Plan

FLOW RATE FOR BLOWOUT

Shell’s C-plan is based on the ADEC well blowout response planning standard of 5,500 barrels per 

day, multiplied by the federal response planning period of 30 days. Uncontrolled well $ow may be 

signi!cantly higher, because other North Slope wells have had production rates in excess of 10,000 

barrels per day when !rst drilled. 

SPILL RECOVERY ESTIMATES

Shell includes a planning assumption that 90 percent of the oil discharged from a blowout 

would be contained and recovered by the primary o"shore response task forces, and that only 10 

percent would escape and drift toward shore. Shell expects that half the oil reaching the nearshore 

environment would be recovered by additional skimming systems deployed from a response 

barge using a tactic similar to the one that was tested during the 2000 broken-ice exercises and 

shown to be limited to very low ice concentrations. The C-plan does not explain how Shell arrived 

at the assumption that 90 percent of the oil would be contained and recovered from the sea 

surface. By comparison, only 3 percent of the estimated 4.9 million barrels of oil spilled during the 

Deepwater Horizon incident was recovered by o"shore containment and skimming operations.

Recovery of such a large amount of oil, though unrealistic as a planning assumption, would create 

a storage crisis, based on the resources Shell has identi!ed in its plan. Shell lists a total of 545,246 

barrels of on-water storage capacity for recovered oil and water. With a blowout scenario of 5,500 

barrels per day, assuming that the oil is recovered as an emulsi!ed oil/water mixture, Shell would 

!ll this available storage on day 13 of the blowout. If Shell were permitted to decant the oil/water 

mixture (separate the oil from the water and discharge the water), then the storage could last 30 

to 45 days.

SOURCE CONTROL

The Shell C-plan is predicated on a number of assumptions. One of the most problematic 

assumptions is that the Frontier Discoverer, the drill ship that would drill the exploratory wells, 

would be able to drill its own relief well if a subsea blowout should occur. This requires that the 

drill ship be undamaged by a well blowout, which is highly unlikely. The two most recent well 

blowouts—the Montara platform blowout in the Timor Sea and the Deepwater Horizon blowout 

in the Gulf of Mexico—involved explosions and !res that damaged the drilling structure. Fire and 
96 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

explosion are not uncommon for well blowouts, because the materials that are released typically 

include $ammable gases. (See list of well blowouts, Table 3-2.) Even if a !re or explosion did not 

occur, ignition of $ammable gases is always a concern.

A blowout typically results in evacuation of personnel from the drill ship, which would make 

starting and moving the ship extremely di#cult. A review of all available data about well blowouts 

worldwide does not show a single example of a drill ship drilling its own relief well after blowing 

out. Thus the Shell strategy is without precedent. During the 1980s, the original exploration plans 

for the Chukchi Sea also called for the drill ship to drill its own relief well in the event of a blowout, 

but before drilling commenced, the operators were required to arrange for a second drill ship to 

be on standby in the Canadian Arctic in case the !rst rig was damaged or unable to complete the 

relief well (Hinkel et al. 1988).

Shell justi!es the drill ship/relief well plan on the basis that several layers of protection are in place 

to prevent a blowout from occurring, and the assumption that the blowout would never be severe 

enough to prevent the drill ship from drilling another well. The Deepwater Horizon provided an 

example of how protective barriers can fail. 

Given the fact that the C-plan is questionable, the 30-day time frame for controlling the well may 

also be overly optimistic. The relief well plan included in the C-plan even acknowledges that it 

could take 34 days to drill a relief well to 14,000 feet true vertical depth. Shell does not consider the 

possibility that more than one attempt may be required to drill a successful relief well. The Montara 

blowout took more than 70 days to control, in part because the !rst four attempts to drill a relief 

well were unsuccessful. 

Shell’s worst-case discharge scenario assumes that a well blowout would occur early in the drilling 

season, allowing enough time to drill a relief well and control the blowout before fall freeze-up 

(October or November) begins to encroach on the drill site. A spill that occurred later in the drilling 

season might not allow enough time to drill a relief well before sea ice conditions made it unsafe 

to continue drilling. Under such a scenario, the well would continue to blow out through the 

winter ice season until well control could be attempted after the spring thaw in May or June. 

WEATHER CONDITIONS

Shell’s C-plan contains a scenario that presumes that the weather, temperature and sea state 

remain consistent throughout the 30-day response period and have no negative impacts on 

response capability and capacity. This is an unrealistic assumption. Even during the Deepwater 

Horizon response, weather and sea state caused response operations to be curtailed several times. 

In the o"shore Chukchi Sea, the combination of wind, waves and dynamic sea ice can severely 

hamper or even preclude oil spill cleanup (Table 6-1). 

Shell states in its C-plan that the well drilling activities would not be conducted after Oct. 31. 

Typically, the Chukchi Sea is ice-free in mid-September. By early September, the ice edge is at its 

northernmost point. During the last week of September, new ice typically begins to form within 

the marginal ice zone. As the temperatures begin to decrease, new ice continues to thicken, and 

the ice edge gradually moves southward. By the second week of October, new ice growth is well 
97

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

underway. The Arctic pack ice will be drifting southwest with concentrations of multiyear ice at 

more than seven-tenths, with the remainder being young ice. As the amount of sunlight rapidly 

declines, temperatures decrease in mid-October, and rapid refreezing of leads and any other 

openings in the ice is expected. Ice will also begin to grow along the Alaskan coast during the !rst 

week of October, with fast ice forming along the Barrow coast by the third week of October.

The average wind speed in mid-September through November for Wainwright, Alaska, is 

approximately 12 mph, with daily gusts averaging 23 mph. The average wind speed and daily 

gust average for Barrow, Alaska, are similar. Sea state data is less reliable, but seas of 10 to 20 feet 

are not uncommon. The plan does not address visibility limits for on-water and aerial surveillance 

and support activities. Fog is persistent throughout the area, with an average number of 21 foggy 

days per month. Heavy fog with visibility less than or equal to one-quarter mile occurs an average 

of three days per month during this time. Fog would make on-water and aerial response activities 

unsafe or unfeasible. 

The Shell C-plan does acknowledge the possibility that oil spilled late in the drilling season could 

become encapsulated in fall freeze-up or trapped under ice $oes through the winter. The spill plan 

presents this as a favorable condition, assuming that any oil trapped over the winter would remain 

in place and be as easy to remove or treat after eight months in the sea ice. Sea ice is dynamic and 

constantly moving, however, and oil trapped under or within ice could be extremely hard to even 

locate in the springtime. Oil trapped under multiyear ice could remain in the marine environment 

for many years. A scenario developed in the mid-1980s for the Chukchi Sea estimated that spilled 

oil trapped in ice could move as much as 300 to 500 miles (Lewbel and Galloway 1984 in NRC 

2003b).

The period from August until freeze-up is typically the most active storm season in the o"shore 

Chukchi, with severe storms resulting in high winds and sea states, freezing spray and coastal 

erosion. An oil spill plan should take into consideration historical weather patterns and plan for the 

possibility that conditions may not be ideal. Federal regulations speci!cally require that worst-case 

oil spill scenarios address “adverse weather conditions,” but the Shell plan, approved by the MMS, 

certainly does not address adverse weather (30 CFR 254.26(d)).

6.2.3 Gapsin Response Capacity for Subsea Well Blowout in the Chukchi Sea

Based on the major response activities described in the Shell scenario and the resource 

requirements to meet the response commitments made in the C-plan, there appear to be major 

gaps in the capacity of existing response equipment and technologies to respond to a blowout 

from a subsea well in the Chukchi Sea or elsewhere in the U.S. Arctic Ocean.3

One major gap apparent in the Shell Chukchi C-plan is that, in many cases, spill response 

operations depend upon the same pieces of equipment or vessels to support multiple functions 

simultaneously. Another problem is a lack of consideration for the logistical challenges of 

3 This analysis takes into consideration only mechanical recovery operations, not the use of chemical dispersants or insitu burning. Although Shell’s Chukchi leases are in federal waters, the C-plan conforms to State of Alaska requirements 

that planholders demonstrate that they can meet their oil spill cleanup requirements solely through mechanical 

recovery. The state of Alaska prioritizes mechanical recovery over dispersant use and in-situ burning.
98 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

mounting a major spill response o"shore in a region with limited coastal infrastructure. The Shell 

C-plan indicates that the primary incident command post would be in Anchorage, Alaska (see 

Figure 2-15). The plan does not identify the number of industry, contractor and agency personnel 

needed to sustain the response. Logistical support and staging areas would also need to be 

established in Barrow, Wainwright, Point Lay or Point Hope, the only coastal communities with 

su#cient airstrips.

In an attempt to demonstrate some of the shortfalls in the level of contingency planning accepted 

for Arctic Ocean oil spills, the major response activities in the Shell C-plan and the response 

limitations are considered, based on the discussion in Section 6.1.

Table 6-3 (at the end of this section) summarizes the resource requirements, task force, function, 

response tactics, minimum required response resources, and source of resources listed in the Shell 

C-plan. The resources summarized are for surveillance and tracking, o"shore recovery, transfer and 

storage of recovered oil, nearshore recovery and sensitive area protection.

Alaska Clean Seas (ACS) is the primary oil spill response contractor for the U.S. Arctic region. The 

Alaska Clean Seas Equipment Manual provides a guide to the location, ownership, type, amount 

and speci!cations of most of the North Slope response equipment (ACS 2009). Although ACS 

has a signi!cant equipment stockpile to support operations in shallower, nearshore waters, it has 

limited o"shore capabilities.

SURVEILLANCE AND TRACKING

The Shell Chukchi Sea contingency plan does not clearly identify the resources that would be 

used to carry out the aerial surveillance of oil on the water. Two helicopters are identi!ed in the 

C-plan. It is assumed that the Twin Otter aircraft with forward-looking infrared radar (FLIR) from 

Kuparuk would be used initially and based in Barrow for this response, but FLIR technology is 

limited by ice conditions (it cannot be used to detect oil under fast ice). It is also a"ected by cloud 

cover and fog and can be used only during daylight. This resource can be obtained through the 

mutual aid contract with North Slope Operators and Alaska Clean Seas. As with all o"shore oil spill 

response operations, other commercial aircraft and helicopters would need to be contracted to 

conduct aerial surveillance and tracking of the oil and to support the operation. (More than 100 

!xed-wing aircraft and helicopters were used during the Deepwater Horizon oil spill response.) An 

impediment to aerial surveillance during this time frame is the presence of fog or ice. As noted, the 

monthly average of foggy days in the region is 21 during the ice-free season.

In the Shell C-plan, spill tracking buoys will also be deployed to assist in determining where 

the oil is being transported and at what rate. In addition to the hand-held tracking buoys, Shell 

plans to track the discharge using satellite technology. In cloud-free conditions, visible imagery 

is an excellent aid. However, because the Arctic has few days that are cloud free, high-resolution 

all-weather imagery will be necessary for consistent operational support. As freeze-up sets in, 

tracking and monitoring the movement of oil will be increasingly di#cult, and innovative options 

or commercially available technology will need to be used. Shell’s contingency plan suggests the 

possible use of the Shell Global Source Light Touch System (gas detector), ground-penetrating 

radar and laser $uorosensors. Although commercially available, all of these technologies are 

experimental when applied to tracking oil that is under or mixed in ice.
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OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

OFFSHORE RECOVERY

Shell’s o"shore recovery revolves around four primary response vessels and eight workboats that 

would be on site for the drilling period and other response resources located hundreds of miles 

from the drill site. MMS never required Shell to demonstrate, beyond its descriptions in the C-plan, 

whether this equipment was su#cient to clean up a worst-case oil spill far o"shore that lasts 30 

days or longer. The immediate availability and signi!cant amount of spill response equipment in 

the Gulf of Mexico after the Deepwater Horizon blowout demonstrates that when a catastrophic 

spill occurs, no amount of equipment is enough. The limited personnel, vessels and a few 

thousand feet of ocean boom that Shell plans for its o"shore spill response would be insu#cient 

for cleaning up a major spill in the remote Chukchi Sea. Alaska Clean Seas has limited equipment 

suitable for o"shore operations. MMS did not require any testing or exercises to explore the limits 

of existing spill cleanup equipment for o"shore response when sea ice is present.

NEARSHORE RECOVERY AND PROTECTION OF SENSITIVE RESOURCES

The Shell C-plan shows that three task forces are assigned to nearshore recovery to apply !ve 

di"erent response tactics. Shell intends to deploy protective boom at seven priority protection 

areas (PPA) identi!ed in the scenario along Chukchi Sea shoreline areas. Table 6-3 summarizes 

the resource requirements for boom, workboats and personnel to deploy all of these strategies 

when they arrive on Day 5. As these activities are going on simultaneously with o"shore recovery 

and nearshore recovery, the resources required to deploy sensitive area protection tactics are 

presumed to be dedicated to sensitive areas and are not available to other task forces. The 

resources listed in the Shell C-plan are:

• Amount of boom required to implement all priority protection strategies is 6,200 feet.

• Fourteen workboats and 44 trained responders/vessel operators to deploy and seven 

workboats and 21 trained responders/vessel operators to tend and maintain boom.

• Mobilization plan for vessels, personnel and boom is unclear from the scenario. ACS 

provides all equipment, vessels and personnel.

• ACS vessels and personnel would probably require transportation via vessel or barge from 

Prudhoe Bay to the protection sites. Some sites have signi!cant draft restrictions.

The Shell C-plan clearly indicates that the shoreline protection will be sharing resources and 

personnel, which will create a con$ict of resource priorities.

SHORELINE IMPACT

Shell’s C-plan discounts the potential for shoreline impacts, noting that it is “highly unlikely that 

oil could impact the nearshore environment in less than six days.” The C-plan goes on to state 

that “even if oil did survive that long in the open ocean, there would be ample time to monitor its 

movement, prepare to intercept and recover it, and to position shoreline protection and cleanup 

crews at priority protection sites well before the oil may arrive.” This statement seems to all but 

dismiss the potential for a spill from the exploration operations to a"ect shoreline areas, even 

though the closest drill site is about 60 miles from the shoreline. 
100 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

A large oil spill would undoubtedly have shoreline impacts, as we have seen time and again in 

major oil spills. The Exxon Valdez oil spill migrated 460 miles and a"ected more than 1,300 miles 

of noncontiguous shoreline. The Deepwater Horizon spill has a"ected coastlines in four Gulf Coast 

states. Little is known about currents and wind direction in the U.S. Arctic Ocean, so it is virtually 

impossible to know what direction the oil will go. During the !rst week of October, ice will begin 

to form along the shoreline, and oil would probably become encapsulated in ice, making access to 

sites and any shoreline cleanup activities challenging.

CASCADING OF ADDITIONAL OIL SPILL RESPONSE RESOURCES

Shell’s C-plan indicates that if additional response resources were needed to adequately clean 

up an oil spill, the company would activate existing contracts with the Marine Spill Response 

Corporation, Oil Spill Response in Southampton, United Kingdom, and the mutual aid agreements 

through Alaska Clean Seas. Personnel and equipment would join the response from other 

locations in Alaska and worldwide. Shell’s C-plan does not explain how these additional resources 

would be mobilized from the various airports (Barrow, Point Hope, Wainwright) to the spill location. 

The infrastructure and road system in the smaller communities are limited and cannot support a 

Deepwater Horizon size response.

Accessing the North Slope communities by vessel also presents a challenge and is weather 

dependent. The entrance to Wainwright Inlet is a narrow, winding channel. Its depth is 

approximately six feet, enough to accommodate shallow-draft barge tra#c, but passage should 

not be attempted without the aid of local guides and/or pilots during open-water season. 

Shoals extend approximately seven-tenths of a mile o" the inlet and are well de!ned by breakers 

during moderate weather. During west storms, the breakers stretch across the channel. Point 

Hope is located on the Chukchi Sea with a nearshore current of 1 knot, increasing to 2 to 3 knots 

near Point Barrow. Barrow can be accessed by vessel during open-water season, but there is no 

protection from heavy weather. 
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OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

Shell Task 

Force 

Purpose and 

Name

Minimum 

Required Response 

Resources1

Potential Shortfalls 

or Operating 

Limitations

ENVIRONMENTAL FACTORS AND OPERATING LIMITATIONS

Winter 

(Jan-March)

Spring 

(April-June)

Summer 

(July-Sept)

Fall 

(Oct-Dec)

Surveillance

and Tracking

(No task 

force number 

assigned in 

C-plan)

1 Kuparuk Twin 

Otter aircraft with 

FLIR

Spill tracking buoy 

system

1 workboat (deploy 

tracking buoys)

6 trained personnel 

per shift

Satellite tracking

Resources not clearly 

identified in Shell 

scenario.

No contract found in 

Shell C-Plan for this 

service.

 Primary limitation 

for aerial operations 

will be associated 

with visibility (57%). 

Day visual flight 

rule (VFR) only for 

field ops. Whiteout, 

blizzard conditions, 

limited daylight 

hours and ice fog.

 Limitations: 

Visibility associated 

with fog, ice fog 

(58%) icing on 

aircraft, day VFR 

operations only for 

field ops.

 Limitations: 

Visibility 

associated with 

fog (49%), day VFR 

operations only 

for field ops.

 Limitations: 

Visibility 

associated with 

whiteouts, fog, ice 

fog (57%) icing on 

aircraft, day VFR 

operations only 

for field ops.

O!shore

Recovery 2

TF-1

1 oil spill response 

vessel (OSRV) 

with 12,000 

bbl storage

1 Transrec 150 

Skimmer

1 OSRV supervisor

1 OSRV operator

3 34-ft workboat 

operators (shared 

with TF-2)

3 34-ft workboat 

crew

7 OSRV deck crew

1 100-bbl bladder

Three 34-ft workboats, 

operators and crew 

are shared with

 TF-2.

Solid ice precludes 

on-water vessel 

operations. 

 Limitations for 

offshore oil recovery 

include: Visibilitywhiteout, blizzard 

conditions, ice 

fog and extreme 

temperatures (58%). 

May-June breakup 

will preclude use of 

vessels nearshore. 

Solid ice present 

offshore precludes 

vessel operations.

 Limitations: 

Broken ice 

conditions and 

open water. Ice 

management 

needed in 

broken ice areas 

for effective 

response. Open 

water affected 

by wind speeds 

and gusts >30 kts 

(21%), visibility 

due to fog (49%).

 Limitations: 

Open water and 

broken ice. Ice 

management 

needed in 

broken ice areas 

for effective 

response. Open 

water affected 

by wind speeds 

and gusts >30 kts 

(34%), visibility 

due to fog 

(57%). Extreme 

temperatures 

would cause icing 

on vessels and 

response recovery 

equipment.

O!shore

Recovery

TF-2 (24 hr)

1 Transrec 150 

skimmer

1 Vessel of 

Opportunity 

Skimming System 

(VOSS) w/ 3,200 bbl 

storage

1 VOSS supervisor

2 VOSS deck crew

3 34-ft workboat 

operator (shared 

with TF-1)

3 34-ft workboat 

crew

Beginning Day 2, 

the TF team leader/

field supervisor is 

accounted for in TF-1.

Solid ice precludes 

on-water vessel 

operations. 

 Limitations for 

offshore oil recovery 

include: Visibilitywhiteout, blizzard 

conditions, ice 

fog and extreme 

temperatures (58%). 

May-June breakup 

will preclude use of 

vessels nearshore. 

Solid ice present 

offshore precludes 

vessel operations.

 Limitations: 

Broken ice 

conditions and 

open water. Ice 

management 

needed in 

broken ice areas 

for effective 

response. Open 

water affected 

by wind speeds 

and gusts >30 kts 

(21%), visibility 

due to fog (49%).

 Limitations: 

Open water and 

broken ice. Ice 

management 

needed in 

broken ice areas 

for effective 

response. Open 

water affected 

by wind speeds 

and gusts >30 kts 

(34%), visibility 

due to fog 

(57%). Extreme 

temperatures 

would cause icing 

on vessels and 

response recovery 

equipment.

Table 6-3. Resource Requirements and Operating Limitations
102 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

Shell Task 

Force 

Purpose and 

Name

Minimum 

Required Response 

Resources1

Potential Shortfalls 

or Operating 

Limitations

ENVIRONMENTAL FACTORS AND OPERATING LIMITATIONS

Winter 

(Jan-March)

Spring 

(April-June)

Summer 

(July-Sept)

Fall 

(Oct-Dec)

Transfer &

Storage of

Recovered

Oil

TF-3

1 Oil Spill Tanker 

(OST) 

1 Tanker Deck 

Person-in-Charge 

(PIC)

1 Tanker operator

3 Tanker deck crew 

(1 per shift)

Crude oil capacity = 

513,000 bbl. All TF-3 

tasks including PIC 

will be performed by 

tanker crew with no 

additional response 

staff from Shell or 

ACS.

Solid ice precludes 

on-water vessel 

operations. 

Solid ice and spring 

breakup conditions 

near retreating 

ice edge would 

preclude the OST to 

be in the area until 

July.

Open water 

affected by wind 

speeds and gusts 

>30 kts (21%), 

visibility due to 

fog (49%).

Open water 

affected by wind 

speeds and 

gusts >30 kts 

(34%), visibility 

due to fog 

(57%). Extreme 

temperatures 

would cause icing 

on vessels and 

response recovery 

equipment. OST 

would need to 

depart region 

prior to freeze-up.

Nearshore

& Shoreline

Recovery

TF-5 (96 hr)

1 oil spill response 

barge (OSRB)/tug 

with16,000 bbl 

capacity

1 OSRB supervisor

1 nearshore 

recovery supervisor

4 Lamor LSC-5 

skimmers (2 per 

vessel)

1 47-ft skimmer 

boat

1 47-ft skimmer 

boat operator

2 47-ft skimmer 

boat crew

3 34-ft workboats

3 34-ft workboat 

operator

3 34-ft workboat 

crew

4 249-bbl storage

200 m boom

6,000-ft coastal 

boom

Solid ice precludes 

on-water vessel 

operations. 

Solid ice and spring 

breakup conditions 

near retreating 

ice edge would 

preclude the OSRB 

to be in the area 

until July.

 Limitations: 

Broken ice 

conditions and 

open water. Ice 

management 

needed in 

broken ice areas 

for effective 

response. Open 

water affected 

by wind speeds 

and gusts >30 kts 

(21%), visibility 

due to fog (49%)

 Limitations: 

Open water and 

broken ice. Ice 

management 

needed in 

broken ice areas 

for effective 

response. Open 

water affected 

by wind speeds 

and gusts >30 kts 

(34%), visibility 

due to fog 

(57%). Extreme 

temperatures 

would cause icing 

on vessels and 

response recovery 

equipment.
103

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

Shell Task 

Force 

Purpose and 

Name

Minimum 

Required Response 

Resources1

Potential Shortfalls 

or Operating 

Limitations

ENVIRONMENTAL FACTORS AND OPERATING LIMITATIONS

Winter 

(Jan-March)

Spring 

(April-June)

Summer 

(July-Sept)

Fall 

(Oct-Dec)

Nearshore

& Shoreline

Recovery

TF-6 (96 hr)

4 workboats 18-22 

ft plus 4 operators 

and 4 crew

2 workboats 29 ft 

plus 2 operators and 

2 crew

2 24-ft workboats 

plus 2 operators and 

2 crew

2 landing craft plus 

2 operators and 2 

crew

18,000-ft boom 

8 shoreline 

protection laborers

Boats and landing 

craft are shared by 

TF-6 and TF-7.

TF-5, TF-6 and TF-7 

operate one 12-hour 

shift per day.

Solid ice precludes 

on-water vessel 

operations. 

Solid ice and spring 

breakup conditions 

near retreating 

ice edge would 

preclude the OSRB 

to be in the area 

until July.

 Limitations: 

Broken ice 

conditions and 

open water. Ice 

management 

needed in 

broken ice areas 

for effective 

response. Open 

water affected 

by wind speeds 

and gusts >30 kts 

(21%), visibility 

due to fog (49%).

 Limitations: 

Open water and 

broken ice. Ice 

management 

needed in 

broken ice areas 

for effective 

response. Open 

water affected 

by wind speeds 

and gusts >30 kts 

(34%), visibility 

due to fog 

(57%). Extreme 

temperatures 

would cause icing 

on vessels and 

response recovery 

equipment.

Nearshore

& Shoreline

Recovery

TF-7

See TF-6 resources

20 oleophilic 

skimmers

36 bladders (500 to 

2,640 gal.)

50 portable folding 

tanks (2,500 gal.)

8 shoreline recovery 

laborers

Trained shoreline 

assessment teams 

(minimum of 4 

personnel per 

team with requisite 

training).

Helicopter for 

transportation. 

Solid ice precludes 

on-water vessel 

operations. 

Solid ice and spring 

breakup conditions 

near retreating ice 

edge and shoreline 

would restrict 

access to beaches 

needing cleanup. 

Visibility 

limitations due 

to fog (49%) to 

support shoreline 

cleanup crews 

via vessel and 

helicopter. 

Freeze-up 

and solid ice 

conditions 

affect access to 

shoreline due to 

ice. Wind speeds 

and gusts >30 kts 

(34%), visibility 

due to fog 

(57%). Extreme 

temperatures 

would cause 

icing of recovery 

equipment. 

Aerial operations 

limitations: icing 

on aircraft, day 

VFR operations 

only for field ops 

(5.5-0 hours).

1 Per task force, with the exception of sensitive area protection, which shows the requirements for deployment of all priority protection sites simultaneously. Sequential 

deployment of sensitive area protection resources will reduce the number of workboats and personnel required but will not affect the total amount of boom.

2 Table 1.6-5 Shell Contingency Plan lists two skimming alternatives to be considered for use by TF-1 but only one option would be used in the scenario.

3 This table contains no TF-4 “Non-mechanical response.” TF-4 includes designation of both a C-130 aircraft (based in Arizona) with integrated dispersant tank and spray 

arms and the chemical dispersant Corexit 9500. This table addresses mechanical recovery options that are primarily in-state and readily available.
104 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

6.2.4 Gapsin Planning and Response Capacity in the Beaufort Sea

Sections 6.2.1 through 6.2.3 of this report discuss the gaps in planning and preparedness for 

oil exploration in federal waters up to 200 miles o"shore in the Chukchi Sea. Many of the same 

challenges described for the Chukchi Sea would carry over to exploratory drilling in areas of 

the Beaufort Sea. A more detailed analysis of the extent and nature of the response gap in both 

the Chukchi and Beaufort seas is warranted and should address the similarities and di"erences 

between the two operating environments. 

Most of the limiting factors discussed in the context of the U.S. Arctic Ocean—such as high winds, 

severe storms, heavy seas, low visibility, cold temperatures and seasonal ice—apply to both the 

Beaufort and Chukchi seas. However, there are di"erences between the two operating areas that 

may alter the challenges.

WATER DEPTHS AND DISTANCE FROM SHORELINE

Existing production operations in state and federal waters of the Beaufort Sea are clustered in 

shallower areas within a few miles of the shoreline (Figure 3-3). Thus far, these operations have 

been conducted from man-made gravel islands at water depths below 80 feet. Expanded drilling 

or production in deeper waters farther from shore may require $oating or bottom-founded 

structures, as discussed in Chapter 3. For now, drilling operations that are conducted from islands 

closer to shore have both advantages and disadvantages from a spill planning perspective. Oil 

spills from exploration and production operations closer to shore will have more rapid shoreline 

impacts. However, blowouts from island drilling structures may be easier to control because the 

blowout preventers are located at the surface rather than underwater. That factor, combined with 

seasonal drilling restrictions, gives responders a better chance of cleaning up oil spilled on top of 

solid ice.

SEASONAL DRILLING

Exploratory drilling in the Beaufort Sea has been conducted during the winter season when the 

nearshore Beaufort is frozen solid and spill response tactics would involve operating vehicles 

and equipment from the solid land-fast ice coverage. Spills on top of solid ice present their own 

challenges but are typically easier to clean up than spills in open water or broken ice during the 

freeze-up, breakup or open-water seasons. Because production operations continue year-round 

in the Beaufort Sea, the potential for a spill during freeze-up or breakup exists, and such a spill 

may be even more challenging because of the operating conditions there. The shallow nearshore 

Beaufort is not deep enough for ice-class vessels to operate; therefore, the small workboats 

that would form the basis of the response would be limited to operating in areas of lower ice 

concentration. The open-water season in the Beaufort Sea is about a month shorter than in the 

Chukchi Sea, further limiting the response window for on-water cleanup.
105

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

WORSTCASE BLOWOUT VOLUMES

Although data are limited on well-bore pressure and potential blowout rates in the Chukchi 

Sea, more information is available about the potential blowout rates for Beaufort Sea wells. The 

contingency plan for the Liberty development project in the Beaufort Sea has the highest $ow 

rates in the U.S. Arctic and a potential open-ori!ce blowout of 20,000 barrels a day. A blowout from 

a Beaufort Sea well that occurs during the end of the brief open-water season could continue 

uncontrolled over the nine-month ice season and result in a spill larger than the Deepwater 

Horizon blowout if oil is trapped within and among sea ice until the spring melt.
106 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

RECOMMENDATIONS7

A great deal of work is required to guide responsible management and ensure that the best 

decisions are made to prevent and respond to oil spills in the Arctic Ocean. Signi!cant gaps exist in 

knowledge, planning, and oversight in the areas of oil spill risks, impacts and response capabilities, 

and these gaps must be closed before the United States moves forward with oil exploration and 

production activities in the Arctic OCS. 

The following recommendations are presented based on the analysis in this report, with the 

goal that implementation of some or all of these initiatives will lead to responsible management 

of the Arctic OCS and prevent oil spills from adversely a"ecting the environment, ecology and 

indigenous people who rely on a pristine Arctic Ocean.

The recommendations o"ered here relate to the key concepts explored in this report:

• The Arctic Ocean is di"erent from any other area of the U.S. OCS.

• Government and industry oil spill plans underestimate blowout risks in the Arctic Ocean.

• An oil spill could devastate the Arctic ecosystem.

• Oil spill response systems are unproved during most of the year in the U.S. Arctic Ocean. 

• An Arctic Ocean oil spill response gap exists.

7.1 Improve Arctic Oil Spill Science, Monitoring and Assessment

The “Guidelines for Arctic Oil and Gas Development,” published by the Arctic Council in 2009, 

cautions:

“Where there are threats of serious or irreversible damage, lack of full scienti"c certainty 

shall not be used as a reason for postponing cost-e#ective measures to prevent 

environmental degradation.”

Baseline science for Arctic marine environments is improving but is still very limited. Research 

is ongoing by the USGS to identify major gaps in Arctic science. Such work is critical to develop 

a comprehensive, collaborative program of research, monitoring, data collection, mapping and 

(Icy Arctic photo: Patrick Kelly/USGS)
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OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

documentation of local and traditional knowledge in the U.S. Arctic. Arctic ecological science, 

monitoring and assessment should be integrated with oil spill prevention and response planning. 

The Arctic features a complex interplay of environmental conditions, climate, wildlife population 

dynamics and human activity. The prospect of conducting baseline studies to better delineate 

environmental and wildlife sensitivities, while increasing our scienti!c knowledge base regarding 

the Arctic ecology and sensitivity to oil spills, is daunting. Yet such research is critical and must be 

initiated before the introduction of new oil spill risks.

7.1.1 Close the Knowledge Gaps Regarding Arctic Oil Spill Impacts

Additional research is needed to better understand the fate and impact of oil spilled in a seasonal 

ice environment and to explore the short- and long-term toxicity of spilled oil to the Arctic 

ecosystem and food webs. 

A 2007 assessment of worldwide oil exploration and production activities in Arctic regions 

emphasizes that the current state of knowledge regarding Arctic oil spill impacts and oil toxicity to 

Arctic species is extremely limited. Signi!cant research is needed on the behavior of oil spilled in 

ice-!lled seas, the vulnerabilities of Arctic ecosystems to oil toxicity, and the short- and long-term 

impact of oil spills on Arctic food webs, plants, animals and people. The 2008 Arctic Oil and Gas 

Assessment Scienti!c Findings and Recommendations discusses these “gaps in knowledge”:

“This assessment has identi"ed many gaps in knowledge of the impacts of Arctic oil 

and gas activities on the environment, biota, and human populations of the Arctic. 

This is partly due to an incomplete understanding of environmental conditions in the 

relevant areas of the Arctic and of the species and populations of the many plants and 

animals that live there as well as their ecological interactions. There is also incomplete 

knowledge of the socio-economic and health e#ects on the human populations of 

the development of the oil and gas industry in the often remote areas. ... Research is 

required on a wide range of the potential biological e#ects of these chemicals under 

conditions and with species and life stages appropriate to the Arctic, including, among 

others, studies of acute and chronic toxicity, genetic e#ects, and combined e#ects with, 

for example, exposure to sunlight. This includes studies of linkages between the diverse 

sub-lethal e#ects and the risks they pose to individuals and populations of Arctic 

animals.” (AMAP 2008b)

Most of the existing knowledge regarding oil toxicity and chemical interactions comes from 

studies on temperate species. Studies from other cold-water oil spills, such as the Exxon Valdez spill 

in sub-Arctic Prince William Sound, suggest that oil spill impacts in cold regions can be signi!cant 

and long-lasting. However, there are many gaps in the current body of knowledge on issues that 

include:

• Transfer and accumulation of toxic compounds within the Arctic food web.

• Secondary or chronic impacts from oil exposure (e.g., reduced fertility, immunosuppression).
108 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

• Relative sensitivities of various life stages of !sh, birds and mammals. 

• Photo-enhancement of oil toxicity. 

• Seasonal variations in oil toxicity sensitivity of various species. 

• Potential impact of global climate change to oil sensitivity and toxicological interactions.

Gaps in knowledge regarding oil toxicology to Arctic species must be closed so that leaders 

can make informed decisions that will not increase the risk of a major oil spill in the U.S. Arctic 

Ocean. In the Norwegian Barents Sea, a study from 2004 through 2009 added to knowledge on 

the sensitivity of Arctic species to dispersed oil and produced water (water discharged during oil 

production, containing some crude oil and other contaminants). The objectives of this study were 

the following: 1) evaluate the relevance of biomarkers (tools used to evaluate exposure levels to 

contaminants such as oil) developed for temperate species to sub-Arctic and Arctic species; 2) 

consider whether biomarkers used in adult species could be applied to juveniles; 3) establish 

baseline levels for biomarkers in key Arctic species in the Barents Sea region; and 4) collect 

data that could be used to establish threshold levels for oil exposure based on biomarker levels 

(Bu"agni et al. 2010).

The Barents Sea study looked at four !sh species in juvenile and adult life cycles. The results of 

this study are relevant to that region only, but similar research on !sh species in the Chukchi and 

Beaufort seas might provide a starting point for establishing critical exposure levels to organisms 

and understanding the potential implications of exposure to spilled oil at various life stages and 

times of year. Some baseline studies have been conducted in the western nearshore Beaufort 

Sea to establish baseline hydrocarbon levels in the region of the Northstar gravel island-based 

production facility (Durell et al. 2006).

The impact of oil spills on polynyas and ice leads is another area of Arctic spill science in need of 

further study. The potential toxicity and adverse e"ects from alternative response methods such as 

chemical dispersants and in-situ burning should also be considered.

Considerable additional research should be conducted, and all meetings, reports and work 

products should be available for public and stakeholder review and input. All research projects 

should be developed using peer-reviewed methodologies, and all results should also be peer 

reviewed. 

7.1.2 Improve Spatial Data on Environmental Sensitivities

 “Ecologically sensitive areas should be mapped, and oil spill trajectory models should 

be further improved and used to determine areas most at risk from oil spills. This would 

improve the basis for attempts to decrease or eliminate the probability of an oil spill 

a#ecting sensitive areas.” (AMAP 2008b)

Limited information has been compiled to date regarding environmental sensitivities in the 

U.S. Arctic Ocean. For at least 800,000 years, there has been some sea ice in the Arctic Ocean. 

Not surprisingly, animals have adapted in many ways to these conditions. At the same time 

that oil development is being proposed in the o"shore Chukchi Sea, Arctic species are facing 
109

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

unprecedented stresses from climate change, which is bringing profound physical and biological 

impacts. The rapid loss of summer sea ice is having unparalleled e"ects on the Arctic ecosystem, 

with some changes already apparent. For example, the distribution of species has begun to shift 

(Grebmeier et al. 2006, Mueter and Litzow 2008) and may alter the structure of Arctic ecology 

(AMAP2008b, Moore and Huntington 2008). The shrinking of the ice has far-reaching e"ects 

on the entire ecosystem, beginning with the phytoplankton that bloom at the ice edge each 

spring. Climate change is expected to have a “widespread, annual, population-level e"ect on 

epontic (under ice) and other lower trophic-level organisms that depend on the summer/autumn 

ice cover,” leading to a major ecological impact at the base of the food chain even without oil 

exploration and production activities (MMS 2008). The loss of summer sea ice cover has impacts 

at all levels of the ecosystem, including e"ects on ice-dependent marine mammals such as walrus 

(Jay and Fischbach 2008) and polar bears (Hunter et al. 2007). Impacts from oil exploration and 

development, especially the potential for oil spills, will further stress an already fragile ecosystem.

To minimize adverse impacts and assist with response priorities, it is necessary to identify and 

protect those areas of the ocean with high importance for the ecosystem, ecological processes 

or species. Important ecological areas (IEAs) can be de!ned as geographical areas that contribute 

disproportionately to an ecosystem’s health, including its productivity, biodiversity, structure, 

function or resilience (Ayers et al. 2010). Furthermore, these areas may be more at risk to harm and 

would bene!t in the long term from e"ective management (Ehler and Douvere 2009). However, 

the Alaskan Arctic Ocean is di#cult to access, particularly in the winter months. As a result, IEAs 

have not been identi!ed for the Chukchi or Beaufort seas, and many of their species are poorly 

understood. IEAs in the Arctic seas are expected to be shifting and variable because of seasonal 

and year-to-year changes in wildlife populations and biological productivity. 

Better observation data (wind, current, visibility and ice conditions) should be developed to 

support oil spill contingency planning and to improve trajectory models. Alaska shore zone 

mapping and imagery should be expanded to include the Arctic.

Regional oil spill contingency planning should include geographic response strategies (GRS) that 

identify priority protection sites and provide protective booming strategies and other tactics that 

may be quickly implemented to protect these areas ahead of a spill trajectory. Currently, sensitive 

sites are identi!ed, but response tactics and strategies are not tested before exploration and 

production operations to ensure success. Su#cient resources must be dedicated to implement 

these tactics.
110 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

7.1.3 Develop Arctic Oil Spill Trajectory Models

“Better knowledge is essential to improve assessments of the transport, fate and e#ects 

of spilled oil in ice-covered waters, including oil under ice carried by currents and oil 

drifting with the sea ice.” (AMAP 2008b)

Better trajectory modeling is needed to develop more realistic oil spill planning scenarios. Existing 

models have virtually no ability to accurately predict how oil and ice interactions will a"ect oil 

movement when sea ice is present (Khelifa 2010). This gap has implications for oil spill planning 

and response. From a planning perspective, the inability to model oil trajectories during various 

ice conditions makes it almost impossible for operators or regulators to assess the potential risks 

from a major oil spill, because we cannot reliably predict where an oil spill would travel and which 

resources might be a"ected. If a major spill were to happen during exploration or production 

operations in the U.S. Arctic Ocean and oil was present in the environment through ice season, 

responders would have a very limited ability to predict how or where the oil might move.

Improved trajectory modeling will require of more data on environmental and weather conditions 

for new operating areas such as the Arctic OCS. Additional real-time observation and monitoring 

systems may need to be developed. This will also require that modelers develop more reliable 

algorithms to predict how sea ice and oil will interact in the Arctic Ocean. 

7.1.4 Consider Cumulative Impacts of Oil Exploration and Production in Arctic OCS

The cumulative impacts of oil exploration and production have been extensively studied in the 

onshore U.S. Arctic. Proposed expansion of oil exploration and production activities into deeper 

waters farther o"shore from the established Prudhoe Bay oil !elds would introduce additional 

strains on the people and ecology of the region. 

It is important to consider the impact of additional activity and infrastructure associated with 

expanded o"shore oil exploration and the development of an enhanced spill response capacity. 

Roads, docks and other transportation infrastructure can have adverse environmental e"ects. 

Changes to the use of coastal areas and OCS waters may a"ect traditional cultural uses and have 

unforeseen impacts on indigenous people. Disruptions to traditional lifestyles brought by new 

infrastructure, changes to subsistence activities and an in$ux of people to the region may all a"ect 

the local people.

7.2 Assess and Plan for Worst-Case Blowout Risks

7.2.1 Conduct Risk Assessment

To reduce the risks associated with uncontrolled spills from oil exploration in the Arctic OCS, it 

is !rst necessary to conduct a comprehensive risk assessment. There are two components to a 

risk assessment: conducting a risk analysis that considers the likelihood and consequences of an 

undesirable event, and identifying risk management measures that target the highest-priority risks.

To calculate risk, a risk analysis is conducted to answer the following questions:
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OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

• What can go wrong?

• How likely is it?

• What are the impacts?

The !rst question is typically answered by developing one or more risk scenarios—in this case, oil 

spill scenarios that describe what could happen based on the speci!c operations to be conducted. 

The second question is answered using a predictive model that estimates the likelihood of 

occurrence for various types of oil spills that have been identi!ed. The third question requires an 

analysis of the potential consequences of all possible spill scenarios, based on the sensitivities 

and vulnerabilities of the local environment, wildlife, culture and socioeconomic resources. The 

answers to these three questions, for all possible scenarios, are a complete expression of the risk 

being assessed. The result may be expressed quantitatively, qualitatively or through a combined 

approach. 

Signi!cant information-gathering is required to conduct an e"ective risk analysis. The evaluation 

of Arctic OCS oil spill risks will require a realistic estimate of oil spill frequency in the o"shore Arctic 

and a synthesis of information about ecological vulnerabilities and environmental sensitivities. 

It also must include realistic assessments of the potential impacts from catastrophic blowout 

scenarios that occur in di"erent seasons and conditions. 

Expression of risks through a risk analysis is only the !rst step; the next step is to identify and 

evaluate risk management options. This requires a prioritization of the identi!ed risks by 

establishing some criteria for risk tolerance and then evaluating risk reduction measures based on 

their appropriateness to reduce or mitigate the highest-priority risks. 

There are several established methodologies for conducting oil spill risk assessments. A project 

is ongoing in the Aleutian Islands using a methodology suggested by the National Academy of 

Sciences. A similar process could be applied to the Arctic Ocean.

7.2.2 Require More Realistic Worst-Case Blowout Scenarios

Worst-case discharge amounts—the maximum spill size that could occur from exploration or 

production operations—should be calculated on the basis of the highest possible $ow rates for 

a well, based on all available data. Higher “default” $ow rates should be established for operations 

in new regions such as the Arctic OCS—where previous o"shore exploration has con!rmed that 

blowouts could exceed (by several orders of magnitude) the state response planning standard 

of 5,500 barrels of oil per day—and based on well data from similar reservoirs located onshore. 

Worst-case discharge estimates should also factor in the time required to stop the blowout. The 

Deepwater Horizon blowout continued for three months. Other blowouts have lasted longer, yet 

many oil spill contingency plans consider only a 15- or 30-day duration. 

7.2.3 Improve Oil Spill Prevention Technologiesfor Arctic Exploration and Production

Blowout prevention technologies and blowout control measures should also be assessed, because 

blowout control is the !rst line of defense against a major oil spill. 
112 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

Additional requirements for reducing blowout risks and improving blowout control in the Arctic 

may include:

• Arctic design standards and best practices. All equipment used for oil exploration and 

production in the Arctic Ocean, including but not limited to vessels, pipelines, wells, tanks, 

processing equipment and structures, should be designed in accordance with Arctic 

engineering practices and should be able to withstand worst-case geological hazards, and 

Arctic temperatures, wind, water and ice hazards that may be encountered. Design criteria 

should be based on actual measurements of worst-case data for the site of development, 

or on conservative estimates. If operations are planned during ice conditions, vessels 

should be certi!ed by the U.S. Coast Guard or the American Bureau of Shipping as Arctic 

Class and should be capable of operating safely in Arctic conditions.

• Emergency shutdown devices (ESDs). ESDs should be installed on the o"shore drilling 

units and facilities to limit the scope of any single failure. Manual and automatic ESDs 

should be installed to allow operators to manually shut down systems, or to allow systems 

to automatically shut down if operators are unable to safely access the system. ESDs 

should be provided for all the primary systems of a drilling unit’s operation and facility 

operation and for fuel transfers. ESD systems should be tested before use and at regular 

intervals thereafter.

• Blowout prevention systems (BOPs). BOPs should be capable of controlling at least 150 

percent of the maximum anticipated pressure; equipped with two sets of blind shear 

rams; inspected by the manufacturer and an independent third-party certi!ed inspector 

before use; tested on a seven-day interval versus the current requirement of 14 days; 

and have reliable emergency backup control systems and immediate access to su#cient 

remote operating vehicles to manually activate a subsea BOP if needed. Shear rams 

should be tested on the pipe planned for use to verify capability to sever that grade of 

pipe. Redundant BOPs should be considered and installed for $oating drilling units when 

technically feasible. 

• Backup drilling rigs on site. To facilitate relief well drilling in the event of a blowout, 

operators should be required to have a drilling rig on standby to initiate relief well drilling 

and to have purpose-built well capping structures (such as the one used during the 

Deepwater Horizon blowout) prefabricated and available on site before drilling begins. Oil 

spill removal organizations (OSROs) operating in the Arctic OCS should demonstrate that 

they have su#cient regional capacity to support an Arctic OCS well blowout. Resident 

blowout control capabilities are needed in the U.S. Arctic. Well control equipment and 

experts should be on site to take immediate action to control the well and/or contracts 

should be in place with well control experts to immediately bring additional personnel, 

equipment and expertise to the site in the event of a blowout.

• Prefabricated containment structures. Containment structures must be designed, 

engineered and tested under Arctic conditions. Such structures—if they can be 
113

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

successfully engineered to withstand the ice and weather conditions in the Arctic 

Ocean—should be part of the toolkit for operators drilling in the U.S. Arctic Ocean.

7.3 Improve Arctic OCS Oil Spill Response Capacity 

7.3.1 Assess Existing Oil Spill Response Capacity for Oil Spillsin Arctic OCS

To develop the response capacity needed to support o"shore exploration and production in the 

Arctic OCS, it is necessary !rst to assess the capabilities of available oil spill response systems, to 

delineate the upper operating limits of equipment and systems, and to identify opportunities to 

improve responsibilities, while also establishing prevention measures to minimize spill risks when 

response capacity may be exceeded. This process should occur before oil exploration activities 

introduce the risk of a catastrophic spill to the Arctic OCS.

Oil spill response capacity is much more than spill response equipment, particularly for o"shore 

areas where on-water response requires considerable logistical support. In addition to the 

booms, skimmers and recovered oil storage devices that make up a typical o"shore or nearshore 

spill response task force, the capacity also includes: the vehicles and vessels that transport the 

equipment from its storage location to the spill site; the workboats, barges, cranes and other 

support equipment that are used to support the on-water response operations; the personnel 

required to operate vehicles and vessels, run equipment and direct the response operations; 

and the tactical plans that outline how all of these components will operate to achieve oil spill 

containment, recovery and cleanup objectives. 

Assessing the e"ectiveness and limitations of oil spill response capacity for a given operation or 

operating area requires complex analysis. To a certain extent, this can be accomplished on paper 

by conducting scenario analyses in which a speci!c spill size, location and trajectory are used to 

map out how and where resources would be applied during a spill, and to assess how much of 

the spilled oil the available resources might be able to recover. However, most oil spill response 

scenarios are predicated on a set of assumptions that require validation through !eld deployment 

exercises (see Section 7.2.2). 

7.3.2 Require Operatorsto Demonstrate Oil Spill Response Capabilities During

Agency-Led Field Exercises

There is little real-world information available regarding the e"ectiveness of Arctic spill response 

systems because there have been no major Arctic o"shore oil spills. Most of our assumptions 

about how spill response systems will perform in the Arctic OCS are derived from small-scale 

laboratory and tank tests, or !eld tests that are limited to a speci!c piece of equipment. The 

information gleaned from such tests may be misleading; for example, a tank test demonstrating 

that a skimmer will not clog until ice concentrations exceed 40 percent coverage does not mean 

that the full oil spill recovery system—vessels, boom, skimmer and storage barge—could operate 

safely or e"ectively up to that limit. The upper limit of a single piece of equipment or an individual 

technology does not guarantee that the response system required to deploy that technique will 

have the same functionality. 
114 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

Government approval of oil spill contingency plans should be based upon demonstrated 

capabilities veri!ed through !eld exercises, unannounced drills and audits. One necessity is fullscale !eld trials, during which multiple vessels are deployed to test tactics in Arctic OCS waters and 

ensure that all components of a response system can operate e"ectively, and then to delineate 

the upper operating limits posed by environmental conditions such as wind, sea state, sea ice and 

visibility. 

During full-scale !eld deployments, equipment is transported to the scene and deployed under 

a range of natural conditions. In some cases, a response system may fail not because of a primary 

equipment malfunction, but because one (or more) of the technologies or support platforms 

does not perform as intended. These support functions may be severely challenged by Arctic 

environmental conditions, remote locations or lack of infrastructure. During a series of !eld trials 

held in the Alaska Beaufort Sea, responders found that the actual limits to a vessel-based skimming 

and recovery system were realized in much lower sea ice concentrations than previously assumed.

Multiagency oversight of these drills and written documentation will help to build a knowledge 

base regarding the limits to oil spill response systems in the Arctic OCS. The plan review and 

approval process for all OCS oil spill response plans should include an opportunity for public 

review and comment and also should include consultation among agencies with roles in oil spill 

prevention and response as well as natural resource trustees.

7.3.3 Improve On-Water Oil Spill Response Systems and Techniquesfor Arctic OCS

Conditions

Oil spill cleanup technologies have been slow to improve, and the basic tools used to contain 

and remove oil spills today are very similar to those in place decades ago. The Deepwater Horizon 

incident led to a number of innovations, forced by the imminent pressure of an exploding oil well. 

Moving forward, a more comprehensive and proactive research-and-development regime should 

be designed to expand the limits of existing spill response technologies, particularly mechanical 

recovery, the only technique that removes oil from the environment. Programs such as the JIP 

are a !rst step in this process, though the JIP had many $aws, including a lack of peer review and 

a lack of transparency during the research. Spill response technologies have not kept pace with 

advances in drilling technologies.

New technologies for subsea containment, such as the one developed and used during the 

Deepwater Horizon spill, should be developed for the Arctic Ocean.

7.4 Conduct an Arctic OCS Oil Spill Response Gap Analysis

A response gap exists whenever environmental conditions exceed the operating limits of oil spill 

cleanup equipment, meaning that if a spill occurred during this time, it could not be contained 

or cleaned up. Although it is clear that the environmental, oceanographic and climatic conditions 

in the Arctic Ocean represent a challenge to existing oil spill cleanup technologies, the extent 

to which these conditions might limit oil spill cleanup is not well understood. An Arctic oil spill 

response gap analysis will provide critical information regarding the oil spill response limits 
115

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

posed by Arctic environmental conditions (temperature, wind, sea ice, visibility) and will calculate 

how frequently those operating limits are reached in the area of oil exploration and production 

operations. 

The methodology for conducting such an analysis involves three key steps:

Quantify the operating limits of o"shore oil spill response systems available to clean up 

oil spills in the Arctic. This process starts with examination of one or more o"shore spill 

response systems (equipment, vessels and personnel) and then consideration of the upper 

operating limits of that system or systems. This is typically determined by the component 

(or components) that is most likely to fail once a given condition—sea state, ice coverage, 

visibility, temperature or wind—is exceeded. When that limit is exceeded, the response system 

would be rendered inoperable. 

Calculate the frequency with which the operating limit is reached. Historical weather data 

and observations are analyzed to determine how frequently each of the limiting factors 

occurs during the operating season. If historical data are not available, modeling may be 

used. Assuming that multiple factors would limit Arctic o"shore spill response operations, 

the analysis would also have to consider the interplay among factors to account for any 

cumulative impacts. (For example, the combination of 10 percent ice coverage and less than 1 

nautical mile visibility may present an operating limit, even though individually neither factor 

represents an upper limit.)

Estimate the response gap by applying the operating limits to the environmental dataset. 

The result of this analysis will characterize the frequency of occurrence of one or more 

environmental factors that would render oil spill cleanup possible, impaired or impossible. 

Such an analysis was completed in Prince William Sound in Alaska in 2007, showing that 

during the winter season at one o"shore location, a response gap existed 65 percent of the 

time.

There is no question that a response gap exists in the Arctic. Once it has been estimated, additional 

oil spill prevention or mitigation measures may then be put into place to reduce the likelihood of a 

spill occurring when no response is possible.
116 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

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129 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

APPENDIXES9

Appendix A: Acronyms and Abbreviations

Appendix B: Glossary

(Ringed seal photo: John Moran)
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OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

Appendix A: Acronyms and Abbreviations

ACIA Arctic Climate Impact Assessment

ACS Alaska Clean Seas

ADEC Alaska Department of Environmental Conservation

AMAP Arctic Monitoring and Assessment Program 

AMOP Arctic and Marine Oil Pollution Technical Seminar

APD Application for Permit to Drill

API American Petroleum Institute

ARCOP Arctic Operational Platform

BBO Billion Barrels of Oil

BCB Bering, Chukchi and Beaufort Seas population

BOEMRE Bureau of Ocean Energy Management, Enforcement and Regulation

BOP Blowout Preventer

BOSS Behavior of Spilled Oil at Sea

BP British Petroleum Exploration & Production Inc.

BPXA British Petroleum Exploration Alaska

COCP Critical Operations and Curtailment Plan

C-PLAN Contingency Plan

DOE Department of Energy

DOI Department of the Interior

EIS Environmental Impact Statement

ESI Environmental Sensitivity Index

FLIR Forward-Looking Infrared Radar

GAO Government Accountability Office

GRS Geographic Response Strategy

IARC International Arctic Research Center

IEA Important Ecological Area

JIC Joint Information Center

JIP Joint Industry Project

MMS Minerals Management Service

NEPA National Environmental Policy Act

NETL National Energy Technology Laboratory

NOAA National Oceanic and Atmospheric Administration

NRC National Research Council

NRT National Response Team

NSIDC National Snow and Ice Data Center

OCS Outer Continental Shelf

ODPCP Oil Discharge Prevention and Contingency Plan
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OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

OSB Ocean Studies Board

OSRB Oil Spill Response Barge

OSRO Oil Spill Removal Organization

OSRV Oil Spill Response Vessel

OST Oil Spill Tanker

PAH Polycyclic Aromatic Hydrocarbon

PIC Person-in-Charge

PPA Priority Protection Area 

PRB Polar Research Board

PTTEP PTTEP Australasia Pty Limited

SAC Science Advisory Council

SERVS Ship Escort Response Vessel Services

SIZONET Seasonal Ice Zone Observing Network

SNAME Society of Naval Architects and Marine Engineers 

SWCC Subsea Well Control and Containment

TAPS Trans Alaska Pipeline System 

TCFG Trillion Cubic Feet of Gas

UAFGI University of Alaska Fairbanks Geophysical Institute

USCG United States Coast Guard

USEIA United States Energy Information Administration

USFWS United States Fish and Wildlife Service

USGS United State Geological Survey

VOC Volatile Organic Compounds

VOSS Vessel of Opportunity Skimming System

WMO World Meteorological Organization

WRCC Western Regional Climate Center

WSF Water-Soluble Fractions
132 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

Appendix B: Glossary

Benthic: Pertaining to the environment and conditions of organisms living at the water 

bottom, or benthos.

Bioaccumulation: The concentration of a substance in a living organism, possibly with 

harmful effects.

Biomagnification: Also known as bioamplification or biological magnification. The increase in 

concentration of a substance that occurs in a food chain as a consequence of persistence, food 

chain energy or low rate of internal degradation/excretion of the substance.

Blowout Preventer (BOP): A set of large valves at the top of a well that may be closed if 

the drilling crew loses control of formation fluids. By closing these valves (usually operated 

remotely via hydraulic actuators), the drilling crew usually regains control of the reservoir, and 

procedures can then be initiated to increase the mud density until it is possible to open the 

BOP and retain pressure control of the formation.

Brash Ice: Accumulations of floating ice made up of fragments not more than 2 meters across; 

the wreckage of other forms of ice.

Bridge: As in to bridge a well; to seal itself with rock fragments from the collapsing formation.

Broken Ice: An operating environment where a body of water has incomplete coverage of 

ice. Broken ice varies from less than 10 percent coverage to greater than 90 percent coverage. 

Mechanical oil spill recovery effectiveness is diminished at ice concentrations greater than 10 

percent and generally precluded at concentrations above 70 percent. 

Calm Water: An operating environment where the sea state is usually less than 1 foot waves 

and currents are less than 0.8 knots; includes waters that are very sheltered from wind and 

waves or very small bodies of water. This is the least demanding operating environment for 

waterborne oil spills.

Candidate Species: A species for which the U.S. Fish and Wildlife Service has on file sufficient 

information on biological vulnerability and threat(s) to support proposals as threatened or 

endangered (under the Endangered Species Act).

Copepods: Small, shrimplike animal of the subphylum Crustacea (includes crabs and lobsters) 

that are only a few millimeters in diameter and are called zooplankton—or animals that float 

in the sea. They eat microscopic algae called phytoplankton. They are an important part of the 

food chain because they are typically eaten by fish.
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OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

Decant: To remove free-water from an oil-water mixture by drawing the water off the bottom 

of the oil-water interface.

Dispersant: A chemical formulation containing surface active agents (surfactants) that lowers 

the surface tension between oil and water and facilitates the breakup and dispersion of oil into 

the water column in the form of finely divided droplets to allow for natural biodegradation.

Downhole: Farther into a well bore, rather than at the Earth’s surface.

Drilling Fluids: Any of a number of liquid and gaseous fluids and mixtures of fluids and solids 

(as solid suspensions, mixtures and emulsions of liquids, gases and solids) used in operations 

to drill bore holes into the Earth. Also known as drilling mud.

Emulsification: A process by which oil forms an emulsion or “mousse” consisting of many 

small droplets of water incorporated into the oil.

Encapsulation: The absorption of a polymer film onto cuttings and well-bore walls to form a 

coat or barrier.

Endangered Species: One that is in danger of extinction throughout all or a significant 

portion of its range.

Entrain: To incorporate with and carry along.

Entrainment: The loss of oil from containment when it is pulled under a boom by a strong 

current; typically occurs when booms are deployed perpendicular to currents greater than 1 

knot (0.5 meter [almost 20 inches] per second).

Fast Ice: Sea ice that forms and remains fast along the coast, where it is attached to the shore, 

an ice wall or an ice front, or between shoals or grounded icebergs.

Federal Waters: Marine waters of the outer continental shelf from the three-mile state waters 

boundary to the border of the U.S. exclusive economic zone, 200 miles from the contiguous 

shoreline. 

Floe: Any relatively flat piece of sea ice 20 meters (22 yards) or more across.

Frazil Ice: Fine spicules or plates of ice, suspended in water.

Geographic Response Strategies (GRSs): Site-specific spill-response methods used to 

protect sensitive coastal environments from the deleterious effects of petroleum or other 

hazardous-substance spills. GRSs provide first responders with specific guidance for a rapid 

deployment of pre-identified actions to protect priority sensitive sites.
134 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

Grease Ice: When crystals have coagulated to form a soupy layer on the surface; a later stage 

of freezing than frazil ice.

Haul-Outs: Locations on land or ice where marine mammals such as walrus and seals climb 

out of the water to rest or nurse their young.

Ice Gouging or Ice Scour: The abrasion of material in contact with moving ice in a sea, ocean 

or other body of water.

Ice Rubble: Fragments of floating ice, 1 to 5 feet high, frozen in water.

Lead: Any fracture or passageway through sea ice that is navigable by surface vessels.

Nearshore: A shallow-water operating environment close to the coast. 

Open Water: An operating environment where the sea state can reach 6 feet and moderate 

waves and whitecaps may occur. Includes open water that is not sheltered from wind and 

waves. This is the most demanding operating environment for waterborne spills.

Pack Ice: In a wide sense, includes any area of sea ice other than fast ice no matter what its 

form or how it is disposed.

Pancake Ice: Predominantly circular pieces of ice from 30 centimeters to 3 meters (1 foot to 10 

feet) in diameter and up to about 10 centimeters (4 inches) thick, with raised rims due to the 

pieces striking against one another.

Phytoplankton: Microscopic marine plant, or algae that floats in the ocean. They convert 

carbon dioxide and sunlight for energy and release oxygen as a waste product. They are at the 

base of the marine food web. In the Arctic food web, they play a very important role as they 

grow on the underside of the ice as in the spring and are a source of food for zooplankton such 

as amphipods.

Polynya: An area of open water surrounded by sea ice.

Protected Water: An operating environment where the sea state can reach 3 feet and small 

waves and whitecaps may occur. Protected waters have limited shelter from wind and waves. 

Protected water falls between open water and calm water in the classification scheme.

Recolonization: The process of a new community of plants and animals coming to inhabit a 

space after a disturbance has displaced most of the flora and fauna.

Sea Ice: Any form of ice found at sea that has originated from the freezing of seawater.
135

OIL SPILL PREVENTION and RESPONSE IN THE U.S. ARCTIC: Unexamined Risks, Unacceptable Consequences

Sea State: A sea state is the general condition of the free surface on a large body of water—

with respect to wind waves and swell—at a certain location and moment. A sea state is 

characterized by statistics, including the wave height, period and power spectrum.

Secondary Containment: Structures, usually dikes or berms, surrounding tanks or other 

storage containers and designed to catch material spilled from the storage containers.

Sessile: A plant or animal that is not able to move freely because it is permanently attached to 

the substrate, such as a rock. Examples of sessile marine plants include algae and such marine 

animals as barnacles and coral.

Slush Ice: Snow that is saturated and mixed with water on land or ice surfaces, or as a viscous 

floating mass in water after a heavy snowfall.

Solid Ice: Where a body of water has complete coverage of ice. Spill response activities may 

occur on solid ice only after it is determined that the ice is of sufficient thickness to safely 

support response personnel and equipment.

Staging Area: Location where incident personnel and equipment are available for tactical 

deployment. Can serve as a check-in location for equipment and personnel reporting to the 

incident.

State Waters: Marine waters out to three miles from the contiguous shoreline, over which the 

state has jurisdiction.

Substrata: The area upon which an organism, such as a clam or barnacle, is attached. It can 

also be a layer of rock or soil immediately beneath the surface of the Earth.

Task Force: A group of resources with common communications and a leader assembled for a 

specific mission. Often used in oil spill response planning and management.

Threatened Species: One that is likely to become endangered within the foreseeable future 

throughout all or a significant portion of its range.

Trophic Level: Trophic levels define the position of an organism in a food web or chain. 

Trophic is a Greek word that means feeding. The first level of a food chain contains the primary 

producers, which are generally the plants and algae that produce their own energy using light 

and carbon dioxide. Animals that eat plants are at the next level, while predators are at the 

third level.

Wave Period: The average amount of time between passages of successive crests (or troughs) 

of waves.

Weathering: The chemical and physical changes that occur once oil has spilled, including 

spreading, evaporation, dissolution, photooxidation, dispersion, biodegradation and 

emulsification.
136 NOVEMBER 2010  U.S. Arctic Program, Pew Environment Group

Well Bay: An area of an oil platform where the wellheads are located. It normally consists of 

two levels, including a lower level where the wellheads are accessed, often along with the 

various well control panels, which will have pressure gauges and controls for hydraulically 

actuated valves, including downhole safety valve and annular safety valve.

Well Bore: A hole created by drilling.
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