Ellicott Slough National Wildlife Refuge

Mailing address:

9500 Thornton Avenue

Newark, CA 94560 

510/792-0222 

Fax: 510/792-5828

http://www.fws.gov/sfbayrefuges/Ellicott/

California Relay Service

TTY: 1 800/735-2929

Voice: 1 800/735-2922

U.S. Fish and Wildlife Service

1 800/344-WILD

http://www.fws.gov

September 2010

Santa Cruz long-toed salamander

Photo: S.Ruth and E.F. Katibah
Disclaimer

CCPs provide long term guidance for management decisions and set forth goals, objectives,

and strategies needed to accomplish refuge purposes and identify the Service’s best estimate

of future needs. These plans detail program planning levels that are sometimes substantially

above current budget allocations and, as such, are primarily for Service strategic planning

and program prioritization purposes. The plans do not constitute a commitment for staffing

increases, operational and maintenance increases, or funding for future land acquisition.

Ellicott Slough 

National Wildlife Refuge

Final Comprehensive Conservation Plan 

and Final Environmental Assessment

Prepared By

US Fish and Wildlife Service

San Francisco Bay National Wildlife Refuge Complex

9500 Thornton Avenue

Newark, California 94560

and

Pacific Southwest Region

2800 Cottage Way, W-1832

Sacramento, California 95825

September 2010

Ellicott Slough NWR - Final Comprehensive Conservation Plan iii

Table of Contents

Abbreviations and Acronyms..........................................................................................................................vi

Chapter 1. Introduction and Background............................................................................................. 1

1.1 Purpose and Need for this CCP . ........................................................................................... 1

1.2 The U.S. Fish and Wildlife Service and the National Wildlife Refuge System . ............. 2

1.2.1 U.S. Fish and Wildlife Service..................................................................................... 2

1.2.2 The National Wildlife Refuge System. ....................................................................... 2

1.2.3 National Wildlife Refuge System Mission and Goals. .............................................. 2

1.3 Legal and Policy Guidance. ..................................................................................................... 2

1.3.1 The Improvement Act ................................................................................................ 3

1.3.2 Refuge System Policies ................................................................................................ 3

1.4 San Francisco Bay National Wildlife Refuge Complex....................................................... 3

1.5 Ellicott Slough National Wildlife Refuge.............................................................................. 3

1.5.1 Location. ......................................................................................................................... 3

1.5.2 Refuge Setting. .............................................................................................................. 3

1.5.3 History of Refuge Establishment and Acquisition. .................................................. 4

1.5.4 Refuge Purposes ........................................................................................................... 7

1.5.5 Ecosystem Context and Related Projects. ................................................................ 8

1.5.6 Conservation Priorities and Initiatives. ..................................................................... 8

1.5.7 Adaptive Management.................................................................................................. 8

Chapter 2. The Comprehensive Conservation Planning Process. ................................................... 9

2.1 The Planning Process: How the CCP was Developed........................................................ 9

2.1.1 Preplanning. ................................................................................................................... 9

2.1.2 Planning Hierarchy. ...................................................................................................... 9

2.1.3 The Core Planning Team.............................................................................................. 10

2.1.4 The Extended Planning Team. .................................................................................... 10

2.2 Public Involvement in Planning.............................................................................................. 11

2.2.1 Issues, Concerns, and Opportunities Identified through Scoping.......................... 11

2.2.2 Additional Management Issues Identified by Staff through Scoping. ................... 11

2.3 Development of Refuge Vision. .............................................................................................. 11

2.4 Development of Refuge Goals, Objectives and Strategies.................................................. 12

2.4.1 Goals .............................................................................................................................. 12

2.4.2 Objectives, Rationale, and Strategies......................................................................... 12

2.5 Development of Alternatives. ................................................................................................. 12

2.6 Selection of the Refuge Proposed Action. ............................................................................. 13

2.7 Plan Implementation................................................................................................................ 13

Chapter 3. Refuge and Resource Description. ..................................................................................... 15

3.1 Geographic/Ecosystem Setting. ............................................................................................. 15

3.2 Description by Refuge Unit. ................................................................................................... 15
iv Ellicott Slough NWR - Final Comprehensive Conservation Plan

3.2.1 Ellicott Unit.................................................................................................................... 15

3.2.2 Calabasas Unit............................................................................................................... 16

3.2.3 Harkins Slough Unit. .................................................................................................... 16

3.2.4 Buena Vista. ................................................................................................................... 17

3.3 Physical Resources................................................................................................................... 17

3.3.1 Climate and Air Quality. ............................................................................................... 17

3.3.2 Climate Change and Greenhouse Gas Emissions . ................................................... 18

3.3.3 Climate Change Regulation. ........................................................................................ 20

3.3.4 Topography. .................................................................................................................... 20

3.3.5 Geology, Soils, and Hydrology...................................................................................... 20

3.3.6 Water Supply and Water Quality. ................................................................................ 22

3.3.7 Hazardous Materials and Contaminants.................................................................... 24

3.4 Biological Resources. ............................................................................................................... 30

3.4.1 Vegetation....................................................................................................................... 30

3.4.2 Wildlife. ........................................................................................................................... 34

3.5 Cultural Resources................................................................................................................... 40

3.5.1 Social and Economic Environment. ............................................................................ 40

3.5.2 Demographics. ............................................................................................................... 41

3.5.3 Traffic and Public Access.............................................................................................. 41

3.5.4 Local Economy and Employment. .............................................................................. 41

3.5.5 Environmental Justice.................................................................................................. 41

Chapter 4. Current Refuge Management and Programs. ................................................................. 43

4.1 Land Management . ................................................................................................................. 43

4.2 Water Management.................................................................................................................. 43

4.3 Wildlife Management............................................................................................................... 43

4.3.1 Mosquito Population Management.............................................................................. 44

4.4 Fire Prevention and Hazard Reduction. ............................................................................... 44

4.5 Law Enforcement and Resource Protection. ....................................................................... 45

4.6 Cultural Resource Management. ........................................................................................... 45

4.7 Facilities Maintenance. ............................................................................................................ 45

4.8 Safety.......................................................................................................................................... 46

4.9 Volunteers and Partners.......................................................................................................... 46

4.10Visitor Programs. ..................................................................................................................... 46

4.11Environmental Education and Interpretation. .................................................................... 46

4.12Fishing and Hunting. ............................................................................................................... 47

4.13Wildlife Observation and Photography.................................................................................. 47

4.14Outreach. ................................................................................................................................... 47

Chapter 5. Management Direction. ........................................................................................................ 49

5.1 Ellicott Slough NWR Vision Statement. ............................................................................... 49

5.2 Refuge Management Goals, Objectives, and Strategies. .................................................... 49

Chapter 6. Plan Implementation............................................................................................................. 61

6.1 Funding and Staffing................................................................................................................ 61

6.2 Step-Down Management Plans. ............................................................................................. 61

6.3 Compatibility Determination.................................................................................................. 63
Ellicott Slough NWR - Final Comprehensive Conservation Plan v

Appendix A - References

Appendix B - Glossary of Terms

Appendix C - Final Environmental Assessment and Finding of No Significant Impact

Appendix D - Plant List 

Appendix E - Section 7, Endangered Species Act Compliance

Appendix F - Wildlife List

Appendix G - Compatibility Determinations

Appendix H - Wilderness Inventory

Appendix I - List of Preparers

Appendix J - Public Involvement and Responses to Comments on the July 2010 Draft 

Comprehensive Conservation Plan and Environmental Assessment (Draft CCP/EA)

Appendix K - Other Environmental Compliance

Appendices

Figure 1. San Francisco Bay NWR Complex Map .................................................................................... 5

Figure 2. Ellicott Slough NWR Location Map........................................................................................... 6

Figure 3. The CCP Process Diagram .........................................................................................................10

Figure 4. Soil Types on the Ellicott Slough NWR ....................................................................................21

Figure 5. Watsonville Slough System .........................................................................................................23

Figure 6. Vegetation – Ellicott Unit............................................................................................................26

Figure 7. Vegetation – Calabasas Unit.......................................................................................................27

Figure 8. Vegetation – Harkins Slough Unit .............................................................................................28

Figure 9. Vegetation – Buena Vista Property............................................................................................29

Figure 10. Visitor Services at Ellicott Slough NWR .................................................................................59

Figures

Tables

Table 1. Key policies related to management of National Wildlife Refuges ........................................ 4

Table 2. Pollutant measures for North Central Coast Air Basin - 2006...............................................18

Table 3. Ellicott Slough NWR - Acreages of habitat types by unit......................................................25

Table 4. Population counts for robust spineflower on Buena Vista.......................................................34

Table 5. Santa Cruz long-toed salamander subpopulation complexes .................................................34

Table 6. Estimated initial capital outlay to fully implement the CCP..................................................62

Table 7. Estimated annual cost to fully implement the CCP ..............................................................63

6.4 Compliance Requirements. ..................................................................................................... 64

6.5 Partnership Opportunities. ..................................................................................................... 64

6.6 Monitoring and Evaluation. .................................................................................................... 64

6.7 Adaptive Management............................................................................................................. 64

6.8 Plan Amendment and Revision. ............................................................................................. 65
vi Ellicott Slough NWR - Final Comprehensive Conservation Plan

Complex San Francisco Bay NWR Complex

Ellicott Slough NWR Ellicott Slough National Wildlife Refuge (Refuge)

Improvement Act National Wildlife Refuge System Improvement Act of 1997 (or 1997 

 Improvement Act)

Plan Comprehensive Conservation Plan (CCP)

Refuge System The National Wildlife Refuge System (NWRS)

Service U.S. Fish and Wildlife Service (USFWS)

ATV All-terrain vehicle

BD Batrachochytrium dendrobatidis

BIDEH Biological Integrity, Diversity and Environmental Health 

 (601 FW3)

CAL FIRE California Department of Forestry and Fire Protection

CCC California Conservation Corps

CCP Comprehensive Conservation Plan (CCP)

CCAMP Central Coast Ambient Monitoring Program

CCRWQCB Central Coast Regional Water Quality Control Board

CDFG California Department of Fish and Game

CEQA California Environmental Quality Act

CNDDB California Natural Diversity Database

CNPS California Native Plant Society

CRLF California red-legged frog 

CTS California tiger salamander

EA Environmental Assessment

EO Executive Order

EPA Environmental Protection Agency

ESA Endangered Species Act of 1973, as amended

FMP Fire Management Plan

FSA Farm Service Agency

FTE Full Time Employee

GHG greenhouse gas

GIS Geographic Information System

IPCC Intergovernmental Panel on Climate Change

Abbreviations and Acronyms 
Ellicott Slough NWR - Final Comprehensive Conservation Plan vii

KOA Kampgrounds of America

MBUAPCD Monterey Bay Unified Air Pollution Control District

MMT million metric tons

MOU Memorandum of Understanding

NEPA National Environmental Policy Act

NRCS Natural Resource Conservation Service

NWR National Wildlife Refuge

NWRS National Wildlife Refuge System (Refuge System)

PG&E Pacific Gas and Electric

PUP Pesticide Use Proposal

RONS Refuge Operating Needs System

SCCMCV Santa Cruz County Mosquito and Vector Control

SCLTS Santa Cruz long-toed salamander

SHPO (California) State Historic Preservation Office

SLAMM Sea-level Affecting Marshes Model

SUP Special Use Permit

TPL Trust for Public Land 

USFWS U.S. Fish and Wildlife Service (Service)

USGS U.S. Geological Survey

VOC volatile organic compounds

WCB Wildlife Conservation Board

WNV West Nile Virus

WUI Wildland Urban Interface 

Ellicott Slough NWR - Final Comprehensive Conservation Plan 1

The U.S. Fish and Wildlife Service (Service) 

manages the Ellicott Slough National Wildlife 

Refuge (Refuge, Ellicott Slough NWR) located in 

Santa Cruz County within the Monterey Bay area, 

California. Established in 1975, the Refuge provides 

vital habitat for the endangered Santa Cruz long-toed 

salamander (Ambystoma macrodactylum croceum), 

the threatened California red-legged frog (Rana 

aurora draytonii), the threatened California tiger 

salamander (Ambystoma californiense), and the 

endangered robust spineflower (Chorizanthe robusta).

The Service prepared this Comprehensive 

Conservation Plan (CCP, Plan) to guide Refuge 

management for the next 15 years. The CCP 

provides a description of the desired future 

conditions and long-range guidance to accomplish 

the purposes for which the Refuge was established. 

The CCP and accompanying environmental 

assessment (EA) address Service legal mandates, 

policies, goals, and National Environmental Policy 

Act (NEPA) compliance. 

The CCP is divided into six chapters: Chapter 1, 

Introduction and Background; Chapter 2, The 

Comprehensive Conservation Planning Process; 

Chapter 3, Refuge and Resource Description; 

Chapter 4, Current Refuge Management and 

Programs; Chapter 5, Management Direction; and 

Chapter 6, Plan Implementation.

1.1 Purpose and Need for this CCP 

No formal management plan currently exists for 

the Refuge. The National Wildlife Refuge System 

(Refuge System, NWRS) Improvement Act of 1997 

(16 United States Code [USC] 668dd-668ee) (1997 

Improvement Act) requires that all refuges be 

managed in accordance with an approved CCP by 

2012. Under the 1997 Improvement Act, the Refuge 

System is to be consistently directed and managed 

to fulfill the specific purpose(s) for which each 

refuge was established as well as the Refuge System 

Mission. The planning process helps the Service 

achieve the refuge purposes and the Refuge System 

mission by identifying specific goals, objectives, 

and strategies to implement on each refuge. The 

purposes of this CCP are as follows:

■ Provide a clear statement of direction for the 

management of the Refuge during the lifetime 

of the CCP.

■ Provide long-term continuity in Refuge 

management.

■ Communicate the Service’s management 

priorities for the Refuge to its neighbors and

the public.

■ Provide an opportunity for the public to help 

shape the future management of the Refuge.

■ Ensure that management programs on the 

Refuge are consistent with the legal and 

policy mandates for the Refuge System and 

the purpose of the Refuge as set forth in 

establishing documentation.

■ Ensure that management of the Refuge is, to 

the extent practicable, consistent with Federal, 

state, and local plans.

Chapter 1. Introduction and Background

Ellicott Slough NWR entrance sign. Photo: USFWS
Chapter 1

2 Ellicott Slough NWR - Final Comprehensive Conservation Plan

■ Provide a basis for budget requests to support 

the Refuge’s needs for staffing, operations, 

maintenance, and capital improvements.

■ Evaluate existing and proposed uses on each of 

the Refuges to ensure that they are compatible 

with the Refuge purpose(s); the Refuge System mission; and the maintenance of biological 

integrity, biodiversity, and environmental health 

(or BIDEH).

1.2 The U.S. Fish and Wildlife 

Service and the National Wildlife 

Refuge System

1.2.1 U.S. Fish and Wildlife Service

The Service is the primary Federal agency 

responsible for conserving, protecting, and enhancing 

the Nation’s fish, wildlife, and plant populations 

and their habitats for the continuing benefit of the 

American people. Although the Service shares 

this responsibility with other Federal, tribal, state, 

local, and private entities, the Service has specific 

responsibilities for migratory birds, threatened and 

endangered species, interjurisdictional fish, and 

certain marine mammals. These are referred to as 

Federal Trust Species. The Service also manages 

the National Wildlife Refuge System and National 

Fish Hatcheries, enforces Federal wildlife laws 

and international treaties related to importing and 

exporting wildlife, assists state fish and wildlife 

programs, and helps other countries develop wildlife 

conservation programs. 

1.2.2 The National Wildlife Refuge System

The National Wildlife Refuge System (Refuge 

System) is the world’s largest collection of 

lands specifically managed for fish and wildlife 

conservation. Unlike other Federal lands that 

are managed under a multiple-use mandate (e.g., 

National Forests and lands administered by the U.S. 

Bureau of Land Management, the Refuge System 

is managed primarily for the benefit of fish, wildlife, 

and plant resources and their habitats. The Refuge 

System consists of more than 551 units that provide 

more than 150 million acres of important habitat 

nationwide for native plants and many species of 

mammals, birds, and fish, including threatened and 

endangered species.

1.2.3 National Wildlife Refuge System 

Mission and Goals

The mission of the Refuge System is “to administer 

a national network of lands and waters for the 

conservation, management and, where appropriate, 

restoration of the fish, wildlife and plant resources 

and their habitats within the United States for 

the benefit of present and future generations of 

Americans” (1997 Improvement Act).

The goals of the Refuge System are:

a. Conserve a diversity of fish, wildlife, and 

plants and their habitats, including species

that are endangered or threatened with 

becoming endangered.

b. Develop and maintain a network of habitats 

for migratory birds, anadromous and

interjurisdictional fish, and marine mammal 

populations that is strategically distributed and 

carefully managed to meet important life history 

needs of these species across their ranges.

c. Conserve those ecosystems; plant communities; 

wetlands of national or international significance; and landscapes and seascapes that are 

unique, rare, declining, or underrepresented in 

existing protection efforts. 

d. Provide and enhance opportunities 

to participate in compatible wildlifedependent recreation (hunting, fishing, 

wildlife observation, and photography, and 

environmental education and interpretation). 

e. Foster understanding and instill appreciation 

of the diversity and interconnectedness of fish, 

wildlife, and plants and their habitats.

1.3 Legal and Policy Guidance

Refuges are guided by the purposes of the individual 

refuge, the mission and goals of the Refuge System, 

Service policy, laws, and international treaties. 

Relevant guidance includes the Refuge Recreation 

Act of 1962, the 1997 Improvement Act, and selected 

portions of the Code of Federal Regulations and the 

U.S. Fish and Wildlife Service Manual. Refuges 

are also governed by a variety of other Federal 

laws, Executive orders (EOs), treaties, interstate 

compacts, regulations, and policies pertaining to the 

conservation and protection of natural and cultural 

resources (see Service Manual 602 FW 1 [1.3]). 
Ellicott Slough NWR - Final Comprehensive Conservation Plan 3

1.3.1 The Improvement Act 

The 1997 Improvement Act, which amends the 

National Wildlife Refuge System Administration 

Act of 1966, serves as an “organic” act for the 

Refuge System and provides comprehensive 

legislation describing how the Refuge System 

should be managed and used by the public. The 

1997 Improvement Act’s main components include 

the following.

■ A strong and singular wildlife conservation 

mission for the Refuge System

■ A recognition of six priority public uses 

of the Refuge System (hunting, fishing, 

wildlife observation and photography, and 

environmental education and interpretation)

■ A requirement that the Secretary of the Interior 

maintain the biological integrity, diversity, and 

environmental health of Refuge System lands

■ A new process for determining compatible uses 

on refuges

■ A requirement for preparing a Comprehensive 

Conservation Plan for each refuge by 2012

1.3.2 Refuge System Policies 

Refuge System policies are found in the land 

use management series (600) of the U.S. Fish 

and Wildlife Service Manual. These policies are 

available online at www.fws.gov/policy/manuals. 

Table 1 provides brief descriptions of key policies 

related to refuge management and use. 

1.4 San Francisco Bay National 

Wildlife Refuge Complex

With the support of citizens and public officials, 

seven refuges have been established in the San 

Francisco and Monterey Bay Areas: Farallon NWR 

(1909), Salinas River NWR (1973), San Pablo Bay 

NWR (1974), San Francisco Bay NWR (1974), 

Ellicott Slough NWR (1975), Antioch Dunes NWR 

(1980), and Marin Islands NWR (1992). These 

seven refuges, stretching from Monterey Bay to 

the Sacramento–San Joaquin River Delta, were 

combined to create the San Francisco Bay NWR 

Complex (Complex) (Figure 1). These refuges 

provide a variety of critical habitat, food, and shelter 

for native plants and animals such as threatened 

and endangered species, species of special concern, 

waterfowl, and many others. Unlike refuges in 

remote locations, each of these seven refuges shares 

the task of implementing wildlife conservation 

objectives while addressing human needs in a 

highly urbanized environment. The Complex is 

administered from a headquarters office located on 

the Don Edwards San Francisco Bay NWR, near 

the city of Fremont.

1.5 Ellicott Slough National 

Wildlife Refuge

1.5.1 Location

The Ellicott Slough National Wildlife Refuge 

(Refuge) is located on the southern coast of Santa 

Cruz County, approximately four miles west of the 

city of Watsonville. Santa Cruz County is part of the 

larger Monterey Bay area and is heavily influenced 

by marine conditions of the Pacific Ocean. This 

area is small but diverse with mountains, foothills, 

valleys, and marine scenery. The soil is productive, 

making the area an important agricultural base. 

Residential and agricultural development surrounds 

the Refuge.

1.5.2 Refuge Setting

Present-day Santa Cruz and Watsonville were 

explored in 1769 by an expedition led by Don Caspar 

de Portola. Settlers came with the founding of the 

Santa Cruz Mission in September 1791 (Watkins 

1925). Farming was first practiced near the Mission 

and even continues today. Wheat, corn, and barley 

were the principal crops, but fruit orchards also 

existed. Raising livestock was also important. 

Logging began in 1832, and numerous mills were 

built to utilize the local timber. California was 

acquired from Mexico by the United States in 

1846. Santa Cruz County was formally organized 

in 1850. In 1851, farmers settled into Pajaro Valley. 

In 1858, commercial apple orchards were started, 

and by 1910, there were a million trees on 14,000 

acres. Other crops that were grown from the late 

1800s through the 1900s included prunes, hops, 

sugar beets, strawberries, and lettuce. The farming 

industry was stimulated greatly when the railroad 

came into the Pajaro Valley in 1870 (Martin 1911). 
Chapter 1

4 Ellicott Slough NWR - Final Comprehensive Conservation Plan

1.5.3 History of Refuge Establishment 

and Acquisition

In 1971, the original owner of the Ellicott Slough 

area intended to rezone the area to develop it into a 

trailer park. However, the proposal was denied by 

the Santa Cruz County commissioners because at 

the time, the parcel contained one of only two known 

active breeding ponds for the Santa Cruz longtoed salamander (USFWS 1975). The California 

Department of Fish and Game (CDFG) later 

acquired the property and some adjacent upland 

in 1973 and designated the 30-acre acquisition as 

a State Ecological Reserve. During that time, 

salamanders were found in significant numbers 

in chaparral and oak woodland up to at least a 

quarter mile from the breeding pond (USFWS 

1975). In 1975, the Service acquired additional 

adjacent upland habitat to protect the salamander’s 

terrestrial lifecycle needs and established Ellicott 

Slough NWR. Beginning with 41 acres in 1975, 87 

acres were added the following year to make up the 

128-acre Ellicott Unit. The 30-acre State Ecological 

Reserve is included in the Ellicott Unit and is 

managed by the Refuge under a Memorandum 

of Understanding (MOU) with the CDFG. Two 

easements are also associated with the Ellicott 

Unit. The Fisher family contributed a 1.12-acre 

Policy Purpose

Refuge System Mission and Goals and Refuge Purposes (601 FW 1)Reiterates and clarifies the Refuge System mission 

and how it relates to the Service mission; explains 

the relationship between the Refuge System mission, 

goals, and purpose(s). It also includes the decision 

making process for determining refuge purposes.

Biological Integrity, Diversity and Environmental 

Health Policy (601 FW 3)

Provides guidance for maintaining and restoring, 

where appropriate, the biological integrity, diversity, 

and environmental health of the Refuge System.

Comprehensive Conservation Planning (602 FW 3) Describes the requirements and processes for developing refuge comprehensive conservation plans.

Appropriate Use (603 FW 1) Describes the initial decision process the refuge manager follows when first considering whether or not to 

allow a proposed use on a refuge. The refuge manager 

must find a use appropriate before undertaking a compatibility review of the use. 

Compatibility (603 FW 2) Details the formal process for determining if a use 

proposed on a National Wildlife Refuge is compatible 

with the Refuge System mission and the purposes for 

which the refuge was established. Units of the Refuge 

System are legally closed to all public access and use, 

including economic uses, unless and until they are 

officially opened through a compatibility determination. Appendix G contains several draft compatibility 

determinations for proposed uses on Ellicott Slough 

NWR. These will be open to public comment with the 

Draft Plan and formalized with the Final Comprehensive Conservation Plan.

Wildlife-Dependent Recreation (605 FW 1-7) Provides specific information and guidance for each of 

the six priority wildlife-dependent uses: the policy for 

the use; guiding principles for the use; guidelines for 

program management; and guidelines for opening the 

specific program.

Table 1. Key policies related to management of National Wildlife Refuges
Ellicott Slough NWR - Final Comprehensive Conservation Plan 5

Figure 1. San Francisco Bay NWR Complex Map

Monterey 

Bay

Antioch Dunes NWR

Redwood City

San Pablo Bay NWR

Marin Islands NWR

Ellicott 

Slough NWR

Salinas 

River NWR

Don Edwards San

San Francisco Francisco Bay NWR Bay

S.F.

Fremont

Oakland

Concord

Vallejo

Monterey

San Jose

Santa Cruz

San Rafael

San Francisco

MARIN

ALAMEDA

SOLANO

SANTA CLARA

CONTRA COSTA

SAN

MATEO

MONTEREY

SANTA CRUZ

SONOMA

NAPA

Farallon NWR

San Francisco Bay National Wildlife Refuge Complex

C

A

L I F

O

R

N I A

NEVADA

Enlarged Area

P

a

c

i

f

i

c

O

c

e

a

n

±

0 10 20 5

km

0 5 10 20

Miles 0 250

Miles
Chapter 1

6 Ellicott Slough NWR - Final Comprehensive Conservation Plan

Figure 2. Ellicott Slough NWR Location Map

Larkin Valley Rd.

San Andreas

Rd.

Willow Crk. Dr.

Fiesta Way

Mar Monte Rd.

Rampart Dr.

Hark ni s Sloug h Rd. Cabrillo Hwy

Buena V si at Dr.

Metvier's Way

Ard illa C y n Rd.

UV1

0 0.25 0.5 1

Miles

±

0 0.25 0.5 1

Kilometers

!

!

Monterey 

Bay

Ellicott Slough

Area Monterey

Santa Cruz

Calabasas

Unit

Buena Vista

Property

Ellicott

Unit

Harkins Slough

Unit

Regional location

California Dept. of Fish and Game

U.S. Fish and Wildlife Service

Land ownership: 

Ellicott Slough National Wildlife Refuge

Refuge Location

C

A

L I F O R N I A

Agreement 

Approved Acquisition Boundary

Land status: 

Easement
Ellicott Slough NWR - Final Comprehensive Conservation Plan 7

conservation easement in 1975, and the Lima family 

contributed a 4.50-acre conservation easement in 

1994. Both easements are within the approved 

Refuge boundary. In total, the 133.24 acres owned 

in fee title by the Service and the 35.11 acres 

managed under easement or agreement comprise 

the 168.35-acre Ellicott Unit today.

In June 1999, the Calabasas Unit was added to 

the Refuge. A single-family home was slated for 

development on this nearly 32-acre parcel but 

was halted due to seismic, septic, and endangered 

species restrictions (Santa Cruz long-toed 

salamander and California red-legged frog were 

found on the property). In 1999, The Trust for 

Public Land (TPL) obtained an option to purchase 

the site, with the intention to sell it to the Wildlife 

Conservation Board (WCB) (USFWS 1999c). The 

WCB was then awarded a Cal Trans Environmental 

Enhancement and Mitigation grant to purchase 

Calabasas for $250,000. The WCB transferred the 

unit, at no cost, to the Service to maintain its coastal 

scrub and pond habitat.

The Harkins Slough Unit was formerly an 

agricultural property farmed for over 40 years by the 

Bencich family. It was reclaimed by the Farm Service 

Agency in 1994 when flooding from the Harkins 

Slough waterway permanently inundated the 

agricultural fields. The 116-acre property was then 

transferred to the Service in 2005 due to its value as 

freshwater wetland habitat for migratory birds. 

The Ellicott Unit (168.35 acres), the Calabasas Unit 

(31.20 acres), and the Harkins Slough Unit (116 

acres) together comprise the Ellicott Slough NWR, 

totaling 315.55 acres.

The 289-acre Buena Vista property was acquired 

by TPL in 2004. Originally, a golf course had been 

planned for the property until the Santa Cruz longtoed salamander and California tiger salamander 

were found to breed in the manmade ephemeral 

pond on site. TPL led efforts to acquire the land, with 

support from state agencies. This property was later 

transferred to the CDFG. The Service is working 

with CDFG to develop an agreement to cooperatively 

manage the property that is within the approved 

acquisition boundary for the Refuge. See Figure 2. 

1.5.4 Refuge Purposes 

Lands within the Refuge System are acquired and 

managed under a variety of legislative acts and 

administrative orders and authorities. The official 

purpose or purposes for a refuge are specified in 

or derived from the law, proclamation, executive 

order, agreement, public land order, funding source, 

donation document, or administrative memorandum 

establishing, authorizing, or expanding a refuge, 

refuge unit, or refuge subunit. The purpose of a 

refuge is defined when it is established or when 

new land is added to an existing refuge. When an 

addition to a refuge is acquired under an authority 

different from the authority used to establish the 

original refuge, the addition takes on the purposes 

of the original refuge, but the original refuge does 

not take on the purposes of the addition. Refuge 

managers must consider all of the purposes. 

However, purposes that deal with the conservation, 

management, and restoration of fish, wildlife, and 

plants and their habitats take precedent over other 

purposes in the management and administration of a 

refuge (601 FW 1.5). 

The Refuge System Improvement Act directs 

the Service to manage each refuge to fulfill the 

mission of the Refuge System, as well as the specific 

purposes for which that refuge was established. 

Refuge purposes are the driving force in developing 

refuge vision statements, goals, objectives and 

strategies in the CCP. Refuge purposes are also 

critical to determining the compatibility of all 

existing and proposed refuge uses.

Ellicott Slough National Wildlife Refuge was 

established under the authority of two acts. These 

acts and the corresponding purposes are:

Endangered Species Act of 1973 (16 U.S.C. 

1531 et seq.) - “...to conserve (A) fish or 

wildlife which are listed as endangered species 

or threatened species .... or (B) plants ...” 

Emergency Wetlands Resources Act of 1986 

(16 U.S.C. 3901-3932) - “... the conservation 

of the wetlands of the Nation in order to 

maintain the public benefits they provide 

and to help fulfill international obligations 

contained in various migratory bird treaties 

and conventions ...”
Chapter 1

8 Ellicott Slough NWR - Final Comprehensive Conservation Plan

1.5.5 Ecosystem Context and Related Projects

To the extent possible, a CCP will assist in 

meeting conservation goals established in existing 

national and regional plans, state fish and wildlife 

conservation plans, and other landscape-scale plans 

covering the same watershed or ecosystem in which 

the refuge resides (602 FW 3.3). The Refuge falls 

within the Central California Ecoregion. This 

ecoregion consists of mountains, hills, valleys, and 

plains in the southern Coast Ranges of California. 

It is close enough to the Pacific Ocean for the 

climate to be modified greatly by marine influence. 

The purpose of establishing these ecoregions is to 

develop and implement goals, priorities, objectives, 

and actions that will ensure an “ecosystem 

approach” to fish and wildlife conservation.

1.5.6 Conservation Priorities and Initiatives

The conservation priorities for Federally-listed 

endangered and threatened species that are present 

at a refuge are frequently reinforced by recovery 

plans, conservation plans, and designation of critical 

habitat. The primary conservation priority for the 

Ellicott Slough NWR is recovering and conserving 

the Santa Cruz long-toed salamander and other 

sensitive amphibians. A revised recovery plan has 

been developed to guide recovery efforts (USFWS 

1999b). The recovery plan has been used to develop 

some of the objectives and strategies in this CCP. 

The Refuge also provides breeding habitat for 

California red-legged frog and California tiger 

salamader (CTS), both of which are Federally-listed 

threatened species. A recovery plan was completed 

for California red-legged frog in 2002, and critical 

habitat was re-designated for the species in 2010. 

Critical habitat for California red-legged frog can 

be found on the Ellicott and Harkins Slough Units, 

as well as the Buena Vista Property. The CTS is 

Federally listed as threatened in Central California 

and endangered in other parts of California (Santa 

Barbara and Sonoma Counties). Critical habitat was 

designated for all CTS populations in 2005, however 

it does not include Santa Cruz County.

In addition to threatened and endangered 

amphibians, the Refuge supports the endangered 

robust spineflower. A recovery plan for robust 

spineflower was completed in 2004 (USFWS 2004a) 

and critical habitat was designated in 2002. Critical 

habitat for spineflower can be found at the Buena 

Vista property. While it is not known whether the 

Federally-listed as threatened Santa Cruz tarplant 

is present at the Refuge, there is designated critical 

habitat at the Harkins Slough Unit.

1.5.7 Adaptive Management

The Service acknowledges that much remains to 

be learned about the species, habitats, and physical 

processes that occur on the Refuge and about the 

ecological interactions between them. It follows 

that uncertainty is an unavoidable component of 

managing natural systems because of the inherent 

variability in these systems and gaps in the 

knowledge of their functions. Adaptive management 

strives to reduce some of that uncertainty and 

improve management over time. It is an iterative 

process of evaluating and refining management 

based on the results of management activities and 

the status of the managed resource. The Service 

has been practicing adaptive management on 

the Refuge since 1991 and plans to continue the 

practice. Accordingly, the management scenario 

proposed in this CCP provides for ongoing 

adaptive management of the Refuge; its adaptive 

management component is described more fully in 

Chapter 6, Plan Implementation. 
Ellicott Slough NWR - Final Comprehensive Conservation Plan 9

Chapter 2. The Comprehensive Conservation 

Planning Process

This CCP/EA for the Refuge is intended to meet 

the dual requirements of compliance with the 1997 

Improvement Act and NEPA of 1969 (42 USC 4321). 

The development of this CCP/EA was also guided 

by the Refuge Planning Policy outlined in Part 602, 

Chapters 1, 3, and 4 of the Service Manual (USFWS 

2000). Service policy, the 1997 Improvement 

Act, and NEPA provide specific guidance for the 

planning process. For example, Service policy and 

NEPA require the Service to actively seek public 

involvement in the preparation of environmental 

documents such as EAs. 

The purpose of the EA is to evaluate and disclose 

the environmental effects of the management actions 

detailed in the proposed action and alternatives 

on the quality of the human environment. NEPA 

requires the Service to give serious consideration 

to all reasonable alternatives, including the “no 

action” alternative, which represents continuation 

of current conditions and management practices. 

Alternative management scenarios were developed 

as part of the planning process and can be found in 

Appendix C (Environment Assessment).

2.1 The Planning Process: How the 

CCP was Developed

Key steps in the CCP planning process are as follows 

and are depicted in the CCP Process diagram.

1. Preplanning.

2. Identifying issues and developing a vision 

statement.

3. Gathering information.

4. Analyzing resource relationships.

5. Developing alternatives and assessing 

environmental effects.

6. Identifying a preferred alternative.

7. Publishing the draft CCP and NEPA document.

8. Documenting public comments on the Draft Plan.

9. Preparing the final CCP.

10. Securing approval of the Regional Director.

11. Implementing the plan.

The CCP may be amended as necessary at any time 

in keeping with the adaptive management strategy. 

Major revisions would require public involvement 

and NEPA review.

2.1.1 Preplanning

The planning process for this CCP began in January 

2008 with the collection of pertinent data and 

selection of team members. A core team and an 

extended team were formed to integrate stakeholder 

input into the planning process (see Appendix I). 

Refuge staff identified four primary areas of focus: 

wildlife management, habitat management, wildlifedependent recreation, and environmental education. 

These areas helped focus comments received from 

the public during the scoping period into potential 

objectives and strategies for the CCP.

2.1.2 Planning Hierarchy

The Service’s planning hierarchy, which determines 

the direction of the goals, objectives, and strategies, 

is a natural progression from the general to the 

specific. Described as a linear process, the planning 

hierarchy is rather a multi-dimensional flow that 

is linked by the refuge purposes, missions, laws, 

mandates, and other statutory requirements. 

■ The refuge purposes provide direction for 

the refuge.

■ A refuge vision broadly reflects the refuge 

purpose(s), the Refuge System mission and 

goals, other statutory requirements, and largerscale plans as appropriate.

■ Goals define general targets in support of 

the vision.
Chapter 2

10 Ellicott Slough NWR - Final Comprehensive Conservation Plan

■ Objectives direct effort into incremental and 

measurable steps toward achieving goals.

■ Strategies identify specific tools to 

accomplish objectives.

In practice, the process of developing vision, goals, 

and objectives is iterative and dynamic. During the 

planning process or as new information becomes 

available, the plan continues to develop.

2.1.3 The Core Planning Team

The planning team responsible for leading the 

CCP effort included Service planners, the Refuge 

manager, the Refuge biologist, and visitor services 

staff from the San Francisco Bay NWR Complex. 

The members were responsible for researching 

and generating the contents of the CCP document 

and participated in the entire planning process. 

Representatives from the California Department 

of Fish and Game (CDFG) were also invited to 

participate. Appendix I lists the members of the 

core team and other participants.

2.1.4 The Extended Planning Team

The extended team is the advisory forum of the 

CCP process. Its role is significant because of the 

Refuge’s history of networking and partnerships 

with local, state and Federal agencies, community 

groups, research institutes, and non-profit 

organizations concerned with the Refuge. Service 

staff identified several participants including state 

and Federal agency officials, local government 

officials, non-profit organizations, community 

groups, and other interested parties. The goal of 

the extended team is to provide technical comments 

on the goals, objectives, and strategies of the CCP 

to improve the Service’s decision-making process. 

Appendix I lists the members in the extended team.

Figure 3. The CCP Process Diagram
Ellicott Slough NWR - Final Comprehensive Conservation Plan 11

2.2 Public Involvement in Planning

Public involvement is an important and required 

component of the CCP and NEPA processes. 

Public outreach allows the Service to provide 

updated information about the Refuge System and 

the Refuge. More importantly, public involvment 

allows Refuge staff to hear public comments, 

concerns, and opportunities. Public input can 

identify important issues regarding the Refuge and 

its surrounding area.

A Notice of Intent to prepare a Comprehensive 

Conservation Plan (CCP) and Environmental 

Assessment was published in the Federal Register on 

July 14, 2008. A planning update, which introduced 

the Refuge and the planning process, was mailed to 

over 100 agency and organization representatives, 

members of the public, media, and elected 

representatives in Santa Cruz County. The Refuge 

held a public scoping period from July 14 through 

August 13, 2008. During this period, upon request, 

the Refuge staff met or spoke directly with neighbors 

and partner organizations, including Watsonville 

Wetlands Watch on October 2, 2008. The substance of 

the comments or issues identified through the scoping 

process is summarized in the Issues, Concerns, and 

Opportunities section that follows.

2.2.1 Issues, Concerns, and Opportunities 

Identified through Scoping

■ Public trespass (e.g., bicycling, hiking, 

horseback riding, dog walking) occurs on the 

Refuge units.

■ Illegal fishing occurs on the Harkins Slough Unit.

■ Vehicular traffic is a major cause of amphibian 

mortality, and roads exist between breeding 

ponds and over-summering habitat.

■ Invasive plants (e.g., eucalyptus: Eucalyptus 

spp.), pampas or jubata grasses (Cortaderia 

spp.), poison hemlock (Conium maculatum), 

New Zealand spinach (Tetragonia 

tetragonioides), and mustard (Brassica sp.) 

continue to threaten native habitats.

■ Intense farming in the area may employ practices 

(such as pesticide and fertilizer use) that have

potentially adverse effects on amphibians.

■ Drought years severely impact Santa Cruz longtoed salamander (SCLTS) productivity and make

it difficult to assess the status of SCLTS and 

California tiger salamander (CTS) populations.

■ Occasional chytrid fungus (Batrachochytrium 

dendrobatidis) outbreaks cause chytridiomycosis, 

which threaten amphibian health.

■ Mosquito control has been allowed in the past 

for nuisance and health reasons; however, the 

potential effects of control to amphibians are 

still being evaluated.

■ Invasive predators of amphibians (e.g., 

bullfrog, crayfish) tend to multiply quickly

and have the potential to decimate native 

amphibian populations. 

■ The effects of climate change (e.g., temperature 

fluctuations and narrowing wildlife habitat 

ranges) on Refuge resouces. (For more 

information on climate change, see Chapter 3.)

2.2.2 Additional Management Issues Identified 

by Staff through Scoping

■ Illegal off-road vehicle use, such as all-terrain 

vehicle (ATV) and motorcycle, in the upland and 

pond habitats on the Calabasas Unit.

■ Few remaining upland habitats and ponds for 

the SCLTS, CTS, and other native amphibians 

due to habitat loss from development.

■ Known SCLTS and CTS sites are noncontiguous, preventing population exchange.

■ Existing Refuge data on SCLTS and CTS is 

sparse, limiting understanding of population 

trends and habitat use.

■ Amphibian malformation outbreaks caused by 

trematode parasites.

2.3 Development of Refuge Vision

A vision statement is developed or reviewed for 

each individual refuge unit as part of the CCP 

process. Vision statements are grounded in the 

unifying mission of the Refuge System and describe 

the desired future conditions of the refuge in the 

long term (more than 15 years). A vision statement 

is based on the refuge’s specific purposes, the 

resources present on the refuge, and any other 
Chapter 2

12 Ellicott Slough NWR - Final Comprehensive Conservation Plan

relevant mandates. Chapter 5 presents the vision 

statement for the Refuge.

2.4 Development of Refuge Goals, 

Objectives and Strategies

The purpose for creating the Refuge was established 

by law, Executive Order, and other mechanisms 

described in Chapter 1. The 1997 Improvement 

Act directs that the planning effort develop and 

revise the management focus of the Refuge 

within the Service’s planning framework-that is, 

the Service mission, the Refuge System mission, 

ecosystem guidelines, and refuge purposes. This is 

accomplished during the CCP process through the 

development of goals, objectives, and strategies. 

Chapter 5 includes the goals, objectives and 

strategies developed for the Refuge.

2.4.1 Goals 

Refuge goals are necessary for outlining the desired 

future conditions of a refuge in clear and succinct 

statements. The Refuge System defines goals 

as a “...descriptive, open-ended, and often broad 

statement of desired future conditions that conveys 

a purpose but does not define measurable units” (602 

FW 1). Each goal is subdivided into one or more 

objectives that define these desired conditions in 

specific, measurable, and time-bounded terms. A 

well-written goal directs work toward achieving a 

refuge’s vision and, ultimately, the purpose(s) of a 

refuge. Collectively, a set of goals is a framework 

within which to make decisions.

2.4.2 Objectives, Rationale, and Strategies

After the refuge goals have been reviewed and 

revised, various objectives, a rationale, and strategies 

are developed to accomplish each of the goals.

Objectives: An objective is defined as a “concise 

statement of what we want to achieve, how much we 

want to achieve, when and where we want to achieve 

it, and who is responsible for the work” (602 FW 1). 

Objectives are incremental steps taken to achieve 

a goal. They are derived from goals and provide a 

foundation for determining strategies, monitoring 

refuge accomplishments, and evaluating success. 

The number of objectives per goal can vary but 

should be developed to comprise those necessary 

to satisfy the goal. In cases where there are many 

objectives, an implementation schedule may be 

developed. All objectives must possess the following 

five properties: specific, measurable, achievable, 

results-oriented, and time-fixed.

Rationale: Each objective should be supported 

by a rationale. The degree of documentation can 

vary, but at a minimum, the rationale should include 

logic, assumptions, and sources of information. 

Articulating a rationale promotes informed debate 

on the objective’s merits, provides continuity in 

management through staff turnover, and allows 

reevaluation of the objective as new information 

becomes available.

Strategy: A strategy is a “specific action, tool, 

technique, or combination of actions, tools, and 

techniques used to meet unit objectives” (602 FW 

1). Well-written goals, objectives, and strategies 

direct work toward achieving the refuge’s vision and 

purpose. Multiple strategies can be necessary to 

support an objective.

2.5 Development of Alternatives

The CCP process includes the development of 

a range of reasonable alternatives that can be 

implemented to meet the goals of the Refuge 

System and the purpose of the Refuge. The Refuge 

System defines alternatives as “...different sets 

of objectives and strategies or means of achieving 

refuge purposes and goals, helping fulfill the Refuge 

System mission, and resolving issues...” (602 FW 

1). NEPA also requires analysis of a no-action

alternative, which constitutes a continuation of 

current conditions and management practices. 

Development of action alternatives is based on 

consideration of input from the scoping period, as 

well as on input from the planning team and other 

Service staff. The EA (Appendix C) describes the 

development of alternatives and assessment of their 

environmental effects, and it identifies the preferred 

management alternative (proposed action). Once a 

preferred alternative is selected, it is developed as 

the objectives and strategies of the CCP.

Three alternatives were identified for analysis; these 

are discussed in detail in the EA (Appendix C).
Ellicott Slough NWR - Final Comprehensive Conservation Plan 13

2.6 Selection of the Refuge 

Proposed Action

The alternatives were analyzed in the EA (Appendix C) to determine their effects on the Refuge 

environment. Based on this analysis, Alternative B 

was selected as the proposed action because it best 

achieves the Refuge goals and purposes in accordance with Refuge System and Service missions. 

Alternative B is founded upon the need for restoring 

habitat, protecting wildlife, and focusing research 

and monitoring programs on priority needs. The 

alternative also integrates environmental education, outreach, and wildlife-dependent recreation 

objectives that will connect the public to the Refuge. 

The management plan set forth in Alternative B is 

described in Chapter 5, Management Direction, and 

Chapter 6, Plan Implementation.

2.7 Plan Implementation

The CCP will be reviewed by Refuge staff to 

coordinate annual work plans and update the 

Refuge Operational Needs System database. This 

database describes the unfunded budget needs 

for each refuge and is the basis upon which the 

Refuge receives funding increases for operational 

needs. The CCP may also be reviewed during 

routine inspections or programmatic evaluations. 

Results of the reviews may indicate a need to 

modify an integral part of plan implementation, 

and management activities may be modified if the 

desired results are not achieved. If minor changes 

are required, the level of public involvement and 

NEPA documentation will be determined by the 

Refuge manager. The CCP will be formally revised 

about every 15 years.

Santa Cruz long-toed salamander juveniles. Photo: USFWS

Ellicott Slough NWR - Final Comprehensive Conservation Plan 15

Chapter 3. Refuge and Resource Description

3.1 Geographic/Ecosystem Setting

The Refuge is located in Santa Cruz County, onehalf mile inland from Monterey Bay and four miles 

west of Watsonville. The Refuge falls within the 

Central California Ecoregion. This ecoregion 

consists of mountains, hills, valleys, and plains in 

the southern Coast Ranges of California. It is close 

enough to the Pacific Ocean for the climate to be 

modified greatly by marine influence. Elevation 

ranges from sea level to 3,800 feet. The Refuge is 

located in the Watsonville Slough system where 

surface waters converge and eventually terminate 

into Monterey Bay. 

3.2 Description by Refuge Unit

3.2.1 Ellicott Unit

The main Ellicott Unit is located on Peaceful 

Valley Drive off of San Andreas Road. A privately 

operated Kampgrounds of America (KOA) 

campground lies on the western border, and 

approximately seven houses, agricultural fields, and 

several small businesses are located in the valley 

along the eastern border. Scattered houses are 

located on the northern and southern boundaries. 

Several California State Parks, open to the public, 

(Manresa and Sunset State Beaches) are also 

within two miles of the Ellicott Unit. The nearby 

agricultural areas are dominated by cash crops 

such as artichokes, strawberries, broccoli, lettuce, 

cauliflower, and cut flowers.

The dominant habitats found on the Ellicott Unit are 

northern coastal shrub, San Andreas coastal live oak 

woodland, riparian woodland, closed-cone coniferous 

forest, and coastal grassland. In addition to the Santa 

Cruz long-toed salamander (SCLTS), California 

tiger salamander (CTS) and small populations of 

the robust spineflower have also been identified as 

Federally-listed species present on the unit. 

Past uses on the unit include livestock grazing, 

farming of berry crops, and off-road vehicle use. A 

residential house was also located on the property 

and was demolished prior to Refuge acquisition.

The ephemeral Ellicott Pond on the Ellicott Unit 

is used by salamanders during breeding. It is 

unknown whether the Ellicott Pond is naturally 

occurring or man-made. In 1997, the Refuge 

attempted to create an additional breeding 

pond on the unit (Prospect Pond). A pond area 

was excavated, and a partial earthen berm was 

constructed to surround the site. Water levels 

were to be controlled by a culvert 

installed through the earthen 

berm. A well was also established 

on the hilltop above the pond to 

augment water levels as needed. 

Plastic piping was laid from the 

well to the pond site. A temporary 

pump and generator were needed 

to transport the water. Subsequent 

years resulted in poor water 

retention. The pond dried too early 

in the season to ensure larvae and 

tadpole metamorphosis, and water 

augmentation from the well would 

have been needed throughout the 

entire spring and summer. Initial 

monitoring surveys showed limited 

Ellicott Unit. Photo: USFWS Pacific tree frog (Pseudacris 
Chapter 3

16 Ellicott Slough NWR - Final Comprehensive Conservation Plan

regilla) use. In 2004, a hydrologic survey of the 

area was conducted, and a new pond design was 

developed. The Service sees a need for further 

study of the hydrologic conditions and possible 

causes of the poor water retention. 

3.2.2 Calabasas Unit

The Calabasas Unit is located within the upper 

portion of Larkin Valley area, parallel to Larkin 

Valley Road where it intersects Mar Monte Avenue. 

It is bordered to the west by Milky Way and to 

the east by a dirt fire road. Ardilla Canyon Road 

is to the south of the unit. The Calabasas Unit is 

surrounded by residential properties and houses. 

Several horse stables and horse pastures are also 

located nearby.

The dominant habitats found on the Calabasas Unit 

are northern coastal shrub, riparian woodland, 

coastal grassland, San Andreas coastal live oak 

woodland, and ephemeral pond. 

Historically, Calabasas Pond was a reservoir with 

an earthen dam across the southern end, and the 

upland habitat was grazed by livestock. Santa 

Cruz County Public Works intentionally breached 

a section of the dam about 1980, after it was 

determined to be structurally unsound. This breach 

created the existing hydrologic site conditions, with 

two to four feet of rainwater accumulating annually 

in the shallow footprint of the former reservoir. 

When the pond exceeds capacity, the excess water 

overtops the lowest southwest section of bank 

and drains along the hillside. The pond typically 

remains wet from late fall through mid summer. 

Although this pond was not originally created for 

salamanders and frogs, it has become a secure 

breeding site for SCLTS with associated oversummering upland habitats.

In 1994, it was observed by the CDFG that 

rainwater spillover was gradually eroding the 

adjacent hillside, as well as potentially threatening 

the integrity of the earthen pond bank. A 

temporary fix of rip rap boulders was placed in the 

wash-out area to prevent further damage. During 

the El Nino winter of 1997–1998, substantially 

above-average rainfall caused a breach in the 

spillway section of earthen bank. The increase in 

water flow and velocity through the wash-out caused 

further scouring of the area. 

In 2006, the Service permanently repaired the 

breach in the Calabasas Pond bank. This action was 

prescribed in the Revised Recovery Plan for the 

Santa Cruz long-toed salamander (USFWS 1999b). 

As part of the breach repair, the bank was replaced 

with a levee and fortified. A water control structure 

was installed in the new bank to manipulate water 

levels and to prevent erosion and bank failure from 

re-occurring during substantially above-average 

rainfall years. 

3.2.3 Harkins Slough Unit

The dominant habitats found on the Harkins Slough 

Unit are former farmlands with approximately 51 

acres of freshwater wetland, coastal grassland, 

San Andreas coastal live oak woodland, northern 

coastal shrub, and native and non-native herbaceous 

vegetation. The unit is bordered to the west and 

south by Harkins Slough Road, off of Buena Vista 

Drive. It is adjacent to the Buena Vista landfill, 

a plant nursery, a residential neighborhood, and 

a correctional facility along the western border. 

Agricultural fields and a former dairy are adjacent 

to the eastern border. 

The Harkins Slough waterway itself continues 

upstream as a channel north of the unit and remains 

a large, open permanent freshwater wetland 

downstream to the south, beyond the flooded 

Harkins Slough Road. It is a natural drainage valley 

that flows to Watsonville Slough, which in turn flows 

into the Pajaro River before draining into the ocean. 

The Refuge staff has observed large numbers of 

gulls using this unit for roosting, probably due to the 

proximity to a landfill. A variety of waterfowl species 

use the slough, including mallard, northern shoveler, 

cinnamon teal, and pintail. Flocks of white pelicans 

have also been observed feeding and roosting. 

The unit contains several buildings, roads, wells, 

and utility infrastructure that are in disrepair. 

The buildings consist of three houses, a barn, 

warehouses, and storage and equipment sheds. 

There are three agricultural and two drinking water 

wells on the site. 

Several parcels within the vicinity of this unit are 

owned by the California Department of Fish and 

Game or are in easements and protected from 

development. In 2009–2010, the Land Trust of 
Ellicott Slough NWR - Final Comprehensive Conservation Plan 17

Santa Cruz County acquired approximately 486 

acres southeast of the Harkins Slough Unit and 

is developing a management plan that includes 

slough restoration.

3.2.4 Buena Vista

The Buena Vista property is two miles west of 

the Watsonville Airport and 1.5 miles west of 

Watsonville. It is bound on the northeast by 

Highway 1, on the south by Fiesta Way and Rancho 

Road, and on the west by cultivated lands east of 

Willow Spring Road. It is a largely undisturbed 

micro-ecosystem consisting of a mosaic of San 

Andreas coastal live oak woodland, northern coastal 

shrub, San Andreas maritime chaparral, and 

Monterey pine woodland. 

Buena Vista Pond is a small manmade ephemeral 

pond on the southeast portion of the site. Santa 

Cruz long-toed salamander and CTS have been 

found to breed at the site. 

Several plants identified on the property are listed 

by the state as species of concern, including robust 

spineflower, Hooker’s manzanita (Arctostaphylos 

hookeri ssp. hookeri), California bottlebrush 

(Elymus californicus), and Kellogg’s horkelia 

(Horkelia cuneata ssp. sericea). Robust spineflower 

has been found on the Buena Vista property, 

however population estimates are not current.

A house and garage are located on Buena Vista; 

they were built in 1951, according to Santa 

Cruz County Assessor’s records. A well is also 

associated with the property and is used to supply 

the residence with water. 

3.3 Physical Resources

3.3.1 Climate and Air Quality

Santa Cruz County has warm summers and mild 

winters. Mean annual temperature in the county 

ranges from 54 to 58 degrees Fahrenheit. Near 

the coast, the difference between the mean daily 

minimum and maximum temperatures ranges from 

about 20 to 30 degrees (NRCS 2007a). In the coastal 

area where the Refuge is located, the mean daily 

temperature is about 50 to 55 degrees Fahrenheit 

minimum and 70 to 75 degrees Fahrenheit 

maximum. The mean daily temperature in January 

is about 35 to 40 degrees Fahrenheit minimum 

and 57 to 62 degrees Fahrenheit maximum. Mean 

Harkins Slough Unit. Photo: USFWS
Chapter 3

18 Ellicott Slough NWR - Final Comprehensive Conservation Plan

annual precipitation of about 30 inches is typical of 

the Santa Cruz area, and 20–25 inches is typical of 

the Watsonville area (NRCS 2007a). 

Air quality is regulated by the Federal Clean Air Act 

(42 U.S.C. §§ 7401, as amended), which mandates 

the establishment of ambient air quality standards 

and requires areas that violate these standards 

to prepare and implement plans to achieve the 

standards by certain deadlines. Areas that do not 

meet Federal primary air quality standards are 

designated as “nonattainment” areas. Areas that 

comply with Federal air quality standards are 

designated as “attainment” areas. Attainment and 

nonattainment designations are pollutant specific. 

Agencies involved with air pollution management 

include the U.S. Environmental Protection Agency, 

California Air Resources Board, and the Monterey 

Bay Unified Air Pollution Control District. State and 

Federal governments have developed the following 

attainment standards for several criteria pollutants. 

■ Particulate matter less than 10 microns in 

diameter (PM10)

■ Ozone

■ Carbon monoxide (CO)

■ Nitrogen dioxide (NO2)

■ Sulfur dioxide (SO2)

■ Sulfates

■ Lead

The Refuge is located in the North Central Coast 

Air Basin. The pollutant measures for 2006 are as 

follows (CARB 2007).

Table 2. Pollutant measures for North Central 

Coast Air Basin - 2006

State 

Standards

Federal 

Standards

Ozone Nonattainment Unclassified/attainment

PM10 Nonattainment Unknown

CO Attainment Attainment

NO2 Attainment Unclassified/

Attainment

SO2 Attainment Unclassified

Sulfates Attainment n/a

Lead Attainment n/a

Source: CARB 2007

3.3.2 Climate Change and Greenhouse 

Gas Emissions 

Global climate change is a problem caused by 

combined worldwide greenhouse gas (GHG) 

emissions, and mitigating global climate change will 

require worldwide solutions. GHGs play a critical 

role in the Earth’s radiation budget by trapping 

infrared radiation emitted from the Earth’s surface, 

which could have otherwise escaped to space. 

Prominent GHGs contributing to this process 

include water vapor, carbon dioxide (C02), nitrous 

oxide (N20), methane (CR.), ozone, and certain 

hydro- and fluorocarbons. This phenomenon, known 

as the “greenhouse effect” keeps the Earth’s 

atmosphere near the surface warmer than it would 

be otherwise and allows for successful habitation 

by humans and other forms of life. Increases in 

these gases lead to more absorption of radiation 

and warm the lower atmosphere further, thereby 

increasing evaporation rates and temperatures 

near the surface. Emissions of GHGs in excess of 

natural ambient concentrations are thought to be 

responsible for the enhancement of the greenhouse 

effect and to contribute to what is termed “global 

warming,” a trend of unnatural warming of the 

Earth’s natural climate. Climate change is a global 

problem, and GHGs are global pollutants, unlike 

criteria air pollutants (such as ozone precursors) 

and toxic air contaminants, which are pollutants of 

regional and local concern (USFWS, CDFG 2009a).

The Intergovernmental Panel on Climate Change 

(IPCC) has been established by the World 

Meteorological Organization and United Nations 

Environment Programme to assess scientific, 

technical and socio- economic information relevant 

for the understanding of climate change, its 

potential impacts and options for adaptation 

and mitigation. The IPCC predicts substantial 

increases in temperatures globally of between 1.1 

to 6.4 degrees Celsius (depending on scenario) 

(Intergovernmental Panel on Climate Change 2007).

Climate change could impact the natural 

environment in California in the following ways, 

among others:

■ Rising sea levels along the California 

coastline, particularly in San Francisco Bay 

and the Sacramento-San Joaquin Delta due to 

ocean expansion; 
Ellicott Slough NWR - Final Comprehensive Conservation Plan 19

■ Extreme-heat conditions, such as heat waves 

and very high temperatures, which could last 

longer and become more frequent; 

■ An increase in heat-related human deaths, 

infectious diseases and a higher risk of 

respiratory problems caused by deteriorating 

air quality;

■ Reduced snow pack and stream flow in the 

Sierra Nevada mountains, affecting winter 

recreation and water supplies; 

■ Potential increase in the severity of winter 

storms, affecting peak stream flows and flooding;

■ Changes in growing season conditions that could 

affect California agriculture, causing variations 

in crop quality and yield;

■ Changes in distribution of plant and wildlife 

species due to changes in temperature, 

competition from colonizing species, changes 

in hydrologic cycles, changes in sea levels, and 

other climate-related effects.

For further discussion of climate change, refer to 

Appendix C – Environmental Assessment.

These changes in California’s climate and 

ecosystems are occurring at a time when California’s 

population is expected to increase from 34 million 

to 59 million by the year 2040 (California Energy 

Commission 2005).

As such, the number of people potentially affected 

by climate change as well as the amount of 

anthropogenic GHG emissions expected under 

a “business as usual” scenario are expected to 

increase. Similar changes as those noted above for 

California would also occur in other parts of the 

world with regional variations in resources affected 

and vulnerability to adverse effects.

GHG emissions in California are attributable 

to human activities associated with industrial 

manufacturing, utilities, transportation, residential, 

and agricultural sectors (California Energy 

Commission 2006) as well as natural processes.

United States Greenhouse Gas Emissions

In 2006, total U.S. GHG emissions were 7,054.2 

million metric tons (MMT) CO2Eq. Overall, total U.S. 

emissions have risen by 14.7 percent from 1990 to 2006.

The primary GHG emitted by human activities 

in the United States was CO2, representing 

approximately 84.8 percent of total GHG emissions. 

The largest source of CO2, and of overall GHG 

emissions, was fossil fuel combustion. CH4, 

emissions, which have declined from 1990 levels, 

resulted primarily from enteric fermentation 

associated with domestic livestock, decomposition 

of wastes in landfills, and natural gas systems. 

Agricultural soil management and mobile source 

fossil fuel combustion were the major sources 

of N2O emissions. The emissions of substitutes 

for ozone depleting substances and emissions 

of HFC-23 during the production of HCFC-22 

were the primary contributors to aggregate HFC 

emissions. Electrical transmission and distribution 

systems accounted for most SF6 emissions, while 

PFC emissions resulted from semiconductor 

manufacturing and as a by-product of primary 

aluminum production (U.S. Environmental 

Protection Agency 2008).

California Greenhouse Gas Emissions

Worldwide, California is the 12th to 16th largest 

emitter of CO2 (California Energy Commission 

2006), and is responsible for approximately 2 

percent of the world’s CO2 emissions (California 

Energy Commission 2006).

Transportation is responsible for 41percent of the 

state’s GHG emissions, followed by the industrial 

sector (23 percent), electricity generation (20 

percent), agriculture and forestry (8 percent) 

and other sources (8 percent) (California Energy 

Commission 2006). Emissions of carbon dioxide 

and nitrous oxide are byproducts of fossil fuel 

combustion, among other sources. Methane, a 

highly potent GHG, results from off-gassing 

associated with agricultural practices and landfills, 

among other sources. Sinks1 of carbon dioxide 

include uptake by vegetation and dissolution into 

the ocean. California GHG emissions in 2002 totaled 

approximately 491 MMT-CO2 eq.

1 A carbon dioxide sink is a resource that absorbs carbon dioxide 

from the atmosphere. The classic example of a sink is a forest in 

which vegetation absorbs carbon dioxide and produces oxygen 

through photosynthesis.
Chapter 3

20 Ellicott Slough NWR - Final Comprehensive Conservation Plan

3.3.3 Climate Change Regulation

Federal Climate Change Regulations

Twelve U.S. states (including California) and 

cities, in conjunction with several environmental 

organizations, sued to force the EPA to regulate 

GHGs as a pollutant pursuant to the Clean Air 

Act (Massachusetts vs. Environmental Protection 

Agency et al. [U.S. Supreme Court No. 05-1120]. 

Argued November 29, 2006. Decided April 2, 2007). 

The court ruled that the plaintiffs had standing to 

sue, that Clean Air Act does give EPA the authority 

to regulate tailpipe emissions of GHG, and the 

EPA is required to review its contention that it has 

discretion in regulating carbon dioxide and other 

GHG emissions. No regulations have been proposed 

by the EPA to date pursuant to this ruling.

In February 2002, President Bush committed 

the United States to a comprehensive strategy to 

reduce the GHG emission intensity of the American 

economy by 18 percent by 2012. In April 2008, 

President Bush announced a new national goal to 

stop the growth in U.S. GHG emissions by 2025. 

Although there is substantial work underway by the 

current administration of President Obama and new 

policies on GHG emissions are expected, no specific 

new policies on GHG emissions have been adopted 

as of March 2010.

Thus, at present, there are no Federal regulations 

specifically limiting the GHG emissions overall.

Department of the Interior Climate 

Change Requirements

Each bureau and office of the Department must 

consider and analyze potential climate change 

impacts when undertaking long-range planning 

exercises, setting priorities for scientific research 

and investigations, developing multi-year 

management plans, and making major decisions 

regarding potential use of resources under the 

Department’s purview. These requirements were 

set forth in Secretary’s Orders No. 3226 and 3285, 

and remain in effect. The organizational changes 

made by this Order will enable the bureaus and 

agencies to fulfill these planning requirements.

The Service’s Climate Change 

Requirements

Increasing carbon dioxide and other greenhouse gas 

emissions from anthropogenic sources have altered 

the temperature over the last century more than any 

other time in history. Such temperature changes can 

have different consequences worldwide from sealevel rise to greater meteorological fluctuations. The 

Service recognizes that a changing climate will affect 

natural resources and has been charged by Congress 

(H. CON. RES. 2006) to address these effects in 

CCPs. This challenge is especially important at the 

Refuge in light of the sensitivity of amphibians to 

temperature fluctuations and narrow habitat ranges. 

For further discussion of climate change, refer to 

Appendix C – Environmental Assessment.

Local Climate Change Regulations

The Monterey Bay Unified Air Pollution Control 

District (MBUAPCD) presently has no guidance 

concerning the California Environmental Quality 

Act (CEQA) evaluation of GHG emissions and no 

regulatory requirements.

3.3.4 Topography

The topography of the Refuge units ranges from 

hilly to flat. The Refuge is closest to the city of 

Watsonville, which has elevation ranging from 20 

to 900 feet. At the Ellicott Unit, elevation varies 

from 120 to 180 feet between the slough and the 

top of the adjoining hills. There are no permanent 

streams, and natural drainage systems are not well 

developed. The groundwater table is less than 150 

feet below the surface. The Buena Vista property is 

surrounded by hilly, wooded terrain. The property 

slopes in elevation from 250 to 450 feet mean sea 

level. The land form includes three ridge lines and 

four drainage valleys extending in a north-south 

direction (Hanna and Associates 2001).

3.3.5 Geology, Soils, and Hydrology

The geology of the Refuge area is described as 

beach and dune sand (Quaternary). There are 

several soil types on the Refuge (see Figure 4). 

Baywood loamy sand is characteristically deep 
Ellicott Slough NWR - Final Comprehensive Conservation Plan 21

Figure 4. Soil Types on the Ellicott Slough NWR

Ardilla C yn Rd.

Metvier s' Way

Mar Monte Ave.

Cabrillo Hwy.

Larkin Valley Rd.

Buena Vista Dr.

San Andreas Rd.

White Rd.

Rampart Rd.

E. Bel Mar Dr.

Alta Dr.

Fiesta Way

Airport Blvd.

Tulsa Ln.

Spring Valley Rd.

Water Tank Rd.

Harkins Slough Rd.

Willow Creek Dr.

Rountree Ln.

Ridgeway St.

1

1

2

4

1

9

5

4

5

3

9

4

8

6

3

6

3

9

4

9

9

5

3

7

3

7

3

8

8

7

4

3

10

8

10

0 0.25 0.5 1

Miles

0 0.5 1 0.25

Kilometers ±

Calabasas

Unit

Buena Vista

Property

Ellicott

Unit

Harkins Slough

Unit

Ellicott Slough National Wildlife Refuge

Soils

 1 - Baywood Loamy sand

 2 - Clear Lake clay

 3 - Elder sandy loam

 4 - Elkhorn sandy loam

 5 - Elkhorn-Pfeiffer complex

 6 - Fluvaquentic Haploxerolls-

 Aquic Xerofluvents

 7 - Pfeiffer gravelly sandy loam

 8 - Tierra-Watsonville complex

 9 - Watsonville loam

10 - Water 

Soil Name

UV1

Sources: 

-USDA, Natural Resources Conservation Service

-National Agriculture Imagery Program, 2009
Chapter 3

22 Ellicott Slough NWR - Final Comprehensive Conservation Plan

and drains somewhat excessively (NRCS 2007b). 

Sand dunes are made up of this soil type. Elder 

sandy loam is considered a well-drained soil and 

typically has a surface layer of dark grayish brown 

and grayish brown, medium acid and slightly acidic 

sandy loam about 23 inches thick. Elkhorn soils are 

well drained and are located on marine terraces and 

old alluvial fans. Typically, the surface layer is very 

dark grayish brown, slightly acid and medium acid 

sandy loam about 21 inches thick. The subsoil to a 

depth of 61 inches is pale brown and variegated light 

gray and very pale brown neutral sandy clay loam. 

Fluvaquentic Haploxerolls-Aquic Xerofluvents 

complex soils are considered moderately well 

drained, while the Tierra-Watsonville complex is 

considered moderately to poorly well-drained. 

Pfeiffer gravelly sandy loam is a deep, well-drained 

soil located on hills. It formed in material weathered 

from granitic rock, sandstone, or marine sediment. 

Watsonville loam consists of very deep, somewhat 

poorly drained soils on old coastal terraces. These 

soils formed in alluvium.

The geology of Buena Vista is relatively uniform and 

is mapped as Pleistocene non-marine Quaternary 

Aromas Formation. The soil at the Buena Vista 

property is described as sandy loam; the ridge soil 

tends to be shallow and finer textured. Soils in the 

lower lying positions tend to have argillic horizons 

(clay-enriched subsoils). Soils in the valleys vary 

from sandy to hydric. Buena Vista is a high-value 

groundwater recharge zone.

The Refuge is located within the Pajaro River 

Watershed. The Pajaro River Watershed is sourced 

by the Pajaro River and local runoff. Within the 

watershed, the Watsonville Slough System carries 

surface water through the different Refuge units. 

It is a remnant of a more extensive wetland and 

estuarine complex. The system has been modified 

to meet adjacent land use needs such as agriculture 

and urban development. The Watsonville Slough 

System currently is made up of six major branch 

sloughs as depicted in Figure 5. This 800-acre 

system is made up of coastal salt marsh, seasonal 

wetlands, brackish and freshwater emergent marsh, 

and riparian communities. The Watsonville Slough 

System also receives runoff from the 13,000-acre 

Pajaro River Watershed, which includes a mix of 

urban, industrial, rural residential, agricultural, 

and open space land uses (California Coastal 

Commission 2006). The Watsonville Slough 

System continues down a broad alluvial flood plain 

with irrigated agriculture as the primary land 

use and finally drains near a small residential 

dunes complex to the Pajaro Lagoon, joining the 

Monterey Bay and Pacific Ocean (Hager et al. 

2004). However, flows have been observed in the 

reverse direction, from the mouth to the watershed. 

Factors of this phenomenon include high ocean 

waves, backwater flow from the neighboring Pajaro 

River, active pumping of the watershed, and land 

subsidence (Hager et al. 2004). The Refuge is 

sensitive to extreme flood events in the sloughs, 

with the Harkins Slough and Calabasas Units 

located within the Federal Emergency Management 

Agency floodplain. 

3.3.6 Water Supply and Water Quality

Santa Cruz County is one of the few California 

counties that are not dependent on water sources 

from outside its boundaries. However, increased 

water demand has exceeded currently developed 

surface sources and depleted groundwater supplies. 

Santa Cruz County primarily depends on surface 

flow and wells for its water supply, with some surface 

water inflow from San Benito County and some 

groundwater inflow from Monterey County (SCRCD 

2008). The Refuge ephemeral ponds are heavily 

dependent on the rainfall captured in this slough 

system and watershed, as well as upland runoff.

Harkins Slough, part of the Watsonville Slough 

System (see Figure 5), is the largest and most 

northerly slough in the system. Its drainage 

initiates in Larkin Valley, flowing eastward under 

Highway One, between Airport Boulevard and 

Buena Vista Road. Near the county landfill, 

Harkins Slough broadens, flooding Harkins Slough 

Road year round. Below this point, the inaccessible 

Gallighan Slough merges with Harkins Slough. 

Continuing south, it merges into Watsonville Slough 

at the Pajaro Valley Water Management Pump 

Station off San Andreas Road, and then flows into 

the Pajaro River and finally into the Monterey Bay 

(Chirco-Mcdonald 2007).

Water quality on the Refuge is heavily influenced 

by agricultural practices in the surrounding 

region. Santa Cruz County is the second smallest 

county in California and the smallest agricultural 

county in California. Santa Cruz County ranked 
Ellicott Slough NWR - Final Comprehensive Conservation Plan 23

Figure 5. Watsonville Slough System. Source: Watsonville Wetlands Watch

(http://watsonvillewetlandswatch.org/images/sloughmapLarge.jpg)
Chapter 3

24 Ellicott Slough NWR - Final Comprehensive Conservation Plan

20th out of 58 counties in value of agricultural 

production in 2005, with farm gate sales totaling 

$418 million (UCCE 2005). Watsonville Slough 

and the Pajaro River (downstream of Watsonville 

Slough) are both listed in the 2006 Federal Clean 

Water Act Section 303(d) as waterbodies that 

do not meet water quality objectives and do not 

support beneficial uses. The listing established a 

priority for developing a control plan to address 

the impairment of these waterbodies. Primary 

pollutants to the Watsonville Slough are pathogens 

from urban runoff and/or storm sewers, unknown 

sources, and nonpoint sources. Pesticides are 

also another stressor on the slough as a result of 

agriculture, irrigated crop production, agriculture 

storm runoff, agriculture irrigation tail water, 

and nonpoint sources (CCRWQCB 2006). Fecal 

coliform is another concern. Sampling by the Santa 

Cruz County Environmental Health Department 

(1977–2000) determined that 10 of 11 sites surveyed 

in the county exceeded the Central Coast Regional 

Water Quality Control Board’s Basin Plan standards 

(Hager et al. 2004). A 2004 sampling of Watsonville 

Slough sites revealed that fecal coliform levels in the 

area compared closely with regional levels (Hager et 

al. 2004). 

Other water quality information for the area is 

limited. No U.S. Geological Survey (USGS) survey 

sites were found in Santa Cruz County. The Coastal 

Watershed Council conducted a Clean Streams 

Citizen Monitoring Program of the Watsonville 

Slough System (in 2004) and the Harkins Slough 

Watershed (in 2007) using volunteer participation 

to gather surface water quality field data. The 

surveys found that the Watsonville Slough System 

has consistently high nitrate and bacteria, as well 

as low dissolved oxygen levels that often exceeded 

the water quality objectives based on the Basin 

Plan developed by the Central Coast Regional 

Water Quality Control Board (CCRWQCB) (Coastal 

Watershed Council 2004). The 2004 survey also 

found that E. coli and total coliform levels exceeded 

state water quality objectives at most of the survey 

stations. Nitrate and ammonia levels also exceeded 

acceptable CCRWQCB levels.

Although Harkins Slough is part of the Watsonville 

Slough System described above, the Harkins 

Slough surveys found low nutrient results, with 

orthophosphates and nitrate having the lowest 

number of exceedences based on unofficial Central 

Coast Ambient Monitoring Program (CCAMP) 

water quality objectives (Coastal Watershed Council 

2007). Dissolved oxygen and pH levels were within 

acceptable ranges of the unofficial CCAMP water 

quality objective. However, the survey results found 

high levels of ammonia, E. coli, and total coliform 

in a majority of the samples. These high levels 

were thought to be attributed to large number of 

birds [gulls] frequenting the survey area and/or 

surrounding livestock fields. Total coliform count 

provides an indicator of pathogen conditions in the 

water. Testing for indicator bacteria monitors the 

potential presence of disease-causing organisms. 

Indicator bacteria are types of bacteria not normally 

found in high numbers in oceans, rivers, or creeks 

but always found in sources of fecal contamination. 

Though they are not typically disease-causing 

organisms themselves, they can be indicative of the 

presence of such organisms. Studies have shown 

that when concentrations of indicator bacteria 

exceed certain levels in waters used for water body 

contact recreation, individuals exposed to these 

waters may have a greater chance of getting sick 

(www.ccamp.org ) (Coastal Watershed Council 2007).

Based upon results from the 2009 program and 

previous years, continued monitoring is a key factor 

in working towards watershed restoration. In 

addition, increased pressure from urban development 

and the region’s intense commercial agriculture 

place significant strain upon the Watsonville Slough 

System, creating further need for study to move 

toward restoration of the watershed.

3.3.7 Hazardous Materials and Contaminants

A contaminant assessment process was conducted 

in May 1999 on the Ellicott Unit (USFWS 1999a). 

The report raised a number of concerns, including 

pesticide exposure from adjacent agricultural lands, 

application of methoprene to vernal breeding ponds, 

and the potential for an accidental spill of hazardous 

material or petroleum compounds from a train 

derailment. Since 2000, the Refuge has not permitted 

the use of methoprene by the Santa Cruz County 

Mosquito and Vector Control District in ponds used 

by SCLTS and CTS for breeding. As of 2010, the 

Refuge has stopped the use of methoprene by the 

Santa Cruz County Mosquito and Vector Control 

District, in ditches that fill seasonally with water, until 
Ellicott Slough NWR - Final Comprehensive Conservation Plan 25

a mosquito management plan and environmental 

compliance are completed.

When the Calabasas Unit was acquired, the 

acquisition assessment noted no known uses or 

sources of hazardous materials on the property. In 

several areas, corroded, non-functional water pipes 

were identified. A Level I Environmental Site 

Assessment was conducted in 1998. Nearby aboveground storage tanks, electrical transmission lines, 

and non-functional water pipes were initially noted 

as potential hazardous materials (USFWS 1998). 

Upon further investigation, the storage tanks and 

water pipes were deemed innocuous.

Whether there are contaminants or hazardous 

materials present on the Buena Vista property is 

unknown; the property has not been surveyed.

During the acquisition assessment of the Harkins 

Slough Unit, Level I and II Pre-Acquisition Surveys 

identified several environmental concerns, including 

neighboring and on-site factors. Neighboring 

factors included impacts to groundwater and soil 

from the adjacent Buena Vista Landfill and nearby 

Western Farm Services, a former commercial 

fertilizer operation. There were a variety of 

discarded heavy equipment and several chemical 

storage containers, some of which were leaking. 

Concerns were noted that that the old containers 

and farming equipment contained contaminants that 

could runoff into the slough. The heavy equipment 

and containers were removed before acquisition.

Soil, surface water, groundwater, and drinking water 

well sampling was also conducted during the preacquisition surveys in 2004 (USFWS 2005b). Soil 

sampling analyzed for volatile organic compounds 

(VOCs), chlorinated pesticides and herbicides, some 

metals, and some nitrate sampling. Of 18 samples, 

only one sample exceeded project screening levels 

(USEPA Region IX Preliminary Remediation GoalsPRG). This sample detected methylene chloride, 

chlordane, chromium, and lead. Low concentrations 

of pesticides and methylene chloride were present 

on the unit. Low VOC levels were apparent but 

considered typical at this location. Arsenic was also 

found in a subsequent 2004 survey.

Ellicott Unit Calabasas 

Unit

Harkins 

Slough Unit

Buena Vista 

Property

Habitat Type Acres* Acres* Acres* Acres*

Acacia stands 0 0 0.2 6.2

Coastal grassland 24.5 5.6 13.8 3.4

Bare/developed/roads 2.7 0.4 0.5 1.2

Northern coastal shrub 41.4 12.6 6.2 51.9

Eucalyptus stands 5.3 0.0 0.0 13.2

San Andreas maritime chaparral 0.0 0.0 0.0 33.1

Closed-cone coniferous forest 19.8 0.0 0.0 21.1

San Andreas coastal live oak woodland 38.2 3.8 8.9 158.8

Ephemeral pond 3.7 1.9 0.0 0.4

Riparian woodland 24.7 6.8 5.2 0.1

Native and non-native herbs 7.0 0.0 6.5 0.0

Water 0.0 0.0 50.8 0.0

Freshwater marsh 0.0 0.0 16.7 0.0

Total Acres 167.3 31.1 108.8 289.4

*Habitat acreages are based on GIS analyses and satellite imagery with limited field sampling, and therefore are 

general estimates.

Table 3. Ellicott Slough NWR - Acreages of habitat types by unit
Chapter 3

26 Ellicott Slough NWR - Final Comprehensive Conservation Plan

Figure 6. Vegetation – Ellicott Unit

San Andreas Rd.

Ellicott Slough Rd.

Buena Vista Dr.

Spring Valley Rd.

±

Ellicott Slough National Wildlife Refuge

Vegetation - Ellicott Unit

0 250 500 1,000 1,500

 feet

0 100 200 400

 meters

Closed-cone coniferous forest

San Andreas coastal live oak woodland

Riparian woodland

Northern coastal shrub

Coastal grassland

Ephemeral pond

Eucalyptus stands

Semi-natural herbaceous stands

Bare/roads/developed
Ellicott Slough NWR - Final Comprehensive Conservation Plan 27

Figure 7. Vegetation – Calabasas Unit

Ardilla Canyon Rd. 

Milky Way

Larkin Valley Rd.

White Rd.

±

Ellicott Slough National Wildlife Refuge

Vegetation - Calabasas Unit

San Andreas coastal live oak woodland

0 200 400 600 100

 feet

0 50 100 200

 meters

Riparian woodland

Northern coastal shrub

Coastal grassland

Ephemeral pond

Bare/roads/developed
Chapter 3

28 Ellicott Slough NWR - Final Comprehensive Conservation Plan

Figure 8. Vegetation – Harkins Slough Unit Harkins Slough Rd.

Rountree Ln.

±

Ellicott Slough National Wildlife Refuge

Vegetation - Harkins Slough Unit

San Andreas coastal live 

oak woodland

Semi-natural herbaceous 

stands

Bare/roads/developed

Riparian woodland

Northern coastal shrub

Coastal grassland

Freshwater marsh

Water

Acacia stands

0 250 500 1,000 1,500

 feet

0 100 200 400

 meters
Ellicott Slough NWR - Final Comprehensive Conservation Plan 29

Figure 9. Vegetation – Buena Vista Property

Willow Crk. Dr.

Cabrillo Hwy

UV1

Cabrillo Hwy.

0 500 1,000 1,500 250

 feet

±

Ellicott Slough National Wildlife Refuge

Vegetation - Buena Vista Property

Buena Vista

Property

Ellicott

Unit

0 100 200 400

 meters

Ephemeral pond

Eucalyptus stands

Acacia stands

Bare/developed/roads

Closed-cone coniferous forest

San Andreas coastal live oak woodland

Riparian woodland

San Andreas maritime chaparral

Northern coastal shrub

Coastal grassland

Freshwater Marsh
Chapter 3

30 Ellicott Slough NWR - Final Comprehensive Conservation Plan

Surface water sampling revealed lead concentrations 

that exceeded the maximum contaminant level 

(treatment action level of 15μg/l and the National 

Recommended Water Quality Criteria for Priority 

Toxic Pollutants criterion). Groundwater sampling 

showed that barium, chromium, lead, selenium, and 

nitrate concentrations exceeded project screening 

levels by a significant margin (USFWS 2005b). 

Drinking water well sampling tested positive for 

coliform bacteria and fecal coliform, indicating 

contamination from human or animal waste. 

Samples taken from buildings for lead and asbestos 

confirmed that lead was found in painted surfaces 

and asbestos in the building materials.

Prior to the transfer of the Harkins Slough Unit 

to the Refuge, the Farm Service Agency (FSA) 

required the former tenants to conduct a clean-up 

of the property. All chemical storage containers and 

the majority of the discarded farming equipment 

were removed from the site.

In 2006, follow-up water quality monitoring 

was conducted for lead in the Harkins Slough 

waterway. Results from the three surface water 

sample collected showed lead concentrations below 

detectable limits. 

In 2006, special funding by the Amphibian Initiative 

of the U.S. Fish and Wildlife Service, Environmental 

Contaminants Program was made available to 

study amphibian abnormalities at the Ellicott and 

Calabasas Ponds. The study coordinators were 

especially interested in Ellicott Pond results, as 

Ellicott Pond was one of the first sites to document 

large numbers of abnormalities caused by trematode 

parasites in the mid 1980s. The survey found that 

the abnormal frog rates at Ellicott and Calabasas 

Units were consistent with the expected background 

abnormal rate of 2–3 percent in anuran populations 

(Stocum 2000). The Refuge received funding again 

in 2008 and 2009 for Calabasas Pond and found that 

sampled rates were above the expected rate both 

years (Tertes pers. comm.). 

3.4 Biological Resources

3.4.1 Vegetation

Ellicott Slough NWR supports a variety of habitat 

types. The habitat types are described in the 

following sections. The habitat types on each of the 

Refuge units and the Buena Vista property are shown 

in the vegetation maps in Figures 6, 7, 8, and 9. A 

summary table of acreages of the various habitat 

types by unit is presented in Table 3. These acreages 

are based on Geographic Information System (GIS) 

analyses and satellite imagery with limited field 

sampling, and therefore are general estimates.

The Refuge has a wide variety of plant communities 

throughout its units. It has forests, woodlands, 

shrublands, grasslands, and freshwater wetlands, to 

name a few. Each habitat is important to maintain 

a complex relationship of plants, animals, and other 

organisms. The combination of habitats provides 

breeding and non-breeding areas for threatened and 

endangered amphibians, resident and migratory 

birds, mammals of varying sizes, and many other 

species. It also provides conditions suitable for 

endangered, rare, native, and invasive trees, shrubs, 

grasses, and forbs. 

California's north coastal forests are divided into 

separate communities that integrate with one

another. The largest and most important of these 

communities are the coastal redwood, Douglas fir, 

and mixed-evergreen forests. From the coast inland, 

species composition is dictated by moisture gradients. 

These gradients are determined by rainfall and the 

ability of soils to retain water. In moderately moist 

areas, farther inland, Douglas fir (Pseudotsuga 

menziesii) becomes dominant. Mixed-evergreen 

forests occur in warmer areas and are highly variable 

in their species composition (CERES 1997). 

Ecologists recognize at least 13 major tree 

communities within California, and 5 of these 

are associated with the coastal regions. There 

are approximately 129 species of native trees in 

California, 63 of which are endemic. It is estimated 

that another 1,000 have been introduced from 

all over the world, but most of these are limited 

to private gardens. Nevertheless, about 30 to 

50 introduced species have become naturalized, 

including the ubiquitous blue gum, Eucalyptus 

globulus (CERES 1997).

Closed-cone Coniferous Forests

Closed-cone coniferous forests are a unique 

California community occurring in patches along 

the coast from Humboldt to Santa Barbara County. 

The name of this community derives from the 
Ellicott Slough NWR - Final Comprehensive Conservation Plan 31

fact that the seed-bearing cones 

remain closed for several years, 

a reproductive adaptation that 

ensures survival. Only age, 

excessive hot weather, or fire 

opens the cones (CERES 1997). 

Douglas fir, Monterey pine 

(Pinus radiata), and knobcone 

pine (Pinus attenuata) grow 

throughout the Refuge. 

San Andreas Coastal Live 

Oak Woodland 

Coastal live oak woodland is 

characterized by hilly slopes 

with thin soils and moderate to 

large amounts of rainfall. The 

oak woodland present in Santa 

Cruz County is locally referred 

to as San Andreas Coastal Live 

Oak Woodland. It is considered 

a sensitive habitat by Santa Cruz 

County because of its high species 

diversity and relative scarcity (USFWS 2005a). Coast 

live oak (Quercus agrifolia) dominates this habitat; 

associated species include coffeeberry, madrone, 

California blackberry (Rubus ursinus), creeping 

snowberry, coyote bush (Baccharis pilularis), and 

poison oak (Toxicodendron diversilobum).

Riparian Woodlands

Riparian woodlands occur in ribbon-like bands along 

ephemeral creeks, ephemeral freshwater ponds, and 

canyon bottoms (USFWS 2005a) where there are 

rich soils and high humidity. Although this unique 

community accounts for less than one per cent of 

California's total forest acreage, it supports one of 

the most diverse ecological communities of plants 

and animals. Tall deciduous trees tower above a 

lush understory of ferns and delicate wildflowers. 

Unfortunately, many riparian woodlands have been 

destroyed during the last century because the fertile 

soils along rivers are among the most sought after 

for agricultural lands and because numerous rivers 

have been channelized for flood control projects 

(CERES 1997). 

Below the canopy of trees, rich riparian soils 

support many species of ferns and willows such as 

the goldenback fern (Pentagramma triangularis), 

Arroyo willow (Salix lasiolepsis), and Sitka willow 

(Salix sitchensis). California blackberry and 

poison oak are frequently encountered shrubs in 

riparian communities. 

Eucalyptus Stands

The invasive blue gum (Eucalyptus spp.) can be 

found in dense patches throughout the Refuge. 

Because of the large amount of leaves, bark, and 

other duff (and the tannins in them) that accumulate 

below each eucalyptus tree, there is little to no 

understory vegetation.

Acacia Stands

For the same reasons it is favored as an erosioncontrol plant, with its easy spreading and resilience, 

wattle (Acacia spp.) is an invasive species. Introduced 

worldwide, it has become an invasive plant that 

is taking over grasslands and the abandoned 

agricultural areas, especially in moderate coastal 

regions where mild climate propagates its spreading. 

California's Coastal Plant Communities

Thirty percent of the state's native plant species 

are endemic to California. Common endemic 

plants include many species of manzanita and 

monkeyflower. Ecologists recognize as many as 80 

Coffeeberry. Photo: USFWS
Chapter 3

32 Ellicott Slough NWR - Final Comprehensive Conservation Plan

different plant communities, constituting what is 

known as the California Floristic Province. Eleven 

of these communities, of which six are non-tree 

communities, are represented along the California 

coast (CERES 1997). 

Coastal Grasses

Until late in the last century, the coastal prairie 

was almost entirely composed of native perennial 

grasses. These relatively slow-growing grasses have 

deep root systems and creeping stems that help to 

ensure their long-term survival; some individual 

plants are known to be more than 100 years old. 

Early European settlers found the naturally 

treeless coastal grasslands ideal for agriculture and 

ranching. As grazing operations expanded, fastgrowing, invasive annual grasses were gradually 

introduced, and these began to out-compete the 

slow-growing, native perennials. Some introductions 

were accidental and others were intentional. Annual 

grasses live only a single growing season, but good 

seed dispersal ensures their return year after year. 

As a result, few intact native grassland communities 

remain today (CERES 1997). 

Representative native coastal grasses include 

species of bentgrass (Agrostis spp.), hairgrass 

(Deschampsia spp.), and oatgrass (Danathonia 

spp.), which can all be found at Buena Vista. 

However, the majority of grasses found at the 

Refuge are invasive. Commonly encountered 

invasive grasses include wild oat (Avena spp.), 

fescue (Vulpia spp.), and brome (Bromus spp). 

Ecologists believe that the presence of annual 

grasses has actually increased the number of 

wildflower species able to survive in this community 

(CERES 1997). Miniature lupine (Lupinus bicolor), 

California buttercup (Ranunculus californicus), 

and the brilliant orange California poppy 

(Eschscholzia californica) are common inhabitants 

of the grassland community. 

Coastal Scrub

Coastal scrub communities are characterized 

by low shrubs and an absence of trees. Types of 

shrubs include either pure stands or mixtures of 

low, thick-leaved evergreens and coarse, deciduous 

species that drop their leaves in response to periodic 

drought conditions. Three representative scrub 

assemblages (not strictly limited to the coast) are 

the northern coastal scrub, southern coastal sage 

scrub (or soft-chaparral), and arid hard-chaparral 

(CERES 1997). 

Northern Coastal Scrub

The Refuge has northern coastal scrub throughout 

its units. Low, shrubby overstory and lush 

herbaceous undergrowth often characterize the 

northern coastal scrub community, which may 

graduate into adjacent coastal prairie. Many 

northern scrub species retain their leaves 

throughout the year. Native coyote brush is the 

most abundant plant in this community and is 

easily identified by its white fall flowers. California 

blackberry and poison oak are other common 

shrubs. The predominantly gray-green northern 

scrub landscape is accented by colorful sticky 

monkeyflower (Mimulus aurantiacus), deerweed 

(Lotus scoparius), and California lilac (Ceanothus

spp.) (CERES 1997). 

San Andreas Maritime Chaparral

The San Andreas maritime chaparral is considered a 

distinctive type of chaparral by Santa Cruz County 

because of its unique species composition (USFWS 

2005a). The chaparral community is dominated 

by two species of manzanita: Hooker’s manzanita, 

which is a rare species endemic to the Monterey 

Bay region of Santa Cruz and Monterey Counties, 

and wooly manzanita (Buena Vista Country Club, 

Inc. 1995). This vegetation type is considered highly 

restricted in distribution in California, with only 207 

acres of San Andreas maritime chaparral remaining. 

Buena Vista includes approximately 33 acres of 

maritime chaparral. 

Freshwater Marshes

Freshwater marsh plants have adapted to their 

aquatic environment in several ways. Most species 

have developed air tubes to their roots, buoyant 

leaves, or porous leaf coverings that enhance gas 

exchange. In contrast to salt marshes, freshwater 

marshes have little, if any, water movement 

(CERES 1997). Freshwater marshes can be found 

throughout the Refuge.

Typical freshwater marsh plants include numerous 

species of sedges; these grass-like plants often 
Ellicott Slough NWR - Final Comprehensive Conservation Plan 33

exceed five feet in height. Sedge (Carex spp.) is 

one of the most common. Familiar cigar-shaped 

cattails (Typha latifolia) form thick stands and 

are so prolific that a single plant can rapidly fill a 

small pond. Bushy, needle-leaved rushes (Juncus 

phaeocephalus) and succulent water parsley 

(Oenanthe sarmentosa) are also typical freshwater 

marsh inhabitants (CERES 1997). 

Freshwater marsh can be found surrounding a 

50-acre permanent pond at the Harkins Slough 

Unit. The pond itself has only a few emergent plant 

species, such as willows and invasive water hyacinth 

(Eichhornia spp.). 

Ephemeral Ponds

Seasonal freshwater ponds occur on Ellicott and 

Calabasas Units and on the Buena Vista property. 

The ponds tend to dry out during late summer. 

The amount and duration of water retention is a 

function of the amount and duration of rainfall 

during the year (Buena Vista County Club, Inc. 

1995). Common plant species include native cattails, 

spikerush (Eleochris spp.), and invasive curly dock 

(Rumex crispus). 

Semi-natural Herbaceous Stands

In addition to invasive tree stands such as 

eucalyptus and acacia mentioned previously, 

there are also many invasive herbaceous plants 

clumped in stands or occurring throughout most 

plant communities at the Refuge. Common 

species include poison hemlock, rosemary, 

mustard, Himalayan blackberry, and pampasgrass 

(Cortaderia selloana) and jubatagrass (C. jubata). 

Threatened and Endangered 

Plant Species

Robust Spineflower

Robust spineflower was Federally-listed as 

endangered on February 4, 1994. It is currently 

known from 10 sites that support a total of 12 

populations (USFWS 2004a). It is restricted to 

sandy soils along the coast and near-coastal areas in 

Santa Cruz and Marin Counties. It is a short-lived 

annual plant that germinates during the winter 

months and generally flowers from April through 

June. On the Refuge, it has been found on the 

Ellicott Unit (with an estimated 5 acres of standing 

plants) and at Buena Vista (10 acres). The species is 

not currently actively managed by Refuge staff.

The robust spineflower relies on sandy soils 

and coastal dune, coastal scrub, and grassland 

communities. Spineflower can grow in sunny 

openings within maritime chaparral and oak 

woodland communities; however, these two 

habitats themselves cannot support robust 

spineflower because of shade and leaf litter. 

Plants have been observed in disturbed areas 

along trails and where gopher disturbance is high 

(Baron, pers. comm.).

Populations of robust spineflower on Buena 

Vista have been followed for more than a decade. 

Available data are listed in Table 4 (CNDDB 

1997, Baron, pers. comm.). On Buena Vista, 

approximately 135 acres of this critical habitat were 

designated for robust spineflower. The Ellicott Unit 

population trends are unknown.

Robust Spineflower. Photo: Sandra Baron
Chapter 3

34 Ellicott Slough NWR - Final Comprehensive Conservation Plan

Table 4. Population counts for robust spineflower 

on Buena Vista

Year Individuals Counted

1993 1,000

1997 1,000

2000 305

2003 3,700

3.4.2 Wildlife

Though the Watsonville Sloughs are a hydrologically 

compromised system (see Geology, Soils, and 

Hydrology in previous text), they are still 

biologically rich and highly valued. It is one of the 

largest remaining freshwater marshlands in the 

California coastal zone, providing critical habitat for 

numerous bird and plant species, including a variety 

of rare and endangered species. Located along the 

Pacific Flyway, it is an important rest stop, breeding 

ground and year-round habitat for over 200 species 

of waterfowl, songbirds, and raptors.

The many habitats of the Refuge provide homes for 

a variety of wildlife. Many species are present on 

the Refuge, including several amphibian, reptile, 

waterfowl, waterbird, raptor, songbird, mammal, 

invertebrate, and aquatic invertebrate species. The 

primary species that are actively surveyed are the 

Federally-listed amphibians. However, several 

surveys have been conducted to start a baseline 

account of birds and mammals. Incidental sightings 

have also proved fruitful in adding wildlife to the 

Refuge species list, such as medium and large 

mammals and reptiles. Though the Refuge is known 

for its amphibians, migratory birds use the Refuge 

for a stopover on the Pacific Flyway, as well as for 

roosting and nesting. Appendix F contains a list of 

wildlife species that occur or potentially occur at the 

Ellicott Slough NWR. An overview of wildlife use of 

the Refuge follows. 

Federally-listed Wildlife Species at the Refuge

Three Federally-listed wildlife species occur on the 

Refuge: Santa Cruz long-toed salamander (SCLTS) 

(Ambystoma macrodactylum croceum), listed as 

endangered; the California tiger salamander (CTS) 

(Ambystoma californiense), listed as threatened; 

and the California red-legged frog (CRLF) (Rana 

aurora draytonii), listed as threatened. Habitat 

for these species range-wide is continually reduced 

due to development, resulting in fragmented areas, 

especially between salamander over-summering 

(upland) habitat and breeding grounds (pond). 

Furthermore, it is difficult to track productivity of 

these species because they spend most of their time 

over-summering underground and only migrate 

during rainy nights. In addition to conducting 

night time surveys in the winter, surveys are also 

conducted in late spring to determine if reproduction 

has occurred. These larval surveys are conducted for 

presence or absence, health, and fitness.

Table 5. Santa Cruz long-toed salamander subpopulation complexes

Santa Cruz metapopulation

Valencia-Seascape Valencia Lagoon and Seascape Ponds and surrounding upland habitat

Larkins Valley Calabasas, Suess, and Olive’s Ponds and surrounding upland habitat

Ellicott-Buena Vista Ellicott, Buena Vista, Ranch Road, Green’s and Anderson’s Ponds and surrounding upland habitat

Freedom Palmer, Racehorse, Tucker, Merk, and Millsap Ponds and surrounding upland 

habitat

Monterey metapopulation

McClusky Zmudowski Pond, Bennett Slough/Struve Pond, McCluskey Slough and surrounding habitat

Elkhorn Oxbow Pond, Lower Cattail Swale, Northern Moro Cojo and Southern Moro 

Cojo Sloughs and surrounding upland habitat

Source: Santa Cruz Long-toed Salamander 5-Year Review (USFWS 2009)
Ellicott Slough NWR - Final Comprehensive Conservation Plan 35

Santa Cruz Long-toed Salamander

SCLTS was among the first animals listed as 

endangered by the Service in 1967 due to several 

factors, most prominently habitat loss and 

fragmentation. At the time, only two breeding 

localities of the species, Valencia Lagoon and 

Ellicott Slough, were known. The presence of the 

SCLTS has been documented at only 24 locations 

in southern Santa Cruz County and northern 

Monterey County. Breeding has been documented 

at 19 of the 24 known locations since the last revised 

recovery plan for the subspecies (USFWS 1999b) 

was published. The subspecies likely has been 

extirpated from two locations: Bennett Slough/

Struve Pond in Monterey County and Rancho 

Road Pond in Santa Cruz County. It is not known 

whether two other previously known breeding 

locations (Green’s Pond and Anderson’s Pond) 

in Santa Cruz County still exist. Additionally, 

breeding has not been documented at Lower 

Moro Cojo Slough (in Monterey County) since 

1990 (USFWS 2009). This species was added 

to California’s endangered species list in 1971, 

with additional protections under the Santa Cruz 

Local Coastal Plan and the Santa Cruz County 

Salamander Protection District zoning regulations. 

SCLTS are found in six metapopulations, four 

of which are located in Santa Cruz County and 

two of which are located in Monterey County. 

Each metapopulation contains one or more 

subpopulations. Metapopulations found in Santa 

Cruz County include Valencia-Seascape, Freedom, 

Larkin Valley, and Ellicott-Buena Vista while 

metapopulations found in Monterey County include 

McCluskey and Elkhorn (see Table 5). The Ellicott 

Unit, Harkins Slough Unit, and Buena Vista 

property are located within the Ellicott-Buena 

Vista metapopulation and the Calabasas Unit of 

the Refuge is located within the Larkin Valley 

metapopulation (USFWS 2009). There is no single 

comprehensive population estimate available, and 

only sporadic surveys have been conducted on some 

parts of some subpopulations. For the purposes of 

this CCP, data and management of only the Larkins 

Valley and Ellicott-Buena Vista complexes will be 

discussed. The Refuge provides both breeding 

(ponds) and over-summering (upland) habitat for 

SCLTS. 

The Larkins Valley complex lies in the upper 

Harkins Slough watershed. The Refuge’s Calabasas 

Pond is located in the Larkins Valley complex and 

is considered a breeding site. The current size and 

status of this salamander subpopulation is unknown, 

but surveys have documented reproduction in 1989, 

1993, 1995, and 2004–2010 (USFWS 1999b, Tertes 

pers. comm. 2010).

SCLTS rely on freshwater ponds for egg 

development, where larvae feed and grow in the 

pond for three to seven months before becoming 

terrestrial. Insufficient precipitation, unusually 

cold weather, parasites, or other unknown factors 

may severely limit recruitment. Adults may go 

several years without successfully breeding. SCLTS 

Santa Cruz long-toed salamander larvae. Photo: USFWS

Adult Santa Cruz long-toed salamander. Photo: Leah Oscar
Chapter 3

36 Ellicott Slough NWR - Final Comprehensive Conservation Plan

apparently are long-lived creatures, possibly living 

for a decade or more (USFWS 2009).

The primary terrestrial habitats for SCLTS are oak 

woodland, woody riparian, and moist coastal scrub 

vegetation types. SCLTS spend the majority of 

their life in these terrestrial habitats, underground 

in small mammal burrows and among the root 

systems of plants in upland chaparral and woodland 

areas of coast live oak or Monterey pine, as well as 

in riparian strips of arroyo willows. These areas 

are desirable because they are protected from heat 

and the drying rays of the sun. From November 

to February, their annual nocturnal migration to 

the breeding ponds occurs. The breeding ponds 

are usually shallow and ephemeral freshwater 

ponds; however, most ponds currently known to be 

used for breeding are artificial. The extent of the 

upland habitat potentially used by SCLTS varies 

from a ring of riparian vegetation on the perimeter 

of the pond to as far as one mile or more out from 

the pond. However, examination of all currently 

available studies on SCLTS reveals that no adults 

have been observed to move more than 0.6 mile 

(straight line distance) from a breeding site where 

they were originally marked. The distance between 

known breeding and over-summering locations 

varies greatly from site to site and apparently 

depends largely upon soil type, vegetation presence 

or absence, vegetation structure or composition, 

and slope, aspect, and size of the breeding pond 

(USFWS 2009).

The Ellicott Slough-Buena Vista complex contains 

five ponds that have been used as breeding 

habitat by SCLTS. Breeding activity has been 

documented at the other sites in the vicinity since 

1993. The Ellicott Pond population was surveyed 

from 1956–1960, and it was estimated that there 

were 8,000–10,000 individuals (USFWS 1999b). A 

population estimate was also conducted during 

1972–1973, yielding an estimated 6,000–8,000 

individuals (Marlow 1973). A survey from 1979–1980 

indicated that Ellicott Pond was used for breeding. 

Approximately 345 adults were found migrating 

to the pond for the breeding season (Reed 1979). 

Juveniles were also seen moving away from the 

pond, indicating successful recruitment. Since then, 

regular monitoring has documented the presence of 

salamanders in most years between 1992 and 2010 

(USFWS 1999b, Tertes pers. comm. 2010). Survival 

of the Ellicott population was threatened in 1970 

when the owner of the breeding site and much of 

the upland attempted to rezone the area for a trailer 

park (Bury and Ruth 1972).

The Buena Vista Pond was created during the 1940s, 

and SCLTS were first found here in 1992. It may 

support several hundred adults, based on trapping 

studies conducted during 1995 (Jennings 1995). An 

additional mark-recapture study was conducted by 

Biosearch Associates in the winter of 2008–2009. 

They estimated the breeding adult population of 

SCLTS at Buena Vista Pond to be 775, with a 95 

percent confidence interval of ± 380 due to low 

number of recaptures. However, due to a shortage 

of rainfall and therefore a shortened hydro-period, 

breeding migration was affected and the population 

size has probably been underestimated (Biosearch 

Associates 2009). The hydro-period is the duration of 

time an ephemeral pond will retain water.

The SCLTS continues to face numerous threats, 

including loss and degradation of both upland 

and breeding habitats from proposed residential 

development, road kill, encroachment of agricultural 

activities and invasive plant and animal species, 

sedimentation, and degraded water quality. 

Disjunct distributions have made SCLTS especially 

susceptible to population declines resulting from 

human-associated factors such as habitat loss. 

Degradation and destruction of aquatic breeding 

habitat was the primary reason for listing this 

species. In Santa Cruz County, the primary threats 

have been road construction and urbanization. 

Other threats include predators such as invasive 

opossums (Didelphis virginiana), striped skunks 

(Mephitis mephitis), raccoons (Procyon lotor), and 

a variety of snakes. Further details of life history 

and biology of the SCLTS are contained in the 

revised Recovery Plan (USFWS 1999b). Although 

the SCLTS is now known from more locations than 

when it was listed and some sites are now protected, 

the overall status of the SCLTS remains tenuous. 

California Tiger Salamander

The CTS, listed as threatened in August 2004, 

inhabits large ephemeral pools and their 

surrounding grasslands throughout the Central 

Valley as well as adjacent foothill and coastal 

grasslands. It is the only native tiger salamander 

species known to occur in its range. It is estimated 
Ellicott Slough NWR - Final Comprehensive Conservation Plan 37

that 75 percent of the original CTS habitat is now 

lost due to anthropogenic impacts and that 55 to 58 

percent of documented historic breeding sites has 

been eliminated (USFWS 2004). 

The CTS life history is similar to the SCLTS, 

requiring shallow ephemeral ponds for breeding in 

the winter months. During the summer months, 

CTS persist in open grasslands, using ground 

squirrel and pocket gopher burrows, as well as deep 

cracks or holes in the ground, for over-summering. 

CTS have been demonstrated to remain active 

throughout the summer, moving small distances 

within burrow systems. Dispersal distances from 

pond breeding sites to upland burrows depend 

on local topography and vegetation, distribution 

of burrows, and climatic conditions. CTS require 

different over-summering habitat from the SCLTS. 

CTS prefer grassland, whereas Santa Cruz longtoed salamanders prefer oak woodland. 

Both breeding and over-summering habitat for CTS 

are provided at the Ellicott Unit and the Buena 

Vista property. Regular monitoring has documented 

the presence of salamanders in most years between 

1993 and 2010 at Ellicott Pond (Tertes pers. comm. 

2010). However, breeding and non-breeding habitat 

use has not been thoroughly assessed at the Refuge. 

In the winter of 2008–2009, two adult female and 11 

adult male CTS were captured at the Buena Vista 

Pond during a mark-recapture study performed 

by Biosearch Associates. Biosearch estimated the 

breeding adult population of CTS at Buena Vista 

Pond to be 16, with a 95 percent confidence interval 

of ± 10. However, due to a shortage of rainfall 

and therefore a shortened hydro-period, breeding 

migration was affected, and the population size 

has probably been underestimated (Biosearch 

Associates 2009). During the study, Biosearch 

also sent CTS tissue for genetic testing. Results 

verified the salamander as the native CTS—and 

not a hybrid. (Biosearch Associates 2009). There 

have been no CTS population studies conducted at 

Ellicott Pond; however, CTS have been found during 

rainy night-time surveys at Ellicott Unit (Tertes, 

pers. comm. 2010). Therefore, while the Ellicott 

Unit and Buena Vista have breeding CTS, there is 

currently no population estimate.

California Red-legged Frog

The CRLF was listed as a threatened species on 

June 24, 1996. It is also listed as a state species 

of concern. The CRLF has been extirpated or 

nearly extinct from 70 percent of its former range. 

Habitat loss and alteration, combined with overexploitation and introduction of invasive predators, 

were important factors in the decline of the CRLF 

in the early to mid-1990s. Primary threats that led 

to its listing status included urban encroachment, 

construction of reservoirs and water diversions, 

contaminants, agriculture, and livestock grazing 

(USFWS 2002). At present, CRLF are known to be 

present in approximately 256 streams or drainages 

from 28 counties, primarily in central coastal 

California (USFWS 2002). 

CRLFs breed from November through April. 

California red-legged frogs spend most of their 

lives in and near sheltered backwaters of ponds, 

marshes, springs, streams, and reservoirs. Deep 

pools with dense stands of overhanging willows 

and an intermixed fringe of cattails are considered 

optimal habitat. California red-legged frog eggs, 

larvae, transformed juveniles, and adults also have 

been found in ephemeral creeks and drainages and 

in artificial ponds devoid of riparian or wetland 

vegetation. Each of the life stages also have been 

observed in artificial environments, such as stock 

ponds, sewage treatment ponds, irrigation ponds, 

wells, canals, golf course ponds, sand and gravel 

pits, and large reservoirs (USFWS 2002). 

Accessibility to sheltering habitat is essential for the 

survival of CRLF within a watershed and may be a 

factor limiting population numbers and distribution. 

Juvenile and adult CRLF have been observed in 

areas of riparian vegetation where they may use 

small mammal burrows, moist litter, and debris 

such as discarded lumber (boards on the ground) 

California tiger salamander juvenile. Photo: Heather Butler
Chapter 3

38 Ellicott Slough NWR - Final Comprehensive Conservation Plan

for sheltering. During wet periods (particularly 

winter and spring), CRLF may move long distances 

between aquatic habitats, often traveling through 

habitats previously considered to be unsuitable 

for frogs. California red-legged frogs have been 

found more than one mile from breeding habitat 

and may reach isolated aquatic habitats up to a mile 

away from the nearest known CRLF populations 

(USFWS 2002). 

The Refuge falls into one of the recovery units for 

this species. Critical habitat has also been designated 

at Ellicott and Harkins Slough Units and the Buena 

Vista Property (USFWS 2010). However, breeding 

and non-breeding habitat use by the CRLF has never 

been thoroughly assessed at the Refuge. Therefore, 

the current status and size of the population at the 

Refuge is unknown. There have been anecdotal 

reports that CRLF have been heard calling at pond 

at the Ellicott Unit; however, no larvae have been 

found in the pond. Pond surveys at the Calabasas 

Unit indicated presence of California red-legged frog 

larvae once in the past 10 years. Ongoing threats, 

which are primarily the result of urbanization 

and agricultural activities, include habitat loss, 

fragmentation, and degradation and establishment of 

invasive vegetation, disease, and predators.

Other Wildlife

Amphibians and Reptiles

In addition to the special status amphibians, a 

variety of other native amphibian species have been 

found on the Refuge, including California slender 

salamander (Batrachoseps attenuatus) and arboreal 

salamander (Aneides lugubris). Pacific tree frogs 

are most commonly seen in or adjacent to seasonal 

and permanent waterbodies, while other amphibians 

are more commonly seen during terrestrial nighttime surveys. Some species found during these 

surveys include ensatina salamander (Ensatina 

eschscholtzii), arboreal salamander, California 

slender salamander, and Pacific tree frog (see 

Appendix F). 

Reptiles are common residents in the upland, 

riparian, and wetland habitats. Reptile species 

recorded during coverboard surveys include western 

fence lizard (Sceloporus occidentalis), southern 

alligator lizard (Elgaria multicarinata), and 

western skink (Eumeces skiltonianus). Additional 

sightings by Refuge personnel during tree removal 

work, plantings, and surveys include ringneck snake 

(Diadophis punctata), racer (Coluber constricta), 

gopher snake (Pituophis melanoleuca), common 

garter snake (Thamnophis sirtalis), and Western 

terrestrial garter snake (Thamnophis elegans). A 

list of wildlife species is included in Appendix F.

Mammals

Many mammalian species are year-round residents 

of the Refuge. A small mammal trapping study in 

1977 by CDFG was the first inventory of mammal 

species on the Refuge. Small mammals, in 

particular, are important to inventory, as the SCLTS 

and CTS use small mammal burrows to oversummer in during the summer months. Species 

captured during the study included California mouse 

(Peromyscus californicus), deer mouse (Peromyscus 

maniculatus), Piñion mouse (Peromyscus truei), 

dusky-footed woodrat (Neotoma fuscipes), and 

California meadow vole (Microtus californicus). 

Since the initial study, Botta’s pocket gopher 

(Thomomys bottae) and California ground squirrel 

(Spermophilus beecheyi) have also been observed 

on the Refuge and identified as important burrow 

contributors. Additional mammals include brush 

rabbit (Sylvilagus bachmani), common muskrat 

(Ondatra zibethicus), mountain lion (Felis concolor), 

bobcat (Felis rufus), coyote (Canis latrans), 

feral pig (Sus scrofa), and mule deer (Odocoileus 

hemionus columbianus). See Appendix F for a 

complete list.

Birds

 The Refuge provides a variety of habitats for a 

great diversity of migratory and resident birds. 

Appendix F provides a list of the birds species 

observed on the Refuge. In 1998, Higley conducted 

single-day, four-season bird surveys at the Ellicott 

Unit, establishing the Refuge bird list (unpublished 

data). Bird walks led by the Santa Cruz Bird Club 

on the Harkins Slough Unit from 2008 to present 

day and ongoing incidental observations by Refuge 

personnel have added to the species list. 

Migratory and resident landbirds can be found 

throughout the Refuge. Birds visit the Refuge 

to breed, forage, and roost. Some common birds 

seen include scrub jay (Aphelocoma coerulescens), 

Anna’s hummingbird (Calypte anna), Northern 
Ellicott Slough NWR - Final Comprehensive Conservation Plan 39

mockingbird (Mimus polyglottos), rock dove 

(Columba livia), American robins (Turdus 

migratorius), Northern flicker (Colaptes auratus), 

and barn swallows (Hirundo rustica). Cedar 

waxwings (Bombycilla cedrorum) and whitecrowned sparrows (Zonotrichia leucophrys) are 

just two of the many landbird species that use the 

Refuge during migration.

Many wading and diving birds use Harkins 

Slough Unit year round, utilizing the Slough and 

adjacent riparian habitats for foraging, roosting, 

and occasionally nesting. Great blue heron (Ardea 

herodias), great egret (Ardea alba), snowy egrets 

(Egretta thula) and double-crested cormorants 

(Phalacrocorax auritus) are seen year round. 

Other waterbirds use the Refuge at various 

times throughout the year, such as American 

bitterns (Botaurus lentiginosus), American coots 

(Fulica americana), and American white pelicans 

(Pelecanus erythrorhynchos).

Many species of raptors (birds of prey) are found 

among the various habitats of the Refuge. Redtailed hawks (Buteo jamaicensis) are the most 

commonly seen raptor at the Refuge; however, 

white-tailed kites (Elanus coeruleus) and American 

kestrels (Falco sparverius) are also common. 

Osprey (Pandion haliaetus) and red-tailed hawks 

(Buteo jamaicensis) are just two of the raptors 

known to nest at the Refuge. 

California quail (Callipepla californica) are common 

residents in the oak woodland scrub found at the 

Refuge. Several species of gulls can be found 

foraging or roosting in Harkins Slough. Many of 

these gulls are supported by the adjacent landfill.

Fish

The Harkins Slough Unit currently provides the 

Refuge’s only permanent, freshwater habitat suitable 

for fish. A one-time dip-net survey in 2006 identified 

prickly sculpin (Cottus asper) and invasive carp. In 

addition, a CDFG warden reported that hardhead 

(Arius felis), bullhead catfish (Ameiurus sp.), and 

Sacramento blackfish (Orthodon microlepidotus) 

were illegally fished at Harkins Slough Unit 

(Schindler, pers. comm. 2010); Harkins Slough is 

closed to the public. It is unknown if other fish persist 

at Harkins Slough Unit. 

Invertebrates

Invertebrate populations are greatest and most 

diverse in aquatic habitats and provide an important 

food base for many fish and wildlife species (e.g., 

salamanders), both aquatic and terrestrial. Common 

aquatic invertebrates include water fleas (family: 

Daphniidae), snails (e.g., planorbid (Planorbella 

tenuis)), clam shrimp (order: Conchostraca), 

fairy shrimp (family: Artemidae), dragonflies and 

damselflies (order: Odonata), waterboatmen (family: 

Corixidae), backswimmers (family: Notonectidae), 

beetles (order: Coleoptera), midges (order: Diptera), 

mosquitoes (family: Culicidae), and worms. 

Terrestrial invertebrates are an important food base 

for many migratory and resident bird species, as 

well as for reptiles, amphibians, and small mammals. 

Common species include ants (family: Formicidae), 

butterflies (order: Lepidoptera), beetles (order 

Coleoptera), grasshoppers (order: Orthoptera), 

ticks (family: Ixodidae), bees and wasps (order: 

Hymenoptera), and moths (order: Lepidoptera).

Biotic Threats to Amphibians

Amphibians face many threats to survival such 

as disease, predators, and trematodes. Chytrid 

fungus (Batrachochytrium dendrobatidis) 

(BD) causes chytridiomycosis, a disease that is 

potentially lethal to most amphibians. The fungus 

attacks the keratinous areas, such as mouth parts 

in tadpoles and hands and feet in adult frogs 

(Hossack et al 2010). BD infection outcomes, such 

as increased sloughing, discolored skin and mouth 

parts, and mortality are species specific (PadgettFlohr 2008). 

Several observations of chytrid fungus infections 

(BD) were recorded on the Refuge over the last 

decade. During a dip-net survey in Calabasas Pond 

in May 2005, a large number of tree frog tadpoles, 

a few California red-legged frog tadpoles and 

several Santa Cruz long-toed salamander larvae 

were found to be emaciated and in poor condition. 

One salamander larvae and one California redlegged frog tadpole were sent to the USGS 

National Health Center (Health Center) to be 

analyzed. Chytrid fungus was confirmed in both 

specimens. The most recent finding of chytrid 

fungus occurred in May 2006 at the Harkins Slough 

Unit. A bullfrog specimen was sent to the Health 

Center and resulted in a positive confirmation for 
Chapter 3

40 Ellicott Slough NWR - Final Comprehensive Conservation Plan

the presence of chytrid fungus on the Harkins 

Slough Unit.

Santa Cruz long-toed salamanders, California 

tiger salamanders, and California red-legged frogs 

are vulnerable to several predators throughout 

their home range, such as crayfish, bullfrogs 

(Rana catesbeiana), fish, birds, garter snakes 

(Thamnophis sp.), aquatic insects, raccoons 

(Procyon lotor) and even adult salamanders. 

These predators can eat amphibian eggs, larvae, 

and adult salamanders, making them a threat to 

special status and native salamanders and frogs 

(USFWS 2009). 

While no Refuge surveys have been conducted 

for invasive wildlife, various species have been 

identified throughout the years. Native predators 

on the Refuge include animals such as garter 

snakes, opossums, great egrets, and raccoons. 

Crayfish, bullfrogs, and carp are a few of the 

invasive species that have been observed on the 

Refuge. Crayfish were discovered during a dipnet survey at Calabasas Pond. The population 

was small, and all crayfish were removed the 

same year. Adult invasive bullfrogs have been 

sporadically observed on the Calabasas and 

Ellicott Units. In 2006, a large, productive 

breeding population of bullfrogs was confirmed on 

the Harkins Slough Unit. In addition to bullfrogs, 

invasive carp have also been observed in large 

numbers at Harkins Slough Unit. There has been 

no control of bullfrogs or carp to date. 

Trematodes, such as Ribeiroia sp., are parasitic 

flatworms that cause infection, limb abnormalities 

and a decline in survivorship in amphibians 

(Johnson et al. 1999). Primary hosts of the adult 

trematode include vertebrates such as birds. 

The bird releases the trematode eggs into the 

environment where they enter an intermediate 

host, such as aquatic planorbid snails, (Planorbella 

tenuis). Larval trematodes from the snail move 

to the second intermediate host, including frog 

and salamander larvae. The larval trematodes 

form cysts on the surface of the tadpoles’ skin 

which penetrates the tissue, resulting in extensive 

inflammation, swelling, and tissue outgrowths 

(Johnson and Sutherland 2003). In the past 

10 years, there has been one known outbreak 

of trematodes at the Ellicott Unit. In 2001, 

both treefrog tadpoles and SCLTS larvae were 

observed with multiple limbs. A few specimens 

were sent to the Health Center and resulted 

in a positive confirmation for the presence of 

trematodes on the Ellicott Unit (Loredo 2010).

3.5 Cultural Resources

An archaeological record search from the California 

State Historic Preservation Office (SHPO) was 

conducted for the Calabasas Unit in October 

1998. No recorded archaeological resources are 

on the property. The parcel is located within an 

area where the likelihood of finding archaeological 

artifacts is high. However, the area has been 

significantly disturbed by recent agricultural 

operations, and it is unlikely that management 

activities would disturb any cultural sites and/

or artifacts. In a 1993 environmental assessment 

done for the creation of Prospect Pond, the Service 

stated that there were no known archaeological 

sites at Ellicott Slough NWR (USFWS 1993). 

In 1993, Calabasas Unit was not a part of the 

Refuge and the 4.5-acre Lima family conservation 

easement was not included within the Refuge 

acquisition boundary. No additional information was 

found regarding archaeological sites on the Ellicott 

or Harkins Slough Units of the Refuge.

No cultural resources were identified in previous 

assessments done for the proposed golf course on 

the Buena Vista property (Carter 1993). The area 

is heavily vegetated, and only 20 percent of the area 

was surveyed. According to Miliken, the Native 

American Aptos/Cajastaca group lived in the area 

(Lonnberg 1994), though no historic resources have 

been observed in the vicinity. The Buena Vista 

property is within the historic Rancho San Andres 

lands, which was given to the Castro family in 1833 

(Carter 1993). 

There are no visible cultural elements on the Refuge 

units. Most of the Refuge is heavily vegetated, 

making visual surveys difficult to conduct. 

3.5.1 Social and Economic Environment

The Refuge is located in Santa Cruz County, which 

is made up of the incorporated cities of Santa 

Cruz, Watsonville, Scotts Valley, and Capitola. 

Agriculture is the foundation of this area. This 

industry is limited to the marine terraces along the 

ocean and bay northwest of Santa Cruz, the section 
Ellicott Slough NWR - Final Comprehensive Conservation Plan 41

of coastal plain southeast of Aptos, the lower hills 

of Corralitos-Watsonville, and the rich, alluvial soils 

in the Pajaro Valley. The Refuge is near many crop 

fields; crops in the area include artichokes, Brussels 

sprouts, strawberries, leeks, broccoli, flowers, 

and iceberg lettuce. Forestry is also an important 

industry in the area, according to the Santa Cruz 

County Resource Conservation District (2010).

Recreation and tourism are also important local 

industries. There are a number of state and county 

parks, including Big Basin State Park and Henry 

Cowell Redwood State Park, that attract visitors 

for hiking, marine sports, rock climbing, fishing and 

nature study activities.

The county has also encountered rapid population 

growth, creating pressure on water and soil 

resources, as well as forested, agricultural, and open 

space areas.

3.5.2 Demographics

There are approximately 250,000 residents in 

Santa Cruz County. The age group distributions 

are 19–64 years old (61.3 percent); 5–18 years old 

(21.5 percent); 65 years old and over (10.6 percent); 

and under 5 years old (6.6 percent). The ethnic 

demographic is divided primarily between White 

persons not Hispanic (62.9 percent); Hispanic or 

Latino (29.3 percent); Asian (4.1 percent); Black (1.3 

percent); American Indian and Alaska Native (1.2 

percent); and Native Hawaiian and Other Pacific 

Islander (0.2 percent). The per capita personal 

income in 1999 was $26,396, and the 2008 median 

household income was $66,495 (USCB 2008).

3.5.3 Traffic and Public Access

Although the Refuge is closed to the public, 

vehicular traffic does occur on the surrounding 

roadways and—in the case of the Ellicott Unit—

through the Refuge. 

San Andreas Road, a major Santa Cruz County 

coastal road, is located on the western border of the 

Ellicott Unit. The busy thoroughfare divides the 

main body of the unit from six acres of unit upland 

habitat on the opposite side of the road. A second 

private road, Peaceful Valley Drive, bisects the main 

portion of the unit and serves as the primary access 

road for residential and business neighbors in the 

valley to the east of the unit. Habitat fragmentation 

due to roads has been an on-going cause for concern, 

as vehicle strike mortality of SCLTS, CTS, and 

Pacific tree frog continues to be recorded during 

amphibian migration surveys (USFWS 1999b, 

USFWS 2004, D. Kodama, pers. comm.).

The Calabasas Unit and Buena Vista property are 

surrounded by county and private roads leading to 

rural residences and small farms. Traffic in these 

areas tends to be sparse, with residents of the area 

being the main users of the roads.

Prior to a portion of the road being permanently 

closed due to flooding, Harkins Slough Road, adjacent 

to the Harkins Slough Unit, was used as a road 

crossing, connecting the west and east sides of the 

Harkins Slough waterway. Subsequent to the road 

closure, traffic on Harkins Slough Road has been 

reduced, limited to use from the surrounding facilities 

and residences on the west side of the waterway.

3.5.4 Local Economy and Employment

Santa Cruz County’s economy is anchored by high 

technology, agriculture, and tourism. The Refuge is 

within San Cruz County limits but does not provide 

any employment opportunities because there are no 

on-site facilities. Access to the Refuge is monitored 

and limited to Refuge staff, volunteers, and Special 

Use Permit holders due to the sensitive nature of 

the wildlife. 

3.5.5 Environmental Justice

On February 11, 1994, the President issued 

Executive Order 12898 (Federal Actions to Address 

Environmental Justice in Minority Populations 

and Low-Income Populations), which directs the 

U.S. Environmental Protection Agency (EPA) 

to ensure that agencies analyze environmental 

effects on minority and low-income communities. 

The purpose of the Executive order is to avoid 

the disproportionate placement of any adverse 

environmental, economic, social, or health impacts 

resulting from Federal actions and policies on 

minority and low-income populations. Minority 

and low-income populations are present in Santa 

Cruz County in the vicinity of the Refuge (see the 

environmental assessment, Appendix C, for an 

analysis of potential effects to minority and low 

income populations).
Chapter 3

42 Ellicott Slough NWR - Final Comprehensive Conservation Plan

Coast live oak and lupine. Photo: USFWS
Ellicott Slough NWR - Final Comprehensive Conservation Plan 43

Chapter 4. Current Refuge Management and Programs

The Refuge currently has no integrated plan to 

guide the management of all of its resources and 

uses. Current management efforts focus on the protection of sensitive species, the enhancement of their 

habitats, and the management of the environmental 

education program. A major emphasis of current 

management is the protection and monitoring of 

threatened and endangered salamanders.

4.1 Land Management 

The Refuge lands are currently closed to the 

public to protect sensitive habitat for Federallylisted species. The primary land management 

activities conducted by Service staff, partners, and 

volunteers include reducing invasive vegetation and 

native plant restoration. Invasive vegetation (e.g., 

eucalyptus, pampasgrass, hemlock) is removed using 

mechanical and chemical methods. Seeds from 

native plants are harvested for propagation at the 

native plant nursery located on the Don Edwards 

San Francisco Bay NWR in Fremont. Restoration 

plantings occur in areas that were cleared of 

invasive vegetation. Volunteers and staff also have 

been developing a comprehensive plant species list 

and specimen catalog.

4.2 Water Management

Very little water manipulation occurs in the ponds on 

the Refuge. The Ellicott Unit has a pump and well to 

augment water levels, when needed, to ensure Santa 

Cruz long-toed salamander (SCLTS) and California 

tiger salamander (CTS) population recruitment. The 

Ellicott Unit has a second well without a pump in 

preparation for a breeding pond (Prospect Pond) that 

was constructed, but is being re-designed to improve 

hydrologic function. Water rights for Calabasas Pond 

from Harkins Slough (from the State of California 

Resources Agency, State Water Resources Control 

Board) were acquired in 1967 and transferred to the 

Refuge with the acquisition of the property. With 

the addition of a new berm and water structure at 

Calabasas in 2006, the Refuge is now able to partially 

control water output.

4.3 Wildlife Management

Wildlife management activities are conducted by the 

Service, partners, and/or volunteers on the Refuge. 

Activities generally focus on unit surveys for listed 

amphibians, but other wildlife is also recorded on 

these surveys. Amphibian surveys—dependent on 

rain events, funding, expertise, and staff availability 

to travel to the Refuge—are not always conducted 

consistently. Night-time amphibian roadside 

surveys to assess SCLTS and CTS population 

recruitment and amphibian health and to compile 

data on mortality from vehicle strikes are conducted 

when possible by staff and volunteers during annual 

rain events. Staff and volunteers also conduct 

annual dip-net surveys to determine breeding 

occurrence and health assessment of amphibian 

larvae and tadpoles. Coverboard surveys are 

conducted to collect baseline data on wildlife species 

diversity, focusing on reptiles, amphibians, small 

mammals, and invertebrates.

Additional staffing and expertise is necessary 

for more complex types of surveys such as drift 

fence, pitfall, and malformation studies. These do 

not occur on a regular basis—only when funding 

opportunities arise. A drift fence and non-lethal 

pitfall trap survey was conducted on the Buena Vista 

property in 2008 to gather baseline SCLTS and 

California tiger salamander. Photo: Gerald and Buff 

Corsi © California Academy of Sciences 
Chapter 4

44 Ellicott Slough NWR - Final Comprehensive Conservation Plan

CTS population data. The Refuge has participated 

in nationwide malformed frog surveys over the 

last several years to determine the prevalence of 

abnormalities on refuges.

A bird species list has been created based upon 

tours led by the Santa Cruz Bird Club and Open 

Space Alliance (Santa Cruz), incidental sightings, 

and past bird surveys.

4.3.1 Mosquito Population Management

Mosquito management activities occur throughout 

the Monterey Bay region where there is a large 

(more than 700,000) human population and where 

there is a long history of mosquito management and 

documented mosquito-borne disease transmission 

to humans and wildlife. Mosquitoes can be vectors 

of disease to both humans and wildlife and, in 

some cases, the disease transmission can result in 

death. Ten California species of mosquito that are 

known vectors of arboviruses or known as major 

pests were evaluated for West Niles Virus (WNV) 

transmission in 2002. All 10 species were infected 

with WNV and were able to transmit the disease 

at some level (Goddard et al. 2002). Culex tarsalis

is considered one of the most efficient laboratory 

vectors of WNV tested from North America and is 

abundant in California and much of western North 

America, where it is involved in the maintenance and 

amplification of western equine encephalomyelitis 

virus and Saint Louis encephalitis virus (Goddard 

et al. 2002). Culex tarsalis larvae are typically 

found in irrigation ditches, ponds, storm sewers, 

and other areas that usually contain abundant 

organic material. Of the 10 mosquito species 

studied by Goddard, Culex tarsalis showed the 

greatest potential to amplify and maintain WNV in 

California. The mosquito species most abundant on 

the Refuge is Ochlerotatus wachinoi, a species not 

known to vector disease.

With the spread of WNV and the potential for 

spread of other mosquito-borne disease across the 

country, there is increasing pressure to manage 

mosquito populations that occur on lands of 

the National Wildlife Refuge System (NWRS), 

especially in urban areas such as the Monterey Bay 

area. The Service understands that mosquitoes 

are a natural component of wetlands, but we also 

recognize that they may pose a threat to human 

and/or wildlife health. NWRS policy allows native 

mosquitoes to exist unless they pose a specific 

wildlife and/or human health threat. 

The Santa Cruz County Mosquito and Vector 

Control (SCCMVC) District has records of their 

treatment of the Ellicott Slough National Wildlife 

Refuge for mosquito management dating back to 

1995. The SCCMVC District’s use of pesticide 

on the Refuge has been monitored and regulated 

through the Service’s annual Pesticide Use 

Proposals and Special Use Permits. Refuge staff 

works cooperatively with the SCCMVC District to 

manage mosquito populations on the Refuge. 

4.4 Fire Prevention and 

Hazard Reduction

The Refuge does not have on-site fire management 

staff or equipment. While there is no dedicated fire 

staff at the Refuge, fire prevention and containment 

on the Refuge is a high priority. Both natural and 

man-made fires present primary concerns for the 

Service. A Fire Management Plan was updated 

Coverboard survey. Photo: USFWS
Ellicott Slough NWR - Final Comprehensive Conservation Plan 45

in 2002, with the main objective of reducing fuel 

accumulations to decrease the potential for large 

wildland fires. Because Refuge staff and trained 

Service fire crews are far from the Refuge (90 miles 

away), all wildland fires are generally reported 

by the public and suppressed by local cooperating 

agencies (Aptos-La Selva Fire District and Cal Fire) 

with oversight from the Service. During the past 10 

years, two fires have been reported on the Refuge. 

In 2007, Cal Fire responded to an arson-caused 

fire at the Harkins Slough Unit. Approximately 

seven acres of grasslands and one abandoned house 

were burned. In 2008, a fire of unknown cause was 

reported on the Ellicott Unit. Cal Fire responded to 

the fire, which burned approximately one-half acre 

of grassland and eucalyptus.

With coordination and funding from the Service’s 

Wildland Urban Interface program, the Refuge 

has worked to reduce hazardous fuel loads on 

the Ellicott Unit. Invasive plant fuel loads 

such as eucalyptus and pampasgrass have been 

mechanically removed with the assistance of 

California Conservation Corps (CCC), Cal Fire 

workforce crews, and Service fire crews stationed 

part-time at San Luis National Wildlife Refuge 

Complex. Other fuel reducing and fire prevention 

projects have included maintaining fire roads and 

creating a fire break between the Refuge and the 

neighboring KOA campground.

4.5 Law Enforcement and 

Resource Protection

Law enforcement officers assigned to the San 

Francisco Bay National Wildlife Refuge Complex 

provide law enforcement support at the Refuge. 

Local CDFG wardens also assist with patrol. Due 

to the distance from Complex headquarters office 

in Fremont (where officers are stationed), the Santa 

Cruz County Sheriff ’s office is the first responder in 

emergency situations. 

Currently all units of Ellicott Slough NWR are 

closed to the public except for research and surveys 

approved by Refuge staff, habitat restoration 

projects, and the Refuge’s environmental education 

program with Renaissance High School.

Although portions of the Refuge are fenced and/

or posted with “area behind this sign closed” 

and boundary signs, unauthorized use does 

occur. Unauthorized hiking and biking have been 

periodically observed on all units. Another common 

violation is illegal trash dumping.

The Calabasas Unit has been subject to offroad vehicle use (e.g., ATV and motorcycle) and 

horseback riding both in the upland habitat and in 

the ephemeral breeding pond during its summer 

dry-down cycle. These unauthorized uses have 

been detrimental to the Refuge in that they have 

damaged sensitive pond habitat, jeopardized 

juvenile salamanders over-summering in the dry 

pond footprint, and created trails through upland 

habitat, which promotes erosion, the spread of 

invasive weeds, and further unauthorized use.

Unauthorized recreational fishing occurs at the 

Harkins Slough Unit. Because there is no public 

infrastructure in place on the unit or regular Refuge 

presence, this illegal use has resulted in cut fences, 

vandalized signs, unauthorized trail and bank 

clearing, and trash accumulation. The abandoned 

houses and buildings on Harkins Slough Unit have 

also attracted vandals and illegal campers.

The Service has a 17.4-acre Farm Service Agency 

easement on the Theriault property located on 

Corralitos Creek, approximately 10 miles from the 

Ellicott Unit. This Theriault easement is not part 

of the Refuge, but the Refuge has management 

responsibilities to oversee and monitor the terms of 

the agreement for resource protection.

4.6 Cultural Resource Management

The Refuge complies with all applicable regulations 

and statutes regarding cultural resources. In 

consultation with the State Historic Preservation 

Officer and the Tribal Historic Preservation Officer 

(if applicable), the Service evaluates the eligibility 

of cultural resources, traditional cultural properties, 

and unique archeological resources on the Refuge 

prior to undertaking ground disturbing activities.

4.7 Facilities Maintenance

There are limited infrastructure and facilities 

located at the Refuge. All of the units have some 

fencing, signs and gates. Structures on the Ellicott 

Unit include a Pacific Gas and Electric (PG&E) 

power box, which supplies electricity to a pump 
Chapter 4

46 Ellicott Slough NWR - Final Comprehensive Conservation Plan

installed in a well located on Service property, and 

power lines and poles that run through the Refuge. 

The pump and well on Ellicott Unit are used to 

augment pond water levels during drought years to 

ensure metamorphosis of SCLTS. Prospect Pond, 

a pond constructed in 1997, is being redesigned 

to remedy hydrologic issues. The Calabasas Unit 

has a water control structure and berm at the 

southwestern end of the Calabasas Pond. There are 

also some remnant structures (house, barn, well, and 

associated facilities) remaining from the previous 

owner on the Harkins Slough Unit.

All residential houses and farm buildings on 

the Harkins Slough Unit have been evaluated 

for structural integrity by Refuge maintenance 

and were found to be structurally unsound. The 

abandoned state of the structures (broken window 

glass, stripped metal wiring, and general vandalism) 

has also added to the hazardous conditions. Five 

unused wells for residential use and irrigation have 

also been noted on the unit.

4.8 Safety

Safety is a priority concern at the Refuge. Poison 

oak, ticks, bees, and wasps are the most common 

issues facing staff and volunteers. There is also the 

potential to have mountain lion or bobcat and human 

interactions on the Refuge. Local fire, police, and 

emergency medical responders are able to provide 

services to each of the units; however, due to a lack 

of cell phone reception, response time to the Refuge 

may not be rapid. A safety officer from the San 

Francisco Bay NWR Complex conducts a safety 

audit of the Refuge annually.

4.9 Volunteers and Partners

Volunteers and partners provide countless hours 

of service for needed management activities on 

the Refuge. Management of this Refuge is reliant 

on relationships with these partners to provide 

maintenance, monitoring, assistance with land 

protection, and a variety of resources. The Refuge 

has benefited from partnerships with several entities 

and individuals, including: 

■ Biosearch Associates

■ California Conservation Corps

■ California Department of Fish and Game

■ Cal Fire

■ Land Trust of Santa Cruz County

■ Open Space Alliance, Santa Cruz

■ Renaissance High School

■ San Francisco Bay National Wildlife Refuge 

Complex Volunteers

■ Santa Cruz Bird Club

■ Santa Cruz County Weed Management Area

■ Trust for Public Land

■ Watsonville Wetlands Watch

4.10 Visitor Programs

The Refuge has restricted public access on some 

of the units based on the sensitivity and limited 

distribution of Federally-protected species that the 

Refuge supports. The Ellicott and Harkins Slough 

Units have restricted access, with Service-guided 

interpretive walks, as requested by resource-related 

organizations. Service-guided environmental 

education is also offered at the Ellicott Unit. 

Permitted on-site activities are supervised by 

Refuge staff to minimize disturbances to wildlife 

and habitat and to contribute to the management 

practices of the Refuge. The Calabasas Unit is 

closed to the public. 

4.11 Environmental Education 

and Interpretation

The Refuge currently partners with Renaissance 

High School, located across from the Ellicott Unit 

on Spring Valley Road, to provide a program that 

focuses on bringing students to the Refuge, where 

they can connect directly with wildlife and habitat 

resources. The goal is to promote awareness and 

foster a sense of stewardship towards the local 

watershed, threatened and endangered species, and 

migratory birds.

The program begins with an in-classroom component 

introducing students to the Refuge, local natural 

resources, and the Service. Throughout the school 

year, students participate in Refuge-guided field trips 

(tours), assisting staff with restoration activities such 

as invasive weed removal, native seed collection, and 

plantings. Students also work with Refuge staff to 

learn the fundamentals of survey data collection. 
Ellicott Slough NWR - Final Comprehensive Conservation Plan 47

Results and observations from these surveys are 

entered into Refuge resource databases and included 

on species lists. At the end of the school year, students 

summarize their experience and newly gained 

knowledge with a final project or report.

4.12 Fishing and Hunting

Recreational fishing and hunting are not currently 

permitted on the Refuge. However, unauthorized 

recreational fishing occurs at the Harkins Slough 

Unit. The Refuge has restricted public access due to 

the sensitivity and limited distribution of Federallylisted species that the Refuge supports. 

4.13 Wildlife Observation 

and Photography

Wildlife observation and photography are not 

currently permitted on the Refuge. The Refuge has 

restricted public access due to the sensitivity and 

limited distribution of Federally-listed species that 

the Refuge supports. See Visitor Programs, above.

4.14 Outreach

Refuge outreach is conducted primarily through 

off-site presentations requested by wildlife related 

organizations, and booths at local festivals such as 

the Santa Cruz Migration Festival. Information on 

the Refuge, the Service, and Federally-listed species 

is provided. Booth activities are geared towards 

teaching children and adults about Santa Cruz longtoed salamander natural history and its unique local 

geographic range.

Ellicott Slough NWR - Final Comprehensive Conservation Plan 49

Chapter 5. Management Direction

5.1 Ellicott Slough NWR 

Vision Statement

Veiled in lush canopies of oak woodland and coastal 

chaparral, Ellicott Slough National Wildlife Refuge 

is one of the few refuges established for amphibians. 

First established for the endangered Santa Cruz 

long-toed salamander, the Refuge also supports 

the threatened California tiger salamander and the 

threatened California red-legged frog. The Refuge 

will sustain, restore, and acquire vital wetland 

and upland components to provide habitat for the 

entire lifecycle of amphibian populations within 

the Watsonville Slough System of the Pajaro Valley 

Watershed. Amphibians and other wildlife will 

flourish in the Refuge’s protected seasonal ponds, 

oak woodland, and chaparral. The Refuge will also 

serve to protect the diminishing natural landscape of 

the Santa Cruz area, which is critical to the survival 

of other threatened, endangered, migratory, and 

other native species. 

The Refuge, surrounded by agricultural fields 

and houses, will also strive to connect with the 

public in nature by providing wildlife observation, 

photography, and interpretation and environmental 

education opportunities that connect the Refuge to 

the local community. The Refuge staff will continue 

to establish and strengthen partnerships with the 

community, conservation groups, academia, and 

other agencies. These partnerships will conserve 

and restore habitats vital to the survival of the 

plants and wildlife of the Refuge.

5.2 Refuge Management Goals, 

Objectives, and Strategies

Refuge management activities are articulated 

through goals, objectives, and strategies in this CCP. 

The Service defines a goal as a “descriptive, openended, and often broad statement of desired future 

conditions that conveys a purpose, but does not 

define measurable units.”

The Service defines objectives as concise 

statements of what will be achieved, how much 

will be achieved, and when and where it will be 

achieved on a refuge. Objectives are derived 

from goals and are accomplished through 

management strategies that specify the actions, 

tools, techniques, or combination thereof. Goals 

were developed to provide management directions 

in four principal areas: wildlife management, 

habitat management, wildlife-dependent public use, 

and cultural or wilderness resources. The seven 

Refuge goals are presented in the following text, 

followed by detailed descriptions of the associated 

objectives, strategies, and rationales that support 

and implement them. 

GOAL 1: Restore, protect, and enhance 

native and special status amphibian 

populations in Santa Cruz County.

Objective 1.1 Conduct research and monitoring 

to determine baseline population size, health, habitat 

use, and movement of native amphibians, especially 

special status species.

Rationale: Federally-listed threatened, 

endangered, and candidate species are trust 

responsibilities under the jurisdiction of the 

Service. Threatened and endangered species, as 

well as those proposed for Federal listing, may 

become extinct due to environmental factors. 

Listed amphibian species known to occur on 

the Refuge include the Santa Cruz long-toed 

salamander (SCLTS), California tiger salamander 

(CTS), and California red-legged frog (CRLF). 

The 1999 Revised Recovery Plan for Santa Cruz 

long-toed salamander and the 2002 Recovery 

Plan for the California red-legged frog identify 

the need for monitoring to assess status, trends, 

habitat use, and threats to develop appropriate 

recovery actions. Refuge management strategies 

will support these objectives. Furthermore, 

understanding how listed species interact with 

their environment and other wildlife will support 

their recovery. 
Chapter 5

50 Ellicott Slough NWR - Final Comprehensive Conservation Plan

Strategies

1.1.1 Identify inventorying, monitoring and 

research needs for determining population size, 

habitat use, and movement of native amphibians 

(e.g., identify amphibian dependence on small 

mammal burrows).

1.1.2 Prioritize and determine who can fulfill the 

inventory, monitoring, and research needs (e.g., 

staff, partners, universities).

1.1.3 Develop partnerships with researchers, 

universities, and others to conduct research and 

monitoring that supports the Refuge management 

needs and contributes to the scientific community.

1.1.4 Standardize monitoring, data collection, 

and storage.

1.1.5 Conduct monitoring to answer inventory 

and research needs.

1.1.5.1 Conduct quantitative night-time surveys 

(during most rain events) to assess population 

recruitment, and compile data on mortality from 

vehicle strikes. 

1.1.5.2 Conduct annual quantitative dip-netting and 

coverboard surveys to obtain baseline information, 

determine breeding occurrence, and health 

assessment of larvae and tadpoles. 

1.1.5.3 Conduct pond and upland drift fence and 

nonlethal pitfall trap surveys to determine baseline 

population size and movement trends to assist with 

identifying high quality habitat requirements and 

informing restoration decisions. 

1.1.5.4 Conduct surveys for presence of California 

red-legged frog (e.g., call counts, seining, eye shine, 

and dip-net).

1.1.5.5 Conduct genetic studies to assess population 

parameters (e.g., effective population size and 

population subdivision).

1.1.6 Participate in nationwide abnormal frog

surveys to determine the prevalence of abnormalities 

in frogs and toads on refuges; evaluate how 

abnormality frequencies vary among sites, refuges, 

and years; and investigate possible causes of the 

abnormalities through targeted follow-up studies. 

Objective 1.2 Within 10 years of Plan approval, 

develop and/or implement management actions for 

ephemeral breeding ponds (Ellicott Pond, Calabasas 

Pond, and Buena Vista Pond) and over-summering 

habitat to support native and special status 

amphibian recruitment.

Rationale: The 1999 Revised Recovery Plan for 

Santa Cruz long-toed salamander and the 2002 

Recovery Plan for the California red-legged frog 

identify the need to ensure that existing ponds 

remain functional breeding sites as a core recovery 

objective. Refuge management strategies will 

support this recovery objective. 

Strategies

1.2.1 Develop a Water Management Plan to 

ensure that existing ponds remain functional 

breeding sites.

1.2.2 Conduct hydrological and soil surveys for 

existing ponds to inform management actions.

1.2.3 Conduct hydrological and soil surveys to 

inform management actions regarding potential 

pond construction locations and ponds for potential 

future acquisition.

Night-time survey. Photo: USFWS
Ellicott Slough NWR - Final Comprehensive Conservation Plan 51

1.2.4 Monitor ponds for siltation, as well as 

for native and invasive vegetation encroachment. 

Summarize data to determine need for excavation or 

vegetation removal.

1.2.5 Continue the planning, redesign, and 

environmental compliance for existing, nonfunctional breeding pond (Prospect Pond). 

1.2.6 Assess the need for and—where 

appropriate—plan, design, and complete 

environmental compliance for additional new 

breeding ponds.

1.2.7 Monitor and research over-summering 

needs (e.g., grassland, oak woodland) and incorporate 

results into restoration efforts and management.

Objective 1.3 Within 10 years of Plan approval, 

conduct feasibility study of potential to restore 

Harkins Slough Unit to provide additional native 

amphibian habitat.

Rationale: The 1999 Revised Recovery Plan for 

Santa Cruz long-toed salamander and 2002 Recovery Plan for the California red-legged frog identify 

the need to restore habitat for amphibians at or 

near their historical localities. The Watsonville 

Slough System, which includes Harkins Slough, 

historically and currently provides habitat for 

these species. Refuge management strategies will 

support this guideline.

Strategies

1.3.1 Conduct a hydrological 

assessment of Harkins Slough.

1.3.2 Identify threats to the 

survival and reproduction of native 

amphibians, and—if feasible—

remove or reduce threats.

Objective 1.4 Identify and 

prioritize direct (e.g., vehicle strike 

mortality, disease) and indirect 

(e.g., contaminants) threats to 

amphibians to develop appropriate 

response measures.

Rationale: The 1999 Revised 

Recovery Plan for Santa Cruz longtoed salamander and 2002 Recovery 

Plan for the California red-legged frog identify 

controlling or eliminating invasive species and/or 

predators as a recovery task for these species. These 

two Recovery Plans also identify reducing humanrelated mortality (e.g., vehicle strike) as recovery 

tasks. Refuge management strategies will support 

these guidelines.

Strategies

1.4.1 Work with partners to minimize vehicle 

strike mortality (e.g., install reduce-speed signs, 

implement an outreach program) and minimize 

additional barriers to movement on and adjacent to 

the Refuge.

1.4.2 Assess long-term vehicle strike mortality 

solutions with other stakeholders (Santa Cruz 

County, Transportation Division of Santa Cruz 

County, and Southern Pacific Railroad); solutions may 

include elevating San Andreas Road, creating tunnels 

under roads, and road closures during rain events.

1.4.3 Understand and determine effects of 

pesticides, including herbicides and mosquito 

abatement procedures (e.g., conduct literature 

review, research). 

1.4.4 Understand and determine sources of 

contaminants (e.g., road runoff, livestock runoff, and 

agricultural practices), their effects, and prevalence 

through surveys and research. If warranted, plan 

Ellicott Pond. Photo: USFWS
Chapter 5

52 Ellicott Slough NWR - Final Comprehensive Conservation Plan

and implement course of action to decrease exposure 

to affected areas.

1.4.5 Research spread of disease and parasites 

among native amphibians and follow best management 

practices to prevent their spread (see Appendix 1 of

the Environmental Assessment, within Appendix C). 

1.4.6 Conduct surveys annually to monitor 

amphibian health (See Objective 1.1).

1.4.7 Rapidly respond to amphibian parasite 

and disease outbreaks by identifying, documenting, 

and notifying National Wildlife Health Center, local 

herpetologists and additional experts.

1.4.8 Assess prevalence of invasive plants and 

animals (See also Objectives 4.1 and 4.2).

1.4.9 Protect sensitive refuge resources from 

potentially adverse effects of wildfires using fire 

suppression actions, prescribed fire, manual and 

mechanical techniques. In planning a prescribed 

fire and mechanical treatments, sensitive resources 

are taken into account, and mitigation measures are 

implemented to protect them. 

Objective 1.5 Within five years of Plan approval, 

develop a map to identify suitable amphibian habitat 

and buffers for protection in perpetuity through fee 

acquisition and easements.

Rationale: The 1999 Revised Recovery Plan 

for Santa Cruz long-toed salamander and 2002 

Recovery Plan for the California red-legged 

frog have developed recovery recommendations, 

including protecting and acquiring suitable habitats 

and buffers for these species. Refuge management 

strategies will support these guidelines.

Strategies

1.5.1 Identify critical breeding, over-summering, 

and movement or migration corridors outside of

the Refuge.

1.5.2 Work with partners (e.g., local, state, and 

Federal land protection agencies and organizations, 

such as the Land Trust of Santa Cruz County, Trust 

for Public Land, Open Space Alliance, and California 

Department of Fish and Game) to prioritize these 

land parcels for protection and acquisition.

1.5.3 Expand Refuge acquisition boundary based 

on prioritized land properties.

Objective 1.6 Within five years of Plan approval, 

establish working group to discuss current 

management actions occurring on the Refuge and 

identify future needs.

Rationale: Because the Refuge manages noncontiguous units in the Watsonville Slough area, 

connectivity between the units is nearly impossible. 

However, there are several partners in the area 

that manage lands for amphibians and have the 

potential to help guide future management of 

Refuge resources. Working with partners on 

a regular basis will help establish consistent 

management of native amphibians in the area.

Strategies

1.6.1 Collaborate annually with researchers 

and land managers to share latest information and 

results of studies to base management actions on 

best data available.

1.6.2 Attend local and national amphibian 

conferences to share and learn about current 

information (e.g., research results).

GOAL 2: Conserve, restore, and enhance 

migratory and other native 

wildlife populations.

Objective 2.1 Within 10 years of Plan approval, 

conduct baseline surveys for presence and abundance 

of birds, fish, mammals, reptiles, and invertebrates to 

determine species diversity at all Refuge units.

Rationale: The Refuge System Policy on Biological 

Integrity, Diversity and Environmental Health 

(601 FW3) (BIDEH) charges Refuge staff to 

assess the Refuge resources through baseline 

population surveys and studies. Documentation of 

the occurrence of fish and wildlife species will meet 

management needs. Monitoring changes in fish and 

wildlife resources is needed to inform management 

decisions or to develop, refine, and evaluate 

achievement of fish, wildlife, and habitat management 

objectives. Survey data may also support regional 

population needs beyond the Refuge. 
Ellicott Slough NWR - Final Comprehensive Conservation Plan 53

Strategies

2.1.1 Develop standardized quantitative and 

qualitative monitoring protocols to be repeated at 

intervals, depending on the species.

2.1.2 Develop database that incorporates new and 

historic data, including spatial information (GIS) on 

core areas.

2.1.3 Conduct surveys using methods such as 

pitfall, coverboard, and black light to identify reptile 

and invertebrate species. 

2.1.4 Seek partnerships to conduct bird surveys 

at all the units, with particular emphasis on

Harkins Slough.

2.1.5 Seek partnerships to identify fish species at 

Harkins Slough.

2.1.6 Conduct mammal surveys (e.g., livetrapping, remotely-triggered photo stations, track 

identification, and scat identification).

GOAL 3: Conserve, restore, and enhance 

grassland, wetland, oak woodland, 

coastal scrub and chaparral plant

communities, and special status 

plant species representative of Santa 

Cruz County.

Objective 3.1 Conduct comprehensive vegetation 

sampling on each Refuge unit every 10 years.

Rationale: Knowledge of the distribution and 

abundance of species, species’ needs, and status is 

critical for the management of the Refuge. Management effectiveness can be evaluated and corrected, 

if needed, based on information gathered from sampling. Sampling will also support regional needs and 

can result in early response to invasive vegetation.

Strategies

3.1.1 Conduct initial baseline vegetation sampling 

within five years.

3.1.2 Develop long-term monitoring protocols 

such as transects, quadrants, and other methods to 

track changes over time.

3.1.3 Using GIS, map sensitive plant species and 

target plant communities, including coastal scrub 

and maritime chaparral, within five years.

3.1.4 Coordinate with local botanists, garden 

clubs, the California Native Plant Society (CNPS), 

universities, volunteers, or others to assist in 

vegetation sampling.

Objective 3.2 Within five years of Plan approval, 

determine the distribution of robust spineflower, 

and possible presence of Santa Cruz tarplant 

(Holocarpha macradenia), and other Federallyand CNPS-listed plant species on the Refuge.

Rationale: The 2004 Recovery Plan for robust 

spineflower identifies the Buena Vista unit and 

surrounding areas as important locations for the 

spineflower. Robust spineflower is currently found 

on the Ellicott Unit and the Buena Vista property; 

however, population estimates are not known or 

not current (respectively). While the Santa Cruz 

tarplant and other listed plant species can be found 

near the Refuge, the extent of these species on the 

Refuge is also not known.

Strategies

3.2.1 Using GIS, map current populations of 

robust spineflower on the Refuge. 

3.2.2 Identify extent of special status and rare 

species such as Santa Cruz tarplant. 

3.2.3 Conduct plant surveys and mapping of 

the entire Refuge. Sample a sub-set area at each 

Refuge unit every 3–5 years, thereafter.

3.2.4 Coordinate with experts about current, 

improved, or new techniques to increase populations.

3.2.5 If warranted, consider plant propagation 

through appropriate local sources.

Objective 3.3 Within five years of Plan approval, 

develop a Habitat Management Plan including an 

adaptive vegetation management plan.

Rationale: An adaptive vegetation management 

plan will efficiently coordinate and prioritize the 

resources and methods needed to restore and 

maintain native habitat. The plan will also facilitate 
Chapter 5

54 Ellicott Slough NWR - Final Comprehensive Conservation Plan

the identification of and prioritize threats to the 

biological integrity of native habitats, enabling a 

quick response. 

Strategies

3.3.1 Seek partners to assist in seed collection 

from native sources to propagate sensitive and/or 

native plant species.

3.3.2 In the development of a Habitat 

Management Plan, consider different methods such 

as chemical, mechanical, grazing, and prescribed fire 

to benefit the wide variety of habitats (e.g., native 

grassland community) that exist on the Refuge.

3.3.3 Develop and implement protocols for 

disease and pest monitoring (e.g., sudden oak death, 

pine bark beetle) and rapid response actions. 

GOAL 4: Conserve and restore Refuge 

resources through the prevention and 

control of invasive species.

Objective 4.1 Within the adaptive vegetation 

management plan, complete and implement an 

adaptive invasive weed management plan that 

prioritizes, evaluates, and emphasizes early 

detection and rapid response efforts. 

Rationale: Invasive species have become the primary 

threat to the Refuge System and the Service’s 

wildlife conservation mission. Invasive species have 

the potential to alter foraging, nesting, and roosting 

habitat of endangered species and other wildlife that 

occur on the Refuge. The biological integrity policy 

identifies the need to control invasive vegetation. 

The Refuge’s proximity to urban environments also 

highlights the importance of vigilant monitoring of 

Refuge units. The National Strategy for Management 

of Invasive Species (April 2003) has been developed 

within the context of the National Invasive Species 

Management Plan [EO 13112], which functions as 

the internal guidance document for invasive species 

management throughout the Refuge System. The 

Plan identifies four goals: 1) Increase the awareness 

of invasive species issues, both internally and 

externally; 2) Reduce the impacts of invasive species 

to allow the Refuge System to more effectively meet 

its fish and wildlife conservation mission and purpose; 

3) Reduce invasive species impacts on the Refuge 

System’s neighbors and communities; and 4) Promote 

and support the development and use of safe and 

effective integrated management techniques to deal 

with invasive species.

Strategies

4.1.1 Explore all feasible control techniques, such 

as chemical, mechanical, grazing, and prescribed fire.

4.1.2 If found to be applicable (in 4.1.1), develop a 

grazing and prescribed fire plan (See Objective 5.2).

4.1.3 Develop a baseline invasive vegetation map 

(See Strategy 3.1.1).

4.1.4 Conduct ongoing surveys through partners 

and volunteers to respond to new occurrences of 

invasive plant species.

4.1.5 Annually determine priority invasive plants 

based on monitoring results.

4.1.6 Control eucalyptus, jubatagrass, and 

pampasgrass through removal, using a variety of 

methods such as mechanical and chemical.

4.1.7 Determine methods for control of French 

broom, targeting outliers and then moving into 

established areas.

4.1.8 Consult with local partners to identify 

invasive weeds in the region that may be considered 

threats to the Refuge.

4.1.9 Develop prevention and early detection 

protocols to reduce the extent and density of newly 

established invasive plants to minimize spread and 

damage to natural resources.

4.1.10 Work with the Santa Cruz Weed 

Management Area to learn new control techniques, 

identify weeds new to the county, and create 

partnerships with local landowners.

4.1.11 Work with partners and neighbors 

to identify and control invasive plants (e.g., 

pampasgrass), facilitating cooperation among those 

working to manage invasive plants.

4.1.12 Implement the most economic, effective, and 

safe control methods for priority weed species, and 

monitor efficacy of control methods (e.g., by mapping). 

Objective 4.2 Within 10 years of Plan approval, 

conduct a baseline assessment of and develop 
Ellicott Slough NWR - Final Comprehensive Conservation Plan 55

possible control methods for invasive wildlife threats 

to native amphibians. 

Rationale: The presence, distribution and 

potential impacts of invasive competitors and 

predators of amphibians are not well understood on 

the Refuge. In addition, invasive wildlife species 

have unknown effects on the Refuge resources. 

As mentioned in Objective 4.1, invasive species 

are a primary threat and priority for the Refuge 

System. The strategies will meet the objectives 

in the Refuge System’s National Strategy for 

Management of Invasive Species.

Strategies

4.2.1 Annually survey to assess prevalence of 

invasive competitors and predators (e.g., bullfrogs,

crayfish, and fish) using methods such as call 

counts, electroshock, seining, eye shine, trapping, 

and dip-netting. 

4.2.2 Based upon survey results, assess the 

control method options and potential impacts, and if 

feasible, implement control measures.

GOAL 5: Promote long-term viability of the 

Pajaro Valley Watershed through 

ecosystem-based management 

(including endangered and 

threatened species management 

across boundaries).

Objective 5.1 Coordinate 

with existing public and private

partnerships and create new ones 

that focus on ecosystem-based 

management collaborations that will 

support the long-term management 

of Refuge resources.

Rationale: The Refuge is made up 

of non-contiguous units, making it 

difficult to provide any connectivity 

between wildlife populations. 

Acquiring additional lands for buffer 

and breeding habitat will be critical 

to the recovery of listed species. The 

Refuge staff intends to work with 

surrounding partners to encourage 

land use practices and potential 

acquisitions that will support the 

needs of the Refuge’s wildlife. The Refuge is also 

reliant on the Pajaro Valley Watershed for its water 

needs to provide breeding habitat to these species. 

Both water quality and quantity are influenced by 

numerous neighboring land uses, which will require 

coordination to protect this watershed. To ensure 

that Refuge needs are addressed, Refuge staff will 

need to take an active role in regional planning.

Strategies

5.1.1 Expand collaboration with the following 

partners to develop long-term ecosystem goals

for the watershed: California Department of Fish 

and Game, Watsonville Wetlands Watch, Elkhorn 

Slough National Estuarine Research Reserve, 

Land Trust of Santa Cruz County, Trust for Public 

Land, and Elkhorn Slough Foundation. 

5.1.2 Develop new partnerships with USGS, 

National Audubon Society, Coastal Conservancy, 

and other local, state, and Federal land protection 

agencies and organizations.

5.1.3 Work with partners to prioritize lands 

within the watershed for protection and acquisition 

(see Objective 1.5).

Objective 5.2 Reduce wildfire risk at the Wildland 

Urban Interface (WUI) to minimize risk to public 

safety and to the Refuge and surrounding resources.

Rationale: The Fire Management Plan (FMP) for 

Ellicott Slough, revised in 2002, outlines procedures 

Dip-netting at Calabasas Pond. Photo: USFWS
Chapter 5

56 Ellicott Slough NWR - Final Comprehensive Conservation Plan

for wildland fire suppression. The FMP furthers 

the mission of the Refuge by providing increased 

protection for Refuge resources. Increasing 

coordination and preparedness to suppress wildland 

fires will help ensure quick responses to fires, which 

have the potential to be devastating to Refuge 

resources and adjacent properties. 

Strategies

5.2.1 Identify and map WUI areas, hazardous 

fuel (e.g., vegetation, structures) locations, and 

sensitive Refuge habitat. Prioritize fuel removal 

based on this information.

5.2.2 Work with local fire departments, California 

Department of Forestry and Fire Protection 

(CAL FIRE), and the Service’s fire management 

representatives to review annually and revise Fire 

Management Plans, as necessary, to include updated 

best management practices for fire prevention, fuel 

reduction strategies, and access.

5.2.3 Develop protocols with local partners to 

respond to fire outbreaks.

5.2.4 Work with partners and neighbors to make 

boundaries fire resistant in accordance with local 

fire codes and endangered species permits (e.g., 

hazardous fuel reduction, fuel breaks).

5.2.5 Remove hazardous fuel loads through manual, 

grazing, mechanical, and prescribed burn methods.

5.2.6 Monitor fuel reduction and assess 

effectiveness.

GOAL 6: Identify, assess, and adapt to current 

and future climate change impacts to 

Refuge resources.

Objective 6.1 Within 10 years of Plan approval, 

conduct an analysis of climate-related scenarios for 

the Refuge through modeling, and assess potential 

impacts to Refuge resources in coordination with the 

regional office.

Rationale: Climate change is already affecting 

wildlife throughout the State (Parmesan and 

Galbraith 2004), and its effects will continue to 

increase. Wetlands are especially sensitive to 

climate change. Nicholls et al. 1999 estimated that 

22 percent of wetland loss will be due to inundation, 

primarily through sea-level rise and other human 

factors. Climate change is also expected to result 

in changes to weather patterns (e.g., stronger 

hurricanes, hotter temperatures, more precipitation) 

and changes in responses to changes in weather 

patterns (e.g., changes in migration, shifts in 

habitat, earlier budding of vegetation) (Pew Center 

2009). This objective also helps achieve Statewide 

Conservation Action I in the California Wildlife 

Action Plan (CDFG 2005).

Strategies

6.1.1 Conduct flood-risk and climate-risk analysis 

of lands on and adjacent to the Refuge.

6.1.2 Work with Service experts and others

to conduct and analyze climate change modeling 

to predict habitat changes for Refuge habitat 

types (e.g., sea-level affecting marshes model 

[SLAMM] modeling). 

6.1.3 Obtain climate change modeling results 

applicable to the Refuge through other agencies 

and partners.

6.1.4 Identify additional acquisition needs based 

upon habitat transitions predicted from climate 

change models.

6.1.5 Promote and support research (through 

other agencies, universities, and consultants) 

that evaluates climate change related effects to 

endangered species populations and ephemeral pond 

hydrology, including analyzing changes in rainfall 

patterns (e.g., duration, timing, and amount) and 

temperature (e.g., air, water).

6.1.6 Identify locations for pond creation and 

acquisition (existing ponds or future pond sites) to 

offset climate change impacts (See Objective 1.5).

6.1.7 Assess effects of climate change on invasive 

species (e.g., weeds, bullfrogs).

6.1.8 Assess effects of climate change on disease 

outbreaks and parasites (e.g., monitoring presence of 

Rana viruses and chytrid in amphibians in relation to 

rising ambient and pond water temperatures).

6.1.9 Assess saltwater intrusion (i.e., effects on 

plants, wildlife) for Harkins Slough as a result of 

sea-level rise.
Ellicott Slough NWR - Final Comprehensive Conservation Plan 57

Objective 6.2 Within 10 years of Plan approval, 

measure the carbon footprint for the operation of 

the Refuge, and implement mitigation measures to 

offset the Refuge’s carbon footprint.

Rationale: This objective meets with the Service’s 

Climate Change policy, which recommends reducing 

Refuge staff carbon footprint to offset climate 

change impacts. The Refuge could also serve as a 

leader in the community to encourage neighbors to 

reduce their own carbon footprints.

Strategies

6.2.1 Using outside expertise, assess the Refuge’s 

carbon footprint.

6.2.2 Improve efficiency where feasible (e.g., 

transportation, energy, recycling).

6.2.3 Educate and empower Refuge visitors about 

climate change effects on Refuge resources and 

green activities that offset climate change.

GOAL 7: Provide the public with accessible, 

safe, high-quality wildlife-oriented 

recreation and environmental 

education opportunities to 

enhance public appreciation and 

understanding of the natural 

resources of the Refuge and the 

Refuge System.

Objective 7.1 Within 10 years of Plan approval, 

remove buildings and other potential safety hazards 

on the Harkins Slough Unit to prepare the unit for 

public access.

Rationale: The Harkins Slough Unit contains

several structures and wells that are safety 

hazards. The abandoned structures are in a 

deteriorated state and structurally unsound, and 

they attract vandals and vagrants. Providing a 

safe public environment is a priority that must be 

addressed before allowing public access. Prior to 

opening the Harkins Slough Unit to public use, 

all safety hazards will be addressed. The houses 

and structures will be demolished and materials 

removed from the property. The houses are known 

to contain asbestos and lead paint, for which safety 

guidelines and laws for removal apply. All wells 

not used for Refuge management purposes will be 

permanently capped. Wells that remain in use will 

be securely locked and fenced. 

Strategies

7.1.1 Cap existing wells in accordance with 

state regulations prior to allowing public access at 

Harkins Slough Unit.

7.1.2 Remove existing abandoned buildings in 

accordance with state regulations prior to allowing 

public access at Harkins Slough Unit.

7.1.3 Install gate at Harkins Slough Unit for 

staff access.

7.1.4 Conserve the Refuge’s cultural resources in 

accordance with all applicable laws.

Objective 7.2 Research, assess, and address 

mosquito-borne disease risks that may affect public 

use, health concerns, and Refuge resources.

Rationale: National Wildlife Refuge System 

policy allows native mosquitoes to exist unless 

they pose a specific wildlife and/or human health 

threat. The Refuge Administration Act, as amended, 

clearly establishes that wildlife conservation is the 

singular NWRS mission. House Report 105-106 

accompanying the National Wildlife Refuge System 

Improvement Act of 1997 states “...the fundamental 

mission of our System is wildlife conservation: 

wildlife and wildlife conservation must come first.” 

Avian and human diseases such as West Nile Virus 

are known to be transmitted through such vectors 

as mosquitoes. The Service will continue to work 

with the local mosquito and vector control district 

to avoid and reduce potential disease and nuisance 

mosquito outbreaks. Mosquito control activities will 

continue on the Refuge until a more comprehensive 

mosquito management plan can be completed to 

determine the precise character, extent, and level 

of abatement activity. The Service will work with 

the district to develop a plan that allows mosquito 

management on Refuge lands, when necessary 

to protect the health and safety of the public or 

a wildlife population, using effective means that 

pose the lowest risk to wildlife and habitats. In 

conjunction with preparing a Mosquito Management 

Plan, the Service will comply with all applicable 

environmental laws, including NEPA.
Chapter 5

58 Ellicott Slough NWR - Final Comprehensive Conservation Plan

Strategies

7.2.1 Continue mosquito control activities 

through the Santa Cruz County Mosquito and 

Vector District and CDFG for public safety and 

protection of Refuge resources. 

7.2.2 Develop a Mosquito Management Plan, 

including thresholds for control, assessment of 

control methods, and best management practices.

7.2.3 Consider alternative methods to chemical 

mosquito control, such as grazing and mowing, to 

reduce vegetation within wetlands that may harbor 

mosquitoes. (See also Strategy 3.3.2.)

Objective 7.3 Ensure the safety of resources, 

property, and visitors. 

Rationale: Increased safety measures would enable 

the Refuge to better fulfill its conservation mission 

and ensure improved experiences for Refuge visitors. 

Strategies

7.3.1 Increase law enforcement patrols.

7.3.2 Develop cooperative agreements with 

state and local agencies to support increased law 

enforcement patrols.

Objective 7.4 Within 10 years of Plan approval, 

work with stakeholders of the Pajaro Valley Watershed 

to assess fishing opportunities in Harkins Slough. 

Rationale: Fishing is identified in the 1997 

Improvement Act as one of six priority public 

uses on refuges. This activity has occurred on 

the Refuge illegally at Harkins Slough Unit and 

resulted in incidental trails, damaged vegetation, 

and disturbance to wildlife. Therefore, the use 

should be analyzed to determine if it is compatible 

and can be allowed. 

Strategies

7.4.1 Identify extent of existing use, impacts of 

use, challenges, and feasibility of fishing at Harkins 

Slough Unit.

7.4.2 Prepare a compatibility determination and, 

if compatible, prepare a fishing plan for the Harkins 

Slough Unit.

Objective 7.5 Within five years of Plan approval, 

provide interpretation, wildlife observation, and 

photography opportunities.

Rationale: Wildlife observation and photography 

are identified in the 1997 Improvement Act as two 

of six priority public use on refuges. The public will 

be encouraged to participate in self-guided trails for 

hiking on the Harkins Slough Unit and guided walks 

on units closed to the public.

Strategies

7.5.1 Provide a parking area, bilingual informational kiosk, and trails at the Harkins Slough Unit. 

7.5.2 Create and install self-guided interpretive 

infrastructure along trails at Harkins Slough Unit.

7.5.3 Lead at least one interpretive or 

informational walk annually at Harkins Slough and 

Ellicott Units, and at Buena Vista property after 

memorandum of agreement with CDFG is finalized.

7.5.4 Install bilingual information signs in front of 

closed units.

7.5.5 Develop and produce a general brochure 

and website about the Refuge.

7.5.6 Monitor impacts of wildlife observation and 

photography on Refuge resources.

7.5.7 Develop a Visitor Services Plan.

Objective 7.6 Offer volunteer opportunities to 

promote stewardship and appreciation of the Refuge.

Rationale: Due to staff size, the Refuge relies 

heavily on volunteer staff to conduct biological

and maintenance needs. The National Wildlife 

Refuge System Volunteer and Partnership 

Enhancement Act of 1998 (P.L. 105-242) identifies 

the importance of volunteers and strengthens the 

Refuge System’s role in developing relationships 

with volunteers. Volunteers possess knowledge, 

skills, and abilities that can enhance the scope 

of refuge operations. Volunteers and Friends 

Organizations may have a local understanding 

of community needs and how the Refuge may 

conduct outreach to the community.
Ellicott Slough NWR - Final Comprehensive Conservation Plan 59

Figure 10. Visitor Services at Ellicott Slough NWR 

Larkin Valley Rd.

San Andreas Rd.

Willow Crk. Dr.

Fiesta W ay

Rampart Dr.

Hark ni s Slough Rd. Cabrillo Hwy

Buena

V si at Dr.

Metvier's Way

Ardi lla Cyn Rd.

Mar Monte Rd.

UV1

0 0.25 0.5 1

Miles ± 0 0.25 0.5 1

Kilometers

Calabasas

Unit

Buena Vista

Property

Ellicott

Unit

Harkins Slough

Unit

Ellicott Slough National Wildlife Refuge

Visitor Services

!i Parking Area

!i

!Ö Trails, Interpretive Panels & Kiosk

!Ö

!] Information Sign

!]

!]

Approved Acquisition Boundary

Ephemeral Ponds

Harkins Slough

 Closed to public.

Public access restricted to

environmental education

program and guided

interpretive walks.

Provide wildlife observation,

photography and interpretation

and environmental education.
Chapter 5

60 Ellicott Slough NWR - Final Comprehensive Conservation Plan

Strategies

7.6.1 Provide volunteer opportunities, such as 

plant propagation, planting, invasive plant removal, 

plant surveys, and wildlife surveys.

7.6.2 Work with local National Audubon Society, 

wildlife, photography, and other organizations to 

offer joint walks, talks, and volunteer opportunities.

7.6.3 Support the development of a Friends 

Organization within the local community.

Objective 7.7 Continue the field-based program 

with Renaissance High School, and expand 

environmental education program to the other local 

elementary, middle, and high schools.

Rationale: Environmental education is identified 

in the 1997 Improvement Act as a priority public 

use that can be allowed when compatible with other 

Refuge purposes. To support this priority public 

use, the Service staff will work with local schools 

to bring children to the Refuge. Local schools are 

surrounded by an urban environment and have 

few opportunities to access natural settings. Conducting an environmental education curriculum on 

site is intended to allow children to promote selfdiscovery and experience the natural environment 

of the Monterey Bay area. The Refuge will partner 

with others to conduct in-class programs to prepare 

students for their field-based experience at the 

Refuge. The program curriculum will be aligned to 

the current Federal, state, and local standards. The 

environmental education program will be managed 

in accordance with Service Manual 605 FW 6 Environmental Education.

Strategies

7.7.1 Develop a field-based environmental 

education program at Ellicott and Harkins 

Slough Units that meets California state 

education standards.

7.7.2 Collaborate with partners (e.g., Watsonville 

Wetland Watch) to expand the in-class environmental 

education curriculum (e.g., develop amphibian life 

cycle curriculum) to other local schools.

7.7.3 Monitor impacts of environmental education 

on Refuge resources.

Objective 7.8 Continue and expand 

environmental programs and outreach to the local 

community and organizations through at least two 

outreach events annually.

Rationale: In 2007, the Service declared that 

“connecting people with nature” is among the 

agency’s highest national priorities (USFWS 2008). 

A connection with nature, whether it’s hiking, fishing, 

camping, hunting, or simply playing outside, helps 

children develop positive attitudes and behaviors 

towards the environment. Positive interactions with 

the environment can lead to a life-long interest in 

enjoying and preserving nature. People’s interest in 

nature is crucial to the Service mission of conserving, 

protecting, and enhancing populations of fish, wildlife, 

plants, and their habitats.

Strategies

7.8.1 Conduct off-site presentations to community 

groups and universities to promote support for 

Refuge resources.

7.8.2 Create and maintain a Refuge website (see 

Strategy 7.5.5).

7.8.3 Develop outreach to the local community 

through mailings and newsletters.

7.8.4 Provide outreach at local festivals (e.g., 

Migration Festival).

7.8.5 Contact the regional Connecting People 

with Nature team and seek advice and/or 

recommendations on ways to connect people to the 

Refuge lands.
Ellicott Slough NWR - Final Comprehensive Conservation Plan 61

Once the CCP has been approved and the 

Service has notified the public of its decision, the 

implementation phase of the CCP process will 

begin. During the next 15 years, the objectives 

and strategies presented in this CCP will be 

implemented; the CCP will serve as the primary 

reference document for all Refuge planning, 

operations, and management until it is formally 

revised at the end of the 15-year period. The 

Service will implement the final CCP with assistance 

from existing and new partner agencies and from 

organizations and from the public.

CCPs provide long-term guidance for management 

decisions and set forth goals, objectives, and 

strategies needed to accomplish refuge purposes 

and identify the Service’s best estimate of future 

needs. These plans detail program planning levels 

that may exceed current budget allocations and, as 

such, are primarily for Service strategic planning 

and program prioritization purposes. Plans do not 

guarantee a commitment of resources.

Activities required to accomplish the management 

strategies discussed in this CCP are referred to as 

projects. Every effort will be made to implement 

these projects by the deadlines established here. 

However, the timing of implementation of the 

management activities proposed in this document is 

contingent upon the following factors:

■ Funding

■ Staffing

■ Completion of step-down management plans

■ Compliance with other Federal regulations

■ Partnerships

■ Results of monitoring and evaluation

6.1 Funding and Staffing

To implement the proposed action and to achieve 

the objectives and goals of this CCP, the Service 

will need additional funding. Needs are recorded 

in the Service Asset Maintenance Management 

Chapter 6. Plan Implementation

System and Refuge Operating Needs System 

(RONS) for the Refuge System. Maintenance 

projects include repair and replacement of existing 

buildings and facilities and removal of unneeded 

infrastructure. RONS projects are proposed new 

Refuge projects that do not represent replacement 

of existing equipment or facilities. RONS projects 

for this Refuge include habitat restoration, wildlife 

monitoring, and visitor services programs. It is 

important to note that additional projects proposed 

in this CCP will be added to the RONS list during 

the life of this CCP. An estimated $2,200,000 in 

initial capital outlay is needed to implement projects 

in the CCP based on 2010 dollars (Table 6). The 

estimated annual cost to fully implement the CCP 

is $383,891 (Table 7). However, costs must be 

incrementally increased for inflation and additional 

activities such as new research studies. 

The Refuge is managed as a satellite refuge within 

the San Francisco Bay NWR Complex. While 

the Refuge manager and wildlife biologist are 

permanently assigned to Ellicott Slough NWR 

duties, the Refuge also receives law enforcement, 

maintenance, environmental education, and 

administrative assistance from staff that support 

the entire Refuge Complex. Salaries constitute a 

significant cost of implementing the CCP. Funding 

for four additional permanent staff is needed to 

implement the objectives and strategies of the CCP 

(Table 7). 

The needs and costs shown in Tables 6 and 7 are 

best estimates and may not entirely reflect the 

costs of managing the Refuge. The expenditures 

are followed by a reference to the number of 

the strategy (from Chapter 5) that expenditure 

implements or supports.

6.2 Step-Down Management Plans

Some objectives in the CCP require more detailed 

planning than the CCP process is designed to 

provide. For these projects, the Service will refer 

to step-down management plans and other plans to 
Chapter 6

62 Ellicott Slough NWR - Final Comprehensive Conservation Plan

Expenditure (related strategies) Unit Cost Priority

Conduct pond and upland drift fence and pitfall trap surveys to determine baseline 

population size and movement trends (includes 3 sites, for 3 consecutive years, at 

~$45,000 per each survey). (1.1.5.3)

$400,000 1

Materials needed to conduct new baseline wildlife surveys. (1.1.5.2, 1.1.5.4, 2.1.3, 

2.1.5, 4.2.1) $45,000 1

Conduct hydrological and soil surveys for existing ponds to inform management actions. (1.2.2) $75,000 1

Conduct hydrological and soil surveys for potential future pond locations. (1.2.3) $75,000 3

Continue the planning and redesign of existing, non-functional breeding pond (Prospect Pond), and complete required NEPA, ESA, and Federal Coastal Zone Management Act compliance and permitting. (1.2.5)

$250,000 2

Conduct a hydrological assessment of Harkins Slough. (1.3.1) $125,000 2

Understand and determine (through surveys and research) sources of contaminants, 

effects, and prevalence. If warranted, plan and implement a course of action to decrease exposure to affected areas. (1.4.4)$100,000 1

Materials needed for GIS system and mapping. (2.1.2, 3.1.3, 3.2.1) $20,000 1

Conduct plant surveys and mapping of the entire Refuge; sample a sub-set area at 

each refuge unit every 3–5 years thereafter. (3.2.3) $40,000 1

Within 5 years of the Plan, develop a Habitat Management Plan including an adaptive 

Habitation Management Plan. (3.3) $75,000 1

Remove hazardous fuel loads through manual, grazing, mechanical, and prescribed 

burn methods. (5.2.5) $80,000 1

Conduct flood-risk and climate-risk analysis of lands on and adjacent to the Refuge. (6.1.1) $50,000 2

Assess effects of climate change on disease outbreaks and parasites (e.g., monitoring 

presence of Rana viruses and chytrid in amphibians in relation to rising ambient and 

pond water temperatures). (6.1.8)

$20,000 1

Assess saltwater intrusion (i.e., effects on plants, wildlife) for Harkins Slough as a 

result of sea-level rise. (6.1.9) $50,000 3

Cap existing wells in accordance with state regulations prior to allowing public access 

at Harkins Slough Unit. (7.1.1) $100,000 1

Remove existing abandoned buildings prior to allowing public access at Harkins 

Slough Unit. (7.1.2) $150,000 1

Install gate at Harkins Slough Unit for staff access. (7.1.3) $10,000 1

Provide parking areas, bilingual informational kiosk, and trails at Harkins Slough 

Unit. (7.5.1) $270,000 1

Create and install self-guided interpretive infrastructure along trails at Harkins 

Slough Unit. (7.5.2) $30,000 2

Install bilingual information signage in front of closed units. (7.5.4) $30,000 3

Develop and produce a general brochure and website. (7.5.5, 7.8.2) $20,000 1

Develop field-based environmental education program at Ellicott and Harkins Slough 

Units that meets California state education standards. (7.7.1) $35,000 1

Conduct boundary surveys of the Ellicott and Harkins Slough Units and Buena 

Vista, and install additional boundary fencing and/or signage. (in support of Goals 

1,2,3,4,5 and 7)

$150,000 1

Total Ellicott Slough NWR (estimated capital outlay) $2,200,000

Table 6. Estimated initial capital outlay to fully implement the CCP
Ellicott Slough NWR - Final Comprehensive Conservation Plan 63

provide additional details necessary to implement 

objectives and strategies in the CCP. A number of 

step-down plans will be developed or updated after 

completion of the CCP, including: 

■ Fire Management Plan (last updated 2002)

■ Mosquito Management Plan

■ Habitat Management Plan

■ Water Management Plan

■ Visitor Services Plan

6.3 Compatibility Determination

Federal law and policy provide the direction and 

planning framework to protect the Refuge System 

from incompatible or harmful human activities and to 

ensure that Americans can enjoy Refuge System land 

and waters. The 1997 Improvement Act is the key 

legislation on managing public uses and compatibility.

Before activities or uses are allowed on a refuge, 

uses must be found to be compatible through a 

written compatibility determination. A compatible 

use is defined as a proposed or existing wildlifedependent recreational use or any other use of 

an national wildlife refuge that, based on sound 

professional judgment, will not materially interfere 

with or detract from the fulfillment of the Refuge 

System mission or the purposes of the refuge. 

Sound professional judgment is defined as a decision 

that is consistent with the principles of the Service’s 

management and administration, available science 

and resources, and adherence to the requirements 

Expenditure Status Unit Quantity Total Cost2

Salaries and Benefits2

Refuge Manager – GS-11 Existing FTE 0.5 $48,593

Wildlife Biologist – GS-9 Existing FTE 0.5 $41,379

Maintenance Worker – WG-7/8 To fulfill Goals 1,2,4,5, 

and 7

Proposed & 

unfunded FTE 0.5 $34,828

Outdoor Recreation Planner – GS-7/9 To fulfill Goal 7 Proposed & 

unfunded FTE 0.5 $36,512

Park Ranger/Law Enforcement – GS-7/9 To fulfill 

Goals 1,2,3,5, and 7

Proposed & 

unfunded FTE 0.5 $37,729

Biological Technician – GS-5/7 To fulfill Goals 1,2,3, 

and 4

Proposed & 

unfunded FTE 0.5 $29,850

Subtotal Salaries and Benefits - Ellicott Slough NWR FTE 3.0 $228,891

Expenditure Total Cost

Programs

Maintenance (repairs, replacement, rentals, etc.) $75,000

Invasive Weed Program (herbicide, materials, contract, equipment repairs and replacements) $50,000

Amphibian Monitoring Program $15,000

Environmental Education Program $15,000

Subtotal Programs - Ellicott Slough NWR $155,000

TOTAL - Ellicott Slough NWR

(annual salaries and benefits budget and annual programs budget) $383,891

1

 Staffing and funding would be sought over the 15-year life of this Plan subject to approval and funding by Congress. 

2

 Estimates are based on 2010 salary levels with 30% added for benefits. Existing salaries are calculated using the 

current grade and step level of the position; proposed salaries are calculated using the highest grade the position will 

attain at a step 1 level. All positions are shared with Salinas River NWR (i.e., 0.5 FTE for Salinas River NWR).

Table 7. Estimated annual cost to fully implement the CCP 1
Chapter 6

64 Ellicott Slough NWR - Final Comprehensive Conservation Plan

of the 1997 Improvement Act and other applicable 

laws. Wildlife-dependent recreational uses may be 

authorized on a refuge when they are compatible 

and not inconsistent with public safety.

Compatibility determinations for environmental 

education and interpretation, mosquito 

management, research, and wildlife observation and 

photography are included in Appendix G.

6.4 Compliance Requirements

This CCP was developed to comply with all Federal 

laws, Executive orders, and legislative acts. For 

information on applicable laws and regulations, see 

the Legal and Policy Guidance section in Chapter 1.

6.5 Partnership Opportunities

Volunteer and Friends Organizations efforts are 

critical to the achievement of Refuge objectives 

and strategies. The Refuge has partnered 

with governmental agencies, nongovernmental 

organizations, and individuals to conduct wildlife 

monitoring, habitat restoration, and facility 

maintenance activities. These partners play an 

important role in helping the Service achieve its 

mission and the Refuge’s goals. The Service will 

continue to rely on these and other partners in the 

future to help implement this CCP and to provide 

input for future CCP updates. In addition, the 

Service will continue to explore other potential 

avenues for partnerships and assistance in the 

monitoring and restoration of the Refuge.

6.6 Monitoring and Evaluation

This CCP is designed to be in effect for a 15-year 

period. The Plan will be reviewed and revised as 

necessary to ensure that established goals and 

objectives are still applicable. The monitoring 

program will focus on issues involving visitor 

services activities, habitat restoration, wildlife 

monitoring, and other management activities. 

Monitoring and evaluation will use the adaptive 

management process. This process includes goal 

and objective setting, and applying management 

tools and strategies, followed by monitoring and 

analysis to measure achievement of objectives and to 

refine management techniques.

Collection of baseline data on amphibian and 

other native wildlife populations will continue. 

This data will be used to update existing species 

lists, determine habitat requirements, and guide 

management actions. Where information gaps 

exist, a concerted effort will be made to obtain 

information. With new information, goals 

and objectives may need modification. Public 

involvement will be encouraged during the 

evaluation process. 

Monitoring of visitor services programs will involve 

the collection of visitor use statistics. Monitoring 

will be done to evaluate the effects of visitor 

services on Refuge habitat, wildlife populations, 

and visitor experience.

6.7 Adaptive Management

Adaptive management is characterized by 

management that monitors the results of policies 

and/or management actions and integrates this 

new information, adjusting policy and management 

actions as necessary (Jacobson 2003). Adaptive 

management promotes flexible, effective decision 

making that can be adjusted in the face of 

uncertainties as outcomes of management actions 

and other events become better understood. 

Careful monitoring of these outcomes advances 

understanding of the system and helps adjust 

policies. Adaptive management incorporates natural 

variability in evaluating ecological resilience and 

productivity (Trulio and Clark 2005). 

Adaptive management provides the framework 

within which biological measures and public use 

can be evaluated by comparing the results of 

management to the expected results of objectives. 

Under the CCP, habitat, wildlife, and public use 

management techniques and specific objectives 

would be regularly evaluated as the results of 

monitoring programs, new technology, and other 

information become available. These periodic 

evaluations would be used over time to adapt both 

the management objectives and the strategies 

to better achieve management goals. Such a 

system embraces uncertainty, reduces option 

foreclosure, and provides new information for 

future decision making, while allowing resource use. 

The management scenario proposed in this CCP 

provides for ongoing adaptive management of the 
Ellicott Slough NWR - Final Comprehensive Conservation Plan 65

Refuge. The CCP may be amended as necessary at 

any time in keeping with the adaptive management 

strategy. However, major changes to the CCP may 

require public involvement processes and additional 

NEPA compliance documentation. The Refuge 

manager will determine the appropriate public 

involvement and NEPA compliance requirements. 

Plan revisions are discussed in the next section.

6.8 Plan Amendment and Revision

The CCP is intended to evolve as the Refuge 

changes; to this end, the 1997 Improvement 

Act specifically requires that CCPs be formally 

revised and updated at least every 15 years. 

The formal revision process would follow the 

same steps as the CCP creation process. In the 

meantime, the Service will review and update this 

CCP periodically if needed, based on the results 

of the adaptive management program. While 

preparing annual work plans and updating the 

Refuge database, Refuge staff will also review 

the CCP. It may also be reviewed during routine 

inspections or programmatic evaluations. Results 

of any or all of these reviews may indicate a need 

to modify the Plan. The goals described in this 

CCP would not change until they are reevaluated 

as part of the formal CCP revision process. 

However, the objectives and strategies may be 

revised to better address changing circumstances 

or to take advantage of increased knowledge of 

the resources on the Refuge. It is the intent of 

the Service that this CCP apply to any new lands 

that may be acquired as part of the Refuge. If 

revisions to the objectives and strategies are 

needed, the Refuge manager will determine the 

appropriate public involvement and associated 

NEPA compliance requirements.

The intent of the CCP is for progress toward and/or 

achievement of Refuge objectives during the lifetime 

of the Plan. Management activities would be phased 

in over time, and implementation is contingent 

upon and subject to the results of monitoring 

and evaluation, funding through Congressional 

appropriations and other sources, and staffing.