Derelict Fishing Gear Assessment Framework 1

Assessing Ecological and Economic Effects of 

Derelict Fishing Gear: a Guiding Framework

Christopher F. G. Jeffrey1, Kirk J. Havens2, H. Ward Slacum, Jr.,

Donna Marie Bilkovic2, Danielle Zaveta3, Andrew M. Scheld2, 

Sean Willard1,John D. Evans4

Revision 1 - Oct. 7, 2016

Prepared for

Marine Debris Program

Office of Response and Restoration

National Oceanic and Atmospheric Administration

Contract DG133E-10-CQ-0034, Task Order 007

Derelict crab pot removal in the Chesapeake Bay (Photo credit: Matt Stewart)

1CSS-Dynamac, Inc. 2Virginia Institute of Marine Science 3Versar, Inc. 4Global Science & Technology, Inc.
i

Assessing Ecological and Economic Effects of Derelict 

Fishing Gear: a Guiding Framework

Revision 1 – Oct. 7, 2016

Table of Contents

Executive Summary ..........................................................................................................................................ii

1. Introduction / Background .....................................................................................................................1

1.1 Background – NOAA’s Marine Debris Program..........................................................................1

1.2 The Problem of Derelict Fishing Gear..........................................................................................1

1.3 Purpose and Scope...........................................................................................................................3

1.4 Intended Audience...........................................................................................................................3

2. Derelict Fishing Gear Assessment Framework ...................................................................................5

3. Characterizing Derelict Gear Density and Spatial Distribution ......................................................8

3.1 Overview.............................................................................................................................................8

3.2 Use of Various Types of Datasets.................................................................................................8

4. Assessing Ecological Effects of Derelict Gear .....................................................................................8

4.1 Overview.............................................................................................................................................9

4.2 Mapping / Quantifying Bycatch Species......................................................................................9

4.3 Quantifying Mortality Rates........................................................................................................ 10

4.4 Mapping Sensitive Habitats......................................................................................................... 11

5. Assessing Economic Costs of Derelict Gear ..................................................................................... 12

5.1 Overview.......................................................................................................................................... 12

5.2 Characterizing Fishing Effort and Harvest.............................................................................. 12

5.3 Decreased Harvests....................................................................................................................... 12

5.4 Habitat Damage ............................................................................................................................. 13

5.5 Navigational Hazard..................................................................................................................... 14

5.6 Replacement Gear ......................................................................................................................... 14

6. Detecting and Removing Derelict Fishing Gear ............................................................................... 15

6.1 Overview.......................................................................................................................................... 15

6.2 Derelict Gear Detection................................................................................................................ 15

6.3 Derelict Gear Removal.................................................................................................................. 16

7. Evaluating Management Implications ................................................................................................ 18

7.1 Spatial and Temporal Management of the Fishery ................................................................ 18

7.2 Data Reviews, Compilation, and Synthesis.............................................................................. 19

7.3 Data Collection Plans to Fill Critical Data Gaps ..................................................................... 19

Appendix A. Global Derelict Fishing Gear Estimates ............................................................................ 20

References ....................................................................................................................................................... 22

Acknowledgments ......................................................................................................................................... 27
Derelict Fishing Gear Assessment Framework ii

Executive Summary

Developing standardized protocols to assess the ecological and socio-economic effects of 

marine debris – especially, derelict fishing gear – is critical for the protection of natural 

resources and for evaluating policies and programs designed to reduce and remove debris. This 

document outlines a Derelict Fishing Gear Assessment Framework to guide the development 

and implementation of derelict gear assessment, management and mitigation. The framework 

draws from techniques and protocols developed to assess derelict crab traps effects in the 

Chesapeake Bay and on past derelict gear assessments either conducted by or known to the 

framework authors. However, this framework is generalized and intended to be used by any 

stakeholder with a need to assess the status of derelict fishing gear and its economic and 

ecological effects on living resources, habitats, ecosystems, and local economies. It provides a 

generalized pathway and processes for assessing the effects of derelict fishing gear, and is 

flexible and scalable so that users of the framework can make informed decisions when data 

are limited, and can tailor it to satisfy their specific assessment goals and objectives if a full 

scale assessment is not required. The framework recommends best practices for each of five 

key elements (Figure 1):

 Characterize the abundance and distributions of derelict gear and associated fisheries;

 Conduct analyses to quantify economic impacts on fishery target and bycatch species;

 Conduct analyses to determine ecological impacts on living resources and critical or 

sensitive habitats;

 Evaluate management implications through scenario driven economic and ecological 

assessments;

 Recommend appropriate management actions and strategies to mitigate negative economic 

and ecological impacts of derelict gear.

Descriptions of appropriate derelict gear metrics are provided with an emphasis on those 

variables and metrics most common among fisheries, and most likely to predict ecological or 

economic effects. For each of the key elements, the framework provides guidance on consistent 

methods for stakeholder engagement, data collection or acquisition, and data analysis.

Section 1 of this document provides a global context and motivation for assessing and 

managing derelict fishing gear. Section 2 outlines the framework and essential ingredients 

including developing conceptual models, planning an analytic approach, evaluating data, and 

developing quantitative models.

Sections 3, 4, and 5 describe technical details and procedures for characterizing the density and 

spatial distribution of active and derelict fishing gear; for mapping and quantifying vital rates 

to assess ecological effects of derelict gear; and for determining data needs and approaches to 

assess economic effects of derelict gear on fisheries. These sections emphasize detailed 

guidelines on required data, information, methods, approaches, protocols, as well as best 

practices and data gaps for each element in the framework. Each section includes descriptions 

of common data, data limitations, modeling, and other analytical techniques.
Derelict Fishing Gear Assessment Framework iii

Section 6 provides an overview of techniques used to detect and remove derelict fishing gear, 

so as to facilitate the collection of data needed to assess their effects on local ecosystems and 

economies. Many techniques to detect and remove derelict fishing gear are available and have 

been applied in various fisheries and habitats. A list of specific techniques and references is 

provided here, along with specific protocols to help guide stakeholders interested in collecting 

needed data to characterize derelict gear or to mitigate their effects through detection and 

removal programs.

The final framework element (Section 7) describes how a structured derelict gear assessment 

can be used to inform resource managers about mitigation options. This section provides 

guidance of how results from derelict fishing gear assessments can be used to relate the 

ecological and economic effects of derelict gear to management implications and 

understanding the factors affecting implementation of mitigating actions. 

The ultimate goal of any derelict fishing gear assessment should be to determine how best to 

manage and mitigate derelict gear effects. This Derelict Fishing Gear Assessment Framework is 

designed to be a flexible, scalable, practical guide to help stakeholders meet this goal.

Figure 1. Conceptual assessment framework to characterize, assess, and mitigate economic and

ecological impacts of derelict fishing gear on fisheries, living resources, habitats, and ecosystems.
Derelict Fishing Gear Assessment Framework 1

1. Introduction / Background

1.1 Background – NOAA’s Marine Debris Program 

Marine debris (including derelict fishing 

gear) is a major stressor to marine 

ecosystems; it threatens habitats, living 

resources, and the provisioning of 

ecosystem goods and services in U.S 

waters and the global oceans.1 The 

Marine Debris Act, signed into law in 

2006 and amended in 2012, defines 

marine debris as “any persistent solid 

material that is manufactured or 

processed and directly or indirectly, 

intentionally or unintentionally, 

disposed of or abandoned into the 

marine environment or the Great 

Lakes.” The Marine Debris Act

establishes the NOAA Marine Debris 

Program “to identify, determine sources of, assess, prevent, reduce, and remove marine debris 

and address the adverse impacts of marine debris on the economy of the United States, the 

marine environment, and navigation safety.”2

1.2 The Problem of Derelict Fishing Gear

The accumulation and effects of derelict fishing gear (traps, pots, nets) is a global problem.3-6

Traps are fished in large numbers and high rates of trap loss plague many of the world’s 

crustacean fisheries (Appendix A, Table A-1; Figure 2); as a result, fishing traps are thought to 

be one of the most common types of derelict gear worldwide.7 This framework focuses on traps 

and stationary nets (i.e. gill nets).

Derelict fishing traps, whether lost by accident or intentionally discarded, have a tendency to 

continually capture animals (termed “ghost fishing”) for variable amounts of time depending 

upon the trap construction and material type.4,9-13 Modern traps are often constructed from rigid 

and durable materials such as vinyl-coated wire or synthetic mesh6,14,15 which can extend the 

time a derelict trap remains functional over the more artisanal traps of the past which were 

made mostly of wood or fiber.16-20 Experiments in the Chesapeake Bay (U.S.A.) indicate that blue 

crab (Callinectes sapidus) traps generally retain their structural integrity for two years or 

more.1,12 Derelict traps can act as a structural attractant for crustaceans or an aggregating 

device for fish.21-25 Blue crabs and other crustaceans are known to be attracted to traps as 

bottom structure whether or not any bait is 

present; with retention rates varying 

according to trap design and intra- and interspecies interactions.4,21-23,26 Animals that are 

captured and die in derelict traps can attract 

Summary of Relevant Goals from the NOAA 

Marine Debris Program Strategic Plan

 Marine Debris Research & Assessment - Identify, 

assess and reduce the impacts of marine debris 

through detection, monitoring, source 

identification and innovative solutions.

 Marine Debris Removal - Support the removal of 

marine debris to reduce its impact on natural 

resources, navigational safety and the economy.

 Marine Debris Prevention - Prevent the 

introduction of marine debris through raising 

awareness and changing behavior.

NOAA Marine Debris Program Strategic Plan: 2016 - 2020 

(October 2015)

Derelict fishing gear can continue to capture 

animals and is sometimes referred to as “ghost 

fishing.” Some derelict traps have been shown 

to continue functioning for up to 15 years.
Derelict Fishing Gear Assessment Framework 2

other animals, which then become entrapped and continue a ‘self or auto-baiting’ cycle.12,13, 27

Catch efficiencies of derelict traps can decline over time;10,28 however, many trap types can 

continue to capture, injure, and kill animals for over two years 4,12-14,29,30 and in some cases can 

remain functional for at least 15 years.31 More durable traps made of predominantly synthetic 

material may cause ecological and economic damage for many years.32

In addition to the direct loss of target species in 

derelict traps due to mortality, derelict traps 

impose an economic cost in terms of reduced 

trap efficiency by competing with active traps 

for the target species resulting in a hidden nonharvestable allotment of target species associated with derelict traps. This loss of harvest can 

compromise the economic vitality of fishery dependent businesses and communities.8

In the Chesapeake Bay, extensive gear removal programs between 2008 and 2014 increased 

blue crab harvest by 38 million pounds (23.8%) over the six year period.33 For the U.S. Atlantic 

and Gulf state blue crab fisheries, extensive gear removals might increase landings by over 40%, 

generating US $62 million in annual revenue benefits. However, large-scale location and removal 

of submerged, unbuoyed traps requires expensive equipment and may not be practical over 

large areas or for extended periods. Fortunately, intensive (focused) removals of derelict traps 

from a few heavily fished areas can also increase local harvests. In the Chesapeake Bay, 

removing as little as 10% of the total number of recovered derelict traps from the 10 most 

heavily fished areas (five in Virginia and five in Maryland) increased the Bay-wide blue crab 

harvest by 14%.33

Figure 2. Global distribution of major crustacean pot and trap fisheries.

8

Total global landings from all crustacean trap fisheries grossing US $20 million or more 

annually (Figure 2) average 615,560 MT and are worth US $2.5 billion (Appendix A, Table A-2). 

Together, these high-value fisheries deploy tens of millions of pots and traps, millions of which 

become derelict each year. Extending findings 

from Chesapeake Bay blue crab to global crustacean fisheries suggests that removing less than 

10% of the derelict pots and traps in these 

Removal of just 10% of derelict traps in the 

world’s largest crustacean fisheries could 

increase harvest by $831,000,000 annually.

Derelict fishing gear can affect harvest by:

 Direct mortality of target species

 Competition with active gear for target 

species.
Derelict Fishing Gear Assessment Framework 3

fisheries could increase landings by 293,929 MT, at a value of US $831 million annually.8,33 Net 

benefits of removal programs will ultimately depend upon trap location and removal costs 

however, which may vary widely.

1.3 Purpose and Scope

Derelict fishing gear is a major concern for coastal resource managers, given its widespread 

occurrence and its far-reaching negative ecosystem impacts. To guide characterizations and 

assessments of the impacts of derelict fishing gear on marine ecosystems, and the fisheries 

they support, we propose a Derelict Gear Assessment Framework as a guide for local assessment and management of derelict fishing gear problems. It provides a generalized but scaled 

approach for assessing derelict fishing gear impacts; describes requisite data and information 

needs for a comprehensive assessment of ecological and economic impacts; and where 

possible, recommends best practices and management actions to remove and prevent 

accumulation of derelict fishing gear and ultimately to mitigate economic and ecological 

impacts.

This Framework is modeled after a recent comprehensive characterization and assessment of 

derelict crab traps in the Chesapeake Bay region.

33

It is applicable to the assessment of derelict 

fishing gear impacts in general and provides a standardized approach for managing derelict 

gear and mitigating their impacts on ecosystems nationally.

1.4 Intended Audience 

This Framework is primarily intended for NOAA Marine Debris Program managers, policy 

makers, natural resource managers, and others who perform work or receive sponsorship 

under NOAA’s Marine Debris Program or follow its guidelines and regulations concerning 

marine debris. The style, language, terminology and concepts described here are intended to be 

useful to a diverse audience including Federal, State, and local agencies, scientists, members of 

the general public, and other stakeholders who may need to characterize marine debris or 

assess its economic and ecological impacts on living resources, habitats, ecosystems, and local 

economies. We hope that this report will be a first step in developing a broad scientific 

consensus about assessments of derelict gear. 
Derelict Fishing Gear Assessment Framework 4

Chesapeake Bay Case Study

The Chesapeake Bay Blue Crab fishery. The guiding

framework detailed here was initially developed for and 

applied to the Chesapeake Bay33, the largest estuary in the 

United States with a fishing industry worth more than $3 

billion a year and accounting for 50% or more of the nation’s 

blue crab (Callinectes sapidus) harvest. The primary gear 

used to harvest blue crabs in the Chesapeake Bay is a rigid 

cube-shaped wire trap, or “crab pot,” galvanized or vinylcoated, and deployed and recovered by a line and buoy 

system. Commercial fishery effort is estimated to be ~600,000 

pots annually.34

Blue Crab management: one population, three sets of 

rules. Chesapeake Bay blue crab is a single population, but it 

is managed differently in the Maryland, Virginia, and Potomac 

River portions of the Bay. Management actions are partially 

linked to the complex life cycle of the blue crab, which 

involves multiple horizontal and vertical migrations, often

across state boundaries. Blue crabs rely on high salinity areas 

in the lower Bay for egg brooding and hatching, larval 

development, and overwintering;

35-37

they inhabit low salinity 

waters of tributaries and creeks in the spring and summer;

35

and when temperatures drop below 9°C they congregate in 

deeper water and bury in muddy sediments.

38-40 Spatial 

patterns of fishing effort follow the crabs’ migration; most crab 

pots are deployed in waters less than 10m deep, in the 

mainstem of the Bay and (in Virginia) in its tributaries.41,42

Data collection. In order to evaluate the ecological and economic impacts of derelict crab pots, information was first 

compiled to determine 1) the distribution and abundance of derelict pots, 2) bycatch capture and mortality, 3) potential damage to sensitive habitats, and 4) the effect on harvest due to competition with derelict traps. After learning of 

potential causes of pot loss from fishers and managers, the distribution of derelict pots was compared statistically 

with these potential causes including boat traffic, storm events, and intentional abandonment.

Data analysis. The study integrated many datasets using a Biogeographic Assessment Framework43to

 identify variables that could predict the distribution and abundance of derelict crab pots, 

 model, estimate, and map the densities and spatial distributions of derelict crab traps, and their impacts on 

populations of crab and other fish and on sensitive habitats; 

 estimate potential impacts of derelict crab trap removals on commercial blue crab harvests;

 conduct sensitivity analyses to identify ways to mitigate the impacts of derelict crab pots. 

Findings and insights.

 Trap loss was due primarily to boat traffic (severing buoy lines, displacing gear) and abandonment (due to aging 

gear, sickness or death of fisher, other).

 Using fisheries independent effort data led to better estimations of derelict fishing gear abundance in areas with 

large management units such as the Maryland mainstem portions of the Bay.

 Each year, derelict pots kill over 3.3 million blue crabs across the Chesapeake Bay (4.5% of the harvest).

 12-20% of crab pots are lost each year; this implies over 145,000 derelict pots in the Bay at any given time.

 Over 40 fish species have been reported captured in derelict pots, including economically important ones. Each 

year derelict pots kill over 3.5 million white perch and nearly 3.6 million Atlantic croaker.

 Extensive gear removal programs spanning 2008-2014 increased blue crab harvest by 38 million lbs over the 6 

year period. In addition, targeted gear removals from a few high-density fishing areas disproportionately 

increased harvests Bay-wide.

Management actions.

 Minimize boat traffic in crabbing areas, and educate boat operators about avoiding pots to reduce pot loss.

 Conduct targeted derelict pot recovery programs to reduce bycatch mortality and to increase catch efficiency 

from lost pots. Also incentivize the removal of abandoned pots by fishers themselves.

 Equip crab pots with biodegradable escape panels to minimize bycatch mortality from lost pots.

Figure 3. Spatial distribution of derelict crab pots 

in the Chesapeake Bay estimated through 

geographically weighted regression.

33
Derelict Fishing Gear Assessment Framework 5

2. Derelict Fishing Gear Assessment Framework

Like traps, other fishing gear affects both the living resources being targeted as well as the 

surrounding habitats in which they live. In turn, the heterogeneity of the seafloor and habitats, 

patchy distributions of targeted living resources, and environmental factors such as seasons, 

storms, and wave action, all affect the location and accumulation of derelict gear. Additionally 

human demography, behavior, as well as availability of access to the marine environment 

directly affect the location and intensity of fishing effort, which ultimately determines the 

occurrence of derelict gear. Developing strategies to manage derelict gear requires a comprehensive approach for characterizing the spatial and temporal distributions of derelict gear, 

assessing their economic and ecological effects, and implementing management strategies to 

mitigate their negative impacts on living resources, habitats, and the marine ecosystems. 

The Framework presented here represents such a comprehensive approach. It provides a fivephased linear process model for characterizing, assessing and mitigating ecological and 

economic impacts of derelict fishing gear on managed living marine resources, habitats, and 

ecosystems (see Figure 1, Executive Summary). It identifies generalized pathways and 

processes needed to:

1. Characterize spatially explicit abundance and distributions of derelict gear and their 

associated fisheries

2. Conduct analyses to quantify economic impacts on fishery target and bycatch species

3. Map and characterize benthic habitats then conduct analyses to determine ecological 

impacts on living resources and critical or sensitive habitats

4. Evaluate management implications through scenario driven economic and ecological 

assessments

5. Recommend for implementation, appropriate management actions and strategies to 

mitigate negative economic and ecological impacts of derelict gear

Subsequent chapters provide more detailed guidelines on required data, information, methods, 

approaches, protocols, as well as best practices and data gaps for each phase of the framework. 

In addition, the Framework provides a tiered approach which allows for informed decisions 

based upon various levels of available data and to adaptively manage impacts of derelict fishing 

gear based upon the particularities of the specific fishery of interest.

Developing a comprehensive framework to manage derelict gear and mitigate their impacts 

involves developing conceptual models, designing an appropriate analytic approach, evaluating 

data to determine minimum requirements, and developing quantitative models. 

Conceptual models. An important first step is to develop conceptual models based on sound 

ecological theory but which are also grounded in socio-economic reality (Figure 4). Conceptual 

models are hierarchical theoretical constructs visualized in flow diagrams to show qualitative 

relationships among components that represent dependent and independent variables within 

complex systems. These models are widely used in systems ecology to hypothesize about direct 

and indirect relationships among various biotic and abiotic elements within a defined and 

bounded system.44,45 A conceptual model will provide a systematic approach for 

(a) identifying components of the ecosystem that could be directly or indirectly affected,

(b) evaluating their relative contribution to hypothesized ecological and economic effects, and

(c) hypothesizing further about possible ways to mitigate negative impacts.
Derelict Fishing Gear Assessment Framework 6

It is important then that conceptual models be based on exhaustive reviews of the scientific 

literature on fisheries and derelict gear. In addition, input from local experts, non-scientists, 

and fisher-folk who are most familiar with local fishery issues will be substantially beneficial.

Design the Analytic Approach. Designing and planning a suitable analytic approach is critically 

important for developing a framework. Planning is useful, not only for developing higher level 

project goals and objectives, but also for developing specific guidelines for conducting quantitative data analyses, ensuring the use of statistically defensible analyses, and increasing the 

likelihood of achieving unambiguous results. Given the paucity of quantitative information 

regarding ecological impacts of derelict gear, it is essential to develop simple but realistic 

hypothesis-driven analyses that will support the higher-level goals and objectives of a derelict 

gear impact assessment project. At the same time, question driven analyses regarding derelict 

gear impacts should be developed within the broader context of the socio-economic, ecological, 

and management issues related to the fishery to ensure the most critical and influential factors 

are being considered.

Planning involves iterative refinement of the hypothetical relationships among conceptual 

model components as well as adding or eliminating input variables based on initial exploratory 

analyses of data, additional literature review, and consultation with management agencies, 

NGOs, and other stakeholders. During the planning stage, it is also necessary to develop a 

Figure 4. An operational (tiered and practical) assessment framework for derelict fishing gear.

Critical / minimum data on derelict fishing gear (DFG) (left panel) enable analyses, metrics, and indicators 

(middle) required to mitigate DFG economic and environmental impacts for long-term sustainability (right).
Derelict Fishing Gear Assessment Framework 7

spatial framework for analysis that defines both the spatial extent of the study area and the 

resolution of the data (i.e. level of detail) needed to characterize derelict gear and quantify 

ecological and economic impacts. An output from sound planning will be the identification of a 

reduced list of input variables that correlate significantly with dependent variables and which 

could be used as predictors of dependent variables that are sparse or expensive to obtain or 

collect (Figure 4). Ideally, input variables should be ubiquitous with broad spatial and temporal 

coverage and correlate significantly with dependent variables of interest that are sparse.

Evaluate Data and Determine Minimum Requirements. Obtaining primary data on the occurrence and distribution of derelict fishing gear can be prohibitively expensive. Hence, relevant 

data regarding the types, distribution, occurrence, and ecological or socioeconomic impacts of 

derelict gear is unavailable in most fisheries. Except for a handful of targeted derelict fishing 

gear removal programs (such as exist in the Chesapeake Bay), much of the existing knowledge 

regarding derelict gear and their impacts derive from secondary data sources and disparate 

programs designed to collect other fisheries-related or ecological data. Consequently, data to be 

used for characterizing derelict gear occurrence and distributions and inferring ecological 

impacts must be carefully evaluated for their suitability to these intended purposes.

Evaluating data to assess derelict gear impacts includes determining the best and most 

appropriate data sources; assessing each dataset’s geographical, temporal, and compositional 

extent and associated gaps; and understanding the uncertainty, errors, and associated caveats 

of the data. Crucial considerations for evaluating data include the following:

 Are the data of appropriate spatial and temporal coverage?

 Do datasets contain enough observations for robust statistical analyses?

 Can disparate datasets be merged for broader spatial and temporal coverage without 

violating the statistical assumptions underlying the initial data collections?

 Will extrapolations of integrated data across geographic space and time provide ecologically 

meaningful relationships rather than spurious associations?

Develop Quantitative Models. Model development involves the use of empirical data to test and 

validate theoretical constructs and hypothesized relationships through explicit mathematical 

functions. Quantitative models consist of three main parts: a response variable whose value 

changes as observational data inputs into the model change, a mathematical function with 

main effect variables and estimated parameters that predict the value of the response variable, 

and random errors that vary systematically according to known statistical distributions. Modeling requires a fundamental understanding of how the main effects and errors are propagated 

through the modeling system. 

A wide variety of modeling approaches are available for use; all share three common steps: 

(1) Selecting an initial model form that would be best suited to the data assembled;

(2) Iteratively fitting the model to the assembled data to estimate unknown parameters; and 

(3) Independently validating the model results against known data to see if the underlying 

model assumptions are plausible. 

Sections 3, 4, and 5 below illustrate the iterative use of various modeling techniques to 

characterize derelict gear density and spatial distribution; to assess ecological impacts to 

bycatch and sensitive habitats; and to determine economic impacts to the fishery.
Derelict Fishing Gear Assessment Framework 8

3. Characterizing Derelict Gear Density and Spatial 

Distribution

3.1 Overview

Characterizing the spatial distribution of derelict fishing gear is crucial for inferring their

ecological and economic impacts in marine ecosystems. The accumulation of derelict fishing 

gear in many aquatic systems varies spatially and temporally. To obtain unbiased estimates of 

the quantity and spatial coverage of derelict gear within an area of concern, it may be costeffective to model gear abundance and distribution, especially for large areas where comprehensive detection surveys and removal programs may be too expensive. When developing a 

model to estimate abundance and occurrence, it is important to select a suitable spatial 

resolution that matches the scale at which ecological inferences will be made and at which 

management decisions to mitigate derelict gear impacts will be effective. Often, selection of an 

optimal spatial resolution for analysis is constrained by the resolution of data available and 

depends on the analytic specific analysis being conducted or question being investigated. 

Derelict gear estimation may require further data collection to refine the spatial domain and 

extent of analysis. A variety of approaches can used to estimate gear abundance and 

occurrence, however the method and data used for these estimates will have different biases 

and limitations.

3.2 Use of Various Types of Datasets

Many types of fisheries-related information may be used for initial characterization of derelict 

gear. For example, fisheries effort data on the amount and location of active gear sets,

combined with reports from fishers about their average rate of gear loss, could be used to 

derive estimates of derelict gear accumulation. Estimates from such data will be constrained by 

the size or spatial scale of the management units applicable to the fisheries data. Additionally, 

fisheries data and reports of gear loss from active fishers may be subject to various biases such 

as the number of individuals interviewed, regional differences, methods or techniques used by 

different fishers, or the fishery regulations under which they operate. For example, incentive 

programs that compensate fishers for lost gear may lead to overestimating rates of gear loss. 

Conversely, fishers may underreport effort data if they are subject to regulations that penalize 

violations of gear limits. Depending on the goal, this type of derelict gear estimation may 

nonetheless be adequate for a coarse understanding of amount and location of gear.

Data on derelict gear occurrence can also be obtained from gear retrieval programs. These often 

have a limited spatial coverage because their implementation costs are relatively high; however

georeferenced data from such programs can be used to estimate (predict) gear abundance over 

larger spatial coverages through geospatial modeling (below).

33 However, it is important to 

understand potential biases inherent in this type of data. For example, interpreting and 

standardizing data from retrieval events requires estimating the retrieval effort: how did search 

efforts (number of hours, number of individuals involved) vary across the recovery area? Were 

there different techniques that would lead to different recovery efficiencies? etc. Furthermore, 

dataset normalization can help stem issues with false zeroes or seemingly low or high derelict 

gear abundances. So while overall concentrations and effects of derelict gear information can be 
Derelict Fishing Gear Assessment Framework 9

inferred from gear retrieval efforts, they are influenced by a wide range of factors. Before 

making broad spatial inferences, it’s important to have a clear understanding of these factors 

throughout the system, and to collect data from a range of areas.

Depending on the amount and quality of data available, a wide range of spatial techniques may

be used for estimating derelict gear quantity – from simple multiplication, kriging, and 

interpolations, to advanced spatial modeling. Modeling requires (i) an understanding of the 

factors that may lead to gear loss and accumulation, (ii) spatial data for those factors, and (iii) a 

known relationship between them. This relationship can be developed using training data or a 

set of locations with known derelict gear abundance along with corresponding factor data at 

those locations. A key advantage of this technique is being able to predict gear abundance at 

different locations when only condition or factor data is available. However, the model’s 

prediction power is only as strong as the modeling relationship between known derelict gear

and contributing factors. As with many modeling techniques, it is important to limit predictions 

within spatial coverage of the training data and training factor values.

4. Assessing Ecological Effects of Derelict Gear

4.1 Overview

Ecological effects of derelict gear can occur at a variety of spatial and temporal scales and 

through several pathways ranging from simple direct interactions with habitat and living 

organisms to more indirect but complex relationships among dynamic populations, sensitive 

habitats, and the fishery. For most managed areas and fisheries, sufficient data do not exist at 

the required spatial coverage or temporal and spatial scales to fully define the ecological 

relationships between derelict gear and the various components of the marine ecosystem. As 

such, the framework provides a systematic and scalable approach for integrating existing data 

and other information on derelict gear, target and bycatch species, and sensitive habitats to 

characterize and assess ecological impacts from derelict gear over broad spatial scales. The 

approach involves using GIS-based models to 

(1) predict densities and define the spatial distribution of derelict gear, 

(2) apply estimated derelict gear capture and mortality rates obtained from experimental 

studies to spatial distributions of target and bycatch species, and 

(3) define the spatial overlap between derelict gear distributions and sensitive habitats. 

4.2 Mapping / Quantifying Bycatch Species

Quantifying ecological impacts of derelict gear on bycatch species requires information on 

catch species composition, rates of gear capture and mortality, and spatial distribution of non 

target species. Experimental field studies can provide crucial and representative data on catch 

composition and mortality rates if they are conducted over extended periods and investigators 

track and record the condition of trapped individuals with enough frequency. However, field 

experiments require rigorous and time intensive field work that may be too difficult and expensive to implement over large areas and sample sizes. In addition to field experiments, valuable 

but conservative data on species composition, capture, and mortality from gear could be 
Derelict Fishing Gear Assessment Framework 10

obtained also from large retrieval programs that periodically remove gear, if the composition 

and condition of the catch is noted when gear is removed. One caution is that seasonal and 

spatial variability may prevent the use of incidental bycatch data in deriving annual catch and 

mortality estimates for derelict gear. In addition, observed estimates of mortality, even from 

experimental studies, may underestimate actual gear mortality unless delayed mortality from 

injury, stress, infection, and fatigue are also considered.6,10,44

Bycatch species in derelict gear may include both managed and unmanaged species. Economically important non-target species or threatened/endangered (T&E) species that are managed 

and/or well-studied may have available data on distributions, abundance, and harvest that can 

greatly help inform potential adverse effects from derelict gear including direct and indirect 

mortality or damage to essential habitat. There may also be enough of the requisite data 

available for non-target non-fisheries species that are well-studied. For example, Diamondback 

terrapin (Malaclemys terrapin) is a species that is at high risk to mortality from active or 

derelict crab traps.47,48In many regions, there are limited data on population sizes for this nonfisheries species; however, the habitat requirements for terrapin are well understood and 

mapping important habitats could serve as a surrogate measure for potential risk to the 

population. This approach could also be used for other T&E species with historically low 

populations that make mortality estimates challenging. Those species that are not managed or 

well-studied may require additional directed studies to assess specific capture and mortality 

rates caused by derelict gear. 

4.3 Quantifying Mortality Rates

In order to establish a sustainable fishery, it is necessary to effectively manage the primary 

sources of fishing mortality, including losses due to derelict gear.49 Animals captured in derelict 

gear, including invertebrates, finfish, turtles, birds, and mammals can starve, cannibalize each 

other, drown, develop infections, and become diseased.4,10,48 Certain crustaceans are known to be 

aggressive and cannibalistic (e.g.. blue crab, Callinectes sapidus), and confinement in traps 

causes death or injury to conspecifics and bycatch.4,23,25 Mortality rates in derelict traps vary 

among fisheries. For example, in the Korean blue crab (Portunus trituberculatus) fishery, the 

elimination of ghost fishing mortality by derelict traps was modeled to have a 14% increase in 

catch50 while Dungeness crab mortality in derelict traps is estimated at 7%, 4.5%, and 2.2% of the 

harvest in various locations along the west coast of North America.27,28,30 In the Chesapeake Bay,

mortality due to derelict crab pots is estimated at about 5% of the harvest.33

Cryptic or unaccounted mortality resulting from derelict gear has been increasingly recognized 

as a source of mortality that can be managed.6,33,49,51 Collecting essential baseline data for 

calculating instantaneous and annual bycatch mortalities by gear type is an important 

consideration for any derelict gear recovery program52 but adequate data is often lacking and, 

thus, is not routinely accounted for in fisheries management.

Data on mortality rates require experimental studies and field observations. Ghost-fishing 

mortalities can be estimated either by monitoring the number and fate of animals that became 

captured, or by placing captive animals in the gear and monitoring their fate over time, with 

monitoring conducted in situ directly by divers and video surveys, or by retrieving a subset of 

the derelict gear at various time intervals.49 Various methods for deriving mortality per unit 

period of time for derelict traps and nets are discussed in some detail elsewhere.4,6,49,53,54
Derelict Fishing Gear Assessment Framework 11

4.4 Mapping Sensitive Habitats

Benthic habitat and living resource maps often characterize and delineate the spatial extents of 

important ecological areas such as areas of high productivity and biodiversity (hotspots); 

locations of special features, communities and key species that are critical to ecosystem 

function and resiliency (e.g. submerged aquatic vegetation, coral reefs, or oyster beds); or rare, 

endangered or functionally vulnerable marine resources (e.g., sea turtles). When these maps are 

combined with georeferenced data on derelict gear occurrence, density, and distribution, the 

degree of spatial overlap between derelict gear and sensitive habitats can be measured and 

used as a proxy for estimating ecological effects at a broader ecosystem level.

The most obvious ecological effect of stationary fishing gear is direct physical disturbance to 

the seafloor. In addition to direct observations of fisheries gear-habitat interactions from field 

and experimental studies, the cumulative ecological effects of derelict gear deployed over large 

areas can be estimated. If the locations and spatial extents of fishing gear and important 

habitats are known, then the degree of interactions between derelict gear and sensitive habitat 

could be inferred through geospatial modeling. In the U.S., large investments in mapping by 

government agencies (e.g., BOEM, NASA, NOAA, USGS) and the private sector (e.g., Google, ESRI), 

along with recent improvements in remote sensing technologies (e.g., satellite, lidar, hydroacoustic sonar) have created a plethora of high resolution (< 100m) benthic and living resource 

distribution maps for many managed areas. Where such maps are not available, qualitative data 

from fishers and other local experts on intensity of various human uses and location of 

targeted resources can be captured through participatory mapping and used to delineate 

perceived ecologically important areas.

Important caveats are that maps should be comprehensive in their spatial coverage (i.e. fully 

represent the study area of interest), have suitable spatial resolutions, and have relatively high 

map accuracy (i.e. users must have a high degree of confidence in the map) if they are to be 

used effectively in identifying ecological effects over broad spatial scales. As an example, when 

modeled distributions of derelict pots in the Chesapeake Bay were intersected with distribution 

maps of two sensitive habitats (submerged aquatic vegetation and oyster beds), results 

suggested minimal spatial overlap between derelict gear and these habitats of concern.33It is 

likely that blue crab operators generally may be avoiding crabbing in submerged aquatic 

vegetation and oyster habitats. However, anecdotal data from trap removal studies suggest that 

derelict traps do occur in some areas with submerged aquatic vegetation. One likely explanation 

is that National Environmental Policy Act requirements restricted derelict pot removal from 

sensitive habitats, and that model predictions of derelict trap spatial occurrence may have been 

underestimated. In addition, although extensive portions of the Chesapeake Bay have been 

mapped for sensitive habitats, spatial coverage of the maps is not 100%, and this could also 

have led to underestimating the degree of spatial overlap between sensitive habitats and 

derelict trap distributions.
Derelict Fishing Gear Assessment Framework 12

5. Assessing Economic Costs of Derelict Gear

5.1 Overview

Economic costs imposed by derelict gear can result through a variety of mechanisms, which 

may vary according to attributes of the fishery, ecosystem, and broader region under consideration. Major categories of costs include: decreased harvests, habitat damage, hazards to 

navigation, and replacement gear.33 To measure these costs, a number of different models can 

be applied to collected and available data. Assessing the economic impacts of derelict gear 

frequently requires comparing status quo economic outcomes and valuations against a 

hypothetical of no or minimal levels of derelict gear (i.e., what economic outcomes or values 

would be without derelict gear). This section discusses fisheries data and four categories of 

economic costs, together with general models and data needed for empirical estimation.

5.2 Characterizing Fishing Effort and Harvest

Integral to understanding the distribution and the potential impact of derelict fishing gear is 

the knowledge of both fishery effort and fishery harvest. Fishing effort, or the measure of 

amount of fishing activity, is often estimated through the combination of effort put into the 

fishery such as the number of hours or days spent fishing and the amount of gear used.

Harvest data is generally reported as the amount of the target species caught and retained from 

a given area for a given period of time.

Both effort and harvest data can be collected from fishery-dependent sources (direct reporting 

from the fishery such as vessels or seafood dealers) or from fishery-independent sources. 

Fisheries scientists or managers often collect fishery-independent data while conducting 

resource-monitoring projects. Although fisheries-dependent data is often easier and cheaper to 

obtain, it is hard to determine its accuracy especially if there is skepticism for potential bias. As 

noted earlier (Section 3.2), special consideration should be taken to review all potential sources 

of bias when fisheries-dependent data is used and to plan for ways to mitigate the bias either 

through conversion or using different sources. Fishery-independent sources often provide less 

biased information and can be tailored to specific applications. Furthermore, effort data 

reported at the state level or for large management units may be too coarse to be used in 

impact assessments when derelict gear presence may vary at more fine spatial scales.

Depending on the fishery and the spatial and temporal scale of the derelict gear assessment, it 

may be necessary to use fisheries-independent data to obtain the spatial and temporal 

resolution needed. 

5.3 Decreased Harvests

Derelict gear may decrease commercial and recreational harvests of target and bycatch species. 

Reductions in harvests arise as a result of reductions in stock as well as from the reduced 

efficiency of actively fished gear. Stock reductions may be significant in fisheries with high 

rates of capture and mortality of target and bycatch species by derelict gear. If derelict gear 

leads to large stock reductions, commercial and recreational harvests may also decrease as 

there is less biomass available to the fishery. Decreased gear efficiency may be significant in 

fisheries where effort is spatially concentrated and where derelict gear acts as an attractant to 
Derelict Fishing Gear Assessment Framework 13

target and bycatch species (e.g., as artificial habitat). If derelict gear attracts and/or captures a 

substantial amount of target or bycatch stocks, commercial and recreational fishers might 

catch and harvest less than they would otherwise (i.e., active gear will be less efficient in the 

presence of derelict gear). The economic costs of harvest reductions can be quantified in terms 

of lost revenues (commercial), lost utility (recreational), or increased fishing costs (commercial 

and recreational). Note that recreational fishers may derive non-consumptive benefits through 

catch-and-release fishing, in which case changes in catch, and the associated changes in utility, 

would be most relevant.

To evaluate economic losses arising from harvest reductions, commercial and/or recreational 

harvests should be modeled. A common specification for harvest is: 

1. H qEX 

In equation (1), harvests (H) are specified as a function of effort (E), the stock of fish (X), and a 

scale factor known as a catchability coefficient (q). Derelict gear may affect both the stock of 

fish (stock reduction) as well as catchability (efficiency reduction). The total difference in 

harvest attributable to derelict gear can be specified as:

2.      H H H qEX qEX

where , q, and 

X

are the harvest, catchability, and fish stock, respectively, in the absence of 

derelict gear. Equation (2) is thus the difference between harvests with and without derelict 

gear. If derelict gear significantly reduces the stock or gear efficiency, (2) would yield a negative 

value indicating harvests would be higher if derelict gear were not present. 

The data needed to evaluate (2) will depend on which mechanism of harvest loss is being 

modeled. In all cases, data on harvests, effort and stock is required. When modeling harvest 

losses arising from stock reductions, it is necessary to estimate

X

. This can be done using 

population models which explicitly incorporate the effects of derelict gear (e.g., as an additional 

source of mortality). Data on derelict gear mortality rates and other factors entering a model of 

stock dynamics (e.g., growth and maturity rates) would therefore be necessary in estimating

X . 

Modeling losses due to decreased gear efficiency requires estimating 

q

. An estimate of 

q

can 

be derived through comparison of harvests across areas and/or times when derelict gear is and 

is not present, or is present to varying degrees, controlling for the effects of differences in 

effort and stock. Scheld et al.8 derived an estimate of 

q

by incorporating derelict gear removals 

into a spatially explicit harvest model. Data on the amounts and location of derelict gear (or 

removals) and harvest is required to estimate 

q .

5.4 Habitat Damage

Derelict gear can cause physical damage to coastal and marine habitats, primarily as a result of 

gear movement and scouring. The economic costs of habitat damage may be significant in areas 

with sensitive or ecologically important habitats, where strong currents, tides, or storm events 

cause substantial movement of derelict gear. Assessing the economic costs of habitat damage 

requires estimates of habitat value and the response of habitat to derelict gear.

Habitat may be valued as an input to production of ecosystem goods and services (e.g., clean 

water or biomass) or as an offset to expenditures on man-made goods/services (e.g., for storm 

protection). Values for these goods and services can be drawn from available data and the 
Derelict Fishing Gear Assessment Framework 14

published literature or estimated by the analyst. Once value estimates are obtained, a 

mechanistic model is necessary to understand how a particular habitat provides the good or 

service and how changes in the amount or extent of that habitat affect provision, and therefore 

habitat value.

The impact of derelict gear on a specific habitat can be found through observation and 

experimentation. Once habitat response to derelict gear has been determined, this information 

can be used together with value estimates and the mechanistic model to assess changes in 

value resulting from changes in the amount or location of derelict gear. Total costs or losses 

from derelict gear can be found through counterfactual comparisons (i.e., comparing habitat 

value with and without derelict gear). Data requirements will depend on the habitat being 

valued and the specific empirical models used, though in general, data on the amounts and 

values of ecosystem goods and services provided by the habitat, as well as habitat response to 

derelict gear will be necessary.

5.5 Navigational Hazard

Derelict gear may pose a navigational hazard to commercial or recreational vessel traffic. 

Economic costs result from necessary changes in navigation to avoid derelict gear as well as 

damage to vessels and equipment. Costs may be significant in areas with heavy commercial or 

recreational traffic.

Quantifying the costs of derelict gear resulting from increased hazards to navigation requires a 

model of route planning or navigation decision-making and/or vessel and equipment damage 

assessments. Fuel, labor, and materials/equipment costs of vessel traffic patterns with and 

without derelict gear can then be evaluated and used to assess costs. Data on vessel traffic, 

vessel and equipment damage, as well as amounts and location of derelict gear would be 

necessary to evaluate these costs.

5.6 Replacement Gear

Fishers may ultimately need to replace the derelict gear. Replacement gear represents an 

economic loss if it would have been more cost effective had the gear not become derelict. These 

costs may be significant when gear is costly, when behavioral changes to reduce loss are 

inexpensive, or if derelict gear physically damages active gear. Note that simply summing 

expenditures on new gear to replace that which becomes derelict will likely produce an 

overestimate of economic losses.

To accurately assess the economic costs of replacement gear, depreciation in value for the gear 

which became derelict would need to be estimated. Additionally, if gear loss could have been 

avoided through changes in fishing practices (e.g., spatial or temporal shifts in effort), the costs 

of such behavioral modifications should be deducted (i.e., current fishing practices offer cost 

savings which should be accounted for). If derelict gear physically damages active gear through 

movement or entanglement, the costs of these damages should also be included. The 

replacement costs or lost value of purposely abandoned gear should not be considered—had 

the gear been of any value to the fisher it would not have been abandoned. The data necessary 

to evaluate replacement gear costs include the cost of new gear, depreciation rates, age of gear 

when it becomes derelict, the costs of behavioral modifications to avoid loss, and estimates of 

damage to actively fished gear.
Derelict Fishing Gear Assessment Framework 15

6. Detecting and Removing Derelict Fishing Gear

6.1 Overview

Derelict fishing gear detection and removal methods depend upon the type of gear and the

physical characteristics of the environment in which the lost gear is located. However, some 

basic guidance and essential baseline data collection is applicable across a suite of stationary 

gear types and can be helpful in providing critical information on the ecological and/or 

economic impacts resulting from derelict gear.

6.2 Derelict Gear Detection

In remote sensing there are generally two important criteria: detection and identification. 

Detection refers to the observation of a potential object of interest while identification reveals 

the object as a specific type.55 Various remote sensing survey methods exist in regard to derelict 

fishing gear ranging from visual to acoustic (Table 1). Visual surveys can utilize divers with or 

without surface supplied air or involve surface observers scanning an area for easily observable 

lost gear. Acoustic surveys (i.e. side scan sonar) are a form of remote sensing where the 

acquisition of information is obtained using a detection system based on the reflection of 

underwater sound waves. Morison and Murphy56summarize projects using these methods to 

detect and identify derelict traps. The basic approach and application of these methods could 

be used to detect and identify any type of derelict fishing gear. Side scan sonar has been shown 

to be very useful in detecting and identifying derelict fishing gear not only because of the 

detection capability but also the GPS tagging of the object location for future recovery.

Bottom trawling or grappling is a direct survey method that usually involves dragging a hook 

and line type device on the bottom of an area in an effort to capture derelict gear. NRC57

describe both trawling and diver type surveys with accompanying pros and cons. The 

appropriate survey method used will vary depending on the survey area environment and gear 

target type and ultimately involves a trade-off between data acquisition and expense.

Regardless of the survey method used, training on various images that will be potentially 

encountered during the survey is critical. The collection of an image database from which image 

calibration and validation can be conducted increases the ability of the observer to differentiate 

between derelict gear and other marine debris and is an important component of any survey.13

An image catalog can be developed by deploying target gear in various aspect configurations 

and degrees of decay from which observers can be trained on image identification.

A vital piece of information to obtain during derelict gear surveys is the specific location of the 

identified item. In sonar surveys, this is usually obtained via GPS12 or, in the case of towed 

divers, by vessel/diver coordinated timed transects.58 Collection of spatially explicit data 

increases the likelihood of derelict fishing gear recovery and provides enhanced analysis in 

regard to the geospatial distribution of derelict gear, relationships to harvest and fishing effort, 

and bycatch distribution as well as the capacity to resurvey the area to obtain gear loss rates.
Derelict Fishing Gear Assessment Framework 16

6.3 Derelict Gear Removal

Determining the regional primary drivers for gear loss (i.e. accidental, abandonment, storms, 

vandalism, equipment failure) is critical for the implementation of any management action. 

Information on the primary drivers of gear loss can be gathered by conversations with fishers 

and management personnel or through surveys of the lost gear. Stakeholders, in particular 

commercial fishers and resource management 

personnel, have regional expertise on derelict 

gear location and the causes of gear loss 

critical to a successful program. Early 

involvement of commercial fishers and 

management personnel in the program 

design, data collection, and program 

modification provides a positive interactive 

experience with the scientific and governmental aspects of natural resource management.66

Table 1. General survey methods to detect and remove derelict fishing traps and nets.

Method Expertise Advantages Challenges References

Side Scan 

Sonar – Hull 

Mounted

Minimal Low cost, GPS marked 

gear, can be programmed 

to scan transects

Limited to relatively shallow zones 

(15m). Limited utility in high relief 

areas

12, 59

Side Scan 

Sonar - AUV

High GPS marked gear, can be 

programmed to scan 

transects, can scan deeper 

than hull mounted

Limited utility in high relief areas, 

entanglement risk, expensive

60

Side Scan 

Sonar -

Towed

Moderate GPS marked gear, can be 

programmed to scan 

transects, can scan deeper 

than hull mounted

Limited utility in high relief areas, 

moderately expensive

13, 30

Diver Moderate 

(shallow) 

to High 

(deep)

Maneuverability, can both 

identify and remove 

debris

Survey area limited, water clarity 

limited, expensive depending on 

depth, entanglement risk

57, 61

Towed diver Moderate Versatile in various 

bottom structure 

conditions, potential for 

multiple data collection 

along survey transect

Survey area limited, water clarity 

limited, restricted movement, some 

entanglement risk

58, 62, 63

Cameras –

submersible 

/towed

High GPS marked gear, visual 

record, access to depths

Limited camera views, limited in low 

visibility situations, can be expensive 

depending on platform

60, 64

Bottom 

trawling / 

grappling by 

transect

Minimal Removal of gear during 

survey

Depending on transect length –

limited geospatial information on 

gear, benthic habitat impacts due to 

indiscriminate bottom trawling / 

grappling

32

Visual

observation

at or near 

the surface

Minimal Removal of abandoned 

gear with attached floats

Limited to easily observable gear, 

misses submerged / un-buoyed gear

65

Derelict Gear Removal Highlights

 Engage commercial fishers and resource 

managers early in the planning

 Where appropriate, hire commercial fishers for 

data collection and derelict gear removal

 Obtain GPS coordinates for all gear removed

 Take pictures of all gear removed

 Collect data on derelict gear bycatch

 Collect data on derelict gear condition
Derelict Fishing Gear Assessment Framework 17

Establishing two-way interactions that produce positive outcomes enhances program legitimacy 

and can be crucial to implementation of management scenarios while direct involvement in 

data collection enables peer to peer knowledge transfer among the stakeholder community. The 

North Carolina Coastal Federation, in partnership with NC Sea Grant, developed a simple 

electronic tablet app for derelict trap data collection (http://www.nccoast.org/crabpot) which

they have successfully implemented 

with NC commercial fishers. 

Educational materials on derelict 

trap removal and data collection are

available at 

http://ccrm.vims.edu/marine_debris

_removal/.

Retrieval methods for derelict gear 

differ based upon the gear type and 

the habitat in which the gear is 

located 61,66 and, in some cases due to 

the potential for damage to benthic 

habitats during removal efforts, it 

may be necessary to assess the cost 

/ benefit of removing derelict gear 

from sensitive habitats. 1,4,12

A protocol for survey and removal of derelict 

fishing gear

1) Determine Primary Drivers of Gear Loss

a) Survey of fishers

b) Survey of management personnel

2) Survey of Derelict Gear

a) Image catalog: Quality Assurance/Quality Control 

(QA/QC) for derelict gear identification

b) Development of a survey design

c) GPS location of derelict gear (critical information)

i) Location relative to sensitive habitat

ii) Location relative to boating activity

iii) Location relative to fishery management areas

iv) Spatial distribution and density

3) Removal of Derelict Gear

a) Pictures of items collected and bycatch 

(also serves as QA/QC for removed gear)

b) Bycatch Documentation

i) Species

ii) Sex

iii) Size

iv) Living/injured/dead

c) Gear Documentation

i) Functional/nonfunctional 

(still capable of trapping animals?)

ii) Buoyed/un-buoyed

iii) Location relative to sensitive habitat 

(seagrass, marsh, reefs, etc.)

iv) Identifying features, labels, tags

v) Escape panels present?

(1) functional/nonfunctional

vi) Biofouling on gear

4) Post Removal of Derelict Gear

a) Match removal data with fishery management areas

i) Harvest data

ii) Fishing effort

b) Dispose of gear responsibly
Derelict Fishing Gear Assessment Framework 18

7. Evaluating Management Implications

The framework presented in this document offers a strategy for characterizing derelict gear 

distributions and associated impacts to ecosystems and the fisheries they support. It provides 

guidance on the key data requirements, data collection methods, and analytic approaches that 

could be used to assess the scope and extent of the derelict gear problems within managed 

fisheries. Through modeling scenarios based on a recent Chesapeake Bay assessment,

33 the 

framework identifies practical and effective management options that can be used for 

mitigating derelict gear impacts within a defined region. Furthermore, the framework can be 

used to structure existing and future derelict gear removal and reduction initiatives so that they 

collect and synthesize baseline data that is essential for informing management actions. Based 

on lessons learned from the Chesapeake Bay assessment, the following are key recommendations for assessing derelict gear distributions and mitigating associated environmental and 

economic impacts.

7.1 Spatial and Temporal Management of the Fishery

Lesson learned: The way in which a fishery is managed can influence the amount of gear that

becomes derelict and may ultimately determine the level to which derelict gear negatively 

impacts the fishery, target and non-target species, and habitats.

Recommendation: Review spatial and temporal management of the fishery. 

Process:

1. Convene meetings of resource managers and fishers to discuss management and primary 

drivers of derelict gear within the fishery.

2. Identify regulations that may contribute to increased abundance of derelict fishing gear and 

their effects. This exercise could also help to guide the approach for identifying geographic 

locations where derelict gear may be more persistent than other areas. Examples of these 

types of regulations include:

2.1.Areas designated as no fishing for a particular gear or off limits to all fishing activity 

(e.g., marine protected areas) tend to have high densities of fishing gear along their 

boundaries, and may have greater concentrations of derelict fishing gear.

2.2.Temporal regulations that would increase the likelihood that certain gear types might 

become derelict. Gear loss could be attributed to instances when certain fishing areas 

are opened for short durations, or opened during seasons when weather events 

contribute to greater gear loss.

3. Evaluate how changes to regulations such as additional enforcement, modifying rules (e.g., 

allowing fishers to remove abandoned gear), spatial and temporal management changes, 

and other mitigation strategies or incentives (e.g., functional cull rings, biodegradable 

panels, derelict gear removal efforts) could modify the effects of derelict gear in a particular 

fishery or environment.

4. Develop scenarios and quantify how modifications identified above would change the 

effects of derelict gear in the fishery or environment.

5. Monitor to determine if any subsequently implemented actions are having the desired effect 

and recruit fishers in the data collection.
Derelict Fishing Gear Assessment Framework 19

7.2 Data Reviews, Compilation, and Synthesis

Lesson learned: The collection of spatially explicit data on derelict gear location, target and 

non target species harvest, and fishing effort allows for robust modeling of ecological and 

economic impacts for management consideration.

Recommendation: Conduct comprehensive and exhaustive data reviews, compilation, and 

synthesis.

Process:

1. Review active gear, derelict gear, and harvest data to determine spatial extent, collection 

method, and potential biases.

2. Review sensitive habitat spatial distribution data (e.g., locations of reefs, shellfish beds, 

aquatic vegetation).

3. Review spatial information on resource overlap between competing interests (e.g.

commercial fishers, recreational boating).

4. Evaluate spatial resolution of data to determine appropriate alignment between management information (e.g., harvest and effort data) and location and abundance of derelict gear.

5. Modify collection and reporting of harvest and effort data to the appropriate spatial and 

temporal scales.

7.3 Data Collection Plans to Fill Critical Data Gaps 

Lesson learned: Critical information gaps on spatial patterns of human use hinder assessments 

of ecological and economic impacts from derelict gear.

Recommendation: Develop and implement data collection plans to fill critical data gaps.

Process:

1. Consider the use of participatory mapping when engaging managers and stakeholders to 

identify spatial use patterns.

2. Review and explore the use of secondary social science data to identify spatial demographic 

patterns over large areas and obtain economic profiles of users.

3. Develop and implement data collection plans such as user and fishing effort surveys to 

quantify recreational fishing effort and recreational uses. For example, anecdotal data and 

information from local fishers in the Chesapeake Bay suggest that recreational crabbing is a 

likely source of derelict gear, but the intensity of recreational fishing effort in the Chesapeake Bay is not fully known.

Relating derelict gear location and removal activities to ecological and economic management 

implications, and understanding the factors affecting implementation of mitigating actions, are

critical to addressing the global issue of derelict fishing gear. This Framework provides a tiered 

approach, based upon various levels of available data, to inform stakeholders and to help them

adaptively manage derelict fishing gear impacts based upon the needs of the particular fishery.
Derelict Fishing Gear Assessment Framework 20

Appendix A. 

Global Derelict Fishing Gear Estimates

Table A-1. Documented effects on select trap fisheries of derelict fishing gear 

constructed with wire or synthetic materials. (Modified from Bilkovic et al.5)

Region

(U.S.A. unless noted)

Traps 

deployed

Annual gear 

loss (%)

Capture or mortality in derelict traps

(individuals per trap per year unless noted) References

Blue Crab - Callinectes sapidus

Maryland ~400,000 10 − 20% 21 (mortality) 13, 67

Virginia 392,175 10 − 30% 50.6 (capture) 12, 66

Virginia ~250,000 20% 18 (mortality) 68

North Carolina >1 million 14 − 21%

12 − 17%

20-30 (mortality); 40.4 (capture) 

(44% mortality in derelict pots)

29, 59, 69

Chesapeake Bay 600,000 –

800,000

12 - 20% 23 (mortality)

totalling 3.3 million / year (~5% of harvest)

33

Florida - Gulf Coast 361,912 30 − 50% − 46

Alabama 26,100 25% − 46

Mississippi − 20 − 30% − 46

Louisiana 870,220 up to 100% 25.8 (mortality) 10, 46

Texas 51,800 35 − 50% − 46

American Lobster - Homarus americanus

Maine 3.2 million 20 − 25% ≥ 33% mortality 70, 71

Caribbean spiny lobster - Panulirus argus

Florida Keys ~500,000 18 - 22% 3.0 – 6.8 20, 72

Dungeness crab - Cancer magister

British Columbia, Canada 26,250 11% 9.3 (7% of the catch in the Fraser River) 28

California - 100,000 traps - 73

Washington state − 12,193 traps 0.058 (mortality) (4.5% of recent harvest) 27

Alaska, southeast 23,000 -

92,000

- Capture: 4.47% of harvest

Mortality: 2.2% of the harvest

30

Tanner crab - Chionoecetes bairdi

Bering Sea, Alaska − 10 – 20% 39% mortality 74

Red king crab - Paralithodes camtschatica

Alaska − 10% 2−7% mortality 75

Womens Bay, Kodiak Island, 

Alaska

- - 40 – 56% mortality 76

Blue swimmer crab - Portunus pelagicus

Queensland, Australia ~9,000 70% 3−223 14

Octopus - Octopus vulgaris

northeast Atlantic Ocean, south 

coast of Portugal

217,929 24% 0.87 77

Sablefish - Anoplopoma fimbria

British Columbia, Canada − − 15−30% of the commercial catch (1977–1983) 78

Various fish and invertebrates

Sultanate of Oman (also used in 

Arab Persian Gulf states)

17,442 20%, 88% 80.51 kg 79, 80
Derelict Fishing Gear Assessment Framework 21

Region

(U.S.A. unless noted)

Traps 

deployed

Annual gear 

loss (%)

Capture or mortality in derelict traps

(individuals per trap per year unless noted) References

Fish traps

St. Thomas & St. John, U.S. 

Virgin Islands

6,500 10 - 20% 22.9 kg 81

Barbados, Caribbean - 25% - 82, 83

Iskenderun Bay, Istanbul, 

Turkey

~5000 11% (traps)

13-65% (nets)

- 84, 85

Lobster and fish traps

Guadeloupe (French West Indies 40,000 50% - 86

Eel traps

Korea ~1 million 15.6% - 87

Table A-2. Gear loss and global landings for major crustacean pot and trap fisheries. 

Annual averages, 2003-2012. (after Scheld et al.8)

Species Gear Loss 

(%)5

Landings 

(MT)

Revenues 

(US$) Major Producers

Blue swimmer crab 

Portunus pelagicus

70 173,647 $199Ma China, Philippines, Indonesia, 

Thailand, Vietnam

American lobster

Homarus americanus

20-25 100,837 $948M Canada, USA

Blue crab

Callinectes sapidus

10-50 98,418 $152M USA

Queen crab/snow crab 

Chionoecetes opilio

NA 113,709 $401M Canada, St. Pierre and Miquelon 

(France), USA

Edible crab

Cancer pagurus

NA 45,783 $49Mb United Kingdom, Ireland, Norway, 

France

Dungeness crab

Metacarcinus magister

11 35,659 $169M USA, Canada

Spiny lobster

Panulirus argus

10-28 34,868 $500M90 Bahamas, Brazil, Cuba, Nicaragua, 

Honduras, USA

King crab

Paralithodes camtschaticus

10 10,137 $99M USA

Stone crab (claws only)

Menippe mercenaria

NA 2,502 $24M USA

TOTAL 615,560 $2.5B

Notes on Table A-2:

Data from: NOAA Office of Science and Technology, National Marine Fisheries Service, Commercial fisheries statistics 

http://www.st.nmfs.noaa.gov/st1/commercial; Food and Agriculture Organization, United Nations, Fisheries and 

Aquaculture Department, http://www.fao.org/fishery/search/en, Fisheries and Oceans Canada http://www.dfompo.gc.ca/stats/commercial/sea-maritimes-eng.htm. 

a

Based on an average price of US $1.15/kg.88

b

Based on 2004-2012 average price of US $1.07/kg.89
Derelict Fishing Gear Assessment Framework 22

References 

1. Arthur, C., Sutton-Grier, A., Murphy, P., Bamford, H. 2014. Out of sight but not out of mind: 

Harmful effects of derelict traps in selected U.S. coastal waters. Marine Pollution Bulletin. 86: 

19-28.

2. United States Congress (112th), 2012. Marine Debris Act Amendments of 2012 (H.R. 1171) 

and United States Congress (109th), 2006. Marine Debris Research, Prevention, and 

Reduction Act. S.362. (33 U.S.C. 1951-1958 (2006))

3. Hérbert, M., G. Miron, M. Moriyasu, R. Vienneau, P. DeGrâce. 2001. Efficiency and ghost 

fishing of snow crab (Chionoecetes opilio) traps in the Gulf of St. Lawrence. Fisheries 

Research 52:143-153.

4. Matsuoka, T., Nakashima, T. & Nagasawa, N. 2005. A review of ghost fishing: scientific 

approaches to evaluation and solutions. Fish. Sci. 71:691–702.

5. Bilkovic, D., K. Havens, D. Stanhope, K. Angstadt. 2012. The use of fully biodegradable 

panels to reduce derelict pot threats to marine fauna. Conservation Biology 26 (6): 957-966.

6. Uhlmann, S. S. & Broadhurst, M. K. 2015. Mitigating unaccounted fishing mortality from 

gillnets and traps. Fish Fish. 16:183–229.

7. Macfadyen, G., Huntington, T. & Cappell, R. 2009. Abandoned, lost or otherwise discarded 

fishing gear (UNEP Regional Seas Reports and Studies, No. 185; FAO Fisheries and Aquaculture Tech. Paper, No. 523; Rome, 2009).

8. Scheld, A. M., Bilkovic, D, Havens, K.J., 2016. The dilemma of derelict Gear. Sci. Rep. 6:19671; 

doi: 10.1038/srep19671.

9. Smolowitz, R.J. 1978. Trap design and ghost fishing: an overview. Mar. Fish. Rev. 40:2-8.

10. Guillory, V. 1993. Ghost fishing by blue crab traps. North Am. J. Fish. Manag. 13: 459–466.

11. Brown, J. & Macfadyen, G. 2007. Ghost fishing in European waters: Impacts and management responses. Mar. Policy 31: 488–504.

12. Havens, K. J., Bilkovic, D. M., Stanhope, D. M., Angstadt, K. T. & Hershner, C. 2008. The 

effects of derelict blue crab traps on marine organisms in the lower York River, Virginia. 

North Am. J. Fish. Manag. 28:1194–1200.

13. Slacum H.W., Jr., S. Giordano, J. Lazar, D. Bruce, C. Little, D. Levin, H. J. Dew- Baxter, L. 

Methratta, D.Wong, R. Corbin. 2009. Quantifying the effects of derelict fishing gear in the 

Maryland portion of Chesapeake Bay. Prepared for the NOAA Marine Debris Program. July 

2009.

14. Campbell, M.J., W.D. Sumpton. 2009. Ghost fishing in the pot fishery for blue swimmer 

crabs Portunus pelagicus in Queensland, Australia. Fisheries Research 95: 246-253.

15. Bae, B. S., An, H. C., Jeong, E. C., Park, H. H., Park, S. W., & Park, C. D. 2010. Fishing power 

estimation of biodegradable traps in the East Sea. Journal of the Korean society of Fisheries 

Technology, 46(4): 292-301.

16. Carr, H. A., and J. Harris. 1997. Ghost fishing gear: Have fishing practices during the past 

few years reduced the impact? Pages 141–151 in J. M. Coe and D. B. Rogers, editors. Marine 

debris, sources, impacts, and solutions. Springer, New York.

17. Slack-Smith, R. J. 2001. Fishing with traps and pots (No. 26). Food & Agriculture Org.
Derelict Fishing Gear Assessment Framework 23

18. Kennedy, V. S., M. Oesterling, W. A. Van Engel. 2007. History of blue crab fisheries on the 

U.S. Atlantic and Gulf coasts. Pages 655–709 in V. Kennedy and L. Cronin, editors. The Blue 

crab: Callinectes sapidus. Maryland Sea Grant College, College Park.

19. Lewis, C. F., Slade, S. L., Maxwell, K. E. & Matthews, T. R. 2009. Lobster trap impact on coral 

reefs: Effects of wind‐driven trap movement. New Zealand Journal of Marine and Freshwater 

Research, 43 (1): 271-282.

20. Butler, C. B., & Matthews, T. R. 2015. Effects of ghost fishing lobster traps in the Florida 

Keys. ICES Journal of Marine Science: Journal du Conseil 72(suppl 1), i185-i198.

21. Parrish, F. A. & Kazama, T. K. 1992. Evaluation of ghost fishing in the Hawaiian lobster 

fishery. Fish. Bull. 90:720–725.

22. Godoy, H., Furevik, D. & Stiansen, S. 2003. Unaccounted mortality of Red King Crab 

(Paralithodes camtschaticus) in deliberately lost pots off Northern Norway. Fish. Res. 64: 

171–177.

23. Sturdivant, S. K. & Clark, K. L. 2011. An evaluation of the effects of blue crab (Callinectes 

sapidus) behavior on the efficacy of crab pots as a tool for estimating population abundance. Fish. Bull. 109:48–55.

24. Newman, S. J., Skepper, C. L., Mitsopoulos, G. E., Wakefield, C. B., Meeuwig, J. J., & Harvey, E. 

S. 2011. Assessment of the potential impacts of trap usage and ghost fishing on the 

Northern Demersal Scalefish Fishery. Reviews in Fisheries Science, 19(2): 74-84.

25. Renchen, G.F., S.J. Pittman, R. Clark, C. Caldow, S. Gall, D. Olsen, R.L. Hill. 2014. Impact of 

derelict fish traps in Caribbean waters: an experimental approach. Bull. Mar. Sci. 90(2): 551-

563.

26. Eggleston, D., Etherington, L., & Elis, W. 1998. Organism response to habitat patchiness: 

species and habitat-dependent recruitment of decapod crustaceans. Journal of experimental 

marine biology and ecology, 223(1): 111-132.

27. Antonelis, K., Huppert, D., Velasquez, D. & June, J. 2011. Dungeness crab mortality due to 

lost traps and a cost-benefit analysis of trap removal in Washington State waters of the 

Salish Sea. North Am. J. Fish. Manag. 31:880–893.

28. Breen, P. A. 1987. Mortality of Dungeness crabs caused by lost traps in the Fraser river 

estuary, British Columbia. North American Journal of Fisheries Management 7: 429–435.

29. Lee, D. 2009. North Carolina Derelict Crab Pots 101: shallow water efforts. Pages 28–34 in 

Morison and Murphy.

56

30. Maselko, J., Bishop, G., & Murphy, P. 2013. Ghost fishing in the Southeast Alaska commercial 

Dungeness crab fishery. North American Journal of Fisheries Management, 33(2): 422-431.

31. Donaldson, A., Gabriel, C., Harvey, B. J., Carolsfeld, J., & Department of Fisheries and 

Oceans, Ottawa, ON (Canada); Canadian Science Advisory Secretariat, Ottawa, ON (Canada). 

2010. Impacts of fishing gears other than bottom trawls, dredges, gillnets and longlines on 

aquatic biodiversity and vulnerable marine ecosystems. Canadian Science Advisory 

Secretariat= Secrétariat canadien de consultation scientifique.

32. Cho, D. 2011. Removing derelict gear from the deep seabed of the East Sea. Marine Policy 

35: 610-614.

33. Bilkovic, D.M., Slacum, Jr., H.W., Havens, K.J., Zaveta, D., Jeffrey, C.F.G., Scheld, A.M., 

Stanhope, D., Angstadt, K., Evans, J.D. 2016. Ecological and Economic Effects of Derelict 

Fishing Gear in the Chesapeake Bay: 2015/2016 Final Assessment Report. Prepared for 

Marine Debris Program, Office of Response and Restoration, National Oceanic and 

Atmospheric Administration.
Derelict Fishing Gear Assessment Framework 24

34. Miller, T.J., Wilbert, M.J., Colton, A.R., Lipcius, R.N., Ralph, G.M., Johnson, E.G., and Kaufman, 

A.G. 2011. Stock assessment of blue crab in Chesapeake Bay. Final report to NOAA 

Chesapeake Bay Office, Annapolis, MD.

35. Van Engel, W.A., 1958. The blue crab and its fishery in Chesapeake Bay: Part 1 –Reproduction, early development, growth, and migration. Commercial Fisheries Review 20 (6):6–17.

36. Turner, H.V., Wolcott, D.L., Wolcott, T.G., Hines, A.H. 2003. Post-mating behavior, intramolt 

growth, and onset of migration to Chesapeake Bay spawning grounds by adult female blue 

crabs, Callinectes sapidus Rathbun. Journal of Experimental Marine Biology and Ecology 295: 

107–130.

37. Aguilar, R., Hines, A.H., Wolcott, T.G., Wolcott, D.L., Kramer, M.A., Lipcius, R.N. 2005. The 

timing and route of movement and migration of postcopulatory female blue crabs, 

Callinectes sapidus Rathbun, from the upper Chesapeake Bay. Journal of Experimental 

Marine Biology and Ecology 319: 117–128.

38. Jensen, O.P., Seppelt, R., Miller, T.J., Bauer, L.J. 2005. Winter distribution of blue crab

Callinectes sapidus in Chesapeake Bay: application and cross-validation of a two stage 

generalized additive model. Marine Ecology Progress Series 299:239–255.

39. Jensen, O.P., Miller, T.J. 2005. Geostatistical analysis of the abundance and winter distribution patterns of the blue crab Callinectes sapidus in Chesapeake Bay. Transactions of the 

American Fisheries Society 134:1582–1598.

40. Smith, S.G., Chang, E.S. 2007. Molting and growth. In: Kennedy, V.S., Cronin, L.E. (Eds.), The 

Blue Crab: Callinectes sapidus. University of Maryland Sea Grant College, College Park, 

Maryland, pp. 197–254.

41. Slacum, Jr., H. W., E. Methratta, J. Dew-Baxter, D. Wong, and R. Corbin. 2011. 2010 Monthly 

commercial blue crab effort survey in the Virginia portion of Chesapeake Bay. Annual report 

to Virginia Marine Resource Commission.

42. Slacum, Jr., H. W., E. Methratta, J. Dew-Baxter, D. Wong, and R. Corbin. 2012. 2011 Monthly 

commercial blue crab effort survey in the Maryland portion of Chesapeake Bay. Annual 

report to Maryland Department of Natural Resources.

43. Caldow, C, Monaco, M. E., Pittman, S.J., Kendall, M. S., Goedeke, T. L., Menza, C., Kinlan, B. P., 

Costa, B. M. 2015. Biogeographic assessments: a framework for information synthesis in 

marine spatial planning. Marine Policy 51: 423-432.

44. Müller, F., Breckling, B., Jopp, F., Reuter, H. 2011. What are the general conditions under 

which ecological models can be applied? In: Jopp, F., Reuter, H., Breckling, B. (Eds.), Modelling Complex Ecological Dynamics. Springer, Berlin, Heidelberg, pp. 13–28.

45. Fath, B., Patten, B.C. 2000. Goal Functions and Network Theory. Presented in Porto Venere 

May 2000 at the Second Conference on Energy.

46. Guillory, V., McMillen-Jackson, A., Hartman, L., Perry, H., Floyd, T., Wagner, T., and Graham, 

G. 2001. Blue crab derelict raps and trap removal programs. Gulf States Marine Fisheries 

Commission, Ocean Springs, Mississippi.

47. Mitro, M. G. 2003. Demography and viability analysis of a diamondback terrapin population. 

Canadian Journal of Zoology 81:716–726.

48. Hart, K. M., and L. B. Crowder. 2011. Mitigating by-catch of diamondback terrapins in crab 

pots. Journal of Wildlife Management 75:264–272.

49. Gilman, E., Suuronen, P., Hall, M. and Kennelly, S. 2013. Causes and methods to estimate 

cryptic sources of fishing mortality. Journal of Fish Biology, 83(4):766-803.
Derelict Fishing Gear Assessment Framework 25

50. Yeon, I., Song, M.Y., Shon, M.H., Hwang, H.J. and Im, Y.J.2010. Possible new management 

measures for stock rebuilding of blue crab, Portunus trituberculatus (Miers), in western 

Korean waters. Proceedings of Korean Applied Industrial Sciences, 5(2): 35.

51. Breen, M., Graham, N., Pol, M., He, P., Reid, D. and Suuronen, P. 2016. Selective fishing and 

balanced harvesting. Fisheries Research doi:10.1016/j.fishres.2016.03.014.

52. NOAA Marine Debris Program. 2015. 2015 Report on the impacts of “ghost fishing” via 

derelict fishing gear. Silver Spring, MD. 25 pp.

53. Gilardi, K.V.K, Carlson-Bremer, D., June, J.A., Antonelis, K. 2010. Marine species mortality in 

derelict fishing nets in Puget Sound, WA and the cost/benefits of derelict net removal. 

Marine Pollution Bulletin 60: 376-382.

54. FAO. 2016. Abandoned, lost or otherwise discarded gillnets and trammel nets: methods to 

estimate ghost fishing mortality, and the status of regional monitoring and management, by 

E. Gilman, F. Chopin, P. Suuronen and B. Kuemlangan. FAO Fisheries and Aquaculture 

Technical Paper No. 600. Rome. Italy

55. Havens, K.J. and Sharp, E.J. 2015. Thermal Imaging Techniques to Survey and Monitor 

Animals in the Wild: A Methodology. Academic Press, 354 pp.

56. Morison, S., and Murphy, P. (eds). 2009. Proceedings of the NOAA submerged derelict trap 

methodology detection workshop. Technical memorandum NOS-OR&R-32. National Oceanic 

and Atmospheric Administration, Silver Spring, Maryland.

57. NRC (Natural Resources Consultants, Inc.). 2013. Deepwater derelict fishing gear removal 

protocols. Report prepared for the National Oceanic and Atmospheric Administration and 

the Northwest Straits Marine Conservation Foundation. Natural Resources Consultants, Inc. 

Seattle, WA, 25p. 

58. Uhrin, A.V., Matthews, T.R., and Lewis, C. 2014. "Lobster trap debris in the Florida Keys 

National Marine Sanctuary: distribution, abundance, density, and patterns of accumulation." 

Marine and Coastal Fisheries 6.1: 20-32.

59. Voss, C.M., J.A. Browder, A. Wood, A. Michaelis. 2015. Factors driving the density of derelict 

crab pots and their associated bycatch in North Carolina waters. Fishery Bulletin 113:378-

390.

60. Olsen, D., & Hill, R. L. 2012. St. Thomas and St. John Trap Fishery: Present Status and Trap 

Loss. Survey and Impact Assessment of Derelict Fish Traps in St. Thomas and St. John, US 

Virgin Islands, 5.

61. Good, T. P., June, J. A., Etnier, M. A., & Broadhurst, G. 2010. Derelict fishing nets in Puget 

Sound and the Northwest Straits: Patterns and threats to marine fauna. Marine Pollution 

Bulletin, 60(1): 39-50.

62. Donohue, M. J., Boland, R. C., Sramek, C. M., & Antonelis, G. A. 2001. Derelict fishing gear in 

the Northwestern Hawaiian Islands: diving surveys and debris removal in 1999 confirm 

threat to coral reef ecosystems. Marine Pollution Bulletin, 42(12): 1301-1312.

63. Martens, J. and Huntington, B.E. 2012. Creating a GIS-based model of marine debris “hot 

spots” to improve efficiency of a lobster trap debris removal program. Marine pollution 

bulletin, 64(5): 949-955.

64. Watters, D. L., Yoklavich, M. M., Love, M. S., & Schroeder, D. M. 2010. Assessing marine 

debris in deep seafloor habitats off California. Marine Pollution Bulletin, 60(1): 131-138.

65. Anderson, J.A. and Alford, A.B. 2014. Ghost fishing activity in derelict blue crab traps in 

Louisiana. Marine Pollution Bulletin, 79(1): .261-267.
Derelict Fishing Gear Assessment Framework 26

66. Havens, K., Bilkovic, D.M., Stanhope, D. and Angstadt, K. 2011. Fishery failure, unemployed 

commercial fishers, and lost blue crab pots: an unexpected success story. Environmental 

Science & Policy, 14(4): 445-450.

67. Giordano, S., Lazar, J., Bruce, D., Little, C., Levin, D., Slacum Jr., H.W., Dew-Baxter, J., Methratta, L., Wong, D. and Corbin, R. 2011. Quantifying the impacts of derelict blue crab traps 

in Chesapeake Bay. In: Carswell, B., McElwee, K. and Morison, S., eds. Proceedings of the Fifth 

International Marine Debris Conference. Technical Memorandum NOS OR&R-38. NOAA: 

Silver Spring, MD.

68. Bilkovic, D., K. Havens, D. Stanhope, K. Angstadt. 2014. Derelict fishing gear in Chesapeake 

Bay, Virginia: spatial patterns and implications for marine fauna. Marine Pollution Bulletin

80: 114-123.

69. NCDMF. 2013. North Carolina Blue Crab (Callinectes sapidus) Fishery Management Plan: 

Amendment 2. North Carolina Department of Environment and Natural Resources. North 

Carolina Division of Marine Fisheries. Morehead City, NC. 408 pp.

70. Smith, M., L. Ludwig, and C. Wilson. 2011. Investigating the ‘ghost fishing’ capacity of 

derelict lobster traps. Pages 331–333 in B. Carswell, K. McElwee, and S. Morison, editors. 

Proceedings of the Fifth international marine debris conference. Technical memorandum 

NOS-OR&R-38. National Oceanic and Atmospheric Administration, Silver Spring, Maryland.

71. Sheldon, W. W., and R. L. Dow. 1975. Trap contributions to losses in the American lobster 

fishery. U.S. National Marine Fisheries Service Fishery Bulletin 73:449–451.

72. Matthews, T. R., and Uhrin, A. V. 2009. Lobster trap loss, ghost fishing, and impact on 

natural resources in Florida Keys National Marine Sanctuary. In Morison and Murphy.56

73. Kennedy, R. 1986. The Dungeness crab of North America. Safish (South Australian Department of Fisheries) 9:35.

74. Kimker, A. 1994. Tanner crab survival in closed pots. Alaska Fishery Research Bulletin

1:179–183.

75. High, W., and D. Worlund. 1979. Escape of king crab (Paralithodes camtschatica) from 

derelict pots. Technical report NMFS SSRF-734. National Oceanic and Atmospheric 

Administration, Washington, D.C.

76. Long, W.C., Cummiskey, P.A. and Munk, J.E. 2014. Effects of ghost fishing on the population 

of red king crab (Paralithodes camtschaticus) in Womens Bay, Kodiak Island, Alaska. Fishery 

Bulletin, 112(2-3):101-112.

77. Erzini, K., L. Bentes, R. Coelho, P. G. Lino, P. Monteiro, J. Ribeiro, and J. M. S. Goncalves. 

2008. Catches in ghost-fishing octopus and fish traps in the northeastern Atlantic Ocean 

(Algarve Portugal). Fisheries Bulletin 106: 321–327.

78. Scarsbrook, J. R., G. A. McFarlane, and W. Shaw. 1988. Effectiveness of experimental escape 

mechanisms in sablefish traps. North American Journal of Fisheries Management 8:158–161.

79. Al-Masroori, H., H. Al-oufi, J. L. McIlwain, and E. McLean. 2004. Catches of lost fish traps 

(ghost fishing) from fishing grounds near Muscat, Sultanate of Oman. Fisheries Research

69:407–414.

80. Al-Masroori, H., H. Al-oufi, and P. McShane. 2009. Causes and mitigations on trap ghost 

fishing in Oman: scientific approach to local fishers’ perception. Journal of Fisheries and 

Aquatic Science 4:129–135.

81. Clark, R., S.J. Pittman, T.A. Battista, and C. Caldow (eds.). 2012. Survey and impact assessment of derelict fish traps in St. Thomas and St. John, U.S. Virgin Islands. NOAA Technical 

Memorandum NOS NCCOS 147. Silver Spring, MD. 51 pp.
Derelict Fishing Gear Assessment Framework 27

82. Wilson, S.B. 1983. A report on the trap fishing industry of Barbados. Division of Fisheries, 

Ministry of Agriculture, Food and Consumer Affairs, Barbados, 32pp.

83. Selliah, N. M. 2000. The Barbados trap fishery: Selecting biodegradable fasteners, testing 

effects of new gear regulations on catch rates, and determining current status. M.Sc. thesis,

University of the West Indies, 82pp.

84. Özyurt, C. E.; Akamca, E.; Kiyağa, V. B.; Taşlıel, A. S. 2008. The rates and reasons of pots lost 

during a fishing season in Iskenderun Bay. Ege J. Fish. Aqua. Sci. 25(2): 147–151.

85. Yıldız, T. and Karakulak, F.S. 2016. Types and extent of fishing gear losses and their causes

in the artisanal fisheries of Istanbul, Turkey. Journal of Applied Ichthyology, 32(3): 432-438.

86. Bouchereau, J.L. and Wuttichaï, B. 2010. October. Relationship between the wreck of smallscale fishing equipment and ghost fishing in Guadeloupe (French West Indies) with 

palliative proposals for a better long-lasting management of biodiversity. In Coastal Zone 

Asia-Pacific Conference-World Small-Scale Fisheries Congress.

87. Kim, S., Park, S.W. and Lee, K. 2014. Fishing performance of environmentally friendly 

tubular pots made of biodegradable resin (PBS/PBAT) for catching the conger eel Conger 

myriaster. Fisheries Science, 80(5): 887-895.

88. The World Bank. 2012. Evaluation of new fishery performance indicators (FPIs): a case study 

of the blue swimming crab fisheries in Indonesia and Philippines. Agriculture and Rural 

Development Discussion Paper 52.

89. Norwegian Directorate of Fisheries. 2015. Economic and biological figures for Norwegian 

fisheries, 2014. Fiskeridirektoratet, Bergen.

90. Gongora, M. 2010. Assessment of Spiny Lobster (Panulirus argus) of Belize based on fishery 

dependent data. United Nations University Fisheries Training Programme, Iceland.

Acknowledgments

We are grateful to the NOAA Marine Debris Program for their oversight and support to this work, 

performed under NOAA SciTech contract # DG133E-10-CQ-0034, Task Order 007.