Abandoned, lost or discarded fishing gear (ALDFG) comprises a significant amount of global marine debris, with diverse impacts to marine environments, wildlife, and the fishing industry. Building evidence on ALDFG is critical to holistically understand the marine debris issue, and to inform the development of solutions that reduce amounts of ALDFG sources and recover existing gear. Substantial work has been and continues to be undertaken around the world to collect data on ALDFG, much of which remains unpublished. To provide a global picture of data on ALDFG, we organized a technical session that brought together seven ALDFG leaders to share their expertise in data collection, retrieval, and awareness-raising. This paper summarizes the technical session to highlight: 1) case studies that feature innovative approaches to ALDFG data collection and retrieval; 2) examples of opportunities to fill data gaps and improve our understanding of wildlife ingestion of and entanglement in ALDFG; and 3) awareness-raising through the development of a publicly accessible global ALDFG database.
Derelict Fishing Gear and Ghost Fishing
Derelict fishing gear is a known stressor to rockfish populations in the Washington waters of the Salish Sea, including two species currently federally protected under the Endangered Species Act. In Washington and British Columbia, rockfish bycatch in actively fished (non-derelict) prawn traps has been documented in spot prawn test fisheries conducted by state and provincial government, and both live and dead rockfish have been found in derelict prawn traps encountered during derelict fishing gear removal operations in Washington. This study calculates rockfish bycatch rates in actively fishing prawn traps and provides preliminary trap loss rates for both commercial and recreational fisheries. Rockfish bycatch rates were determined through analysis of Washington Department of Fish and Wildlife (WDFW) Spot Prawn Test Fishery Data collected from 2004 to 2013. Data from WDFW creel surveys were used to update preliminary prawn trap loss rates. Interviews with WDFW marine enforcement officers were conducted to estimate the number of lost traps that are recovered before becoming derelict. The overall rockfish catch rates in Washington waters of the Salish Sea were 0.023 rockfish per trap drop, with considerable spatial and temporal variability. The lowest catch rates were consistently seen in Marine Area 7 (San Juan Islands and North Puget Sound); while the highest catch rates were seen in Marine Area 11 (south-central Puget Sound). The trap loss rate estimated for the recreational fishery is 2.33% of all traps fished. We estimate that over the years 2012 and 2013 an average of 653 recreational prawn traps became derelict each year. The accumulation of derelict prawn traps has a mostly unknown effect on benthic habitats of Puget Sound, which warrants additional research. While rockfish bycatch and prawn trap loss rates reported here are low, our findings support evaluating methods to reduce rockfish encounters with prawn traps.
North Atlantic right whales (Eubalaena glacialis) are highly endangered and frequently exposed to a myriad of human activities and stressors in their industrialized habitat. Entanglements in fixed fishing gear represent a particularly pervasive and often drawn-out source of anthropogenic morbidity and mortality to the species. To better understand both the physiological response to entanglement, and to determine fundamental parameters such as acquisition, duration, and severity of entanglement, we measured a suite of biogeochemical markers in the baleen of an adult female that died from a well-documented chronic entanglement in 2005 (whale Eg2301). Steroid hormones (cortisol, corticosterone, estradiol, and progesterone), thyroid hormones (triiodothyronine (T3) and thyroxine (T4)), and stable isotopes (δ13C and δ15N) were all measured in a longitudinally sampled baleen plate. This yielded an 8-year profile of foraging and migration behavior, stress response, and reproduction. Stable isotopes cycled in annual patterns that reflect the animal's north-south migration behavior and seasonally abundant zooplankton diet. A progesterone peak, lasting approximately 23 months, was associated with the single known calving event (in 2002) for this female. Estradiol, cortisol, corticosterone, T3, and T4 were also elevated, although variably so, during the progesterone peak. This whale was initially sighted with a fishing gear entanglement in September 2004, but the hormone panel suggests that the animal first interacted with the gear as early as June 2004. Elevated δ15N, T3, and T4 indicate that Eg2301 potentially experienced increased energy expenditure, significant lipid catabolism, and thermal stress approximately 3 months before the initial sighting with fishing gear. All hormones in the panel (except cortisol) were elevated above baseline by September 2004. This novel study illustrates the value of using baleen to reconstruct recent temporal profiles and as a comparative matrix in which key physiological indicators of individual whales can be used to understand the impacts of anthropogenic activity on threatened whale populations.
Derelict fishing nets comprise a significant amount of the marine debris in the world's oceans and on its shorelines. These ‘ghost nets’ result in economic losses for the fishing industry, pose hazards to navigation at sea, and can entangle marine and terrestrial wildlife. Ghost nets are an acute problem along Australia's northern coastline, with most nets originating from Southeast Asian fishing vessels outside Australia's Exclusive Economic Zone (EEZ). To understand the causes of gear loss and identify tractable solutions to this transboundary problem, Australian and Indonesian fishers (N = 54) were asked why, when and in what circumstances and conditions they are likely to lose gear. Fishers identified snagging of nets (78%) and gear conflicts (19%) as the main causes of gear loss. These interviews informed the development of a fault tree, as a tool to identify the chain of events that result in gear loss or abandonment. The fault tree analysis provides recommendations for interventions and improvements in regional fisheries management to reduce fishing gear loss ultimately resulting from overcrowding, overcapacity and illegal, unreported and unregulated Fishing (IUU).
In May 2016, the World Animal Protection appointed fisheries consultants Poseidon Aquatic Resource Management Ltd (Poseidon) of the UK to undertake a series of work packages. The objective was to support the GGGI’ s ‘Define best practices and inform policies’ working group in developing best practice guidance on the management of fishing gear.
The first output was a brief scoping study to provide:
I. a working quantification of the main fishing gears used on a global basis
II. a brief summary of the main characteristics of these gears regarding user type, geographical usage and contribution to ALDFG.
This first part of the work was submitted to World Animal Protection on 16 May 2016.
The second output was the identification of management options and mechanisms for responsible fishing gear use. It was also to include recommendations on how this could be developed into a best practice framework for managing fishing gear.
This second activity examined two main elements. First, it looked at the current management options for fishing gear. This included the use of tags and other identification of fishing gear, gear marking, gear storage to and from fishing grounds and gear retrieval in case of loss or temporary abandonment. It then examined how these are implemented – for example through legislation, codes of conduct or inclusion in third party and other certification schemes. This part of the study was the basis for the framework (see next) and has been issued as a standalone document, entitled ‘Part 1: Overview and Current Status’.
The purpose of this third and final output of the study was to develop a ‘best practice’ framework for the management of fishing gear. Its scope is defined in Part 1 of document, is global in nature, and covers a wide range of fishing gears and users.
As a framework, it focuses on the most commonly used gear types, both in industrial and artisanal fisheries. The framework is relevant to a broad spectrum of stakeholders. These include gear manufacturers, fishers, port authorities, fisheries management authorities, seafood companies and other interested parties.
This framework will be adopted by the GGGI, developed further and targeted at specific stakeholders.
Large whales are frequently entangled in fishing gear and sometimes swim while carrying gear for days to years. Entangled whales are subject to additional drag forces requiring increased thrust power and energy expenditure over time. To classify entanglement cases and aid potential disentanglement efforts, it is useful to know how long an entangled whale might survive, given the unique configurations of the gear they are towing. This study establishes an approach to predict drag forces on fishing gear that entangles whales, and applies this method to ten North Atlantic right whale cases to estimate the resulting increase in energy expenditure and the critical entanglement duration that could lead to death. Estimated gear drag ranged 11–275 N. Most entanglements were resolved before critical entanglement durations (mean ± SD 216 ± 260 days) were reached. These estimates can assist real-time development of disentanglement action plans and U.S. Federal Serious Injury assessments required for protected species.
Northeast coral gardens provide vital breeding and feeding habitats for fishes of conservation and commercial importance. Such habitats are increasingly at risk of destruction as a result of over fishing, ocean warming, acidification and marine litter.
A key cause for concern regarding the vulnerability of coral gardens to damage from any source is their slow growth rate, and thereby their ability to recover from damage. Hence protected areas are being put in place, which exclude the use of towed demersal fishing gear.
Citizen scientists observed that gorgonian coral (Pink Sea Fans) skeletons were stranding on beaches entangled in marine debris (sea fangles) across southwest England. Further, SCUBA divers reported that gorgonian corals were being caught up and damaged in lost fishing gear and other marine litter.
To determine the cause of the damage to coral gardens, sea fangles were collected and analysed.
The sea fangles were made up of a diverse range of litter from fishing and domestic sources, however, the majority comprised of fishing gear (P < 0.05).
Marine Protected Areas can protect coral gardens from direct fishing pressure, but risks still remain from ghost fishing pressure, demonstrating the need for sources of litter into the environment to be reduced and existing litter removed.
The EU Marine Strategy Framework Directive (MSFD) outlines targets for marine litter by 2020. This study highlights the importance of adhering to the MSFD and/or creating more ambitious regulation if the UK re-write existing legislation following BREXIT.
Fishing is the major human activity within the ‘semi-enclosed’ Arafura and Timor Seas (ATS). Since the early 2000’s, Australia’s sparsely populated, remote northern shores have reported very high levels of foreign, fishing-related marine debris. Limited information is available about the temporal and spatial variation of this fishing debris or its origin. We examine trends in derelict fishing nets (and marine debris) at multiple sites in the Northern Territory and Gulf of Carpentaria and, explore its potential origin and relationship with fishing activity in the region. Further, we investigate temporal trends in domestic and foreign fishing activity (legal and illegal) in the ATS and also foreign fishing vessel sightings in the northern waters of the Australian Exclusive Economic Zone (AEEZ). Our results confirm that foreign fishing debris (nets, rope and gear) is the major source of marine debris (63%) on Australia’s northern shores. Over the period 2003–2008, a total of 2305 derelict fishing nets were washed ashore; of these, 89% were identified of foreign origin (i.e. manufacture), compared to 11% attributed to Australian fishing vessels or fisheries. Industrial foreign and Indonesian-flagged fisheries – particularly, illegal, unreported and unregulated (IUU) trawling activity – and small-scale Indonesian IUU fisheries (primarily targeting shark) in the Arafura Sea are likely the major sources of these nets. Derelict nets comprised mostly trawl nets (71%) and gillnets/drift nets (12%); with 95% of all identified net sourced from the nations of Taiwan, Indonesia, Thailand and Korea. Our data also supports consistent under-reporting by these foreign trawl operators in the Indonesian Exclusive Economic Zone (IEEZ) of the ATS.
The arrival and increase in derelict nets in northern Australia post-2000 coincided with sharp increases in both industrial foreign fishing (illegal, legal) and Indonesian small-scale fisheries within the IEEZ waters of the ATS. Including, over the period 2000–2007, a 2-fold increase in ‘non-motorised’ vessels, and a 5-fold increase in the number of motorised vessels, particularly in vessels less than 5GT. Further, this major increase in fishing activity in the IEEZ corresponded to a 3-fold increase in foreign fishing vessels (FFVs) (legal, illegal) sightings in northern Australian waters. Within the AEEZ, derelict net loads and sightings of illegal FFVs, both peaked and reached a maximum in 2005 (188 kg km−1yr; 6956 vessels) and then sharply reduced (>80%) following major border control, surveillance and security operations in the northern Australia in 2005–2006. However, post-2007, illegal FFV sightings inside the AEEZ have increased again. Significantly, derelict nets and small-scale IUU fishing activity in the AEEZ is linked to a broader pattern of poverty, overfishing and displacement of small scale fishers in coastal fisheries in the Arafura Sea (and South East Asia), due primarily to the expansion of industrial (illegal, legal) trawl fisheries. Strengthening of regional fisheries management (particularly under the RPOA-IUU) is urgently required to tackle IUU fishing, the key source of fishing debris in the ATS. While fisheries capacity reduction is a critical priority, it needs to be supported by a regional multi-sectoral response framed within the context of food security and rural economic development.
Ghost gear – abandoned, lost, or otherwise discarded fishing gear – has been recognised as a global environmental challenge since the mid-1980s, and yet little social science attention has fallen on the phenomenon. This paper explores how the burden of global fisheries, materialised through its gear, is experienced and managed. How is ghost gear encountered? How is it understood? What influence does it have, and what responses does it provoke? To consider these questions, the paper begins with detailing of an encounter with ghost gear and Aboriginal rangers on the eastern coast of the Gulf of Carpentaria, northern Australia. Understanding encounters as tangles of interlaced threads, rather than isolated intimacies, the paper also follows ghost gear beyond the experience of beach clean-up. How ghost gear journeys to this beach, and the mobilities and meetings that occur during its travels is explored, as well as the policy responses to ghost gear that figure it primarily as marine debris to be managed through territorial control as isolated ‘waste’. These more-than-human stories offer insights into the distributed agencies, complex relations, and differential responsibilities involved in the phenomenon of ghost gear, and efforts to deal with it as part of land-sea assemblies.
Groupers are highly targeted and vulnerable reef fishes. The effects of fishing pressure on the density of three reef fishes were investigated in 21 islands outside (n=15) and inside (n=6) a Marine Protected Area (MPA) at the Paraty Bay, Brazilian southeastern coast. Two valued groupers (Epinephelus marginatus and Mycteroperca acutirostris) and a non-target grunt (Haemulon aurolineatum) were studied. The total biomass of fish caught in each island was considered as a measure of current fishing pressure, while the island distance from the villages was considered as a measure of past fishing pressure. Fish densities were recordedin number and biomass. The biomass of M. acutirostris was inversely related to current fishing pressure, which did not affect the other two fishes. The density of E. marginatus increased with the island distance from one of the fishing villages, which indicated that past fishing may have had decreased the abundance of E. marginatus. Densities of the three fishes and fishing pressure did not differ between islands inside and outside the MPA. Data on fishing pressure, densities of groupers and coral cover were combined here to assign conservation scores to islands. A redefinition of MPA boundaries to reconcile fish conservation, fishing activities and fishers’ food security was proposed.