Eric L Gilman

Pelagic Ecosystems Research Group

Mangrove ecosystems are threatened by climate change. We review the state of knowledge of mangrove vulnerability and responses to predicted climate change and consider adaptation options. Based on available evidence, of all the climate change outcomes, relative sea-level rise may be the greatest threat to mangroves. Most mangrove sediment surface e...

A performance assessment was conducted of regional fisheries management organi-zations' (RFMOs') bycatch governance, one element of an ecosystem approach to fisheries management. Obtaining a mean score of 25%, with a 64% CV, collectively the RFMOs have large governance deficits. Individually, there has been mixed pro-gress, with some RFMOs having m...

Bycatch in fisheries can have profound effects on the abundance of species with relatively low resilience to increased mortality, can alter the evolutionary characteristics and concomitant fitness of affected populations through heritable trait-based selective removals, and can alter ecosystem functions, structure and services through food web trop...

Discarding by fisheries is one of the most wasteful human marine activities, yet we have few estimates of its scale. Reliable estimates of global discards are essential for sustainable fisheries management. Using United Nations Food and Agriculture Organization databases on country-specific landings, we estimated the discard rate and magnitude for...

Fisheries can profoundly impact co‐occurring species exposed to incidental capture. Spatiotemporal fisheries management holds substantial potential to balance socioeconomic benefits with ecological costs to threatened bycatch species. This study estimated the effect of the spatial and temporal distribution of effort by a western Pacific Ocean tuna...

Robust estimates of the relative efficacies of alternative management interventions are essential for developing evidence-informed fisheries bycatch policy. Bycatch is a major threat to the conservation of albatrosses and other pelagic seabirds. Branchline weighting is one approach prescribed by regional fisheries management organizations and the A...

Ecological data are being opportunistically synthesised at unprecedented scales in response to the global biodiversity and climate crises. Such syntheses are often only possible through large-scale, international, multidisciplinary collaborations and provide important pathways for addressing urgent conservation questions. Although large collaborati...

Sliding fishing weights can contribute to mitigating seabird bycatch and reduce crew safety risks in pelagic longline fisheries. Demonstrations of sliding fishing weights were conducted in pelagic longline fisheries of Hawaii, Japan and Taiwan in order to increase the longline fishing industry awareness of the availability of the technology, and to...

Several odontocete species depredate catch and bait from fishing gear, resulting in their bycatch and causing substantial economic costs. There are no known mitigation methods for odontocete depredation in pelagic longline fisheries that are effective, do not harm odontocetes and are commercially viable. Understanding odontocetes’ depredation strat...

Fisheries can have profound impacts on co-occurring species exposed to incidental capture, particularly those with life history traits that make them vulnerable to elevated mortality levels. Fisheries spatial management holds substantial potential to balance socioeconomic benefits and costs to threatened bycatch species. This study analyzed observe...

Fisheries can have profound impacts on co-occurring species exposed to incidental capture, particularly those with life history traits that make them vulnerable to elevated mortality levels. Fisheries spatial management holds substantial potential to balance socioeconomic benefits and costs to threatened bycatch species. This study analyzed observe...

Several odontocete species depredate catch and bait from fishing gear, which can lead to bycatch and substantial economic costs. There are no known odontocete depredation mitigation methods for pelagic longline fisheries that are effective, do not harm odontocetes and are economically viable. Using observer data from the Hawaii-based tuna longline...

There has been growing concern over the sustainability of marine megafauna exposed to bycatch fishing mortality. This study assembled databases of mitigation methods for at-risk species exposed to pelagic longline, tuna purse seine and drift gillnet fisheries. The databases enable the discovery of bycatch mitigation methods and enable accounting fo...

Static and dynamic area-based management tools hold substantial potential to balance socioeconomic benefits derived from fisheries and costs from bycatch mortality of at-risk species. Palau longline fisheries have high bycatch of at-risk species including the olive ridley marine turtle and silky and blue sharks. This study analyzed a two decades-lo...

Fisheries can adversely affect threatened bycatch species and vulnerable marine ecosystems (VMEs). Thresholds are unique amongst bycatch management methods in providing flexibility in individual participants' approaches to avoid exceeding limits, and particularly for individual vessel quotas , in incentivizing the innovation of effective and commer...

There is growing concern over the conservation status of sharks and relatives exposed to fishing mortality. The Food and Agriculture Organization of the United Nations in 1999 adopted the International Plan of Action for the Conservation and Management of Sharks (IPOA) which provides nations with advice on adopting and implementing national plans....

There is growing concern over the conservation status of sharks and relatives exposedto fishing mortality. The Food and Agriculture Organization of the United Nations in1999 adopted the International Plan of Action for the Conservation and Managementof Sharks (IPOA), which provides nations with advice on adopting and implementingnational plans. An...

The rapid expansion of the global footprint of marine capture fisheries over recent decades, combined with the transition to synthetic and more durable materials used for fishing gear components, has resulted in increasingly problematic adverse ecological and socioeconomic effects from abandoned, lost and discarded fishing gear (ALDFG). Adverse imp...

Marine megafauna exposed to fisheries bycatch belong to some of the most threatened taxonomic groups and include apex and mesopredators that contribute to ecosystem regulation. Fisheries bycatch is a major threat to the conservation of albatrosses, large petrels and other pelagic seabirds. Using data sourced from a fisheries electronic monitoring s...

Fisheries bycatch is the foremost threat to the conservation of many marine species. Evaluation of alternative bycatch management strategies can account for the relative strength of evidence, contribution to achieving objectives, costs to commercial viability, likelihood of compliance and tradeoffs from multispecies conflicts. This study describes...

This circular benchmarks the status of the development of minimum standards for fisheries electronic monitoring systems by intergovernmental organizations and arrangements.

Given that over 1 million seabirds are estimated to be killed incidentally in fishing operations each year and at-sea mortality poses the greatest threat to many seabird species and populations, reducing the bycatch of seabirds is a paramount priority of seabird conservation efforts. This chapter reviews methodological approaches to determine the b...

Climate change is predicted to alter the distributions of tropical tuna stocks in the Pacific Ocean. Recent modelling projects significant future shifts in tuna biomass from west to east, and from national jurisdictions to high seas areas. As the distributions of these stocks change, the relevant regional fisheries management organisations (RFMOs)—...

Policy decisions should be guided by the relative degree of risk of error and bias and strength of evidence of the efficacy of alternative management interventions. This study describes the benefits and limitations of applying a sequential evidence hierarchy to evaluate alternative fisheries bycatch management strategies. Fisheries bycatch is an ob...

Shark depredation is a complex social-ecological issue that affects a range of fisheries worldwide. Increasing concern about the impacts of shark depredation, and how it intersects with the broader context of fisheries management, has driven recent research in this area, especially in Australia and the United States. This review synthesises these r...

Apex and mesopredators such as elasmobranchs are important for maintaining ocean health and are the focus of conservation efforts to mitigate exposure to fishing and other anthropogenic hazards. Quantifying fishing mortality components such as at-vessel mortality (AVM) is necessary for effective bycatch management. We assembled a database for 61 el...

Marine population modeling, which underpins the scientific advice to support fisheries interventions, is an active research field with recent advancements to address modern challenges (e.g., climate change) and enduring issues (e.g., data limitations). Based on discussions during the ‘Land of Plenty’ session at the 2021 World Fisheries Congress, we...

Monitoring of the ecological and social, including economic aspects of uses of wild species is critical for sustainable use. Progress towards achieving the Sustainable Development Goals and the Aichi Biodiversity Targets is assessed using global indicators, however to date, there is not a comprehensive set of global indicators able to monitor statu...

Derelict fishing gear causes substantial adverse ecological and socioeconomic impacts. This study determined the rate of production of derelict gear from an Iranian Persian Gulf fishery using a type of fishing pot regionally known as gargoor. From November 2018 to July 2020, fishermen were surveyed and pots were marked in Jofreh, Jalali and Ganaveh...

There has been increasing recognition of the need to address adverse ecological and socioeconomic effects of abandoned, lost and discarded fishing gear (ALDFG). This component of marine debris has been progressively problematic over recent decades with the rapid expansion of global fisheries’ footprint and effort, and the transition to synthetic an...

Over the past 4 decades there has been a growing concern for the conservation status of elasmobranchs (sharks and rays). In 2002, the first elasmobranch species were added to Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Less than 20 yr later, there were 39 species on Appendix II and 5 o...

Fisheries bycatch threatens the viability of some seabird populations and reduces fishing efficiency. Albatross bycatch in a US North Pacific tuna longline fishery has increased over the past decade and now exceeds 1,000 annual captures. Seabirds interacting with this fishery reach hooks at depths up to 1 m. A branchline weight’s mass and distance...

Participatory decision tools enable stakeholders to reconcile conflicting natural resources management objectives. Fisheries targeting highly productive species can have profound impacts on co-occurring bycatch species with low fecundity and other life history traits that make them vulnerable to anthropogenic sources of mortality. This study develo...

Background and objectives The environmental effects of static gear fishing include habitat-level effects such as permanent changes to the physical environment and the structure of the benthic and epibenthic communities. Ecosystems subjected to prolonged exposure to pressure from static gear may undergo permanent changes and may never regain their p...

For many years, tremendous effort has been dedicated to developing new industrial tuna fisheries, while their adverse impacts on threatened marine species have received relatively little attention. In tuna fisheries, bycatch is the major anthropogenic threat to marine megafauna in general, particularly sharks. Research on the development of gear te...

The pelagic fisheries beyond the continental shelves are currently managed with a range of tools largely based on regulating effort or target catch. These tools comprise both static and dynamic area‐based approaches to include gear limitations, closed areas and bycatch limits. There are increasing calls for additional area‐based interventions, part...

Bycatch on pelagic tuna longlines has contributed to population declines in several far-ranging, oceanic species and presents a conservation challenge that area-based management tools are increasingly promoted to address. In January 2020 the Republic of Palau, concerned about the impacts of longline fishing in its waters, closed 80% of its exclusiv...

The collection of accurate fisheries catch data is critical to ensuring sustainable management of tuna fisheries, mitigating their environmental impacts and for managing transboundary fish stocks. These challenges are exemplified by the western Pacific tuna longline fishery, who’s management includes >26 nations, but is informed by critically low c...

Overexploitation is currently the main cause of marine defaunation. Vulnerability to overexploitation varies across populations. Determining which populations are of highest ecological risk from fishing mortality guides management. Because no single approach is optimal across taxonomic groups, a multi-model ensemble of relative risk estimates for a...

arising from n. Queiroz et al. Nature https://doi. Many shark species worldwide are vulnerable to overexploitation due to fishing. Using only the horizontal spatial overlap between the space use of 23 satellite-tracked shark species and the fishing distribution of pelagic longline fisheries tracked using an automatic identification system, Queiroz...

Derelict fishing gear is a highly visible source of marine plastic pollution, causing mortality and ecosystem degradation with uncertain long‐term consequences. The quantity of derelict gear entering the oceans remains unknown because of heterogeneity in fishing gear and effort, as well as inadequate monitoring. Prior studies have been limited in s...

Industrial fishing, instrumental in feeding the world's population while providing a livelihood to many people, also presents a variety of hazards to the health of the ocean, including the accumulation of derelict fishing gear. Although direct evidence of harm from derelict gear is abundant, efforts to quantify and assess the threats posed by it ar...

As fisheries with seabird interactions increasingly use Electronic Monitoring (EM) systems to meet monitoring requirements, ACAP recognizes the need for guidelines for EM systems to meet objectives of monitoring seabird interactions. These ACAP guidelines define how fisheries EM systems can be designed to meet objectives of fisheries monitoring tha...

Albatross bycatch has been increasing over the past decade in the US central North Pacific tuna longline fishery. A controlled field experiment was used to assess the efficacy of bird scaring or tori lines as a seabird bycatch mitigation measure for this fishery in a 3-factor sampling design with other mitigation methods (blue-dyed bait, offal disc...

Derelict abandoned, lost and discarded fishing gear have profound adverse effects. We assessed gear-specific relative risks from derelict gear to rank-order fishing methods based on: derelict gear production rates, gear quantity indicators of catch weight and area of fishing grounds, and adverse consequences from derelict gear. The latter accounted...

Marine mammals can play important ecological roles in aquatic ecosystems, and their presence can be key to community structure and function. Consequently, marine mammals are often considered indicators of ecosystem health and flagship species. Yet, historical population declines caused by exploitation, and additional current threats, such as climat...

Bycatch in pelagic longline fisheries threatens the viability of some seabird populations and reduces fishing efficiency. A branchline fishing weight’s mass and distance from the hook significantly explain seabird catch risk during setting and hauling. We surveyed Hawaii tuna longline fishers to obtain their perspectives on the practicality, safety...

Fisheries can profoundly affect bycatch species with 'slow' life history traits. Managing bait type offers one tool to control species selectivity. Different species and sizes of marine predators have different prey, and hence bait, preferences. This preference is a function of a bait's chemical, visual, acoustic and textural characteristics and si...

Marine protected areas (MPAs) can contribute to protecting biodiversity and managing ocean activities, including fishing. There is, however, limited evidence of ecological responses to blue water MPAs. We conducted the first comprehensive evaluation of impacts on fisheries production and ecological responses to pelagic MPAs of the Pacific Remote Is...

Marine protected areas (MPAs) can contribute to protecting biodiversity and managing ocean activities, including fishing. There is, however, limited evidence of ecological responses to blue water MPAs. We conducted the first comprehensive evaluation of impacts on fisheries production and ecological responses to pelagic MPAs of the Pacific Remote Is...

Fisheries electronic monitoring (EM) is increasingly being used to augment human observer programs and provide coverage where none previously existed. This study identified observer data fields prioritized for research and compliance monitoring that were not collected by a pilot EM system and compared estimates made by the EM system and observer pr...

Fisheries electronic monitoring (EM) is increasingly being used to augment human observer programs and provide coverage where none previously existed. This study identified observer data fields prioritized for research and compliance monitoring that were not collected by a pilot EM system and compared estimates made by the EM system and observer pr...

There has been a recent proliferation of large-scale marine protected areas (MPAs) containing pelagic habitats. These contribute substantially towards meeting the area-based goal of Aichi Biodiversity Target 11 and to managing pelagic ecosystem pressures, including fishing. We assessed theoretical and empirical evidence for the achievement of ecolo...

1. Fisheries-dependent data underpin essential scientific and management applications. Electronic monitoring (EM) systems are increasingly being used to supplement human observer programmes and provide coverage where none previously existed. 2. Candidate methods were identified to expand EM functionalities to collect data fields of human observer...

Accurate data on discards, the proportion of the catch that fishers do not retain, is necessary to achieve socioeconomically and ecologically sustainable fisheries. We review conventional and emerging approaches to monitor and manage discards. At-sea human observer programs currently produce the most accurate data on discards. Electronic monitoring...

Robust assessments of the effects of fishing require accounting for components of fishing mortality, including post-release fishing mortality (Fr). Random-effects meta-analysis synthesized Fr in seven pelagic shark species captured, tagged and released with 401 pop-up satellite archival tags compiled from 33 studies and three gears (longline, purse...

A Third Assessment of Global Marine Fisheries Discards

Workshop report on the relative promise of a alternative seabird bycatch mitigation methods for use in Hawaii’s pelagic longline fisheries.

Accounting for components of fishing mortality, including post-release mortality (Fr ), is necessary for robust assessments of the effects of fishing. Forty-eight blue (Prionace glauca) and 35 silky sharks (Carcharhinus falciformis) were tagged with pop-up satellite archival tags to monitor Fr rates from pelagic longline vessels in the western trop...

Data from fisheries observer programs support fundamental research and management applications, ranging from conducting stock assessments to assessing the performance of ecosystem-based harvest strategies. Electronic monitoring (EM) systems are increasingly being used to augment conventional coverage by human onboard observers, as well as to provid...

Pelagic fisheries can have profound effects on ecosystem structure and functioning, affecting ecosystem services, including fisheries production, and threaten vulnerable bycatch species. Controlling hook size could manage the species- and size-selectivity and survival of target and incidental catch. To test this hypothesis, we conducted experimenta...

KEY FINDINGS  There were no significant differences in catch composition, nominal mean catch rates, and mean discard rates from logbook data with versus without electronic monitoring (EM) systems. The presence of EM appears to not change fisher logbook data recording behavior.  Mean catch rates for combined tunas, other teleosts, combined elasmob...

• Catch rates from electronic monitoring (EM) data were about an order of magnitude higher than from logbook data. The species richness from logbook data was about half of that from EM data. Logbook data are very likely inaccurate due to substantial underreporting. • There were no significant differences in catch composition, nominal mean catch ra...

Fish aggregating devices (FADs) used by tuna purse seine fisheries improve fishing efficiency relative to other purse seine fishing strategies and make it possible to successfully fish in new areas. However, when not responsibly managed, FADs can cause adverse effects. Abandoned, lost and otherwise discarded FADs cause ghost fishing, damage sensiti...

Monitoring and managing fisheries bycatch is increasingly recognized as a critical component of robust fisheries management frameworks. This review, addressing this subject, begins by defining bycatch and analyzing the reasons it happens, from accidental to intentional discarding. It identifies the most common species composing bycatch of the main...

Monitoring live and dead discarded catch contributes to effective fisheries management and ecological and socioeconomic sustainability. We determined contemporary rates and levels of discards in global tuna fisheries. An estimated 265,279 t (52,283-478,275 95% CI) is annually discarded by global tuna fisheries, composing about 5% of the weight of t...

This chapter assesses the response of mangrove ecosystems to possible outcomes of climate change, with regard to the following categories: (i) distribution, diversity, and community composition, (ii) physiology of flora and fauna, (iii) water budget, (iv) productivity and remineralization, (v) carbon storage in biomass and sediments, and (vi) the f...

Pelagic longline fisheries for relatively fecund tuna and tuna‐like species can have large adverse effects on incidentally caught species with low‐fecundity, including elasmobranchs. Analyses of observer programme data from the Fiji longline fishery from 2011 to 2014 were conducted to characterize the shark and ray catch composition and identify fa...