Fisheries Bycatch

The Magnuson-Stevens Fishery Conservation and Management Act (MSA) is the primary law that codifies marine fisheries management in United States federal waters. The MSA was amended in 2006 with Section 610, an international provision that directs the Secretary of Commerce to unilaterally identify foreign nations engaged in the incidental capture (bycatch) of protected living marine resources (PLMRs) under specific conditions. In 2013 the United States identified Mexico for bycatch of a PLMR – the North Pacific loggerhead turtle – representing the first time a nation has been identified for bycatch under section 610. This paper evaluates the initial effects of the identification on loggerhead bycatch management efforts in Mexico and provides policy recommendations for improving the law and its implementation. In the wake of the unilateral identification, Mexico downplayed and denied the bycatch problem that their agencies had previously accepted and cancelled a bycatch research partnership between their federal fisheries science agency and U.S. researchers. Moreover, fishers invested in bycatch reduction and monitoring programs ceased to participate, jeopardizing their understanding of the problem and their co-development of bycatch solutions. However, the identification and subsequent consultation process ultimately resulted in Mexico implementing federal loggerhead bycatch regulations that are temporarily comparable with relevant U.S. measures. These regulations establish a temporary fisheries reserve (authorized for two years) that includes monitoring of bycatch, a loggerhead bycatch mortality cap, temporal and spatial restrictions on fishing gear and practices, and a closure of all finfish fisheries during the summer of 2016. As a result, turtle bycatch was likely substantially reduced in 2016, but at the cost of artisanal fishers' entire seasonal income. Policy recommendations are made, highlighting the need to: 1) better assess the socioeconomic, political, and environmental consequences associated with using the threat of trade sanctions to compel nations to reduce their bycatch; and 2) facilitate a more consistent consideration of bycatch data across nations such that the current policy does not create a disincentive for other nations to assess or report PLMR bycatch.

Tuna gillnet fishery of Pakistan employs more than 500 fishing
boats that operate in offshore waters. In addition to tuna,
gillnet also catches large quantities of by-catch fish species
including billfishes, pelagic sharks, dolphin fishes as well as
marine turtles and cetaceans, which are protected species. High
by-catch of these non-target animals affects their population in
the area. The paper provides information on by-catch and
suggests measures that can be adopted as alternate fishing
methods to minimize mortality of endangered and threatened
cetaceans and turtles.

Marine megafauna (elasmobranchs, marine mammals, turtles, and seabirds) are important ecologically and economically because many species often occupy upper trophic levels as adults and are essential for marine-based tourism in many areas of the world. This group of species is also heavily impacted by fishing because most have late sexual maturity, longevity, and low reproductive output, which affects their ability to recover from depletion. In Galapagos, marine megafauna species are protected from fishing throughout the marine reserve and are the main attraction for marine-based tourism, helping generate millions of dollars in revenue annually. Despite their importance in the archipelago, these species are being caught as bycatch in the multiple artisanal longlining projects that have been carried out since the implementation of the reserve in 1998. Longlining was originally proposed as a way of redirecting fishing effort from the severely depleted coastal-demersal species to pelagic fish such as yellowfin tuna and swordfish. Although all these projects have resulted in high bycatch of megafauna, longline fishing projects have continued without independent scientific studies to evaluate their impact, largely due to poor objective definition, data collection, and enforcement. To fill in this knowledge gap, we analyzed data of the fifth experimental longline fishing project undertaken in 2012-2013 to describe the fishery, identify variables affecting the composition and quantity of bycatch, and suggest mitigation strategies. This experimental project had twelve vessels, which deployed 42,007 hooks catching 4893 individuals of 33 species, mostly yellowfin tuna and swordfish. Of those, 16 species were protected megafauna, particularly blacktip sharks (Carcharhinus limbatus) and oceanic manta (Mobula birostris). These species were regularly captured during the two seasons and in the three bioregions that occur in the archipelago, suggesting little potential to mitigate their catch. As an alternative, we identified 14 hotspots where yellowfin tuna and swordfish could be harvested in large numbers sustainably through more selective fishing techniques such as pole fishing, a method that is also more economical for artisanal fishers. In an archipelago where the main economic activity is marine wildlife tourism, the implementation of an extractive and unselective activity such as pelagic longing fishing should be avoided to ensure the sustainability of the Galapagos marine ecosystem and its booming tourism industry.

This study examined the feasibility of gear substitution as a means to reduce bycatch and habitat impacts of fisheries, using a social-ecological systems approach. The U.S. west coast sablefish fishery is an excellent subject for this study, because it permits three different gear types and has a problem with bycatch of overfished species. Bycatch rates were highest in trawls and lowest in pots.  Combining interview data with findings from a previous study, affirmed that habitat impacts were highest with trawls and lowest with longlines. Interviews with 44 individuals analyzed using grounded theory  yielded several common themes in the opinions of gear substitution. Positive opinion themes included that it would allow better management of the fish populations by reducing bycatch and would allow more business options, flexibility, and increased profit for some trawlers. The main negative opinion theme was that gear substitution could decrease landings needed to support shoreside infrastructure.  Most stakeholder groups saw some benefit in gear substitution. Notably, the trawlers voiced a unanimous preference for converting to pots rather than longlines.  A scenario analysis revealed that the preferable management option would be long-term gear conversion, but incentives are likely to be an important means of encouraging gear conversion. This ecological impacts rapid assessment provided a regional assessment of bycatch and habitat impacts that had never been conducted before for these gear types. It also provided scientific support for a regulatory change that legally allows trawlers to practice gear substitution.

ARTICLE INFO ABSTRACT Bycatch is the global concern and it is causing number of problems to the fisheries. Recent WWF report estimates that 40% of marine catches and discards are juveniles. Higher level of bycatch has impact on diversity, community structure and biomass. Bannin very good approach for managing the fisheries. Nowadays bycatch reduction devices based on different aspects are being developed to make the fishing practices, environment friendly but it needs to be implemented p fishers to recover the future stock. FAO has given the Code of Conduct for Responsible Fisheries which encourages the nations to make policies for the management of fisheries impact of bycatch in fisheries and regulations and guidelines needs to be followed for managing the fisheries. Copyright©2016, Deepika et al. This is an open access article distributed under the Creative Commons Att distribution, and reproduction in any medium, provided the original work is properly cited.

Trawling remains a controversial method of fishing
due to the perceived lack of selectivity of the trawl net
and the resultant capture of a huge quantity and diversity
of non-target species, including endangered species
such as sea turtles, coupled with its effect on the
marine ecosystem. The impacts of trawling on the
physical, chemical and biological environment of the
marine ecosystem and the diversity and quantity of
by-catch and discards remain poorly documented for
the tropical waters. In India, the by-catch landed at
fishing harbours are utilized mainly for the production
of manure and animal feed. Further, by-catch reduction
devices have not been implemented in the
field. This review article, besides analysing the impact
of trawling, highlights the need for adopting policies
and practices that reduce the level of by-catch, the
need for ecosystem-based management to ensure longterm
sustainability of oceanic resources, and the adoption
of a precautionary approach with emphasis on
reducing, and if possible avoiding discards.

To provide a means of evaluating changes in bycatch over the last 10 years and inform the current review of the Commonwealth Policy on Fisheries Bycatch, an examination of the existing data is required, together with a description of the changes that have occurred in each fishery that specifically (or indirectly) relate to bycatch.  This report provides background information on the existing data on bycatch from key Commonwealth fisheries. The fisheries considered are the Southern and Eastern Scalefish and Shark Fishery (SESSF), the Northern Prawn Fishery (NPF), Sub-Antarctic Fisheries, the Coral Sea Fishery (CSF), the Eastern Tuna and Billfish Fishery (ETBF) and the Small Pelagic Fishery (SPF). Outcomes achieved include the documentation of the data collected, the bycatch management processes that have been put in place and the temporal trends in observations of bycatch and bycatch composition.

Vaquita (Phocoena sinus) is the most endangered marine mammal of the Planet and the one with the most limited distribution – some 3000km² in Nortwest Mexico (Up-per Gulf of California, UGC). The most important threat to the vaquita is bycatch in gillnets used to catch shrimp and finfish in the UGC. The International Commission for Vaquita Recovery (CIRVA) affirms that the only way for saving vaquita is elimi-nating gillnets from its habitat. Since 2004, the World Wildlife Fund (WWF) works with the Mexican Institute of Fisheries (INAPESCA) for developing alternative shrimp and finfish fishing gear for that end. From 2009 to 2013, both institutions con-ducted six experimental assessments for a selective trawl system, called RS-INP-MX, demonstrating its effectiveness when gillnets are absent. Since 2013, Mexican fisheries regulations mandate the gradual substitution of shrimp driftnets by the RS-INP-MX. Additionally, in 2012, WWF and INAPESCA tested nine alternative fishing gears for finfish and molluscs to substitute drift gillnets, using a research vessel as experi-mental platform. Finfish trawl, hook longlines, and fish traps resulted as promising options and additional assessments were continued on board artisanal fishing boats: hook longlines delivered positive revenues, small trawl for finfish revealed operative issues on board artisanal boats and result for fish traps were inconclusive. Non-profit civil organizations for conservation, such as WWF and Pronatura, have been helpful for identifying skilled fishers willing for using alternative fishing gears; undertaking fieldwork and data analysis and meta-analysis; building financial and market capaci-ties among interested fishers and undertaking in-depth experiments for testing spe-cific hypothesis. Vaquita population continues declining at an alarming rate. Experts urge to identify and effectively transfer alternative fishing gear for commercial fisher-ies at UGC in the next 12 months.

In trawling a significant portion of the captured fauna has no commercial value and is returned to the sea, causing biological and ecological changes, with impacts on the food chain, modifying processes of energy transfer in the ecosystem. Studies on the feeding habits of demersal fish provide basic information for understanding species trophic relations. Thus, this work aimed the undestandment of the feeding habits of the most abundant fish present in the bycatch of the Xiphopenaeus kroyeri artisanal fisheries of the coast of Santa Catarina, through the analysis of stomach contents, describing patterns of similarity, overlap and trophic structure. Sampling took place seasonally, from November 2009 to August 2010, in Balneario Barra do Sul, Porto Belo and Penha. Whaling vessels from the artisanal shrimping fleet were used for trawling. After sorting the specimens, they were frozen until the completion of biometrics and stomach content analysis. Information obtained through analysis of stomach contents were quantified via the Kawakami-Vazzoler feeding index, combining the frequency of occurrence and the relative volume of the items. Species of Sciaenidae family were the most abundant. Ctenosciaena gracilicirrhus, Cynoscion jamaicensis, Larimus breviceps, Menticirrhus americanus, Stellifer brasiliensis and S. rastrifer were classified as crab eaters, while Isopisthus parvipinnis crab eater/piscivore, Micropogonias furnieri as annelid eater/crab eater and Paralonchurus brasiliensis as annelid eater, however species were found to have very similar diets, altering the intake of certain items between seasons and locations. According Morisita overlap index, 9 cases of overlap were observed in Balneario Barra do Sul, 9 in Penha and 20 in Porto Belo. The bipartite foodwebs showed generality in the intake of food, with most species carrying multiple trophic interactions. Once the Sciaenidade family is the most abundant and diverse in the sea-bob-shrimp bycatch, iv its removal seems to directly influence the ecosystem processes in the region, with most species performing a wide range of interactions. Therefore their removal will gradually change the stability of benthic community.

We assess the performance of circle hooks, which are promoted as a measure for improving the survival of marine turtles following interactions with pelagic longlines. We conducted experiments off eastern Australia on commercial fishing vessels that alternated circle hooks (mostly size 14/0) and Japanese tuna hooks along their longlines. Most animals were hooked in the lip or jaw, regardless of hook type. There was no difference in the mean size of animals caught on the two types of hook, except for striped marlin (Tetrapturus audax), which tended to be larger on tuna hooks. Most species had an equal or lower probability of being alive on circle hooks than tuna hooks. Catch rates on circle hooks exceeded those on tuna hooks for most species. These included several target species, such as albacore tuna (Thunnus alalunga), yellowfin tuna (Thunnus albacares) and striped marlin, and bycatch, including several shark species. The differences in catch rates were large enough to increase total catches and financial returns. The financial benefits of increased catches outweighed the costs of converting to circle hooks. The results indicate that the adoption of small circle hooks by longliners will not be detrimental to financial returns.

We assess the performance of wire leaders, which some jurisdictions have banned to reduce shark mortality from pelagic longline fishing. Experiments were conducted off north-eastern Australia on commercial vessels that deployed equal numbers of wire and nylon monofilament leaders randomly along their longlines. Catch rates of several species, including sharks, were lower on nylon than on wire leaders, probably because those animals often escape by biting through the nylon leaders. High bite-off rates indicate that as many animals escape from nylon leaders as are caught on nylon leaders. The fate of escaped animals is not known, although large sharks are more likely to survive than are small animals. By contrast, catch rates of valuable bigeye tuna (Thunnus obesus) were higher on nylon than on wire leaders. Bigeye tuna are probably able to see wire leaders and avoid those hooks. The financial benefits of increased bigeye tuna catches outweigh the costs associated with banning wire leaders, such as increased rates of gear loss. Thus, banning wire leaders is an effective way of reducing shark catches that fishers should be keen to adopt.

Almost all Rajiformes are viviparous without placentas, and their embryos are nourished by yolk sacks accompanied in
some cases by uterine milk. However, there are few studies of biological aspects of the species in this group in Colombia.
This study aimed to analyze some reproductive aspects of Narcine bancroftii (Griffith y Smith, 1834), Diplobatis guamachensis
Martin, 1957, and Rhinobatos percellens (Walbaum, 1792), captured as bycatch of the shrimp trawling fishery in
two zones (north and south) of the Colombian Caribbean during the second semester of 2004. Samples were caught from
the same fleet’s fishing tasks, and corresponded to one-fifth of the homogenized discard, taken randomly from one of the
four nets in the ship. Individuals of the three species were brought to the laboratory for further morphometry measurements,
taxonomic identification and determination of the maturity state. The maturity state differentiation was based on claspers
development and sperm presence for males, and in the size and development of the ovaries, eggs, and embryos for females.
Females of N. bancroftii showed immaturity and spawned states, while the males were mature. The individuals of D.
guamachensis were represented by maturity females with embryos, and maturity males, whereas those of R. percellens were
characterized as maturity females with embryos and spawned states, and maturity males. The presence of uterine milk in
individuals of N. bancroftii, and embryos in D. guamachensis were the first known reports in the literature for this country.

Bycatch of non-target species in commercial fisheries is a major source of anthropogenic injury and mortality for marine megafauna, including marine turtles. Their long life histories and large-scale habitat use increase the risk of interaction with multiple fleets and gear types, with consequences for population decline or collapse. However, assessment of bycatch species rarely extends beyond a single-fishery management approach, without considering the impacts of additional bycatch incurred in other fisheries. To demonstrate the need for cross-jurisdictional assessment of turtle bycatch, we evaluate the cumulative patterns of turtle bycatch in Australian commercial fisheries. We sourced logbook bycatch records from multiple fisheries in three separate management jurisdictions over the period 2000–2013. The highest bycatch per unit effort values were reported in pelagic gillnets, otter trawls and pelagic longlines. Spatial analysis revealed a bycatch 'hotspot' in the Gulf of Carpentaria, where commercial fisheries impact multiple turtle species and genetic stocks. Our results illustrate the need to set cumulative bycatch quotas for marine turtles, and to evaluate turtle bycatch at the population level instead of separately within individual fisheries. We stress the need for timely collaboration between management agencies in order to implement effective, biologically relevant management strategies for marine turtles and other vulnerable taxa.

Macrourids are among the most abundant and diverse demersal fishes in all deep oceans, including the Southwestern Brazilian continental slope. Although not targeted by Brazilian fisheries, they suffer impact similar than the target species, being among the most discarded fishes by deep bottom trawling.
Trophic Ecology: Data from research surveys and commercial fishing were used to analyze the trophic ecology of four species inhabiting the upper slope of southern Brazil: Coelorinchus marinii, Malacocephalus occidentalis, M. laevis and Lucigadus ori. For the two abundant ones, ontogenetic changes, seasonal variations, intra- and interspecific dietary overlap, parasite fauna and aspects of functional morphology are also described. C.marinii had an extremely diverse diet, preying infauna, epifauna, plankton, necton and carcasses.
M.occidentalis fed on larger and nektonic prey, but also included crabs and carcasses in the diet. Both species showed ontogenetic shifts and seasonal variations in diet composition, both leading to changes in intra- and interspecific diet overlap patterns. Species showed quite distinct feeding anatomy and proportions of body with mouth size, reflecting on feeding strategies. There was little interspecific food overlap. In most cases when the diet was more similar there was a spatial segregation. The coexistence of these species appears to be facilitated by the development of different functional morphologies and feeding strategies. A considerable portion of the diet of these species is due to the consumption of carcasses of pelagic and mesopelagic organisms, and even insects, bypassing the benthic trophic web. Conservative (minimum) estimates of the mean weight
of carcasses in diet ranged from 3 to 20%, increasing with the size of the predators and towards deeper waters. C.marinii showed a lower consumption of carcasses and a high proportion of mesopelagic fishes and cephalopods, however, the analysis of the feeding morphology and prey size leads to believe that most of these two groups of prey were consumed as carcasses. This source of food bypass the detritus food chains and connect the concentrations of macrourids to fluctuations in the abundance of epi and mesopelagic organisms and to oceanographic processes that increase their concentration and mortality (e.g. mesoscale anticyclonic eddies).

Distribution, Biomass and Oceanography: Data from two seasonal bottom trawl surveys were used to provide information on distribution, abundances, densities, sizecomposition and biomass estimates for seven species: Coelorinchus marinii, Malacocephalus occidentalis, M. laevis, Lucigadus ori, Hymenocephalus billsam, Ventrifossa macropogon and V. mucocephalus. The total biomass was estimated in 5.5 and 8.3 kt respectively in winter-spring and summer-autumn. C.marinii and M.occidentalis comprised 98% of the biomass. For these two abundant species, surface maps were made with spawning areas, feeding index, sex and immature/mature ratios, and were related to
oceanographic processes, providing insights on strategies and important processes regulating distribution and abundance patterns. Both species showed a marked seasonal variation in the extent and location of spawning areas. Most C.marinii females were mature (90%), suggesting an early maturation during pelagic phase and acquiring demersal habit just prior the onset of maturation, while M.occidentalis showed few matures females and settle to bottom well before maturity. Temperature rather than depth seems to be the main factor regulating the batimetric distribution of both species. We describe three processes responsible for distribution and abundance patterns found in these species. Different patterns of spatial segregation were found in both species, related with depth, sex and maturity. It is suggested that areas with high biomass Macrouridae (scavengers) are induced by zones of occurrence semi-permanent mesoscale processes (e.g. eddies). These processes increase productivity and enable large biomass of short-lived organisms found in the upper layers, and also increase the concentration, mortality and availability of carcasses, favoring scavenger predators. These processes may be responsible for inconsistencies in biomass of megafauna and macrofauna found in some studies, where biomass of megafauna was of the same order of magnitude or larger than macrofauna, contradicting the Eltonian principle. It is suggested that future studies attempt to relate mesoscale processes with the biomass of potential short-lived prey in surface waters and higher biomass of scavengers. This work highlights the importance of the study of ocean dynamics, combining biological and oceanographic observations, trying to understand the role of mesoscale physical processes on the distribution and abundance patterns of species.

The interaction of small cetaceans with fishing gear is considered a major conservation issue worldwide. Between April and September 2009 a study was conducted to assess the level of bycatch in artisanal fisheries of Puerto Lopez, Salango and Machalilla, on the central coast of Ecuador. For this purpose 185 trips of boats using gillnets and purse seine nets as fishing gear were monitored. During the study, seven cetaceans of four different species were caught: two bottlenose dolphins Tursiops truncatus (28.57%), one dwarf sperm whale Kogia sima (14.28%), two Risso's dolphins Grampus griseus (28.57%) and two spotted dolphins Stenella attenuata (28.57%). All cases occurred in gillnets with 5-inches wide mesh. The estimated average mortality rate was 0.07 dolphins/day. August was the month with the highest bycatch rate (0.18 dolphins/day).These results indicate an increase of the bycatch rate compared with previous studies. Fishermen showed interest and willingness to collaborate o...

Mitigating the environmental impact of commercial fishing, by avoiding, minimizing and compensating for adverse effects, is core business for fisheries management authorities globally. The complex interplay of ecological, economic, and social considerations has often resulted in bycatch management being reactive, confrontational and costly. In many cases it has been difficult to demonstrate success and to establish whether bycatch management has been efficient or effective. This article proposes standards for bycatch management following reviews of literature, international agreements and Australian domestic fishery management policies, and consideration by many technical experts and several stakeholder representatives. The standards have been developed using Australian Commonwealth fisheries – and the international fisheries agreements to which Australia is party – as a baseline, but should be applicable to both domestic and regional/international governance systems. The proposed standards involve quantifying fisheries bycatch, agreeing on operational objectives, assessing the effects of fishing on bycatch populations, establishing the cost-effectiveness of mitigation measures, and evaluating performance. The standards encourage domestic management measures that are consistent with the guidance and requirements of international agreements and regional fisheries management organisations. The importance of engaging stakeholders throughout the process is recognised. The standards provide a framework for measuring performance and a checklist of actions for managing bycatch at a fishery level. They have the potential to facilitate the development of more strategic and effective approaches to bycatch management, with defined goals, monitoring systems, and adaptive decision-making. This review of past bycatch management, including the application of the proposed standards to the mitigation of shark bycatch in an Australian longline fishery, demonstrates that the proposed standards are operationally feasible but that they have not always been applied. Specifically, monitoring the performance of bycatch management measures has not always followed their implementation. Crown

This study evaluates local-scale drivers of shark harvests in India, one of the world’s largest shark fishing nations. Focusing on key harbours in the states of Gujarat and Maharashtra, which together contribute 54% of India’s shark harvest, this study uses a semi-structured survey to examine the practices of shark fishers and traders, their knowledge of shark trade and policy, and perceptions of shark declines. Findings indicate that a domestic market for shark meat is presently the main local driver for harvests rather than the global trade in shark fins. Sharks are mostly non-target catch, landed whole, contributing to the protein needs of coastal communities. Consumer demand is the greatest for small-bodied and juvenile sharks. Perceived steep declines in shark numbers and sizes have had economic impacts on fishers and traders. The unregulated domestic market for shark meat is a key challenge requiring nuanced local approaches that diverge from global shark conservation priorities.

Fishing using mobile gears such as trawlnets has been identified as one of the major threats to the
marine biodiversity and to the sustainability of marine fisheries. Studies on the fish fauna associated
with bycatch of bottom trawlers of Kerala, on the southwest coast of India recorded 217 species
classified under 21 orders, 90 families and 154 genera. Among the fish fauna in the trawl bycatch,
103 species (47%) belonged to the trophic level 3.5-3.99, 56 species (26%) to the trophic level 3.0-
3.49, 40 species (18%) to the trophic level 4.0-4.49, 13 species (6%) to the trophic level 2.5-2.99 and
five species (2%) to the trophic level 2.0-2.49. The diversity indices recorded significantly higher values
for the trophic level 3.5-3.99 and it was the lowest for the trophic level 2.0-2.49. In general, the
dominant fraction of fish fauna (73%) of the trawl bycatch represented by 159 species was the mid
level carnivores included in the trophic level 3.0-3.99. The diversity of fish fauna in the trawl bycatch
differed significantly at different trophic levels; presence of large number of mid level carnivores in
the trawl bycatch may indicate large scale removal of top level predators from the ecosystem. The
length class distribution of fishes of the trawl bycatch at various trophic levels showed that fishes in
the length group below 15cm were dominant in all the trophic levels. The mean trophic index of fish
species in the trawl bycatch was estimated as 3.12. Reduction of fishing pressure and use of bycatch
reduction devices are suggested for the sustainable management of trawl bycatch in the southwest coast
of India.

Fisheries bycatch is a recognized threat to marine megafauna. Addressing bycatch of pelagic species however is challenging owing to the dynamic nature of marine environments and vagility of these organisms. In order to assess the potential for species to overlap with fisheries, we propose applying dynamic habitat models to determine relative probabilities of species occurrence for specific oceanographic conditions. We demonstrate this approach by modelling habitats for Laysan (Phoebastria immutabilis) and black-footed albatrosses (Phoebastria nigripes) using telemetry data and relating their occurrence probabilities to observations of Hawaii-based longline fisheries in 1997–2000. We found that modelled habitat preference probabilities of black-footed albatrosses were high within some areas of the fishing range of the Hawaiian fleet and such preferences were important in explaining bycatch occurrence. Conversely, modelled habitats of Laysan albatrosses overlapped little with Hawaii-based longline fisheries and did little to explain the bycatch of this species. Estimated patterns of albatross habitat overlap with the Hawaiian fleet corresponded to bycatch observations: black-footed albatrosses were more frequently caught in this fishery despite being 10 times less abundant than Laysan albatrosses. This case study demonstrates that dynamic habitat models based on telemetry data may help to project interactions with pelagic animals relative to environmental features and that such an approach can serve as a tool to guide conservation and management decisions.

ABSTRACT This study examined the feasibility of gear substitution as a means to reduce bycatch and habitat impacts of fisheries, using a social–ecological systems approach. The U.S. west coast sablefish fishery is an excellent subject for this study, because it permits three different gear types and has a problem with bycatch of overfished species. Bycatch rates were highest in trawls and lowest in pots. Combining interview data with findings from a previous study, affirmed that habitat impacts were highest with trawls and lowest with longlines. Interviews with 44 individuals analyzed using grounded theory yielded several common themes in the opinions of gear substitution. Positive opinion themes included that it would allow better management of the fish populations by reducing bycatch and would allow more business options, flexibility, and increased profit for some trawlers. The main negative opinion theme was that gear substitution could decrease landings needed to support shoreside infrastructure. Most stakeholder groups saw some benefit in gear substitution. Notably, the trawlers voiced a unanimous preference for converting to pots rather than longlines. A scenario analysis revealed that the preferable management option would be long-term gear conversion, but incentives are likely to be an important means of encouraging gear conversion. This ecological impacts rapid assessment provided a regional evaluation of bycatch and habitat impacts that had never been conducted before for these gear types. It also provided scientific support for a regulatory change that legally allows trawlers to practice gear substitution.

The exploitation of elasmobranchs in Argentina reached the same levels that conducted some species to the extinction in other fisheries around the world. Although some species show strong evidences of declines (school shark, sand-tiger shark, copper shark, and some species of skates), few and soft actions were adopted by the national fisheries authorities in order to prevent the same catastrophes in Argentine seas. Even so, the mortality of elasmobranchs in bottom trawl gear is species-specific and it has not been estimated until today. So, differences in the survivorship were not evaluated in a conservation approach.
In the Puerto Quequén coastal bottom trawl fishery at least 23 chondrichthyan species were identified, from which 14 are commercial species (Tamini, 2001). Differences in survivorship of the commercial species could be use as a management tool to mitigate the fish mortality by bottom trawlers. Since mature males and females specimens of elasmobranch are easy to recognize, species with medium to high survivorship could be protected by a ban for reproductive females. This ban needs some other tools to be successful (e.g. an educational plan for the fishery community). This conservation tool helps to stop the depletion of the species of elasmobranchs threatened by the over-fishing, sets a seed for the development of a conservation plan for elasmobranchs in Argentina and works in order to transform coastal fisheries into a sustainable activity for the conservation of both fish and fishers. Surveys onboard the commercial coastal fleet at Puerto Quequén, allow us to estimate the figures of fatalities and survivors in elasmobranchs captured by the bottom trawlers. In the case of survivors we estimate the real chances of the fishes to survive. Based in this result we make a management recommendation to the national and local authorities to mitigate the fishing mortality of the reproductive specimens.

The seasonal and spatial demographics are summarized for seabirds killed incidentally during gear modification trials for a demersal longline fishery in the Bering Sea. We examined 417 carcasses, including Northern Fulmar Fulmarus glacialis (n = 205), Glaucous-winged Gull Larus glaucescens (n = 103), Short-tailed Shearwater Puffinus tenuirostris (n = 48), Glaucous Gull Larus hyperboreus (n = 23), Slaty-backed Gull Larus schistisagus (n = 4), Black-legged Kittiwake Rissa tridactyla (n = 1), Laysan Albatross Diomedea immutabilis (n = 1), and unidentified gull species Larus spp. (n = 32). There was a significant male bias in the sex ratio of fulmars but not of gulls or shearwaters. For the top three species killed, the age composition of resident species was dominated numerically by adults (Northern Fulmar—86%; Glaucous-winged Gull—63%), whereas migrant species were primarily immature birds (Short-tailed Shearwater—71%). The majority of migratory Short-tailed Shearwaters (88%) were caught in July and August, whereas 70% of resident fulmars and gulls were caught in October and November. Age-class frequencies did not differ by month of capture, indicating that adult mortality is substantial. Eighty percent of the fulmars caught during July and August were within 200 km of two colonies in the Bering Sea, whereas only 7% of fulmars were caught in the same area during September to November. This is one of the first demographic summaries of seabird bycatch in Alaska longline fisheries. Additional studies of the species, age and sex of seabirds subject to fisheries-related mortality will provide data necessary to evaluate population-level impacts.

The Mediterranean Sea is a biodiversity hotspot where intense fishing pressure is associated with high bycatch rates of protected species (sea turtles and cetaceans) and top predators (sharks). Since the conservation of these species has become a priority, fishery scientists are faced with the challenge of reducing incidental catch, which entails high rates of mortality. Among the species threatened by fishing activities, the loggerhead turtle (Car-etta caretta) is a charismatic species considered as "vulnerable" at the global scale. In the Mediterranean Sea trawl nets are the gears with the highest probability of catching protected species incidentally. A new flexible Turtle Excluder Device (TED) was tested for the first time on commercial bottom trawlers to assess its effectiveness in reducing bycatch in the Mediterranean Sea. Analysis of the total catches of the hauls made with and without the TED showed that the difference in terms of weight was not significant. The catch of the main commercial species showed similar rates without a significant loss of size (i.e. total length) with the exception of the largest anglerfish (Lophius spp.). The bycatch of control nets included mostly rays and sharks, but never turtles, although the authors learned from the crews of other vessels operating in the same areas at the time of the trials that they had caught some loggerhead turtles. Our study demonstrates that TED scan be adopted without significantly affecting commercial catch. This informs fishers and managers for a practical and effective means that may reduce the bycatch of threatened species in coastal Mediter-ranean demersal multispecies fisheries. The measures involving gear modifications require significant investment but they are technically feasible and are capable of improving the conservation prospects of these endangered species. Besides ensuring normal earnings, the TED induced a significant reduction of debris and litter in the codend, thus reducing catch sorting time and improving catch quality. PLOS ONE | https://doi.org/10.1371/journal.pone.