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Purpose: The Comorian fisheries land around 20 000 t fish annually, for the domestic market. The fleet is divided into a handful of segments, all of them artisanal in nature and practices, using a variety of gear and fishing strategies. Some fishers use fish aggregating devices installed in the territorial waters. This study aims at understanding the comparative environmental impacts of the Comorian fisheries segments, as well as the efficiency of fisheries operations as compared with similar fisheries and alternative sources of animal proteins for the domestic population. Material and methods: This study applied life cycle assessment to estimate, comparatively, the environmental impacts of the different types of fishing unit, segregated by island, boat size and gear, as well as against alternative sources of protein for the Comorian population and neighbouring artisanal fisheries. Results and discussion: Comorian fisheries, whose landings are dominated by tunas, seem less efficient than other regional small-scale fisheries and feature higher environmental impacts than alternative animal protein sources available in the country. The widely adopted practice of trolling, highly energy intensive, dominates Comorian fisheries. Passive gear-based fishing strategies also feature higher than expected energy-related impacts. The environmental benefits of using fish aggregating devices are not clear. The impacts on biodiversity are a cause for concern, especially in the reef areas off Mohéli. Conclusions: Given the cost of public investment on FADs, the fragility of the devices (a FAD can be lost or become ineffective fairly quickly if it is not maintained), and the supposedly significant impact of the FAD network on domestic tuna fishing yields, data on FADs is essential for decision-makers. Other elements for fisheries decision-makers, which are currently lacking, include the monitoring of octopus and reef fish stocks, the effect of co-management agreements on stocks and ecosystems, and a sustainable data collection strategy. The latter would be helpful to better understand the relative importance of fishing strategies, particularly FADs, in relation to fuel intensity. Improving the Comorian fishery's efficiency would be a key driver to improve its sustainability. [ABSTRACT FROM AUTHOR]

Abstract Global wild-capture fisheries are a large and diverse sector requiring various tools for fisheries-dependant data collection and effective Monitoring, Control and Surveillance (MCS). Here we present a novel protocol to collect eDNA from brine tanks onboard commercial longline vessels to reconstruct catch composition. We collected samples from nine vessels operating out of the Eastern Tuna Billfish Fishery, Australia, validating eDNA results with reliable catch data consisting of seven target and bycatch species. Environmental DNA was highly effective for detecting species retained on vessels without contamination or false positives. For four vessels, logbook data and eDNA were consistent with detections of all species. The remaining vessels detected all species except for rare catches of short-billed spearfish (Tetrapturus angustirostris). Similarities between rank abundance distributions of catch and eDNA reads were observed with logbook data mirrored when eDNA sequences were organised into rank order abundance. The method was effective at identifying highly abundant taxa retained in brine tanks- tuna (Thunnus spp.), swordfish (Xiphias gladius), marlin (Kajijia audax), and Atlantic Pomfret (Brama brama). Further research is required to validate how eDNA and other molecular monitoring tools can be scaled and applied to provide solutions for monitoring challenges in the fisheries sector.

Abstract: Harnessing the economic potential of the oceans is key to combating poverty, enhancing food security, and strengthening economies. But the concomitant risk of intensified resource extraction to migratory species is worrying given these species contribute to important ecological processes, often underpin alternative livelihoods, and are mostly already threatened. We thus sought to quantify the potential conflict between key economic activities (5 fisheries and hydrocarbon exploitation) and sea turtle migration corridors in a region with rapid economic development: southern and eastern Africa. We satellite tracked the movement of 20 loggerhead (Caretta caretta) and 14 leatherback (Dermochelys coriacea) turtles during their postnesting migrations. We used movement‐based kernel density estimation to identify migration corridors for each species. We overlaid these corridors on maps of the distribution and intensity of economic activities, quantified the extent of overlap and threat posed by each activity on each species, and compared the effects of activities. These results were compared with annual bycatch rates in the respective fisheries. Both species’ 3 corridors overlapped most with longline fishing, but the effect was worse for leatherbacks: their bycatch rates of approximately 1500/year were substantial relative to the regional population size of <100 nesting females/annum. This bycatch rate is likely slowing population growth. Artisanal fisheries may be of greater concern for loggerheads than for leatherbacks, but the population appears to be withstanding the high bycatch rates because it is increasing exponentially. The hydrocarbon industry currently has a moderately low impact on both species, but mining in key areas (e.g., Southern Mozambique) may undermine >50 years of conservation, potentially affecting >80% of loggerheads, 33% of the (critically endangered) leatherbacks, and their nesting beaches. We support establishing blue economies (i.e., generating wealth from the ocean), but oceans need to be carefully zoned and responsibly managed in both space and time to achieve economic (resource extraction), ecological (conservation, maintenance of processes), and social (maintenance of alternative livelihood opportunities, alleviate poverty) objectives. [ABSTRACT FROM AUTHOR]

Considerable time and money are expended in the pursuit of catching fish with hooks (e.g., handlining, angling, longlining, trolling, drumlining) across the recreational, commercial and subsistence fishing sectors. The fish and other aquatic organisms (e.g., squid) that are captured are not a random sample of the population because external (e.g., turbidity) and underlying internal variables (e.g., morphology) contribute to variation in vulnerability to hooks. Vulnerability is the probability of capture for any given fish in a given location at a given time and mechanistically explains the population-level catchability coefficient, which is a fundamental and usually time-varying (i.e., dynamic) variable in fisheries science and stock assessment. The mechanistic drivers of individual vulnerability to capture are thus of interest to fishers by affecting catch rates, but are also of considerable importance to fisheries managers whenever hook-and-line-generated data contribute to stock assessments. In this paper, individual vulnerability to hooks is conceptualized as a dynamic state, in which individual fish switch between vulnerable and invulnerable states as a function of three interdependent key processes: an individual fish's internal state, its encounter with the gear, and the characteristics of the encountered gear. We develop a new conceptual framework of 'vulnerability,' summarize the major drivers of fish vulnerability, and conclude that fish vulnerability involves complex processes. To understand vulnerability, a shift to interdisciplinary research and the integration of ecophysiology, fish ecology, fisheries ecology and human movement ecology, facilitated by new technological developments, is required. [ABSTRACT FROM AUTHOR]

Illegal exploitation of resources is a cause of environmental degradation worldwide. The effectiveness of conservation initiatives such as marine protected areas relies on users' compliance with regulations. Although compliance can be motivated by social norms (e.g. peer pressure and legitimacy), some enforcement is commonly necessary. Enforcement is expensive, particularly in areas far from land, but costs can be reduced by optimizing enforcement. We present a case study of how enforcement could be optimized at Cocos Island National Park, Costa Rica, an offshore protected area and World Heritage Site. By analysing patrol records we determined the spatial and temporal distribution of illegal fishing and its relationship to patrol effort. Illegal fishing was concentrated on a seamount within the Park and peaked during the third year-quarter, probably as a result of oceanographic conditions. The lunar cycle in conjunction with the time of year significantly influenced the occurrence of incursions. The predictability of illegal fishing in space and time facilitates the optimization of patrol effort. Repeat offenders are common in the Park and we suggest that unenforced regulations and weak governance are partly to blame. We provide recommendations for efficient distribution of patrol effort in space and time, establishing adequate governance and policy, and designing marine protected areas to improve compliance. Our methods and recommendations are applicable to other protected areas and managed natural resources. [ABSTRACT FROM PUBLISHER]

This study analyses depredation by killer whales (Orcinus orca) and false killer whales (Pseudorca crassidens) on catches of the Uruguayan pelagic longline fishery in the Southwestern Atlantic Ocean between 1998 and 2007. Data were collected by scientific observers from the National Observer Program of the Tuna Fleet operating in the area between 19°-40.5°S and 20°-54°W. Depredation occurred in 67 of the 1029 sets and was restricted to the area from 25°-40.5°S to 27°-53°W, though larger proportions of depredation (DP: percentage of total fish caught damaged by cetaceans) were observed in the Brazil-Malvinas (Falkland) Confluence area (34°-37°S and 51°-53°W) where most of the fishing effort was concentrated. Depredation occurred year-round though intra-annual variability in its intensity was recorded. The overall DP was 0.37% and was slightly higher in autumn. The spatial analysis showed that DP within grids of 1 x 1° was homogeneous and generally <2.5%. Ten out of 57 fish species caught by the fishery were depredated by cetaceans. Swordfish (Xiphias gladius) showed the highest DP per species (1.17%). Using the frequency of resources selectivity index of Ivlev, it was determined that swordfish was selected as a preferred prey in 43.9% of the sets with depredation. Generalized linear models indicated that distance to coast, year, and vessel were significant variables in explaining the number of fish depredated per fishing event. The presence of killer whales in the fishing ground seems not to affect the catch per unit effort by the longline fishery. The losses caused by depredation of cetaceans on the catch are low with probably minor economic effects to the Uruguayan longline fishing industry. [ABSTRACT FROM AUTHOR]

Bycatch is one of the main causes of human-caused mortality and population decline of many marine mammals. Monitoring bycatch is the first step to understand the impact of the fisheries on the species affected. Understanding how the interaction between marine mammals and fishing operations varies in space and time, and how it is influenced by environmental variables, is essential for designing mitigation strategies to reduce bycatch mortality. In this paper, we use data gathered by scientific observers and a fishing skipper to analyse marine mammals bycatch by the Uruguayan pelagic longline fishery operating in the Southwestern Atlantic Ocean from 1996 to 2007. The total bycatch per unit effort (Bcpue) was 0.0150 marine mammals/1000 hooks and the highest values (~0.2) were recorded between 37°-38°S and 49°-51°W. Total cetacean Bcpue during the study period was low (0.0051 cetacean/1000 hooks) and occurred between 32°-37°S and 46°-54°W. Generalized additive models showed that cetaceans' bycatch was mainly affected by the depth, sea surface temperature, and season. Although cetaceans were captured year-round, the highest values were registered in spring months, most bycatch events occurred over the continental slope (median = 619 m) and in waters with a median temperature of 19.7°C. The bycatch of pinnipeds was influenced by depth, location, and season. Pinniped bycatch occurred mainly in winter, in waters ranging from 80 to 5000 m of depth (median = 2366 m) between 34°-37°S (median = 35.9°S) and 54°-49°W (median = 51.8°W). The spatial analysis showed that most bycatch events occurred within the Brazil-Malvinas Confluence zone, an area of high productivity where the pelagic longline fleet concentrates its fishing effort and where marine mammals probably concentrate to feed. [ABSTRACT FROM AUTHOR]

Red tree corals (Primnoa pacifica), the largest structure-forming gorgonians in the North Pacific Ocean, form dense thickets in some areas. These thickets are a dominant benthic habitat feature in the Gulf of Alaska (GOA), yet little is known about the ecosystems they support. In 2005, we used a submersible to study the ecology of thickets inside or near five small areas of the eastern GOA later designated in 2006 as habitat areas of particular concern (HAPCs)--areas closed to all bottom contact fishing. We show that red tree corals are keystone species in habitats where they form thickets (mean density 0.52 corals m-2)--the densest and largest thickets documented anywhere. Measured sponge densities (2.51 sponges m-2) were also among the highest documented anywhere. The corals and sponges in the study areas provide essential fish habitat for some fish species, and we show with logistic regression models modified with a scaled binomial variance that bedrock, while important habitat for some fish, is even more important when paired with corals and sponges. Red tree corals were not equally distributed with regard to habitat characteristics, and we show that their presence was correlated with bedrock substrate, moderate to high seabed roughness, and slope .108. Most corals and sponges are vulnerable to disturbance from long lining, the principal bottom contact fishing in this region, but the larger corals and sponges are the most vulnerable. We observed evidence of infrequent recruitment events and a strong pulse of predation, apparently from fishing gear induced trauma, that could exacerbate slow recovery of red tree corals from disturbance. Some red tree coral thickets are provided protection within designated HAPCs and some are not. Modifications to long line gear and an expanded network of HAPCs could help preserve these keystone species and the ecosystems they support. [ABSTRACT FROM AUTHOR]

Recreational fishing is a vital component of the tourism economy in Baja California Sur (BCS), Mexico, although several artisanal and industrial fisheries continue to operate in the region. The commercial long-liner fleet in particular is widely held to be responsible both for diminishing shark populations and declines in billfish through bycatch. Using available fisheries and ecosystem data, we develop an Ecopath with Ecosim (EwE) model to represent current ecosystem and fishing dynamics in BCS and explore the ecological and economic effects of specific fisheries policy measures. Results suggest that currently mandated bycatch limits for the longlining fleet will have little effect on marlin abundance in the area. In an overfished ecosystem, decreasing fishing effort can result in higher overall catches through population rebuilding. While perhaps ecologically justified, increases in the abundance of sharks, a top predator, can have negative effects on other valued species in the ecosystem. The effects of these trophic dynamics must not be overlooked, as they can negate or even reverse desired outcomes from fisheries management. [Copyright &y& Elsevier]

Abstract: The stress associated with commercial and recreational fishing of saithe (Pollachius virens Linnaeus) was investigated on fish caught with a rod and reel at the pier<10s or 4–5min at 100m depth and after 6–12h of soaking on a longline or chased to exhaustion for 15min. Results show that hooking caused an acute stress reaction accompanied by accumulating blood lactate and pCO2 levels accompanied by the acidification of the muscle. After 6–12h of soaking, the longlined had a significant increase in blood glucose levels, Na+, K+, hemoglobin content and hematocrit values. During soaking the longlined fish had restored their acid–base balance, having significant higher blood pH and HCO3 − levels, reflecting hyperventilation. Only one case of hypoxia was observed. None of the 767 investigated fish that was hauled onboard had died during soaking. We conclude that angling causes a long and short term stress effect on P. virens, but survival is related to animal capability to restore acid–base balance during soaking. [Copyright &y& Elsevier]

Abstract: Given the widely recognized need to better protect the oceans but limited resources to do so, methods for prioritizing potential protected area sites are important. This is particularly true for the open oceans, where few protected areas currently exist and data availability is limited. Here, we examine the relationship between the distributions of tuna and billfish species richness (an indicator of pelagic biodiversity), the human impact drivers of fishing pressure (quantified as cumulative removals) and sea surface temperature increase (quantified as the increase in large positive anomalies) in tropical to temperate oceans at the scale of a 5°×5° grid. We investigate relationships using Generalised Additive Models and Regression Tree analysis, and identify the top 50 “hotspot” cells for species richness and each of the two impact drivers. We find that both impact drivers significantly overlap with high species richness, but relationships are complex, non-linear and ocean-basin specific. Higher fishing pressure is associated with higher species richness in the Indian and Pacific Oceans, and this overlap is particularly prominent in the central Pacific, and in the Indian Ocean around Sri Lanka. In the Pacific and Atlantic Oceans, species richness is generally higher in areas that have seen lower levels of change in sea surface temperature and only one cell, near Easter Island, is a hotspot for species richness and sea surface temperature increase. While species richness and impact drivers overlap in some areas, there are many areas with high species richness and limited apparent impact. This suggests that area-based conservation strategies that aim to protect areas of high pelagic biodiversity may be achievable with limited displacement of fishing effort. [Copyright &y& Elsevier]

Worldwide ecosystems are modified by human activities and climate change. To be able to predict future changes, it is necessary to understand their respective role on population dynamics. Among the most threatened species are top predators because of their position in the food web. Albatross populations are potentially affected by both human activities, especially longline fisheries, and climatic fluctuations. Based on long-term data (1985–2006), we conducted through a comparative approach a demographic analysis (adult survival and breeding success) on four albatross species breeding on the Indian Ocean sub-Antarctic Islands to assess the relative impact of climate and fisheries during and outside the breeding season. The study revealed that adult survival of almost all species was not affected by climate, and therefore probably canalized against climatic variations, but was negatively affected by tuna longlining effort in three species. Breeding success was affected by climate, with contrasted effects between species, with Southern Oscillation Index having an impact on all species but one. Differences in demographic responses depended on the foraging zone and season. In order to predict population trajectories of seabirds such as albatrosses, our results show the importance of assessing the relative influence of fishing and climate impacts on demography. [ABSTRACT FROM AUTHOR]

Many seabird populations are currently decreasing, especially albatrosses for which the primary threat is recognised to be mortality in fisheries. Introduced predators, climate change and other factors such as diseases can also have large impacts on seabirds. Here, we assessed the relative effect of three potential threats: climate, fisheries and diseases on the demography of an endangered marine predator and modelled its population dynamics to project its size under different scenarios. We based our study on a long-term monitoring of a colony of individually marked Indian yellow-nosed albatrosses at Amsterdam Island, subtropical Indian Ocean, that has declined during the past twenty years. We found no evidence for an impact of legal tuna longlining on demographic parameters. Hatching success was lower during El Niño years but survival (0.902±0.011) was not affected by climatic factors. Avian cholera caused high chick mortality (0.808±0.181) which in turn probably triggered the high emigration rate (0.038±0.011) through dispersal of failed breeders. This colony has a high risk of extinction. However, the rest of the population at Amsterdam Island seemingly not affected to the same extent, declined but stabilised since 1998. Matrix models indicated that lowered adult survival and the very low breeding success, resulting in low recruitment, have both contributed to the decline of the yellow-nosed albatross colony until the mid-1990s, but that more recent decline was primarily caused by low fledging success. Our results highlight that potential threats such as fisheries, diseases or climate have to be considered simultaneously to disentangle their roles when assessing the conservation status of a marine predator species. [Copyright &y& Elsevier]

We integrated satellite-tracking data from black-footed albatrosses (Phoebastria nigripes; n =7) and Laysan albatrosses captured in Alaska (Phoebastria immutabilis; n =18) with data on fishing effort and distribution from commercial fisheries in the North Pacific in order to assess potential risk from bycatch. Albatrosses were satellite-tagged at-sea in the Central Aleutian Islands, Alaska, and tracked during the post-breeding season, July–October 2005 and 2006. In Alaskan waters, fishing effort occurred almost exclusively within continental shelf and slope waters. Potential fishery interaction for black-footed albatrosses, which most often frequented shelf-slope waters, was greatest with sablefish (Anoplopoma fimbria) longline and pot fisheries and with the Pacific halibut (Hippoglossus stenolepsis) longline fishery. In contrast, Laysan albatrosses spent as much time over oceanic waters beyond the continental shelf and slope, thereby overlapping less with fisheries in Alaska than black-footed albatrosses. Regionally, Laysan albatrosses had the greatest potential fishery interaction with the Atka mackerel (Pleurogrammus monopterygius) trawl fishery in the Western Aleutian Islands and the sablefish pot fishery in the Central Aleutian Islands. Black-footed albatrosses ranged further beyond Alaskan waters than Laysan albatrosses, overlapping west coast Canada fisheries and pelagic longline fisheries in the subarctic transition domain; Laysan albatrosses remained north of these pelagic fisheries. Due to inter-specific differences in oceanic distribution and habitat use, the overlap of fisheries with the post-breeding distribution of black-footed albatrosses is greater than that for Laysan albatrosses, highlighting inter-specific differences in potential vulnerability to bycatch and risk of population-level impacts from fisheries. [Copyright &y& Elsevier]

Abstract: Many authors have suggested the use of a cap and trade auction system to help reduce bycatch—the incidental take of species by fishing gear targeting other species—of sea turtles in the Hawaii-based swordfish longline fishery. However, we know of no quantitative evaluations of the method. We present a simple mathematical model to serve as a framework to evaluate bycatch auction systems quantitatively. We conclude that cap and trade auction systems have the potential to reduce sea turtle bycatch by creating a financial incentive, while keeping permit costs down to 2–3% of total revenues. While stringent regulations aimed at conserving endangered sea turtles would still be essential, implementation of an auction for issuing transferable bycatch permits would likely enhance the economic efficiency of the fleet. Sea turtle mortality could be reduced further if a shrinking cap on total turtle mortality was introduced, taking advantage of the incentives for reducing turtle mortality that are introduced by the cap and trade auction system. [Copyright &y& Elsevier]

Abstract: A manufactured bait, Norbait© 700E, and two natural baits, clams and herring, were tested to compare catch of haddock and Atlantic cod using longlines in a cod conservation zone. Trials on a commercial fishing vessel demonstrated that the manufactured bait had the lowest catches of cod and the lowest ratio of cod to legal-sized haddock compared to either natural bait. Interactions of bait type, area of set, and trip confounded the effects of bait on catch. Based on the haddock catch per unit effort (CPUE), estimates of economic viability using only the manufactured bait suggested that a fishery may be infeasible. Use of Norbait© to limit Atlantic cod bycatch in haddock longline fisheries may require fishery-by-fishery evaluation. [Copyright &y& Elsevier]

Abstract: In the Northwest Atlantic, bycatch of depleted groundfish stocks in the haddock fishery on Georges Bank is an ongoing concern. In recent years, this fishery on the American side of Georges Bank has been limited by high bycatch rates of cod. Considerable conservation engineering work has been done to address the problem, including experiments with different longline baits and modifications to otter trawl gear. Fabricated baits have shown promise for increased selectivity when longlining, but it has sometimes been difficult to establish whether low cod catch rates with fabricated baits have resulted from bait selectivity or from a low abundance of cod in the area. In this study, we compare catch rates of cod and haddock between otter trawls and longline gear in experimental and commercial fishing on Georges Bank in the summer of 2005. We also compare cod bycatch rates among longlines baited with squid, herring, or fabricated baits (mainly Norbait 700E) in Georges Bank Closed Area 1, from October 2003 to June 2005. Records from the Northeast Fisheries Observer Program were combined with data collected by the Cape Cod Commercial Hook Fishermen''s Association (CCCHFA), and compared using generalized linear models. In the Eastern US-Canada Resource Sharing Area (EUSCA) in the summer of 2005 catch of cod per haddock by weight was significantly lower when fishing with longline gear (0.008–0.045kg cod per kg haddock) than with otter trawl gear (0.059–0.826kg cod per kg haddock), in all months and areas. Cod bycatch rates were also significantly lower for longlines fishing for haddock than for otter trawls fishing for groundfish species other than haddock. In Closed Area 1, statistically significant differences in cod to haddock ratios were found between baits, with squid catching the highest amount of cod, fabricated baits catching the lowest amount, and herring at an intermediate level. The development of fishing methods that minimize cod bycatch is a high priority in many regions of the North Atlantic. These results indicate that longlines with fabricated bait have the potential to maintain a very low catch of cod while fishing for haddock. [Copyright &y& Elsevier]

1. The impact of climate on marine ecosystems is now well documented, but remains complex. Climate change may interact with human activities to effect population dynamics. In addition, in migratory species conditions are different between the breeding and wintering grounds, resulting in more complex dynamics. All these possible effects should be considered to predict the future of endangered species, but very few studies have investigated such combined interactions. 2. As a case study, we assessed the relative impact of fisheries and of oceanographic conditions in breeding and wintering sites on adult survival and breeding success of a population of the endangered black-browed albatross Thalassarche melanophrys in the Kerguelen Islands, Southern Indian Ocean. This study was based on long-term monitoring of individually marked individuals (1979–2005) and identification by tracking studies and band recoveries of the oceanic feeding zones used during breeding and non-breeding seasons. 3. Breeding success was variable until 1997 and then declined gradually, from 0·88 to 0·48 chicks per egg laid. It was favoured by positive sea-surface temperature anomalies (SSTA) and trawl fishery during the breeding period, whereas it was negatively affected by positive SSTA around Tasmania, where the species winters. Adult survival was 0·918 ± 0·004 on average and increased with SSTA during incubation, but decreased significantly with high tuna longlining effort in the wintering zone. 4. Our analyses show that demographic parameters were influenced by both climate and fisheries in both breeding and wintering grounds, but with different effect size. Black-browed albatross breeding success was more favoured by trawlers’ offal and discards than by any of the seasonally/spatially oceanographic conditions, whereas their survival was equally affected by tuna longline fishery through incidental by-catch and spring SSTA. 5. Synthesis and applications. Our work underlines that a comprehensive knowledge of the life history of a species in all the habitats used is important to disentangle the respective roles of environmental conditions and human factors on population dynamics. Identification of these effects is required when proposing effective conservation measures, because the conservation of threatened species may depend on their wintering country's exclusive economic zones. [ABSTRACT FROM AUTHOR]

Abstract: We conducted a satellite tracking study of the endangered short-tailed albatross (Phoebastria albatrus) to determine post-breeding season distribution, the amount of time spent within exclusive economic zones of Pacific Rim countries, and assess factors affecting spatial and temporal overlap with commercial fisheries in Alaska. We obtained 6709 locations for 14 albatrosses (131–808 locations and 51–138 days of tracking per bird). Albatrosses ranged widely throughout the North Pacific Rim, spending the majority of time within the exclusive economics zones of Japan, Russia (Kuril Islands and Kamchatka Peninsula), and the United States (Aleutian Islands and Bering Sea, Alaska). We found evidence for gender and age-related differences in distribution and, therefore, potential interaction with regional fisheries. Overall, albatrosses spent the greatest proportion of time within the Alaska exclusive economic zone. Within Alaska, albatrosses occurred most frequently in fishery management zones that encompassed the Aleutian Islands, Bering Sea, and south of the Alaska Peninsula. Short-tailed albatrosses had the greatest potential overlap with fisheries that occurred along continental shelf break and slope regions, e.g., longlining for sablefish (Anoplopoma fimbria), where albatrosses occurred most often. Some birds, however, also made frequent excursions onto the extensive Bering Sea shelf, suggesting significant potential for interactions with the large-scale walleye pollock (Theragra chalcogramma) and Pacific cod (Gadus macrocephalus) fisheries. Alaskan longline fishing fleets have been proactive in using seabird deterrent devices, however, our data further emphasize that such efforts beyond the Alaska exclusive economic zone would provide a greater conservation benefit for this species. [Copyright &y& Elsevier]

Abstract: Myers and Worm claim that their analyses of catch rates following the commencement of industrial longline fishing for tuna and billfishes show that these longline fisheries rapidly depleted the abundance of these large oceanic predators by 90% (Myers RA, Worm B. Rapid worldwide depletion of predatory fish communities. Nature 2003;423:280–3). Their analyses were published in a high profile science journal along with an accompanying press release, which then attracted substantial international media focus and public attention. This media focus in turn has been used as a base for advocating major marine policy changes for pelagic tuna fisheries (e.g. a minimum of a 50% reduction in catches and establishment of extensive marine reserves). However, among numerous scientific experts involved in tuna and pelagic fishery research substantial concerns exist that Myers and Worm''s analyses provide a misleading picture of the status of large predatory pelagic fishes. These concerns are reviewed using data from the Indian Ocean for illustrative purposes and indicate that the initial longline catches were not responsible for a rapid depletion of the main tuna and billfish stocks nor were they threatening the overall sustainability of these stocks. However, the status of a number of theses stocks is of concern as a result of large increases in catches in more recent years. The debate sparked by Myers and Worm''s paper should not distract from the critical problem of developing and implementing effective international management policies. In addition to implications for fishery management, the publication, peer-review, scientific response and publicity process associated with the publication of Myers and Worm''s paper are discussed. Concerns are raised that if these become standard practices for articles in high profile science journals that this would undermine the trust placed in such journal to provide an accurate and well-balanced representation of the most important new scientific findings and in their role to inform policy decisions based on these findings. [Copyright &y& Elsevier]

We identify changes in the pelagic fish community of the tropical Pacific Ocean by comparing recent data collected by observers on longline fishing vessels with data from a 1950s scientific survey when industrial fishing commenced. A major shift in size composition and indices of species abundance and community biomass accompanied the start of fishing. The largest and most abundant predators, such as sharks and large tunas, suffered the greatest declines in abundance (21 % on average). They also showed striking reductions in mean body mass. For example, the mean mass of blue shark (Prionace glauca) was 52 kg in the 1950s compared to 22 kg in the 1990s. The estimated abundance of this species was 13% of that in the 1950s. Overall, the biomass of large predators fell by a factor of 10 between the periods. By contrast, several small and formerly rare species increased in abundance, e.g., pelagic stingray (Dasyatis violacea). However, the increases in small species did not balance the reductions in the biomass of large predators. Of three possible explanations (fishing, environmental variation, and sampling bias), available evidence indicates fishing to be the most likely cause for the observed patterns. [ABSTRACT FROM AUTHOR]

Seabirds scavenge baits from the hooks of commercial longlines, resulting in incidental seabird mortality and bait loss. As interactions between seabirds and longline fishing may cause seabird populations to decline and reduce gear efficiency, the potential of various mitigation measures to solve this problem has been tested. Four fishing experiments were conducted in commercial longlining in the north Atlantic to investigate the effectiveness of a bird-scaring line, underwater setting and a line shooter in reducing seabird bycatch during longline setting. These results are reviewed and the performance of the mitigation measures is evaluated. The great majority of the birds caught were northern fulmars (Fulmarus glacialis). Accidental catches of birds were reduced by all three methods, most clearly by the bird-scaring line. A total of 185 000 hooks were set with this mitigation measure in place, and only two birds were caught compared with 205 for control lines with a similar number of hooks set without any mitigation measure. The experiments also reduced bait loss and increased target species catch rates when mitigation measures were used. Increased catch rates are important incentives for fishermen to employ mitigation measures. It is concluded that the bird-scaring line is the most feasible and effective mitigation measure in the north Atlantic longline fishery, and the results reviewed should have relevance to longline fisheries worldwide in which interactions with Fulmarus spp. occur. [Copyright &y& Elsevier]

• Acoustic detection of killer whale interaction with blue eye fishery occurred many hours prior to visual observations. • Large underestimation of the extent of killer whale depredation and fish loss due to missed interactions. • Killer whale interaction across long distances (>1000 km) suggests intentional following of fishing vessels. • Successive interactions reduced through long distance travel between fishing grounds, a consideration for fishers. Removal of target catch from longlines by marine mammals, known as depredation, is a global issue creating animal welfare, socioeconomic and management concerns. The killer whale (Orcinus orca) is a key species of concern for longline depredation due to their global presence and ability to remove large quantities of caught fish. Currently, data on whale behaviours around fishing vessels, including timing of depredation and ability to follow vessels, is not completely understood. This lack of knowledge prevents a complete assessment of depredation both spatially and temporally, which is important to reduce the chance of underestimating depredation events. Our study utilised both photo-identification and acoustics as complementary approaches to investigate depredation on the blue-eye trevalla (Hyperoglyphe antarctica) demersal longline fishery in Australia. Of the 14 d when depredations were recorded acoustic detection of killer whales prior to visual confirmations occurred in 13 (93 %). Photo-identification revealed individuals repeatedly interacting with the vessel, sometimes over long distances (>1000 km), with increasing inter-depredation times as the vessel travelled further. These findings suggest that killer whales move to known fishing areas well before detection from surface monitoring occurs. While this study has revealed aspects of killer whale behaviours when encountering and interacting with longline fisheries, it has highlighted how traditional monitoring methods underestimate depredation and that this aspect needs to be further investigated. [ABSTRACT FROM AUTHOR]