Bycatch in gillnet fisheries – An overlooked threat to waterbird populations

Žydelis, Ramūnas; Bellebaum, Jochen; Österblom, Henrik; Vetemaa, Markus; Schirmeister, Bernd; Stīpniece, Antra; Dagys, Mindaugas; Eerden, Mennobart van; Garthe, Stefan

doi:10.1016/j.biocon.2009.02.025

Cited by 141 publications

(84 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Common fishing methods and gear classes include: dredges, bottom gillnets, midwater gillnets, hook and line, bottom longlines, pelagic longlines, pots and traps, purse seines, bottom trawls, and midwater trawls. Almost all seabird bycatch occurs in longline (pelagic and demersal), gillnet, and bottom otter trawl fisheries (Chuenpagdee et al 2003, Sullivan et al 2006, Zydelis et al 2009, Anderson et al 2011, Croxall et al 2012. Seabird mortality related to bottom otter trawls is a more recent concern (Sullivan et al 2006).…”

Section: Impacts Of Commercial Fisheries On Migratory Birdsmentioning

confidence: 99%

Mortality of Migratory Birds from Marine Commercial Fisheries and Offshore Oil and Gas Production in Canada

Ellis¹,

Wilhelm²,

Hedd³

et al. 2013

ACE

View full text Add to dashboard Cite

. 2013. Mortality of migratory birds from marine commercial fisheries and offshore oil and gas production in Canada. Avian Conservation and Ecology 8(2): 4. http://dx.doi.org/10.5751/ACE-00589-080204 ABSTRACT. There is an imminent need for conservation and best-practice management efforts in marine ecosystems where global-scale declines in the biodiversity and biomass of large vertebrate predators are increasing and marine communities are being altered. We examine two marine-based industries that incidentally take migratory birds in Canada: (1) commercial fisheries, through bycatch, and (2) offshore oil and gas exploration, development, and production. We summarize information from the scientific literature and technical reports and also present new information from recently analyzed data to assess the magnitude and scope of mortality. Fisheries bycatch was responsible for the highest levels of incidental take of migratory bird species; estimated combined take in the longline, gillnet, and bottom otter trawl fisheries within the Atlantic, including the Gulf of St. Lawrence, and Pacific regions was 2679 to 45,586 birds per year. For the offshore oil and gas sector, mortality estimates ranged from 188 to 4494 deaths per year due to the discharge of produced waters resulting in oil sheens and collisions with platforms and vessels; however these estimates for the oil and gas sector are based on many untested assumptions. In spite of the uncertainties, we feel levels of mortality from these two industries are unlikely to affect the marine bird community in Canada, but some effects on local populations from bycatch are likely. Further research and monitoring will be required to: (1) better estimate fisheriesrelated mortality for vulnerable species and populations that may be impacted by local fisheries, (2) determine the effects of oil sheens from produced waters, and attraction to platforms and associated mortality from collisions, sheens, and flaring, so that better estimates of mortality from the offshore oil and gas sector can be obtained, and (3) determine impacts associated with accidental spills, which are not included in our current assessment. With a better understanding of the direct mortality of marine birds from industry, appropriate mitigation and management actions can be implemented. Cooperation from industry for data collection, research to fill knowledge gaps, and implementation of mitigation approaches will all be needed to conserve marine birds in Canada.RÉSUMÉ. Dans les écosystèmes marins, le déclin de la biodiversité et de la biomasse des grands prédateurs vertébrés s'accentue à l'échelle globale et les communautés marines subissent de plus en plus de perturbations. Étant donné la situation, il est important de faire des efforts de conservation et de pratiques exemplaires de gestion pour ces écosystèmes. Nous avons examiné deux industries du milieu marin qui entraînent des prises accessoires d'oiseaux migrateurs au Canada : 1) la pêche commerciale; et 2) l'exploration, le développement et l'exploi...

show abstract

Section: Impacts Of Commercial Fisheries On Migratory Birdsmentioning

confidence: 99%

Mortality of Migratory Birds from Marine Commercial Fisheries and Offshore Oil and Gas Production in Canada

Ellis¹,

Wilhelm²,

Hedd³

et al. 2013

ACE

View full text Add to dashboard Cite

show abstract

“…The surge of research interest seen during that period may now be beginning to slow, though the issue of bycatch remains of key importance to the conservation of many marine species Žydelis et al 2009;Gilman et al 2010;Reeves et al 2013) .…”

Section: Discussionmentioning

confidence: 99%

“…The incidental capture or bycatch of non-commercial species in fishing gear is widely recognized as an important threat to the conservation status of many animal populations Žydelis et al 2009Gilman et al 2010;Reeves et al 2013). Air breathing taxa including birds, turtles and marine mammals are particularly vulnerable because of their requirement to surface at regular intervals.…”

Section: Introductionmentioning

confidence: 99%

Disentangling the causes of protected‐species bycatch in gillnet fisheries

Northridge

Coram

Kingston

et al. 2017

Conservation Biology

View full text Add to dashboard Cite

Gillnet fisheries are widely thought to pose a conservation threat to many populations of marine mammals, seabirds and turtles. Gillnet fisheries also support a significant proportion of small-scale fishing communities worldwide. Despite a large number of studies on protected species bycatch in recent decades, relatively few have examined the underlying causes of bycatch, and fewer still have looked at the issue from a multi-taxon perspective. We used three bibliographic databases and one search engine to identify studies by year of publication and taxon. The majority of studies on the mechanisms of gillnet bycatch are not This article is protected by copyright. All rights reserved. 2 accessible through mainstream published literature sources. Many are reported in technical papers, government reports and University theses. We reviewed over 600 published and unpublished studies of bycatch where causal or correlative factors were considered, and identified therein 28 environmental, operational, technical and behavioral factors that might plausibly be associated with higher or lower bycatch rates of the three taxa. Of the factors considered, 11 were found to have been associated with potential bycatch reduction in two out of the three taxa, while three factors (water depth, mesh size and net height) were associated with trends in bycatch rate for all three taxa. These findings provide a basis to guide further experimental work to test hypotheses about which factors most influence bycatch rates, and to explore ways of managing fishing activities and/or improving gear design to minimize the incidental capture of species of conservation concern, whilst ensuring the viability of the fisheries concerned.

show abstract

“…Beached bird surveys have been widely used to monitor the impact of oil pollution in the oceans since the beginning of the twentieth century [8–10]. This scientific approach is also useful to investigate a number of threats to seabirds across the world’s oceans [11], such as storms and adverse weather conditions [12], lack of food under decreased productivity conditions [7], bycatch [13, 14], entanglements and ingestion of debris [15, 16], diseases [17] and contamination by chemical pollutants [18, 19]. …”

Section: Introductionmentioning

confidence: 99%

Environmental Predictors of Seabird Wrecks in a Tropical Coastal Area

2016

View full text Add to dashboard Cite

Beached bird surveys have been widely used to monitor the impact of oil pollution in the oceans. However, separating the combined effects of oil pollution, environmental variables and methodological aspects of beach monitoring on seabird stranding patterns is a challenging task. The effects of a comprehensive set of oceanographic and climatic variables and oil pollution on seabird strandings in a tropical area of Brazil were investigated herein, using two robust and innovative methods: Generalized Linear Mixed Models and Structural Equation Modeling. We assessed strandings of four resident seabird species along 480 km of beaches divided into 11 sampling areas, between November 2010 and September 2013. We found that increasing the distance from the nearest breeding island reduce the seabird stranding events. Storm activity and biological productivity were the most important factors affecting the stranding events of brown boobies Sula leucogaster, Cabot’s terns Thalasseus acuflavidus and kelp gulls Larus dominicanus. These species are also indirectly affected by warm tropical waters, which reduce chlorophyll-a concentrations. Beach surveys are, thus, useful to investigate the mortality rates of resident species near breeding sites, where individuals are more abundant and exposed to local factors associated with at-sea mortality. In contrast, conservation actions and monitoring programs for far-ranging seabird species are needed in more distant foraging areas. Furthermore, beach monitoring programs investigating the impact of oil pollution on seabirds need to account for the effects of environmental factors on stranding patterns. The present study also demonstrated that seabirds inhabiting tropical coastal waters are sensitive to climate conditions such as adverse weather, which are expected to increase in frequency and intensity in next decades.

show abstract

Bycatch in gillnet fisheries – An overlooked threat to waterbird populations

Cited by 141 publications

References 38 publications

Mortality of Migratory Birds from Marine Commercial Fisheries and Offshore Oil and Gas Production in Canada

Mortality of Migratory Birds from Marine Commercial Fisheries and Offshore Oil and Gas Production in Canada

Disentangling the causes of protected‐species bycatch in gillnet fisheries

Environmental Predictors of Seabird Wrecks in a Tropical Coastal Area

Contact Info

Product

Resources

About