Reviews and Overviews of Seabird Bycatch

This is an annotated bibliography of useful background in the form of scientific and technical reports in the following categories:

Bycatch and Fisheries Background
Seabird Background
Regionally Specific Resources


A note on the availability of references

African Penguins Spheniscus demersus at Boulders, Western Cape Province, South Africa. Photo by Caroline Pott. 

Many of these papers are now available free on the web.  Where possible, links are provided.  Notornis, Auk, Condor, PLoS One, Marine Ornithology (and its other incarnations and sister publications: Cormorant, Atlantic Seabirds) publications, are freely available (some through SORA), as are older (5 or more years) papers from Marine Ecology Progress Series.  In addition, authors sometimes provide copies of their work on their personal pages, so it is always worth doing a search for the paper’s title. To resolve DOIs (provided for some, but not all papers) use the resolver at:

Bycatch and Fisheries Background

Information Gaps

Pott and Wiedenfeld showed that there are significant gaps in our knowledge about seabird bycatch, especially in the Caribbean, South Atlantic, Indian Ocean, and western Pacific Ocean. Knowledge of seabird bycatch is also limited for artisanal fisheries and even in some large-scale fisheries, such as industrially-deployed seines. 

  • Pott, C., and D. A. Wiedenfeld. 2017. Information gaps limit our understanding of seabird bycatch in global fisheries. Biological Conservation 210: 192-204. doi:10.1016/j.biocon.2017.04.002

Anderson et al. provide regional and fishery by fishery estimates of the magnitude of longline fisheries bycatch, and also include a knowledge gap analysis. 

  • Anderson, O. R. J., C. J. Small, J. P. Croxall, E. K. Dunn, B. J. Sullivan, O. Yates, and A. Black.  2011.  Global Seabird Bycatch in Longline Fisheries.  Endangered Species Research 14(2): 91–106. doi:10.3354/esr00347.

Global Impacts of Specific Gear Types

Žydelis et al. is an excellent overview of the impacts of gillnets with a region by region analysis and a useful appendix with susceptibility analysis and references of bycatch in gillnets for each of 343 species. 

  • Žydelis, R., Small, C., & French, G. 2013. The incidental catch of seabirds in gillnet fisheries: A global review. Biological Conservation 162 : 76–88. doi:10.1016/j.biocon.2013.04.002

In the following two papers, Zhou, Jiao, and Browder assess the vulnerability of seabirds to longlines, including how to estimate total bycatch when observer coverage is low.

Jiménez et al. evaluated bycatch mitigation methods. 

  • Jiménez, S., A. Domingo, H. Winker, D. Parker, D. Gianuca, T. Neves, R. Coelho, and S. Kerwath. 2020. Toward mitigation of seabird bycatch: Large-scale effectiveness of night setting and Tori lines across multiple pelagic longline fleets. Biological Conservation 247: 108642. doi:10.1016/j.biocon.2020.108642

This Northridge paper contributed to the information that resulted in U.N. Resolution 46/215 which banned the use of drift nets on the high seas, although they are still in use within the Exclusive Economic Zones of some countries. Now dated, it lacks species-level information for birds, but has historic effort and descriptive information region by region of drift net fisheries.  

Global Fishing Effort

The first two of the following three papers together provide an excellent historical overview of fishing effort.  Anticamara et al. (2011) explore the effort of particular fishing nations and gear types, and Swartz et al. (2010) address the geographic distribution of where effort is employed. The third paper focuses specifically on the development of longline fishing in the Southern Ocean and is rich in effort information, including estimates of IUU (Illegal, unregulated, unreported) fishing effort. 

Compiling information from FAO and in-country statistics, Stewart et al. map coastal fishing intensity for 6 regions: West Africa, the West Indian Ocean, Southeast Asia, the Eastern Tropical Pacific, the Caribbean, and the Southwest Atlantic. 

Bycatch Hotspots and Overlap with Fisheries

Lewison et al. identify hotspots of areas that experience high levels of bycatch amongst three taxa and amongst three gear types (longline, gillnet and trawl).  They pinpoint the southwest Atlantic as a hotspot  for seabirds bycatch, the southwest Atlantic and Mediterranean for turtles, and the eastern Pacific Ocean for marine mammals.  They also noted some significant differences in bycatch intensity among gears and regions.

Karpouzi et al. is a hotspot analysis which highlights areas of overlap between fisheries and seabirds, using both foraging ranges and dietary requirements.  Includes a number of good maps.  

Observer Coverage and Measuring Bycatch

Duffy and Schneider offer several ways of assessing and describing bycatch, whereas Glenmarec et al. evaluate methods for detecting and measuring seabird bycatch.

  • Duffy, D.C. &Schneider, D.C. 1994. Seabird-fishery interactions: a manager's guide, in: Nettleship, D.N. et al. (Ed.) (1994). Seabirds on Islands: threats, case studies and action plans. Proceedings of the Seabird Specialist Group Workshop held at the XX World Conference of the International Council for Bird Preservation, University of Waikato, Hamilton, New Zealand, 19-20 November 1990. Birdlife Conservation Series, 1: pp. 26-38.
  • Glemarec, G., L. Kindt-Larsen, L. Scherffenberg Lundgaard, and F. Larsen. 2020. Assessing seabird bycatch in gillenet fisheries using electronic monitoring. Biological Conservation 243: 208-461.

A paper by Lewison et al. is brief, with useful figures of geographic distribution of observer data to 2005, map of global fishing effort, and table presenting the international nature of some species’ ranges.

This paper describes digital tools to statistically assess bycatch.

  • Curtis, K.A., and J.V. Carretta. 2020. ObsCovgTools: Assessing observer coverage needed to document and estimate rare event bycatch. Fisheries Research 225:105493

Effect of Fishing on Seabird Communities

These two papers provide very general overviews of the variety of impacts (direct and indirect) that fisheries have on seabird communities.  Tasker et al. treat bycatch, stock depletion and discards on a region by region basis, and Furness has a slight North Sea focus.  Good introductory material.

Fish in net.  Photo by antpun/Shutterstock.  


Seabird Background

This recent book helps with identifcation of seabirds, with many photos and some maps.

  • Howell, S. N. G., and K. Zufelt. 2019. Oceanic Birds of the World. Princeton University Press, Princeton, NJ, USA.

This paper explores patterns in the threats faced by 346 species of seabird, with a wealth of tables and figures, and includes priority actions.  Supplementary materials contain additional useful maps and tables. 

Spatz et al. review the biogeography of threatened (IUCN categories VU, EN, CR) seabird species, and Appendix 1 is a list the number of islands upon which each species depends.  "Ninety seabird species (92% of all island-breeding threatened seabird species) were breeding on at least one of the islands with invasive species present; 23 species had 100% of their population(s) on these islands."

  • Spatz, D. R., K. M. Newton, R. Heinz, B. Tershy, N. D. Holmes, S. H. M. Butchart and D. A. Croll. 2014. The Biogeography of Globally Threatened Seabirds and Island Conservation Opportunities. Conservation Biology, 28: 1282–1290. doi: 10.1111/cobi.12279

This very useful paper has a review (Table 4) of over 50 seabird species and their interactions with gear by region, as well as more in-depth ecological and bycatch information for 24 species of New Zealand breeding seabirds.  It also contains a series of useful tables exploring fisheries elsewhere in the world through which New Zealand breeding birds forage.  Due to its length, this document is provided in 3 parts: Part 1Part 2, Part 3.

While the main body of the text focuses on conservation opportunities in New Zealand, the latter half (pgs 44-63) of the below document provides an excellent, illustrated overview of seabirds, their biology and threats they face.



The WCPFC maintains a database, the Bycatch Management Information System of bycatch references which can be searched by gear type, author, date, topic, and keywords, including volumes of technical papers on mitigation techniques. It has become a very comprehensive source, especially for high-seas tuna and billfish fisheries.

New Zealand maintains a database for animals caught within its EEZ.  The Australian Antarctic Division Biodiversity Database has georeferenced locations of observations, although these are limited for some species.

Additional databases can be found on the External Resources page.


Regionally Specific


This paper is a risk assessment of 41 seabird species (60 populations) to fishing fleets of more than 30 nations using multiple gears in the Atlantic and Mediterranean.

Jiménez et al. describe and characterize the annual changes in the seabird assemblage off Uruguay and include information about the species’ interest in discards, and identifies the highest risk period as May to November.

Hedd et al. cover the area from Baffin Bay through Davis Strait and the Labrador Sea to the Scotian Shelf and Grand Banks.

This paper covers the period 1992-2012, and is useful for showing areas and seasons when most seabirds were caught.

Zollett reviews information on 49 fisheries in the Atlantic USA, of which 39 have documented bycatch.  Information is also broken down by gear and specific fishery (in the supplementary online materials). Sigourney et al. cover a more recent period, through 2016.

This paper covers seabird bycatch in the South Atlantic.

United States (Northwest Atlantic and Northeast Pacific)

The U. S. National Bycatch Report was published in 2011. Update 3 provides data through 2014.

  • Benaka, L. R., D. Bullock, A. L. Hoover, and N. A. Olsen (editors). 2019. U.S. National Bycatch Report First Edition Update 3. U.S. Dept. of Commerce, NOAA. NOAA Technical Memorandum NMFS-F/SPO-190, 95 p. Accessed from:

Moore et al. is a good overview of past and present bycatch issues in the United States with some species-specific information.

  • Moore, J. E., B. P. Wallace, R. L. Lewison, R. Žydelis, T. M. Cox, and L. B. Crowder. 2009. A review of marine mammal, sea turtle and seabird bycatch in USA fisheries and the role of policy in shaping management. Marine Policy, 33(3): 435–451. doi:10.1016/j.marpol.2008.09.003

Lewison et al. use USA Pacific and Atlantic longline bycatch data to identify spatial hotspots of bycatch amongst seabirds cetaceans, and turtles, revealing Georges Banks, the northern part of the Greater, and the eastern part of the Lesser Antilles and the waters surrounding the Hawaiian Islands as hotpots of multispecies bycatch. 

  • Lewison, R. L., C. Soykan, and J. Franklin. 2009. Mapping the bycatch seascape: multispecies and multi-scale spatial patterns of fisheries bycatch. Ecological Applications 19(4): 920–930.

Indian Ocean

This paper uses data on seven western Indian Ocean breeding seabirds to identify foraging hotspots in the region: the Seychelles basin, southern Mozambique Channel around Europa Island, The Walters Shoals (south of Madagascar), The Mascarene Archipelago and Tromelin Island and the Central Indian Ocean.

  • LeCorre, M., Jaeger, A., Pinet, P., Kappes, M. A., Weimerskirch, H., Catry, T, Ramos,  J. A., Russell,  J. C., Shah, Nirma, and Jaquemet, S. 2012. Tracking seabirds to identify potential Marine Protected Areas in the tropical western Indian Ocean. Biological Conservation, 156, 83–93.


The following two papers cover the area of the Western Central Pacific Fisheries Commission. Waugh et al. is a risk analysis for 70 species pf procellariids to longline fishing in the Western and Central Pacific.  Tables 1 and 2 are excellent references for the region. 

  • Waugh, S. M., D. P. Filippi, D. S. Kirby, E. Abraham, and N. Walker.  2012. Ecological Risk Assessment for seabird interactions in Western and Central Pacific longline fisheries. Marine Policy 36 (4): 933-946.
  • Peatman, T., E. Abraham, D. Ochi, D. Webber, and N. Smith. 2019. Estimation of seabird mortality across the WCPFC Convention Area. Fifteenth regular session scientific committee. Pohnpei, Federated States of Micronesia, Western and Central Pacific Fisheries Commission.

A precursor paper also includes an analysis of most of these same species with vulnerability further assessed by season (Northern Hemisphere convention).

This paper covers U.S. fisheries in the Northwest Pacific.

Although this paper only covers a small area of the world (California), it provides information on a topic not often studied.

  • Donnelly-Greenan, E. L., H. M. Nevins, and J. T. Harvey. 2019. Entangled seabird and marine mammal reports from citizen science surveys from coastal California (1997-2017). Marine Pollution Bulletin 149:110557.


These papers provide analysis of the interactions with, and impacts of fisheries on seabirds in the Afrotropics (there are several studies from southern Africa). Cooper & Petersen and Kemper et al. have species-specific information. Hagen & Wanless update and expand upon Cooper & Petersen. Hagen & Wanless take a gear and regional approach, and include a set of very specific recommended actions. 

  • Cooper, J., and S. Petersen, S. 2009. Potential Impacts of Marine Fisheries on Migratory Seabirds within the Afrotropical Region. Report to the African-Eurasian Waterbird Agreement (p. 239). Rondebosch: Animal Demography Unit, University of Cape Town.
  • Hagen, C., and R. M. Wanless. 2014. Potential impacts of marine fisheries on migratory seabirds within the Afrotropical region. Unpublished report to the African-Eurasian Waterbird Agreement. 
  • Kemper, J., L. G. Underhill, R. J. Crawford, and S. P. Kirkman. 2007. Revision of the conservation status of seabirds and seals breeding in the Benguela Ecosystem. Chapter 42 of the Final report of the BCLME (Benguela Current Large Marine Ecosystem) project on top predators as biological indicators of ecosystem change in the BCLME. Avian Demography Unit, Cape Town, 697–704.

This study evaluated extremely high rates of seabird mortality prior to the 2015 requirement to use mitigation methods, and the impacts on reduction of mortality resulting from the use of mitigation.


New Zealand and Australia both have databases which record some bycatch for their areas.

Taylor's two-part paper is similar to the Robertson paper listed, above, but with more complete treatment of all New Zealand-breeding species, including terrestrial threats and past and proposed conservation action.  In two parts: threatened species (Part A) and non-threatened species (Part B).

Richard et al. explore temporal and spatial patterns of seabirds attending or sighted from fishing vessels and includes breakdowns by year and fishery type (trawl, longline, setnet, purse seine).  Has some excellent maps. 

Although dated, Baker et al. is a great introductory overview of all Procellariiformes breeding in, or visiting Australian waters, and the threats they are facing on land and at sea, as well as the legislative frameworks in Australia.

Rockhopper Penguins Eudyptes spp. Photo by Fredy Theurig/Shutterstock.

UK and territories

Part of a Special Issue [Volume 156, Pages 1-148 (November–December 2012) Seabirds and Marine Protected Areas planning], Thaxter et al. review the available literature on the foraging ranges of 25 species of UK seabirds. 

  • Thaxter, C. B., B. Lascelles, K. Sugar, A. S. C. P. Cook, S. Roos, M. Bolton, R. H. W. Langston, and N. H. K. Burton. 2012. Seabird foraging ranges as a preliminary tool for identifying candidate Marine Protected Areas. Biological Conservation 156: 53–61. doi:10.1016/j.biocon.2011.12.009

Focused on the UK overseas territories, this paper examines the available information on bycatch species of turtles, marine mammals and birds region by region.  Also has a useful annex which reviews the various regional and international bodies and their jurisdictions. 

French Territories

Introduction to the French Subantarctic Territories and the avian inhabitants. (In French)

Similar to the Indian Ocean hotspot analysis above (LeCorre et al. 2012) this paper uses tracking data on 10 species breeding within French territories to identify regions important to multiple species.

  • Delord, K., C. Barbraud, C.-A. Bost, B. Deceuninck, T. Lefebvre, R. Lutz, T. Micol, R. A. Phillips, P. N. Trathan, and H. Weimerskirch. 2014. Areas of importance for seabirds tracked from French southern territories and recommendations for conservation. Marine Policy, 48: 1–13.

Southern Ocean

Seabird impacts by the Southern Ocean krill fisheries is poorly known. Arana and Rolleri provide four years of data from Western Antarctica.