Agnew DJ, Pearce J, Pramod G, Peatman T, Watson R, Beddington JR, Pitcher TJ (2009) Estimating the worldwide extent of illegal fishing. PLOS ONE 4:e4570 PubMed Crossref

ACAP (Agreement on the Conservation of Albatrosses and Petrels) (2010) ACAP species assessment: grey-headed albatross Thalassarche chrysostoma. ACAP Secretariat, Hobart. acap.aq/acap-species/248-grey-headed-albatross/file (accessed 18 May 2025) Link

ACAP (2025) ACAP data portal. ACAP Secretariat, Hobart. Link

Avila IC, Kaschner K, Dormann CF (2018) Current global risks to marine mammals: taking stock of the threats. Biol Conserv 221:44-58 Crossref

Baker GB, Komyakova V, Wellbelove A, Beynon N, Haward M (2024) The implementation of ACAP Best Practice Advice to mitigate seabird bycatch in fisheries: issues and options. Mar Policy 160:105879 Crossref

Barbraud C, Rolland V, Jenouvrier S, Nevoux M, Delord K, Weimerskirch H (2012) Effects of climate change and fisheries bycatch on Southern Ocean seabirds: a review. Mar Ecol Prog Ser 454:285-307 Crossref

Beal M, Dias MP, Phillips RA, Oppel S and others (2021) Global political responsibility for the conservation of albatrosses and large petrels. Sci Adv 7:eabd7225 PubMed Crossref

Bell JB, Fischer JH, Carneiro AP, Griffiths S and others (2025) Evaluating the effectiveness of seabird bycatch mitigation measures for pelagic longlines in the South Atlantic. Biol Conserv 302:110981 Crossref

Bennison A, Adlard S, Banyard AC, Blockley F and others (2024) A case study of highly pathogenic avian influenza (HPAI) H5N1 at Bird Island, South Georgia: the first documented outbreak in the subantarctic region. Bird Study 71:380-391 Crossref

Bird JP, Martin R, Akçakaya HR, Gilroy J and others (2020) Generation lengths of the world’s birds and their implications for extinction risk. Conserv Biol 34:1252-1261 PubMed Crossref

BirdLife International (2025) IUCN Red List for birds. Link

Brothers N, Ledingham R (2008) The avifauna of Bishop and Clerk Islets and its relationship to nearby Macquarie Island. Pap Proc R Soc Tasmania 142:117-121

Bugoni L, Mancini PL, Monteiro DS, Nascimento L, Neves TS (2008) Seabird bycatch in the Brazilian pelagic longline fishery and a review of capture rates in the southwestern Atlantic Ocean. Endang Species Res 5:137-147 Crossref

Bugoni L, Neves TS, Leite NOJ, Carvalho D and others (2008) Potential bycatch of seabirds and turtles in hook-and-line fisheries of the Itaipava Fleet, Brazil. Fish Res 90:217-224 Crossref

Bustamante P, Carravieri A, Goutte A, Barbraud C and others (2016) High feather mercury concentrations in the wandering albatross are related to sex, breeding status and trophic ecology with no demographic consequences. Environ Res 144:1-10 PubMed Crossref

Carneiro AP, Clark BL, Pearmain EJ, Clavelle T, Wood AG, Phillips RA (2022) Fine-scale associations between wandering albatrosses and fisheries in the southwest Atlantic Ocean. Biol Conserv 276:109796 Crossref

Clark G (1984) Report to the British Antarctic Survey on the ‘Totorore’ expedition to South Georgia, 13 August-17 October, 1984. British Antarctic Survey Archives, Cambridge

Clay TA, Small C, Tuck GN, Pardo D and others (2019) A comprehensive large-scale assessment of fisheries bycatch risk to threatened seabird populations. J Appl Ecol 56:1882-1893 Crossref

Collins MA, Hollyman PR, Clark J, Söffker M, Yates O, Phillips RA (2021) Mitigating the impact of longline fisheries on seabirds: Lessons learned from the South Georgia Patagonian toothfish fishery (CCAMLR Subarea 48.3). Mar Policy 131:104618 Crossref

Da Rocha N, Oppel S, Prince S, Matjila S and others (2021) Reduction in seabird mortality in Namibian fisheries following the introduction of bycatch regulation. Biol Conserv 253:108915 Crossref

Dias MP, Martin R, Pearmain EJ, Burfield IJ and others (2019) Threats to seabirds: a global assessment. Biol Conserv 237:525-537 Crossref

Droguett D, Arredondo C, Dougnac C, Kusch A, Montiel A, Vila A (2023) Native avian predators for the world’s black-browed albatross (Thalassarche melanophrys) breeding colony in inner waters of Tierra del Fuego, Chile. Polar Biol 46:77-85 Crossref

Dulvy NK, Pacoureau N, Rigby CL, Pollom RA and others (2021) Overfishing drives over one-third of all sharks and rays toward a global extinction crisis. Curr Biol 31:4773-4787 PubMed Crossref

Ersts PJ (2023) DotDotGoose (v1.6). American Museum of Natural History, Center for Biodiversity and Conservation. Link

Favero M, Blanco G, Copello S, Seco Pon JP and others (2013) Seabird bycatch in the Argentinean demersal longline fishery, 2001-2010. Endang Species Res 19:187-199 Crossref

Frankish CK, Cunningham C, Manica A, Clay TA, Prince S, Phillips RA (2021) Tracking juveniles confirms fisheries-bycatch hotspot for an endangered albatross. Biol Conserv 261:109288 Crossref

Frost P (2020) Status of Campbell Island and grey-headed mollymawks on the northern coasts of Campbell Island, November 2019. Science Support Service, Whanganui

Glaum P, Cocco V, Valdovinos FS (2020) Integrating economic dynamics into ecological networks: the case of fishery sustainability. Sci Adv 6:eaaz4891 PubMed Crossref

Goetz KT, Stephenson F, Hoskins A, Bindoff AD and others (2022) Data quality influences the predicted distribution and habitat of four Southern-Hemisphere albatross species. Front Mar Sci 9:782923 Crossref

Good S, Baker G, Gummery M, Votier S, Phillips R (2020) National Plans of Action (NPOAs) for reducing seabird bycatch: Developing best practice for assessing and managing fisheries impacts. Biol Conserv 247:108592 Crossref

Goutte A, Barbraud C, Meillère A, Carravieri A and others (2014) Demographic consequences of heavy metals and persistent organic pollutants in a vulnerable long-lived bird, the wandering albatross. Proc R Soc B 281:20133313 PubMed

Inoue Y, Yokawa K, Minami H, Ochi D, Sato N, Katsumata N (2012) Distribution of seabird bycatch using data collected by Japanese observers in 1997-2009 in the ICCAT area. Collect Vol Sci Pap ICCAT 68:1738-1753

Jiménez S, Domingo A, Brazeiro A, Defeo O and others (2016) Sex-related variation in the vulnerability of wandering albatrosses to pelagic longline fleets. Anim Conserv 19:281-295 Crossref

Jiménez S, Domingo A, Winker H, Parker D and others (2020) Towards mitigation of seabird bycatch: large-scale effectiveness of night setting and Tori lines across multiple pelagic longline fleets. Biol Conserv 247:108642 Crossref

Kawaguchi S, Atkinson A, Bahlburg D, Bernard KS and others (2024) Climate change impacts on Antarctic krill behaviour and population dynamics. Nat Rev Earth Environ 5:43-58 Crossref

Lane JV, Jeglinski JW, Avery-Gomm S, Ballstaedt E and others (2024) High pathogenicity avian influenza (H5N1) in Northern Gannets (Morus bassanus): Global spread, clinical signs and demographic consequences. Ibis 166:633-650 Crossref

Lawton K, Robertson G, Valencia J, Wienecke B, Kirkwood R (2003) The status of black-browed albatrosses Thalassarche melanophrys at Diego de Almagro Island, Chile. Ibis 145:502-505 Crossref

Leguia M, Garcia-Glaessner A, Muñoz-Saavedra B, Juarez D and others (2023) Highly pathogenic avian influenza A (H5N1) in marine mammals and seabirds in Peru. Nat Commun 14:5489 PubMed Crossref

Lewison RL, Johnson AF, Verutes GM (2018) Embracing complexity and complexity-awareness in marine megafauna conservation and research. Front Mar Sci 5:207 Crossref

Maree BA, Wanless RM, Fairweather TP, Sullivan BJ, Yates O (2014) Significant reductions in mortality of threatened seabirds in a South African trawl fishery. Anim Conserv 17:520-529 Crossref

Michael PE, Thomson R, Barbraud C, Delord K and others (2017) Illegal fishing bycatch overshadows climate as a driver of albatross population decline. Mar Ecol Prog Ser 579:185-199 Crossref

Mills WF, Bustamante P, McGill RA, Anderson OR and others (2020) Mercury exposure in an endangered albatross: long-term changes and consequences for breeding success. Proc R Soc B 287:20202683 PubMed

Mills WF, Xavier JC, Bearhop S, Cherel Y, Votier S, Waluda CM, Phillips RA (2020) Long-term trends in albatross diets in relation to prey availability and breeding success. Mar Biol 167:29 Crossref

Mills WF, Bustamante P, Ramírez F, Forero MG, Phillips RA (2024) Mercury concentrations in feathers of albatrosses and large petrels at South Georgia: contemporary patterns and comparisons with past decades. Arch Environ Contam Toxicol 86:363-374 PubMed Crossref

Nel DC, Ryan PG, Watkins BP (2002) Seabird mortality in the Patagonian toothfish longline fishery around the Prince Edward Islands, 1996-2000. Antarct Sci 14:151-161 Crossref

Nel DC, Taylor F, Ryan PG, Cooper J (2003) Population dynamics of the wandering albatross Diomedea exulans at Marion Island: longline fishing and environmental influences. S Afr J Mar Sci 25:503-517 Crossref

Pardo D, Forcada J, Wood AG, Tuck GN and others (2017) Additive effects of climate and fisheries drive ongoing declines in multiple albatross species. Proc Natl Acad Sci USA 114:E10829-E10837 PubMed Crossref

Phillips RA, Waluda CM (2020) Albatrosses and petrels at South Georgia as sentinels of marine debris input from vessels in the southwest Atlantic Ocean. Environ Int 136:105443 PubMed Crossref

Phillips RA, Ridley C, Reid K, Pugh PJA, Tuck GN, Harrison N (2010) Ingestion of fishing gear and entanglements of seabirds: monitoring and implications for management. Biol Conserv 143:501-512 Crossref

Phillips RA, Gales R, Baker G, Double M and others (2016) The conservation status and priorities for albatrosses and large petrels. Biol Conserv 201:169-183 Crossref

Phillips RA, Fort J, Dias MP (2023) Conservation status and overview of threats to seabirds. In: Young L, VanderWerf E (eds) Conservation of marine birds. Elsevier, Amsterdam, p 33-56

Pimiento C, Leprieur F, Silvestro D, Lefcheck J and others (2020) Functional diversity of marine megafauna in the Anthropocene. Sci Adv 6:eaay7650 PubMed Crossref

Pohlmann A, Stejskal O, King J, Bouwhuis S and others (2023) Mass mortality among colony-breeding seabirds in the German Wadden Sea in 2022 due to distinct genotypes of HPAIV H5N1 clade 2.3.4.4b. J Gen Virol 104:001834 PubMed Crossref

Poncet S, Robertson G, Phillips RA, Lawton K, Phalan B, Trathan PN, Croxall JP (2006) Status and distribution of wandering, black-browed and grey-headed albatrosses breeding at South Georgia. Polar Biol 29:772-781 Crossref

Poncet S, Wolfaardt AC, Black A, Browning S and others (2017) Recent trends in numbers of wandering (Diomedea exulans), black-browed (Thalassarche melanophris) and grey-headed (T. chrysostoma) albatrosses breeding at South Georgia. Polar Biol 40:1347-1358 Crossref

R Core Team (2023) R: a language and environment for statistical computing. R foundation for statistical computing, Vienna

Rackete C, Poncet S, Good SD, Phillips RA, Passfield K, Trathan P (2021) Variation among colonies in breeding success and population trajectories of wandering albatrosses Diomedea exulans at South Georgia. Polar Biol 44:221-227 Crossref

Robertson G, Moreno CA, Lawton K, Arata J, Valencia J, Kirkwood R (2007) An estimate of the population sizes of black-browed (Thalassarche melanophrys) and grey-headed (T. chrysostoma) albatrosses breeding in the Diego Ramírez Archipelago, Chile. Emu 107:239-244 Crossref

Robertson G, Moreno CA, Lawton K, Kirkwood R, Valencia J (2008) Comparison of census methods for black-browed albatrosses breeding at the Ildefonso Archipelago, Chile. Polar Biol 31:153-162 Crossref

Robertson G, Moreno C, Arata JA, Candy SG and others (2014) Black-browed albatross numbers in Chile increase in response to reduced mortality in fisheries. Biol Conserv 169:319-333 Crossref

Robertson G, Wienecke B, Suazo CG, Lawton K, Arata JA, Moreno C (2017) Continued increase in the number of black-browed albatrosses (Thalassarche melanophris) at Diego Ramírez, Chile. Polar Biol 40:1035-1042 Crossref

Rolland V, Barbraud C, Weimerskirch H (2008) Combined effects of fisheries and climate on a migratory long-lived marine predator. J Appl Ecol 45:4-13 Crossref

Rollinson D, Wanless R, Ryan P (2017) Patterns and trends in seabird bycatch in the pelagic longline fishery off South Africa. Afr J Mar Sci 39:9-25 Crossref

Ryan PG, Jones MGW, Dyer BM, Upfold L, Crawford RJM (2009) Recent population estimates and trends in numbers of albatrosses and giant petrels breeding at the sub-Antarctic Prince Edward Islands. Afr J Mar Sci 31:409-417 Crossref

Spatz DR, Holmes ND, Will DJ, Hein S and others (2022) The global contribution of invasive vertebrate eradication as a key island restoration tool. Sci Rep 12:13391 PubMed Crossref

Stevens KL, Altwegg R, Connan M, Ryan PG (2024) Population growth of the grey-headed albatross population on Marion Island inferred using three analysis methods. Antarct Sci 36:449-459 Crossref

Sumaila UR, Lam VW, Miller DD, Teh L and others (2015) Winners and losers in a world where the high seas is closed to fishing. Sci Rep 5:8481 PubMed Crossref

Tavares S, Xavier JC, Phillips RA, Pereira ME, Pardal MA (2013) Influence of age, sex and breeding status on mercury accumulation patterns in the wandering albatross Diomedea exulans. Environ Pollut 181:315-320 PubMed Crossref

Tennyson AJD, Imber MJ, Taylor R (1998) Numbers of black-browed mollymawks (Diomedea m. melanophrys) and white-capped mollymawks (D. cauta steadi) at the Antipodes Islands in 1994-95 and their population trends in the New Zealand region. Notornis 45:157-166 Crossref

Terauds A, Gales R, Baker GB, Alderman R (2006) Population and survival trends of Wandering Albatrosses (Diomedea exulans) breeding on Macquarie Island. Emu 106:211-218 Crossref

Tuck GN, Phillips RA, Small C, Thompson RB and others (2011) An assessment of seabird-fishery interactions in the Atlantic Ocean. ICES J Mar Sci 68:1628-1637 Crossref

Warwick-Evans V, Pearmain EJ, Thorne LH, Phillips RA (in press) Spatial segregation and bycatch risk as potential drivers of population trends of wandering albatrosses at South Georgia. Conserv Biol

Waugh S, Weimerskirch H, Moore PJ, Sagar PM (1999) Population dynamics of black-browed and grey-headed albatrosses Diomedea melanophrys and D. chrysostoma at Campbell Island, New Zealand, 1942-96. Ibis 141:216-225 Crossref

Weimerskirch H, Zotier R, Jouventin P (1989) The avifauna of the Kerguelen Islands. Emu 89:15-29 Crossref

Weimerskirch H, Brothers N, Jouventin P (1997) Population dynamics of wandering albatross Diomedea exulans and Amsterdam albatross D. amsterdamensis in the Indian Ocean and their relationships with long-line fisheries: conservation implications. Biol Conserv 79:257-270 Crossref

Weimerskirch H, Delord K, Barbraud C, Le Bouard F, Ryan PG, Fretwell P, Marteau C (2018) Status and trends of albatrosses in the French southern territories, western Indian Ocean. Polar Biol 41:1963-1972 Crossref

Woehler EJ, Auman HJ, Riddle MJ (2002) Long-term population increase of black-browed albatrosses Thalassarche melanophrys at Heard Island, 1947/1948-2000/2001. Polar Biol 25:921-927 Crossref

Wolfaardt A (2012) An assessment of the population trends and conservation status of black-browed albatrosses in the Falkland Islands. Paper submitted to the First Meeting of the Population and Conservation Status Working Group of the Agreement on the Conservation of Albatrosses and Petrels (ACAP) Advisory Committee, 29-30 April 2013, La Rochelle. PaCSWG1 Doc 14

Handling Editor:
Rory Wilson, Swansea, UK

Reviewers:
N. Carlile and 2 anonymous referees

Acknowledgements:

We are grateful to the ‘Vinson of Antarctica’ crew, including Justino Borreguero, Tor Bovim, Skip Novak, Jennifer Coombs and Dion Poncet, to the MV ‘Pharos SG’ crew, including Paul Morrison, George Gittins, Scott Thain, Sarah Doherty, Danniel Georgeson, Emilio Zelada Reyes, Williams Rojas, Juan Retamales Concha, James Witherley, Robert Berry, Simon Peacock, Peter Keen, Jorge Carvajal Urbina, Jorge Gonzalez Tapia, Jonathan Franco Orozco, Leonardo Alvarez Benavides and Liam McRae, and to Vicki Foster and Karen Wolstenholme for support during the surveys. Dan McKenzie, Freya Blockley, Marcia Blyth, Timothy Fokes, George Day and Isabel Stubbs kindly assisted with data collection on Bird Island. We thank the 3 referees for their useful comments which helped improve the manuscript. Funding was provided by the Government of South Georgia and the South Sandwich Islands, Friends of South Georgia Island, South Georgia Heritage Trust, Antarctic Research Trust, Peter Smith Charitable Trust for Nature, UK Blue Belt Programme and Natural Environment Research Council (NERC). This work represents a contribution to the Ecosystems component of the British Antarctic Survey Polar Science for a Sustainable Planet strategy, funded by NERC.