The importance of fisheries in shaping the ecology of black-browed albatrosses in the Falkland Islands

Funding bodies: Fortuna Ltd.; FIG (Environmental Studies Budget)

PhD affiliations: University of Exeter (UK), ISPA Instituto Universitário (Portugal), SAERI, Falkland Islands Fisheries Department

Fish & Ships: A bird’s eye view (Penguin News, May 22, 2020)

Project overview

The aim of this PhD is to improve our understanding of albatross-fishery interactions in the Southwest Atlantic, focussing on the feeding ecology and demography of the world’s largest population of BBA. Specifically, this research focuses on the mitigation of harmful interactions with fishing gear, and establishing the importance of fishery discards to the diet structure and spatial distribution of breeding albatross.

Project Objectives

  • Chapter 1 investigates the effectiveness of discard management as a mitigation measure to reduce BBA bycatch in the Falkland Islands trawl fleet.
  • Chapter 2 uses multi-year BBA chick regurgitates to quantify diet and discard consumption, and relate this to prey availability and breeding success.
  • Chapter 3 applies complementary dietary assessment techniques of stomach contents and stable isotopes to investigate chick diet from two colonies across two consecutive breeding seasons.
  • Finally, Chapter 4 uses multi-annual and multi-colony GPS tracking data to identify important foraging areas by breeding BBA in relation to spatially explicit fishing effort obtained from remote sensing (Global Fishing Watch). The Chapter further explores areas and fleets of highest fishery exposure.

Amanda Kuepfer

Supervisors: Dr. Stephen Votier (University of Exeter); Dr. Paulo Catry (ISPA Instituto Universitário), Dr. Paul Brickle (SAERI), Dr. Alexander Arkhipkin (Falkland Islands Fisheries Department)

Dates: Jan 2019 – Feb 2023

Paper Citation

  • Kuepfer A, Sherley RB, Brickle P, Arkhipkin A, Votier SC (2022) Strategic discarding reduces seabird numbers and contact rates with trawl fishery gears in the Southwest Atlantic. Biol Conserv 266:109462. doi: 10.1016/j.biocon.2022.109462
  • Kuepfer  A, Votier SC, Sherley RB, Ventura F, Matias R, Anderson O, Brickle P, Arkhipkin A, Catry P. (2022) Prey-switching to fishery discards does not compensate for poor natural foraging conditions in breeding albatross. ICES J Mar Sci. 0, 1 – 13. doi: 10.1093/icesjms/fsac069
  • Ventura F, Granadeiro JP, Lukacs PM, Kuepfer A, Catry P (2021) Environmental variability directly affects the prevalence of divorce in monogamous albatrosses. Proc. R. Soc. B Biol. Sci. 288, 20212112. https://doi.org/10.1098/rspb.2021.2112
  • Reid T, Yates O, Crofts S, Kuepfer A (2021) Interactions between seabirds and pelagic squid-jigging vessels in the south-west Atlantic. Aquat Conserv Mar Freshw Ecosyst 1–9. doi: 10.1002/aqc.3503

Research undertaken 2020-2021:

  • Discards and seabird-vessel interactions (Chapter 1)

Analysis and write-up of the discard management study were undertaken, with the manuscript submitted for peer reviewed publication in April 2021. Peer-review publication of this work is listed as a high priority under the Falkland Islands National Plan of Action for reducing incidental catch in trawl fisheries (Kuepfer et al., 2018, Objective 7.1).

The publication is now available as Kuepfer et al. (2022a). https://www.sciencedirect.com/science/article/abs/pii/S0006320722000155

  • Chick diet I – Multi-annual trends in discard use by chicks (Chapter 2)

This study uses chick regurgitate data collected during eight seasons between 2004 and 2020. In 2020/2021, data collection and preparation were finalised, and data analysis and write-up undertaken. This study is now available as a peer-reviewed publication under Kuepfer et al. (2022b). https://academic.oup.com/icesjms/advance-article-abstract/doi/10.1093/icesjms/fsac069/6582866

  • Chick diet II – Discard use in chicks, as assessed through a complementary diet approach (Chapter 3)

Due to COVID-19 restrictions, the stable isotope samples collected in February and March 2020 were processed by a paid Assistant Researcher at the University between March and July 2021. NERC funding of approx. £5000 remained available for the analysis of the stable isotope samples.

Highlights for July 2021- June 22

The first two chapters of this PhD were finalised and published 

Chapter 2 found that bird abundance and gear collision rates were positively related. Compared to continuous discarding, batch discarding significantly reduced seabird abundance and gear collisions, while zero discarding eliminated gear collisions altogether. Our findings validate batch discarding as an effective seabird-bycatch mitigation measure in trawl fisheries where zero discarding is not possible, but highlight the importance of complete waste storage between batches.

Chapter 3 showed that BBA chicks are primarily fed natural prey, but that discard consumption can vary significantly between years. Specifically, discard consumption was positively related to increased discard availability, but also increased in years of higher sea surface temperature and lower breeding success. Overall, the findings suggest that although natural prey are the preferred diet, BBA switch to discards when natural foraging conditions are compromised. While fishery discards may act as a buffer, we show that they do not compensate for poor natural foraging conditions for breeding albatrosses in the long term. ­

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