Annual migrations, vertical habitat use and fidelity of Atlantic bluefin tuna tracked from waters off the United Kingdom

Abstract Understanding the spatial ecology of commercially exploited species is vital for their conservation. Atlantic bluefin tuna (Thunnus thynnus, ABT) are increasingly observed in northeast Atlantic waters, yet knowledge of these individuals’ spatial ecology remains limited. We investigate the h...

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Main Authors: Thomas W. Horton, Francis C. T. Binney, Samantha Birch, Barbara A. Block, Owen M. Exeter, Francesco Garzon, Alex Plaster, David Righton, Jeroen van der Kooij, Matthew J. Witt, Lucy A. Hawkes
Format: Article
Language:English
Published: Nature Portfolio 2025-01-01
Series:Scientific Reports
Online Access:https://doi.org/10.1038/s41598-024-80861-w
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author Thomas W. Horton
Francis C. T. Binney
Samantha Birch
Barbara A. Block
Owen M. Exeter
Francesco Garzon
Alex Plaster
David Righton
Jeroen van der Kooij
Matthew J. Witt
Lucy A. Hawkes
author_facet Thomas W. Horton
Francis C. T. Binney
Samantha Birch
Barbara A. Block
Owen M. Exeter
Francesco Garzon
Alex Plaster
David Righton
Jeroen van der Kooij
Matthew J. Witt
Lucy A. Hawkes
author_sort Thomas W. Horton
collection DOAJ
description Abstract Understanding the spatial ecology of commercially exploited species is vital for their conservation. Atlantic bluefin tuna (Thunnus thynnus, ABT) are increasingly observed in northeast Atlantic waters, yet knowledge of these individuals’ spatial ecology remains limited. We investigate the horizontal and vertical habitat use of ABT (158 to 241 cm curved fork length; CFL) tracked from waters off the United Kingdom (UK) using pop-up satellite archival tags (n = 63). Analyses reveal distinctive movements from the UK to the Bay of Biscay (BoB) and Central North Atlantic between September and December, and size-specific habitat preferences in May and July—all ABT < 175 cm CFL inhabiting the BoB and 73% of ABT ≥ 175 the Mediterranean Sea. All ABT tracked for more than 300 days (n = 25) returned to waters off the UK the following year, where most stayed (n = 22; 88%) and three continuing north with deployments ending off northwest Ireland. ABT mostly occupied waters between 0 and 20 m (daytime 49 ± 6% of time; nighttime 71 ± 6%). Vertical habitat use was coupled with illumination, mean depth occupied, maximum depth reached, and vertical movement rate increased during the daytime and when moons were brightest. These data provide valuable insights into the spatial ecology of ABT reoccupying northerly foraging areas following decades of absence.
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spelling doaj-art-e09a24db37e8463a99794cd4347f0c8e2025-08-20T03:11:07ZengNature PortfolioScientific Reports2045-23222025-01-0115111310.1038/s41598-024-80861-wAnnual migrations, vertical habitat use and fidelity of Atlantic bluefin tuna tracked from waters off the United KingdomThomas W. Horton0Francis C. T. Binney1Samantha Birch2Barbara A. Block3Owen M. Exeter4Francesco Garzon5Alex Plaster6David Righton7Jeroen van der Kooij8Matthew J. Witt9Lucy A. Hawkes10Environment and Sustainability Institute, University of ExeterGovernment of Jersey Marine Resources, Natural Environment, Howard Davis FarmCentre for Environment, Fisheries and Aquaculture ScienceDepartment of Oceans, Stanford UniversityCentre for Ecology and Conservation, University of ExeterEnvironment and Sustainability Institute, University of ExeterGovernment of Jersey Marine Resources, Natural Environment, Howard Davis FarmCentre for Environment, Fisheries and Aquaculture ScienceCentre for Environment, Fisheries and Aquaculture ScienceEnvironment and Sustainability Institute, University of ExeterEnvironment and Sustainability Institute, University of ExeterAbstract Understanding the spatial ecology of commercially exploited species is vital for their conservation. Atlantic bluefin tuna (Thunnus thynnus, ABT) are increasingly observed in northeast Atlantic waters, yet knowledge of these individuals’ spatial ecology remains limited. We investigate the horizontal and vertical habitat use of ABT (158 to 241 cm curved fork length; CFL) tracked from waters off the United Kingdom (UK) using pop-up satellite archival tags (n = 63). Analyses reveal distinctive movements from the UK to the Bay of Biscay (BoB) and Central North Atlantic between September and December, and size-specific habitat preferences in May and July—all ABT < 175 cm CFL inhabiting the BoB and 73% of ABT ≥ 175 the Mediterranean Sea. All ABT tracked for more than 300 days (n = 25) returned to waters off the UK the following year, where most stayed (n = 22; 88%) and three continuing north with deployments ending off northwest Ireland. ABT mostly occupied waters between 0 and 20 m (daytime 49 ± 6% of time; nighttime 71 ± 6%). Vertical habitat use was coupled with illumination, mean depth occupied, maximum depth reached, and vertical movement rate increased during the daytime and when moons were brightest. These data provide valuable insights into the spatial ecology of ABT reoccupying northerly foraging areas following decades of absence.https://doi.org/10.1038/s41598-024-80861-w
spellingShingle Thomas W. Horton
Francis C. T. Binney
Samantha Birch
Barbara A. Block
Owen M. Exeter
Francesco Garzon
Alex Plaster
David Righton
Jeroen van der Kooij
Matthew J. Witt
Lucy A. Hawkes
Annual migrations, vertical habitat use and fidelity of Atlantic bluefin tuna tracked from waters off the United Kingdom
Scientific Reports
title Annual migrations, vertical habitat use and fidelity of Atlantic bluefin tuna tracked from waters off the United Kingdom
title_full Annual migrations, vertical habitat use and fidelity of Atlantic bluefin tuna tracked from waters off the United Kingdom
title_fullStr Annual migrations, vertical habitat use and fidelity of Atlantic bluefin tuna tracked from waters off the United Kingdom
title_full_unstemmed Annual migrations, vertical habitat use and fidelity of Atlantic bluefin tuna tracked from waters off the United Kingdom
title_short Annual migrations, vertical habitat use and fidelity of Atlantic bluefin tuna tracked from waters off the United Kingdom
title_sort annual migrations vertical habitat use and fidelity of atlantic bluefin tuna tracked from waters off the united kingdom
url https://doi.org/10.1038/s41598-024-80861-w
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