@article{fdi:010079897,
  title = {{S}urfacing and vertical behaviour of {A}tlantic bluefin tuna ({T}hunnus thynnus) in the {M}editerranean {S}ea : implications for aerial surveys},
  author = {{B}auer, {R}. {K}. and {F}orget, {F}abien and {F}romentin, {J}. {M}. and {C}apello, {M}anuela},
  editor = {},
  language = {{ENG}},
  abstract = {{A}tlantic bluefin tuna ({T}hunnus thynnus) ({ABFT}) frequently engage in surface basking and foraging behaviour that makes them detectable from afar. {T}his behaviour is utilized for the development of fisheries-independent abundance indices based on aerial surveys, although changes in the surface-feeding dynamics of {ABFT} are not yet accounted for. {W}e investigated the daytime surfacing behaviour of {ABFT} at different temporal and vertical resolutions based on 24 individuals (117-158 cm fork length), tagged with pop-up archival tags in the {G}ulf of {L}ion, {NW}-{M}editerranean {S}ea between 2015 and 2016. {T}he results suggest that {ABFT} remain usually <2 min continuously within the visible surface (0-1 m) during daytime. {ABFT} presence in the 0-1 and 0-20 m layers varied over time and between individuals but showed a seasonal decline towards autumn with the breakdown of thermal stratification. {F}urthermore, the rate of surfacing events was highly correlated with the time spent in the 0-20 m layer. {G}eolocation estimates confirm a strong site fidelity of {ABFT} during the aerial survey period ({A}ugust-{O}ctober) in the {G}ulf of {L}ion. {O}ur results support the choice of the survey region and period, but related indices should account for the seasonality of {ABFT} surface behaviour [i.e. the time spent in the 0-20 m layer.},
  keywords = {abundance index ; archival tags ; surface availability ; thermal stratification ; vertical behaviour ; {MEDITERRANEE}},
  booktitle = {},
  journal = {{I}ces {J}ournal of {M}arine {S}cience},
  volume = {77},
  numero = {5},
  pages = {1979--1991},
  ISSN = {1054-3139},
  year = {2020},
  DOI = {10.1093/icesjms/fsaa083},
  URL = {https://www.documentation.ird.fr/hor/fdi:010079897},
}