Chemical signatures in fin spine edge of Atlantic bluefin tuna (Thunnus thynnus) can serve as habitat markers of geographically distinct marine environments
Patricia Lastra Luque,
Iraide Artetxe-Arrate,
Gorka Bidegain,
Saburo Sakai,
Fanny Claverie,
Christophe Pécheyran,
Igaratza Fraile,
Hilario Murua,
Jose Luis Varela,
Antonio Medina,
Haritz Arrizabalaga
Affiliations
Patricia Lastra Luque
AZTI, Marine Research, Basque Research and Technology Alliance (BRTA), Pasaia, Spain; Corresponding author.
Iraide Artetxe-Arrate
AZTI, Marine Research, Basque Research and Technology Alliance (BRTA), Pasaia, Spain
Gorka Bidegain
Department of Applied Mathematics, Engineering School of Bilbao, University of the Basque Country (UPV/EHU), Plaza Torres Quevedo 1, 48013, Bilbao, Spain; Research Centre for Experimental Marine Biology and Biotechnology, Plentzia Marine Station PiEUPV/EHU, Areatza Pasalekua z/g, 48620 Plentzia, Spain
Saburo Sakai
Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Biogeochemistry Program, Yokosuka, Japan
Fanny Claverie
Universite de Pau et des Pays de l’Adour, E2S UPPA, CNRS, IPREM, Pau, France
Christophe Pécheyran
Universite de Pau et des Pays de l’Adour, E2S UPPA, CNRS, IPREM, Pau, France
Igaratza Fraile
AZTI, Marine Research, Basque Research and Technology Alliance (BRTA), Pasaia, Spain
Hilario Murua
International Sustainability Seafood Foundation (ISSF), Pittsburgh PA, United States
Jose Luis Varela
Departamento de Biología, Universidad de Cádiz, Campus de Excelencia Internacional del Mar (CEI·MAR), Av. República Saharaui s/n, 11510 Puerto Real, Cádiz, Spain
Antonio Medina
Departamento de Biología, Universidad de Cádiz, Campus de Excelencia Internacional del Mar (CEI·MAR), Av. República Saharaui s/n, 11510 Puerto Real, Cádiz, Spain
Haritz Arrizabalaga
AZTI, Marine Research, Basque Research and Technology Alliance (BRTA), Pasaia, Spain
Chemical fingerprints in otoliths are commonly used as natural habitat markers in fishes. Alternatively, the first dorsal fin spine can provide valuable chemical information and may be more suitable for studying (i) endangered fish species that cannot be sacrificed for their otoliths or (ii) fishes for which otoliths might not be available because of management or commercial reasons. Here, we studied multi-element chemistry of fin spine edges collected from Atlantic bluefin tuna (ABFT; Thunnus thynnus) (Linnaeus, 1758) to investigate the utility of the fin spine edge as a natural habitat marker. We determined stable isotopic δ18O and δ13C ratios, as well as concentrations of the tracer elements Mg, Mn, Li, Ba, and Sr, at the edge of ABFT fin spines, and then we used these measures to discriminate ABFT individuals among capture regions (i.e., the eastern Atlantic Ocean or Mediterranean Sea). Isotope ratios and tracer element concentrations, and especially a combined multi-element approach, were able to effectively discriminate individuals by capture region. The Mg, Mn, Li, and δ18O concentrations were the strongest variables driving this discrimination. Overall, our results demonstrate that chemical signatures are consistently retained in the ABFT fin spine edge and support the use of fin spine edges for discerning habitat use. The fin spine chemistry as a minimally invasive sampling method, combined with otolith chemistry, genetic markers, and tagging efforts can help us to reconstruct fish movements, providing a deeper understanding of the spatial population dynamics of this iconic fish species.
