| Autor: |
Ferter K; Institute of Marine Research , Bergen 5005, Norway., Pagniello CMLS; Hopkins Marine Station, Stanford University , Pacific Grove, CA 93950, USA.; Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa , Kaneohe, HI 96744, USA., Block BA; Hopkins Marine Station, Stanford University , Pacific Grove, CA 93950, USA., Bjelland O; Institute of Marine Research , Bergen 5005, Norway., Castleton MR; Hopkins Marine Station, Stanford University , Pacific Grove, CA 93950, USA., Tracey SR; Institute for Marine and Antarctic Studies, University of Tasmania , Hobart, Tasmania 7001, Australia., Reimer TEJ; Hopkins Marine Station, Stanford University , Pacific Grove, CA 93950, USA., Sundelöf A; Department of Aquatic Resources, Institute of Marine Research, Swedish University of Agricultural Sciences , Lysekil 54330, Sweden., Onandia I; AZTI Marine Research, Basque Research and Technology Alliance (BRTA) , Sukarrieta 48395, Spain., Wiech M; Institute of Marine Research , Bergen 5005, Norway., Alemany F; ICCAT, International Commission for the Conservation of Atlantic Tunas , Madrid 28002, Spain., Nøttestad L; Institute of Marine Research , Bergen 5005, Norway. |
| Abstrakt: |
Atlantic bluefin tuna (ABFT; Thunnus thynnus ) is a highly migratory species. To investigate the migrations and vertical behaviours of ABFT migrating to Nordic waters, we deployed pop-up satellite archival transmitting tags on 25 ABFT off Norway (curved fork length: 228-292 cm). We obtained 16 full-year migrations, which differed between individuals, and physically recovered 13 tags, which provided 4699 days of archival depth and temperature data. ABFT occupied waters from the Arctic Circle to as far south as Cabo Verde, Africa, and occupied depths down to 1190 m and temperatures from 0.5 to 27.8°C. During their annual migrations, ABFT spent, on average, 68 days in Norwegian waters, 65 days in the Newfoundland Basin, 35 days around the Canary Islands and 33 days in the West European Basin. Most ABFT entered the Mediterranean Sea with a mean entry date of 13 May and visited known spawning grounds, staying, on average, 44 days. All ABFT with full-year deployments returned to Norwegian waters. ABFT displayed high site-fidelity and dynamic vertical diving behaviours that varied between hotspots and seasons. These spatiotemporal data provide important ecological knowledge for sustainable management and the conservation of the recently recovered eastern ABFT stock. |
