WWF tagging project brings new understanding of bluefin tuna migration 
http://wwf.panda.org/what_we_do/where_w ... na-tagging
Dr Pablo Cermeño, Tuna Tagging Coordinator for WWF Mediterranean, holds up a tuna tracking tag.WWF's new report on its ambitious project to tag and track Atlantic bluefin tuna in the Mediterranean reveals surprising first results.
The new understanding of the migratory behaviour of this enigmatic species made possible by WWF's On the Med tuna trail project research will help make fisheries management more sustainable.
Starting in 2008, several tagging expeditions were carried out across the Mediterranean to determine Atlantic bluefin tuna trajectories and behaviour.
Tagging activities during 2008 were concentrated in the western Mediterranean, while in 2009 the Adriatic Sea area - where tagging with "pop-up" satellite tags on wild adult tuna had never taken place before - was also covered. Internal archival tags were used for juvenile tunas.
In total 4 pop-up and 21 archival tags were deployed in 2008, while 11 pop-up and 2 archival tags were used in 2009. Weights of tagged bluefin tuna ranged from 12 to 200 kg. Data from all pop-up tags was successfully recovered and their retention rates ranged from 1 to 172 days.
One extra special 2008 archival tag was recovered after the tuna had roamed free for 391 days, providing unprecedented information on bluefin migratory behaviour for a full year's life cycle.
None of the tagged tunas left the Mediterranean Sea during the whole tracking period. Results even suggest a residence pattern for large adults north of the Balearic Islands in late summer, as well as a link between the Gulf of Lions and the Tyrrhenian Sea, and between the Adriatic Sea and the Libyan coast.
"These results of WWF's tuna tagging work in the Mediterranean Sea have provided surprising and valuable insights into bluefin behaviour," said Dr Sergi Tudela, Head of Fisheries at WWF Mediterranean. "WWF has distributed its new findings widely and is urging fisheries decision-makers to apply the precautionary principle in Atlantic bluefin tuna management: until impacts on the species are fully understood, extreme caution must be applied."
The current project expires at the end of 2010 but there are plans to continue the Mediterranean bluefin tuna tagging field work in the years to come.
WWF's On the Med tuna trail bluefin tagging project is made possible thanks to financial support from the Prince Albert II of Monaco Foundation.
Anmelden
Registrieren
FAQ
Suche
