Thursday, July 3, 2008

TGF @ Atlantic Bluefin Tuna Stock Assessment

The 2008 Atlantic bluefin tuna stock assessment session concludes its business tomorrow in Madrid, Spain. The Tag-A-Giant Foundation was represented at the meeting by Dr. Andre Boustany, a post-doctoral research associate at Duke University. He presented a paper to the scientific body on the preliminary results of TGF's October 2007 tagging campaign in the Gulf of St. Lawrence, Canada. For pop-ups to date, three of the six tags that remained on fish beyond the onset of the breeding season have popped up in the Gulf of Mexico and three in the western North Atlantic. The tagging data support the hypothesis that strong linkages exist between the Gulf of St. Lawrence fish, the North Carolina foraging grounds and the Gulf of Mexico spawning grounds. To date, none of the fish has a geoposition in the eastern Atlantic management unit (east of 45W longitude). Six additional tags are due to pop-up in the near future.

Drs. Nathan Taylor and Murdoch McAllister from the University of British Columbia presented a new stock assessment model developed with the support of TGF that incorporates cross-over rates of the eastern and western stocks estimated from electronic tagging and chemical analyses of bluefin earbones, or otoliths. By better accounting for the significant percentage of fish from the eastern population that are taken in West Atlantic fisheries, the new model should lead to a better estimate of the number of bluefin tuna from both stocks remaining in the Atlantic Ocean.

The 2008 stock assessment results will be finalized and released in September.

1 comment:

Jerry A said...

The term Western Atlantic was a political not a scientific thing created in 1981. These beautiful kings of the ocean go where they want when they want and will never conform to lines drawn on a map. This disingenuous apperoach is why ICCAT has failed all these years. "TO UNDERSTAND THAT YOU DO NOT UNDERSTAND ID THE BEGINING OF WISDOM" Those of us that were there know where this began, shame on them.