AMHERST, Mass. A first-of-its-kind study of bigeye tuna movements in the northwestern Atlantic Ocean led by Molly Lutcavage, director of the Large Pelagics Research Center at the University of Massachusetts Amherst, found among other things that these fish cover a wide geographical range with pronounced north-south movements from Georges Bank to the Brazilian shelf, and they favor a high-use area off Cape Hatteras southwest of Bermuda for foraging.
This NOAA-funded research, which used a new approach to study one of the most important commercial tuna species in the Atlantic, provides the longest available fishery-independent record of bigeye tuna movements to date. Data should help researchers to further characterize habitat use and assess the need for more monitoring in high-catch areas.
Results appear this week in an early online edition of the Canadian Journal of Fisheries and Aquatic Science.
Fisheries oceanographer Lutcavage says, "Although Atlantic bigeye tuna are delivering high prices to the U.S. commercial fleet and are highly sought by recreational fishermen and fishing tournaments, there's been a surprising lack of scientific research on this species. And in contrast to the Pacific, where tuna fisheries programs have deployed over 400,000 tags over 25 years, the Atlantic lacks the fisheries infrastructure that would increase the odds of recovering tags. We have to rely on popup satellite tags that are fishery independent to make sure we get information back from the tuna."
Two earlier electronic tagging studies by others yielded relatively short tracking data, 113 days or fewer, and did not allow for seasonal analysis of movement or exploration of an alternate stock composition hypotheses, Lutcavage and colleagues note. Bigeye are currently managed as a single Atlantic stock, she explains, and the greater resolution of habitat use and migratory behavior revealed in this study are important first st
|Contact: Janet Lathrop|
University of Massachusetts at Amherst