Researchers used a new approach to study Atlantic bigeye tuna, Thunnus obesus, one of the most commercially important tuna species in the world.
Bigeye tuna, Thunnus obesus, is one of the most commercially important tuna species in the world. Photo credit: shin–k via photopin cc.
Funded by NOAA, researchers at the University of Massachusetts Amherst used electronic tags to track bigeye tuna throughout the Atlantic. The fishery-independent data collected from the tags will help researchers better characterize habitat use and assess the need for additional monitoring in areas where bigeye are known to use.
“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,” Molly Lutcavage, director of the Large Pelagics Research Center at UMass Amherst explained in a news release. “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.”
Bigeye tuna are currently managed as a single stock in the Atlantic, but it’s possible that they could be divided, depending on their migratory behavior and habitat use. That’s why long-term, seasonal data is vital for the most effective management.
Lutcavage and colleagues deployed 21 pop-up satellite archival tags (PSAT) between 2008 and 2010 in the northwest Atlantic. They were able to collect “full-resolution time series data” from nine tags and found that bigeye cover a wide geographical range with “pronounced north-south movements” between Georges Bank (near Cape Cod, MA) and the Brazilian shelf. The researchers also identified Cape Hatteras, southwest of Bermuda, as a high-use foraging area.
In addition to tracking the location of the tuna, the PSATs collected temperature, light level, and pressure data, allowing NOAA to characterize possible relationships between bigeye tuna movement, behavior, and environmental factors.
The study authors hope that their results will help inform the upcoming tagging effort by the International Commission for the Conservation of Atlantic Tuna (ICCAT) and assist ICCAT scientists as they plan new bigeye population research.
To learn more:
- Read the full news release: UMass Amherst Study of Bigeye Tuna in Northwest Atlantic Uses New Tracking Methods.
- Find the full study online: Movements and oceanographic associations of bigeye tuna (Thunnus obesus) in the Northwest Atlantic.
Copyright © 2014 by Marine Science Today, a publication of Marine Science Today LLC.
