AMHERST, Mass. – The first juvenile bluefin tuna tagged as part of a new three-year international research program was recovered this month, caught by two U.S. recreational fishermen off Long Island and New Jersey. It had been tagged in the Bay of Biscay in Spain last August. This recapture marks the start of a new international collaborative tuna tagging project aimed at improved fishery management.
A collaborative effort of the University of Massachusetts Amherst’s Large Pelagics Research Center (LPRC) at the Marine Station in Gloucester, the International Commission for the Conservation of Atlantic Tuna (ICCAT) in Madrid, NOAA’s Southeast Fisheries Science Center in Miami and AZTI Tecnalia of Sukarrieta, Spain, the goal of the Grande Bluefin Year Program (GBYP) is to learn more about Atlantic bluefin tuna fishing and mortality rates and rates of mixing between eastern and western populations.
GBYP’s central task is a scientific tagging program for which researchers including UMass Amherst scientists led by marine biologist Molly Lutcavage, hope to deploy 15,000 tags in the eastern Atlantic and 4,000 in the western Atlantic in young bluefin tuna, one to three years old. At those ages, they range from 12 to 50 inches from nose to base of the tail.
Lutcavage explains, “By its nature, this important Atlantic-wide tagging program places fishermen in a central role as science partners. It requires that fishermen recover and report fish and recapture information to us. We only obtain the data needed for updating bluefin population assessments if the tagged tuna are recaptured and reported. So it’s essential that we have the help of the recreational fleets when they catch one of these young fish in order to help improve bluefin population estimates.”
For the U.S. GBYP, fishermen are asked to look for “spaghetti-like” ID tags on any bluefin they catch. These are six-inch long, brightly colored and implanted near one or both sides of the fish’s second dorsal fin. Fishermen reporting a catch can send a data record that includes the tag itself, the recovery date and location with latitude and longitude, the fish’s overall body length and round weight, when possible.
To encourage reporting, the researchers will reward people who return a GBYP tag with a T-shirt and a reward ranging from $50 to $1,000. Also, photos will be posted on the lab’s Facebook page, with maps showing where each fish was tagged and recaptured.
Results from this international program, funded by NOAA and ICCAT, will help bluefin scientists produce more accurate estimates of the degree of mixing between eastern and western Atlantic bluefin tuna populations and contribute to improved bluefin management and stock rebuilding efforts.
The Large Pelagics Research Center's Program Manager, Emily Chandler, and Research Assistant, Bart DiFiore, get ready to release a tagged juvenile bluefin tuna off the coast of NJ, as part of the GBYP Atlantic-wide bluefin tagging project.
Photo credit: Captain Rich Kosztyu