Sport fishermen who target bluefin tuna can be a critical part of a grand new study to learn more about Atlantic bluefin fishing and mortality rates, as well as the rates of mixing between eastern and western populations, by watching for spaghetti tags in fish they bring to the boat.
In fact, the three-year study is titled the Grande Bluefin Year Program by those making up the cooperative research program.
The first juvenile bluefin tuna tagged as part of the international research program was recovered this month 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.
The effort is collaborative, including: 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 Tunas (ICCAT) in Madrid, NOAA’s Southeast Fisheries Science Center in Miami and AZTI Tecnalia of Sukarrieta, Spain.
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 one- to three-year-old bluefin tuna in the eastern Atlantic and 4,000 in the western Atlantic. At those ages, the bluefin will 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. (However, fish can be released successfully after removing a tag.)
To encourage reporting, the researchers will reward people who return a program 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.
For more information, visit the Large Pelagics Research Center website.