UNH Recovers Tuna Tag With Help From Cape Hatteras Mom

By Erika Mantz, Media Relations
February 20, 2008

Alexis and Ashley Hodges with the tag. Courtesy photos.

One of 32 new X Tags deployed on juvenile bluefin tuna off Cape Cod last year by the Large Pelagics Research Center at UNH was found on a Cape Hatteras beach on Valentine’s Day. Recovery of the “popup” satellite, or PSAT tag, will allow researchers to obtain more information about the migration of these highly valuable fish, which can easily swim across the Atlantic and back many times over their lifespan.

The LPRC bluefin experts and their colleagues deployed 32 tags on juvenile bluefin in 2007, and eight more on giant bluefin in Canadian waters. The tags – each costing approximately $4,000 -- are programmed to report after 12 months but sometimes the tags detach early from the fish. Sometimes the dart and tether attaching the tag to the fish pull out, or are bitten off by another fish. The recovered tag was an early release; the center has had three reports in the past few weeks – two near Cape Hatteras and one northeast of Bermuda.

When the tag releases from the fish it pops up to the surface and its radio transmitter sends the logged data to a receiver on a NOAA satellite. The data, which consists of depth, temperature and location information for the entire period the tag remains on this fish, is then relayed to LPRC Director Molly Lutcavage and the tag manufacturer, Microwave Telemetry, Inc.

Molly Lutcavage tagging a fish.

If the tag is prematurely released, or if a fish dies (none have since the tagging program’s start in 1997), it will start transmitting the data. The tags transmit the logged data for about 30 days. If the actual tag is recovered higher resolution data that can't be transmitted to the satellite can be recovered about the fish.

“We’re actually happy to have data coming in early, because this is the first time anyone has put a popup satellite tag on juvenile bluefin, and we were anxious to learn where they would go after leaving New England waters in the fall,” Lutcavage said. “Very little is known about where they go after leaving coastal waters in the summer and fall until they show up again the next season.”

“The process of recovering this tag has been a great learning opportunity for the Large Pelagics lab and the Hatteras students and their parents,” Lutcavage added. “The tag finders now know more about this magnificent fish, and have had a first hand look at the very latest technologies that fisheries scientists use to track marine animals. Bluefin tuna are an extremely valuable fisheries resource that has been in the news for months, Adult bluefin are disappearing from our coastal waters, and the US commercial fisheries off New England and the Carolinas are suffering, probably due to the vast overfishing by foreign and pirate fleets in the Mediterranean and Eastern Atlantic.”

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