Atlantic bluefin tuna losing weight

DURHAM, N.C., Aug. 28 (UPI) -- A U.S. study says the condition of bluefin tuna in the Gulf of Maine has declined in quality since the 1990s.

Researchers at the University of New Hampshire said an analysis of logbooks from a commercial tuna grader corroborated observations by fishermen and others that the number of giant bluefin in the Gulf of Maine is declining and their quality is lower.

The findings, published in Fishery Bulletin, indicate potential changes in food sources, shifts in reproductive or migratory patterns, or the impact of fishing may be the cause of this decline, the university said Friday in a news release.

"Fat content is in high demand for the market, because that’s what makes the meat taste good," said study author Walter Golet, a doctoral. candidate in UNH’s Large Pelagics Research Lab. A large, well-marbled fish can command upward of $50 per pound on the sushi market, the report said.

"One of the big consequences of not fattening as much is the potential impact it could have on reproduction," Golet said. "Reduced energy stores can often force a fish to skip spawning in a particular year."