A giant Atlantic bluefin tuna weighing more than half a ton had the honor of being fitted with the 1000th electronic tracking tag placed on this threatened species when it was caught and released on Monday (October 20) in the Gulf of St. Lawrence off Port Hood, Nova Scotia.

The Atlantic bluefin tuna is the largest and most sought-after of all tunas, weighing as much as 1,400 pounds and capable of fetching as much as $50,000 or more in Asian markets where its meat is a prized commodity, one big reason why its numbers have declined precipitously since the 1970s.

Giant bluefin tuna are in trouble, primarily because the powerful muscles that propel their extensive ocean migrations come with an Achilles' heel: They're tasty.

The quality of giant bluefin tuna caught in the Gulf of Maine has declined significantly since the early 1990s, researchers at the University of New Hampshire have found by analyzing detailed logbooks from a commercial tuna grader at the Yankee Fisherman’s Co-op.