Seamounts Species Spotlight: Bluefin Tuna

The New England Coral Canyons and Seamounts are a special area 150 miles off the coast of Cape Cod. The unique geological formations make this area a biological hotspot, attracting many unique species. This blog post is part 3 in a series that profiles some of these incredible animals.

Just imagine a 10-foot long, steel blue, torpedo-shaped body darting through the water of the open ocean and it’s easy to understand why the Atlantic Bluefin tuna is at the top of the oceanic food chain.

This predator is one of the ocean’s most impressive swimmers, built for quick and calculated movements as its body is smooth with retractable fins, allowing it to minimize drag and maximize speed. Tuna also go far: some individuals have been observed making multiple migrations between the United States and Europe each year.

These world travelers spend their summers feasting upon herring and eels in the waters of the Gulf of Maine. At some 1,500 pounds, tuna prefer to swallow prey whole and are considered a very aggressive predator. To maximize vision (presumably helping with predatory ability), tuna are even partially warm-blooded, a rare trait for a fish.

Mating Grounds Discovered Near Canyons and Seamounts

Many details of the fish’s behavior were unknown until recently. A study released this year revealed the discovery and confirmation of a previously unknown mating ground in the “Slope Sea,” an area of ocean between the Gulf Stream and continental shelf, which includes much of the New England Coral Canyons and Seamounts area. The area was identified after poppy seed-sized larvae were detected in the waters with further analysis confirming their birthplace.

Much attention has been paid in recent years to the Atlantic Bluefin tuna’s close relative, Pacific Bluefin tuna, an incredibly popular and valuable commodity in places across Asia. In 2013, a Pacific Bluefin went for a record $1.76 million in Tokyo.

The Pacific Bluefin’s global fame has, unfortunately, spelled collapse for global stocks. All three species of Bluefin tuna – Atlantic, Pacific, and Southern – are at risk of collapse because of human predation. The Atlantic population has decreased by as much as 51 percent in just three generations.

As a completely migratory species, comprehensive management has proven difficult, with responsibility currently falling to the International Commission for the Conservation of Atlantic Tuna (ICCAT). Currently, there is effort being placed on monitoring and accurately reporting the origins of each landing along with strict catch limits.

As we continue to discover more about these powerful fish, it is important that we protect the areas that they rely on, such as their feeding and breeding grounds. The discovery of a North Atlantic breeding ground requires much more study so managers can learn more about how to better manage this species. Permanently protected the New England Canyons and Seamounts is an excellent step in the right direction.