At a time when our Gulf of Mexico bluefin stock is vitally important to protect, where every last fish that makes it out of the Gulf is vital to the future of this fishery, when it is imperative they spawn without disturbance, an oil spill happens.
Atlantic bluefin tuna are comprised of several populations and the bluefin that gets the largest are from the Gulf of Mexico spawning stock. Over the past three years we’ve been working in Canada to tag the largest fish- to see where the bluefin spawn. From analyzing fish carrying electronic tags we have learned these “Canadian” bluefin go often to the region just north of the Loop current right where the shelf break occurs (see track below). Here on the frontal edge of the Loop Current, the bluefin spawn- leaving their eggs to hatch into larvae. They require warm temperatures and spectacularly clean water. Unfortunately where the oil spill is occurring is essential bluefin spawning habitat. These are places that are the most important in our waters to protect.
Map shows the track from an 8-1/2 foot long Atlantic bluefin tuna tagged off Nova Scotia that swam into the Gulf of Mexico, spent several weeks in the spawning area, then departed (yellow track). The dark blob off Louisiana is the estimated coverage area of the oil spill as of May 3.
Our TAG team spent five years working in the Gulf of Mexico, trying to establish the critical spawning habitat for this species - one of the largest fish in the sea. We saw the seismic boats from several companies out on the shelf break searching with sound for oil. Blasting right where the tuna were spawning. It bothered me back then and I told the head of NOAA about the problem (Dr. Rollie Schmitten). I often wondered if they (the oil companies) had an environmental impact statement that included the bluefin tuna. In these waters not only are bluefin spawning, but many other large pelagics as well- blue marlin, swordfish, and later in the spring, yellowfin tuna. Springtime is a time of renewal in the Gulf of Mexico. This place is the fertile nursery grounds to America’s North American fisheries- so the pain may reach far beyond the shores of Louisiana. For the future of the Atlantic bluefin in North American waters, let’s hope that BP and the Federal government act quickly to shut down the leaks.
-Dr. Barbara Block