The continued fouling of the Gulf of Mexico with crude oil from the wreckage of BP's Deepwater Horizon rig could not have occurred at a worse place or time for the future of the bluefin tuna and other large migratory species, the locally-based director of the Large Pelagics Research Center said Thursday.
In the spring, the Gulf becomes a nursery for bluefin, big eye and yellowfin tuna and swordfish too, explained marine biologist and center director Molly Lutcavage, who is working out of Gloucester.
"The Gulf is the major nursery and so this couldn't have been worse," she said in an interview.
Lutcavage said new research into the migratory patterns of the bluefin — which arrive in waters off Gloucester during the summer and is fished recreationally and commercially through the fall — suggests the species may breed in areas in addition to the Gulf, or may not breed annually.
In the wake of the oiling of the Gulf — caused by the April 20 BP Deepwater rupture — either of those complexities would serve the species' longterm interests, she said.
"As a key aspect of their life histories," Lutcavage said, "it would be really stupid to put their eggs in one basket (the Gulf). It seems very logical that they hedge their bets."
That's especially the case, she said, for an alpha predator that cruises the waters of the world, routinely logging thousands of miles a year.
The research by Lutcavage and Benjamin Galuardi, Francois Royer, Walt Golet and John Logan — all of the pelagics center — and John Neilson of the New Brunswick (Canada) Department of Fisheries and Oceans, was published in the May issue of the Canadian Journal of Fisheries and Aquatic Sciences.
The study, carried out in partnership with fishermen, was undertaken while the research center was located at the University of New Hampshire. The center, however, has since migrated to the University of Massachusetts at Amherst and the Massachusetts Marine Fisheries Institute, and relocated to Gloucester, where Lutcavage resides.
Lutcavage said the "basis of this work was the "complete partnerships we have with the fishermen.
"The questions we ask were first brought to us by fishermen," she said.
Funded by the National Marine Fisheries Service and conducted as cooperative research with fishermen, the study was done by applying electronic popup satellite tags to mature bluefin caught off the coast of Nova Scotia and on Georges Bank.
In 2005 and 2006, 41 tags were deployed in an effort to gain an understanding of the migration paths and behavior and also identify the spawning areas of the fish, said Lutcavage, who began studying tuna in 1993.
In all, she said, the research center has tagged about 400 tuna. The popup satellite technology allows tracking without recapturing the fish, which were part of what has been thought of as the "western" stock of bluefin.
Lutcavage said that the more that's known about bluefin, the less likely it is that the species can be viewed as divided into two distinct stocks, one in the Western Atlantic and the other in the Eastern.
"They're much more complicated than it seems," she said.
The study, titled "Complex migration routes of Atlantic bluefin tuna question current population structure paradigm," was undertaken to gain an understanding of why the so-called western stock "has dramatically declined despite rebuilding efforts."
"Despite a rebuilding plan for the western stock," the authors wrote, "catches from 2005-2008 have declined. The U.S. commercial fishery, which operates primarily in New England, caught only 10 percent to 27 percent of the allocated western quota."
Earlier this year, the bluefin tuna was proposed — but not approved — for listing under the Convention on International Trade in Endangered Species. But fierce debate continues about the best methods of managing stocks of this wide-ranging, fast-growing fish that brings such an alpha price as sushi.
The bluefins that arrive just offshore in frenetic schools — the "football" bluefin of 50 to 100 pounds — might be no more than 2- to 3-years-old.
"They are among the fastest growing fish, growing a millimeter a day, and are swimming within a week of hatching," said Lutcavage.
The oil spill, she said, "will have an impact on a significant portion of this year's spawning population. We have huge concerns."
Worse yet for the bluefin are the vertical depths of the range — 3,000 feet or more — and growing body of evidence of deepwater plumes of dispersed oil throughout the Gulf.
Richard Gaines can be reached at 978-283-7000, x3464, or rgaines@gloucestertimes.com.
Vatican in Chaos After Butler Arrested for Leaks
Jimmy Carter Endorses Egypt's Election Results
Biden Addresses West Point Graduating Class
Dozens of Children Killed in New Syria Attack
Raw Video: Activists Allege Massacre in Syria
NJ Man Charged With Murder in Death of Patz
Support, Fun for Kids of Fallen Soldiers at Camp
Fugitive Penguin Caught, Returned to Aquarium
50 Years Later, Underground Fire Still Burning
Light Show Transforms Sydney Opera House
Raw Video: Unruly Passenger Restrained in Miami
Raw Video: Robber Uses Drive-thru Window
Raw Video: Dragon Arrives at Space Station
Calif.'s Coronado Named Nation's Best Beach
CEO Salaries Become Sore Issue in Labor Disputes
