When you mention tuna, most minds probably swim to the ubiquitous cans of the fish, or maybe a delectable piece of sashimi decked out with roe and wasabi.
But when Stanford biology professor Barbara Block contemplates tuna, her mind goes to images of bluefin tuna — the massive, speedy fish that regularly traverse oceans in a single year.
“Over a lifetime they might travel tens of thousands of miles,” Block said, flanked by California's Monterey Bay.
Block is warning that the bluefin, once thought to be incredibly bountiful, is now facing peril because of decades of overfishing.
Some 80 percent of bluefin caught are used in sushi — a single fish possibly reaching 900 pounds and fetching upwards of $100,000, making them incredibly valuable. After years of fishing, scientists caution the world’s current bluefin population is only four percent of what it once was.
“There’s concern in our global oceans that the biodiversity of tuna is being reduced to such levels that we may not be able to recover the fish,” Block said.
This week, Block was part of a unique symposium in Monterey where 200 scientists, policy makers and fishery managers gathered for a first-of-its kind think tank on the future of bluefin tuna.
Over three days the group pondered the science, worldwide fishing quotas and how disparate nations will have to band together to stem the bluefin’s steady march toward peril.
“We have academic colleagues all sitting in the same room from around the world,” Block said, “trying to sort out what are the best tools we can use to make sure bluefin have a future on our planet.”
One of the issues with the bluefin is their penchant for international travel, roaming across vast physical boundaries and economic zones.
Researchers said because their journeys put them in various countries with conflicting science and policies, there is little consensus on how to set fishing quotas that would stabilize the bluefin numbers.
“Bluefin is a global fish, they travel the global path,” Block said. “And so we have to work as nations to solve the problem.”
That means pledging more money to fund bluefin studies, according to researchers, though gathering that data is notoriously challenging because of the speed and distance the fish travel.
“One of the biggest problems with these tuna though is we don’t have good scientific data to make a plan for recovery,” said Julie Packard, executive director of the Monterey Bay Aquarium where large bluefin swim in massive aquariums.
“People are interested in supporting their families and communities for the longer term,” Jeffries said in Monterey, where he was attending the Bluefin Futures Symposium. “By far the best way to do that is often to reduce the quota, make the fish sustainable.”
Adjacent to the Monterey Bay Aquarium, Stanford University operates the Hopkins Marine Station research facility, which includes the only U.S. facility devoted to studying bluefin. Block said her team is a world pioneer in the development of electronic tagging for bluefin.
“So what we’re trying to do is inspire people to do a better job with the modern tools of science,” Block said during a break from the meetings, “and apply it to bluefin now and make sure they have a future in our oceans long after we’re gone.”