Catherine Kilduff has a childhood memory of summering in Vineyard Haven and having a day at the beach when she found a number of spider crabs. She recalled hand-feeding one of the crabs with the meat she plucked from a limpet. It was June, an early visit to the Island. “I must have been 11 or 12 years old,” she said.

She relived that experience during a recent visit to the Island when she and her husband, Patrick, watched as their three-and-a-half-year-old son, Lane, reeled in his first fish, a scup. He caught it from the beach near the Vineyard Haven Yacht Club. “I never heard him yell so loud — ‘I caught a fish!’” she recounted.

Mrs. Kilduff, her husband, and their two children (the younger is Lila, who had just turned one), were here for a week of respite visiting family.

But her experience as a child on that Vineyard beach years ago led to a career that has been dedicated to saving the world’s oceans and the diverse marine life they support. Mrs. Kilduff is an attorney for the Center for Biological Diversity and their oceans program, based in San Francisco. The center has been actively leading an effort to list the Atlantic bluefin tuna as an endangered species.

In late May the National Oceanic and Atmospheric Administration rejected the designation, instead listing bluefin tuna as a species of concern. Now Mrs. Kilduff and her center are heading up a consumer boycott against the consumption of bluefin tuna, calling it “one of the most imperiled fish on the planet.”

As for Mrs. Kilduff, her love for the ocean began with Vineyard summers. “I wanted to be a marine biologist. I spent my winters in Norfolk, which is also on the water, on the shores of the Chesapeake Bay, but growing up here, sailing,” she said. “Sailing is so much better here than it is on the Chesapeake Bay. The wind is so much better here.”

Ten years ago, she graduated from Dartmouth College with a degree in ecology and evolutionary biology. From there she went on to obtain a master’s of science degree from the College of William and Mary’s Virginia Institute of Marine Science. “I studied invasive species. These are organisms that have traveled the world in the ballast of ships. The policy aspect was really interesting to me. It is so much easier to stop them from coming here, than it is to solve a problem once they are here.”

After her work on the Asian rapa whelk, she took a two-year Sea Grant marine policy fellowship that put her into Washington, D.C., working as a legislative staff member for the U.S. House Resources Committee, Subcommittee on Fisheries, Wildlife and Oceans. “I was on Capitol Hill for almost three years, working on fisheries issues. It was the first time I worked on tuna,” she said.

In 2003, she attended a weeklong meeting of the International Commission for the Conservation of Atlantic Tunas (ICCAT) in Dublin, Ireland. She said she was so struck by the way the policies were adopted at that meeting, the next year she decided to become an attorney. “You arrive there and all the policy is done within a week. Even though the National Marine Fisheries Service had done plenty of preparation for the meeting, the drafting and coming up with the language that goes into the decision making is written that week. All the negotiations, all the decisions are made,” she said.

“I came from Capitol Hill, where you work on resolutions that can take months, years to get written and adopted,” she said. By contrast, at ICCAT she saw the work speed along. Watching the process, she said: “That inspired me to go to law school.” She obtained her law degree from the University of Virginia.

The dilemma of protecting the bluefin tuna was a project she inherited when she accepted her position a year and a half ago. The Center for Biological Diversity is a nonprofit advocacy organization that examines troubled natural resources from plants and animals on the land to those in the sea. “We have a few staff, three working on the ocean. We have a wide range of issues. There are species affected by climate change, like black abalone, which is decimated by disease off the California coast. The disease has increased by global warming. We are looking a lot at ocean acidification and how it affects the shells of oysters on the West Coast, particularly,” she said. She continued:

“Oyster farmers are having some tough years with the reproduction of oysters; I think that ocean acidification may be the primary culprit. The science behind ocean acidification is very sound. The scientists say we need to act now, because it is happening. There is no uncertainty with ocean acidification.”

But of all the issues the center faces, Mrs. Kilduff said the troubled bluefin tuna is really quite simple; it is all about overfishing, she said. “If we stop overfishing them, they would probably recover. But it is hard to do, because bluefin tuna are worth so much money. Global trade is high and compliance is really poor, despite what [was] said in the decision [declining to list the fish as endangered].”

Even without the endangered species designation, Mrs. Kilduff said her organization will continue to monitor the problem. Next on the list for examination is the use of harmful fishing gear. “In the last 40 years fishermen have used more and more harmful fishing gear to the ecosystem,” she said. “The pelagic longline, which is miles and miles of hooks, fishing 12 hours at a time, will catch everything . . . you don’t have to use destructive fishing gear to sustain a community.

“Longlining has the potential of being done much more cleanly than it is now. But in general it shouldn’t be done at all,” she concluded.