Between one-fifth and one-third of all the wild-caught seafood that comes into the United States may be caught by vessels engaging in “pirate fishing, a new report says. The leading seafood trade association disputes the numbers in the study but says it remains committed to fighting the problem.

The report, written by researchers at the University of British Columbia and to be published in Marine Policy magazine, puts the value of the catch from illegal, unregulated and underreported (IUU) fishing at between $1 billion and $2 billion annually, or between 15% and 26% of the total value of wild-caught imports.

Vessels classified as participating in IUU fishing are designated as such because they regularly ignore domestic and international fishing laws, fish in areas closed or restricted to commercial fishing, target endangered and at-risk species, and use illegal gear.

“This study unfortunately confirms what we have long suspected–that seafood from pirate fishing is getting into our markets, said Beckie Zisser of the environmental group Oceana, which has been documenting issues of fraud and illegal fishing in the seafood industry. “Illegal fishing undercuts honest fishermen and seafood businesses that play by the rules, and the U.S. should not be incentivizing pirate fishers by creating a legal market for their products.

The best way to rid the market of pirate-caught fish is to institute a system of traceability that tracks each fish from the time it is caught until the time it is sold, she said. “Before seafood crosses our borders and enters our markets, it needs to have documentation that verifies that it was legally caught, and that the fish traveled a transparent path from the fishing vessel to our dinner plates, Ms. Zisser said.

The National Fisheries Institute, which in 2007 created the Better Seafood Board to combat fish fraud, said while it supports efforts to fight pirate fishing, it has serious doubts about the numbers reported in this study.We find this report, however, a bit skewed. To begin by proposing that 10% to 20% of domestic seafood comes from IUU fishing suggests the author’s other conclusions may be suspect, an NFI spokesman said. “Experts who know fisheries management would not accept the suggestion that as much as 20% of the U.S. catch is IUU.

It’s important to discuss these issues surrounding IUU fishing in a reasonable, responsible manner, NFI said, or one risks “straying from anecdotal to hyperbolic and thus discounting the whole conversation.

IUU fishing also is often associated with other serious problems such as drug trafficking, human slavery, organized crime and maritime security, said the World Wildlife Fund. “This study reinforces what the fishing industry, governments and conservationists have been saying for a long time: Illegal fishing is a major global problem and threatens the long-term health of our oceans and the livelihoods they support, said Michele Kuruc, vice president for marine conservation at World Wildlife Fund, which helped underwrite the study.

A bill that would mandate traceability systems be in placethe Safety and Fraud Enforcement for Seafood Act–is pending in Congress. In addition to requiring fish be tracked from the time they are caught, supporters say, the bill will improve seafood inspections and give consumers more information on which to make informed purchasing decisions.

“As one of the planet’s largest consumers of seafood, the U.S. has an enormous impact on the global seafood trade and the obligation to drive international progress to stop illegally caught fish from entering it, Ms. Kuruc said.

The U.S. took a step forward last week when it ratified the Port Statement Measures Agreement to prevent, deter and eliminate IUU fishing, but can do more, WWF said. “By expanding traceability requirements across all fisheries, the U.S. can catalyze international efforts to prevent illegal fish from mixing with legal product throughout global supply chains, said Ms. Kuruc.

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