Article doubts Exxon oil ruined herring

A continuing controversy has been whether the 1989 Exxon Valdez oil spill caused the collapse and poor recovery of Pacific herring in Alaska’s Prince William Sound.

A new article in the international journal Reviews in Fish Biology and Fisheries says no.

“We have assessed the evidence for and against the principal decline and poor recovery hypotheses and find no evidence that oil exposure from the Exxon Valdez oil spill… led to either the decline or poor recovery of PWS herring,” the article concludes.

The authors are affiliated with the U.S. Department of Energy’s marine research laboratory in Washington state, the Scripps Institution of Oceanography in California and other research organizations. They acknowledge ExxonMobil Corp. at the end of the lengthy article for having “supported this effort.”

The researchers also discount other hypotheses in the herring collapse, such as overfishing and disease, and instead conclude that poor nutrition was “the most probable cause” of the 1993 herring decline, with the fish’s “nutritional status” beginning to decline before the 11-million-gallon oil spill occurred.

The lack of recovery since then is attributable to ocean environmental factors; feeding conflicts between young herring and juvenile pink salmon released from the Sound’s major salmon hatcheries; and humpback whales eating potentially large numbers of adult herring, the article says.

The Sound’s once lucrative commercial herring fisheries have been closed since 1999, and the stock remains depressed. In other areas of Alaska, such as Sitka Sound and Togiak Bay, fishermen are enjoying robust herring harvests.

The Exxon Valdez Oil Spill Trustee Council has put considerable effort into restoring herring in the Sound. While the council currently lists some species as having recovered from the spill, including pink salmon, harbor seals and birds such as bald eagles, it classifies herring as “not recovering.”

—Wesley Loy