November 28, 2014 — More than 25 years after the Exxon Valdez disaster in Prince William Sound, once bountiful Pacific herring stocks still have not recovered from the toxic oil spill, the Exxon Valdez Oil Spill Trustee Council has concluded.
Meeting in Anchorage on Nov. 19, the council concluded that the status of Pacific herring should remain unchanged as "not recovering," said Elise Hsieh, executive director of the council.
"EVOSTC staff noted that additional data had been received the week before the meeting from trust agency staff that shifted the previous understanding of available data and thus the recovery status recommendation had been revised the prior week," Hsieh said.
The council's recommendation to keep the status of Pacific herring status quo while approving most other updates in its Nov. 10 update on injured resources and services. Pacific herring, as the report notes, are an ecologically and commercially important species in the Prince William Sound ecosystem. They are central to the marine food web, providing food to marine mammals, birds, invertebrates and other fish. Herring are also commercially fished for food, bait, sac-roe and spawn on kelp.
When Pacific herring spawned in intertidal and sub-tidal habitats of the Sound shortly after the spill on March 24, 1989, all age classes and a significant portion of spawning habitats and staging areas in the Sound were contaminated by oil.
Juvenile and adult herring would normally come to the surface at night to feed and would have had increased exposure probability at this time to the oil. Lesions and elevated hydrocarbon levels were documented in some adult Pacific herring from the area of the spill. Laboratory studies showed abnormalities and possible depressed immune functions in Pacific herring exposed to oil, the EVOSTC report on injured resources and services note.
But the report was edited, on the recommendation of ADF&G, to delete comments that while significant adult mortality was not observed in 1989, "this would not be unexpected given the heavy predation or scavenging by different groups of predators." The report also said that egg mortalities and larval deformities of Pacific herring were also documented in the 1989 year class, but that population level effects of the spill were never clearly established.
The report, http://www.evostc.state.ak.us/static/PDFs/IRS_Update_DRAFT_11-10-14.pdf, also noted that cutthroat trout and rockfish are very likely recovered.
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