Quake's effect on sea life lasts decades

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FAIRBANKS, Alaska, April 25 (UPI) -- Marine invertebrates living on the seafloor needed 26 years to fully recover from Alaska's Great Earthquake of 1964, a University of Alaska scientist says.

"The earthquake, which measured 9.2 on the Richter scale, and the tsunami waves that followed, impacted every marine community in Prince William Sound," said Arny Blanchard, a research assistant professor at the University of Alaska Fairbanks.

Findings by Blanchard and university colleagues, published in the journal Marine Environmental Research, shed light on how long it takes for seafloor ecosystems to recover after earthquakes, a university release said Monday.

The 1964 earthquake and resulting tsunami wreaked havoc on intertidal beaches and the seafloor of Port Valdez, the researchers said, causing whole communities of bottom-dwelling marine invertebrates such as sea worms, snails and clams, to change or, in some cases, disappear.

The diversity and abundance of marine invertebrates in Port Valdez was highly variable for decades compared to other glacial fjords, primarily as a result of the earthquake, researchers said.

Only over time has the community of animals stabilized, they say, and today the balance of bottom-dwelling animals finally looks more like an undisturbed glacial fjord.

Samples collected in 2010 marked the fourth decade of sampling in Port Valdez, making it one of the longest-running research projects at the university's School of Fisheries and Ocean Sciences, the release said.