Unalaska, AK – The third annual Western Alaska Interdisciplinary Science Conference opened in Unalaska this week with a poster session and a reception. Posters ranged in topic from growing potatoes in rural Alaska, researching contaminants in bird eggs, and sampling nuclear test sites on Amchitka.

One of the posters from the Alaska Maritime National Wildlife Refuge focused on the effects of the 2008 Kasatochi eruption, which covered the entire island with a thick layer of ash and completely changed its topography. Biologist Jeff Williams joined a team of scientists to look at all aspects of that change, from soil to geology and insects to marine mammals. Biologists had a summer field camp on the island for 13 years before the eruption, so they knew approximately how many birds and marine mammals were affected by it.

Williams said about 20,000 to 30,000 young birds that couldn't fly died at the time of the eruption, but many adults survived.

"The eruption happened late in the season when most of them were finishing their breeding season. It happened during the day when the species that only come to the colony at night were actually away, out at sea, foraging. And it happened in three different eruptions. The first two eruptions were kind of ash poor but gas rich, so a lot of gasses were emitted. So that might have given birds warning, to escape. The third eruption was very ash intensive and completely covered the island and extended it out 400 meters or so," Williams said.

The adults tried to return to Kasatochi to breed in the summer of 2009, but most of the nesting sites on the cliffs and the foraging sites in the grass were covered in ash.

"If you're a sea bird, you make your living out at sea. If you can't come back to find a breeding spot, whether that's on a grassy field like a gull or in rocky crevices for things like auklets, that nested there in abundance, then you basically abandon your attempt for the year and attempt to go support yourself and not your young."

Williams said sea birds live 30 to 60 years, depending on the species, so missing one breeding cycle will not have a significant impact on the population as a whole.

Sea lions, however, were the only species that did well on the island after the eruption. "The shoreline over the course of the winter from 2008 to 2009 eroded away [the ash on] their breeding sites, so they had access to the sites they did before the eruption. So, just like many of the adult seabirds, they had escaped the eruption. They swam away. But then they came back in the same numbers and they pupped a little bit more than they had in the past. So they're the only species of any bird and mammal that breed on Kasatochi that was successful."