Sand Dollars to Sea Stars!

Friday September 5 from 3:30 to 5:30 pm.

— from Russel Barsh —

A mystery surrounding Seastar Wasting Syndrome: healthy seastars piled up with sick ones do not always get sick!

A mystery surrounding Seastar Wasting Syndrome: healthy seastars piled up with sick ones do not always get sick!

Back-to-back talks at the Library on the sand dollars and sea stars of East Sound round off this summer’s public programs of the Indian Island Marine Health Observatory and Kwiaht.

The presenters are Amy Henry, a University of Chicago doctoral candidate in evolutionary biology; and Russel Barsh, director of the local nonprofit conservation biology laboratory, Kwiaht.

Amy Henry leads off with an update on her sand dollar experiments at Crescent Beach, now in their second year. Crescent Beach has extensive eelgrass meadows as well as the largest concentration of sand dollars in San Juan County. Sand dollars and eelgrass seem incompatible: only one or the other is found within any particular patch of sand. If part of the beach is disturbed by a storm or human activity, which returns first, eelgrass or sand dollars? What factors determine the outcome of the race? Amy Henry’s experiment aims to understand the rules of the sand dollar-eelgrass ecological chess game.

Russel Barsh follows with a review of the impact of Seastar Wasting Syndrome at Indian Island, and prospects for recovery. Thousands of Ochre Stars converge at Indian Island each year to feast on shellfish and to spawn. This year, up to 90 percent of them died of SWS, mainly during the July heat wave. What can we expect in 2015? Is SWS a seastar apocalypse, or an example of parasites and disease serving a periodic regulatory function in ecosystems? Clues can be found in studies of two previous outbreaks of SWS on the Pacific Coast, as well as data collected at Indian Island this summer.

If you find sand dollars and sea stars beautiful, mysterious, or strange, come to the Echinoderm Double-Header on September 5 and learn how research on Orcas Island is shedding new light on the some of the ocean’s oldest inhabitants.

For more information on this event, email kwiaht@gmail.com

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