Friday, May 1, 2015

Sea Star Update

Regular visitors to Haystack Rock last year were witness to the sea star wasting disease that claimed many of the stars on the Pacific Coast from California to Alaska. The wasting was first reported in June 2013 but was not seen at Haystack Rock until the early summer of 2014. Symptoms included twisted limbs, lesions and disintegration of external tissue. After extensive research by many researchers the wasting has found to be caused by the sea star-associated densovirus. The virus has been found in seawater and sediment and has even been found in sea stars collected in the 1940's. Sea stars with larger amounts of the virus in their system showed the more extreme cases of wasting. Researchers are still trying to determine why the virus, which has been around for a long time, is causing disease now. High populations of sea stars just prior to the wasting event and warmer seas are two areas that are being investigated.


Adult sea star with Wasting Disease

In the last month we have seen sea stars returning to Haystack Rock, particularly adult stars on the north side. These adult stars are likely at least 5 years old, indicating they did not succumb to the wasting last year. Observations by HRAP staff and volunteers last year indicated that stars exposed on a more frequent basis had a harder time fighting off the virus. Hence, sea stars on the front and sides of Haystack Rock were hit the hardest with the wasting. Those on the back side of Haystack and on the Needles are exposed less; they survived in greater numbers and may be moving to the intertidal where now there is no competition.

Students from Seaside High School conducted a survey of the stars on April 20th. The survey was funded by a grant from Youth Learning As Citizen Environmental Scientists. HRAP coordinator, Samantha Ferber, visited the school's marine biology class prior to the survey to teach the students about  sea star wasting, the implication of the sea star die-off, and the monitoring protocol in preparation for their visit.


HRAP Coordinator Samantha Ferber
with Seaside High School citizen scientists


Surveying at Haystack Rock

The survey found 36 stars on the needles, most of them juveniles, and only one with wasting lesions. Twenty-six stars were found on the boulders north of the rock, most were adults and only one with lesions. Finally, the south wall had 36 stars, mostly juveniles with none showing lesions.


Surveying the Boulders north of Haystack Rock


Seaside High School citizen scientist 
recording survey data

Its great to see the sea stars returning to Haystack Rock and the Needles. Observation and star counting will continue throughout the year!

We are always thrilled to have new volunteers who want to help protect the habitat of Haystack Rock for all the creatures that depend on it for their survival. Ask an HRAP interpreter how you can get involved - we are on the beach every day at low tide!

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