Adverse Effects of Hyposalinity from Stormwater Runoff on the Aggregating Anemone, Anthopleura elegantissima, in the Marine Intertidal Zone

Abstract

Coastal watersheds strongly impact the near-shore marine environ- <br /><br />ment with freshwater inundation and runoff from the land. At Leo Carillo State <br /><br />Beach in Malibu, California, we have noticed marked effects of stormwater runoff <br /><br />on the local marine fauna. The aggregating sea anemone expels symbiotic algae <br /><br />under the influence of hyposaline stress, causing bleaching. The number and <br /><br />distribution of bleached sea anemones have increased dramatically from 1992 to <br /><br />1995 at Leo Carillo State Beach under the influence of increased rainfall and the <br /><br />artificial broadening of the arroyo channel at its mouth.