Meeting Abstract
Mortality from disease may play a critical role in food web dynamics of the intertidal zone. The sea star, Pisaster ochraceus, is a keystone species in the intertidal zone and are currently being affected by Sea Star Wasting Disease (SSWD). We have noticed a drastic decrease in populations of sea stars on the north coast of the rocky intertidal since 2013. If the numbers of P. ochraceus are on the decline due to SSWD, then we might predict increasing populations of their prey population, which include chiton, limpets and other snail species. This could potentially result in an increased food supply for other Asteroids. Since July of 2014 we have sampled 4 transect bands, each 3 x 30 m. running from onshore to offshore on four different sites in Northern California. For each transect band we have recorded the number of stars and the following for each individual: disease status, radius, and location in the intertidal zone. Every 5 meters along each transect band we have also recorded the mobile invertebrate species within a 0.25m2 quadrat. I predict that I will find increasing populations of snails, limpets, and chitons associated with declining populations of P. ochraceus. If my prediction is correct and the current population of stars is no longer able to maintain a steady-state population of their invertebrate prey, a new opportunity may develop for another predator in the intertidal zone.
