Meeting Abstract
In a world facing climate change, it is vital that we understand how ecologically significant marine species will be impacted by increasing temperatures and decreasing seawater pH. One ecologically important species in California and Oregon is the giant green anemone (Anthopleura xanthogrammica), which has two photosynthetic algal symbionts that make these anemones important primary producers in the intertidal zone. This study is to investivating the effects of changes in temperature and pH on anemones and their symbionts over a natural gradient along the coast of California and Oregon. Algal cell counts, chlorophyll a measurements, mitotic index, and anemone oral disk diameter are being used to evaluate abundance of symbionts and health of both symbionts and anemones. This study is testing the hypothesis that symbiont amount and animal size will both increase under conditions of higher temperature and lower pH. Sampling for this project occurred in late May and early August 2016 including Fogarty Creek, OR (44.84°N), Cape Arago, OR (43.31°N), Cape Mendocino, CA (40.34°N), and Bodega Head State Marine Reserve, CA (38.32°N). Historical data from the OMEGAS group was used to characterize the sites. In May, Fogarty Creek is the warmest site, and temperature decreases from north to south; all sites are significantly different from each other (p<0.05). At the same time, the northern sites are more basic, while the southern sites are more acidic. In August, these trends are reversed. Analysis of May samples and processing of August samples is currently in progress. The results of this study will help inform environmental policies, since radical ecological shifts may occur if anemones are able to outcompete other ecologically important intertidal species.
