- Ocean acidification has led to many issues regarding the decline of calcifying organisms, such as
coralline algae. Acidified sea water inhibits precipitation of CaCO3 that affects the structure and
growth of coralline algae. Therefore, non-calcifying algae may outcompete calcifying algae in the
intertidal systems with future acidic ocean condition. Variety species of algae possibly have a
different habitat architecture that may attract diverse kinds of epifauna. One of the most abundant
algal epifauna in Oregon’s rocky intertidal system are snails (Gastropoda). They are an important
grazer of mussels in rocky intertidal communities. Considering the importance of gastropods in
intertidal communities and their relationship with macroalgae, we examined the dependence of
gastropods to coralline algae. Algal sampling (n = 72) was done at Yachats State Recreational
Park, Oregon. For each sample collected, the number of epifauna and algal density were measured.
We found that gastropods did not have preferences to specific type of algae. In contrast, nongastropods
had a preference towards coralline algae in comparison to fleshy algae. However,
further studies are needed to elucidate the relationship coralline algae and epifauna community.