Diversity and Disturbance: How Mussels and Sea Stars Strengthen the Rocky Intertidal Community

Abstract

In the rocky intertidal zone, tides and rocks set the stage. Together they create habitat for a diverse community of species adapted to a world both underwater (high tide) and exposed to air (low tide). In some protected areas, like national parks, we study rocky intertidal ecosystems as vital signs of nature’s health. Studying them helps us understand the impact of disturbances, which play an important role in shaping these communities. Some disturbances, like the tides, happen daily. Others, like diseases, might happen once every decade. This article is about how tides and diseases affect two important members of rocky intertidal communities—mussels and sea stars. We explain the roles these organisms play and what happened when ochre sea stars, an important species in these habitats, suffered a major disease outbreak. Last, we emphasize the importance of protecting these vital ecosystems so we can continue to learn about the health of the natural environment.