Does the diversity of kelp forest macrofauna increase with wave exposure?

Kelp (Laminaria hyperborea (Gunn.) Foslie) forests support a diverse community of invertebrates. The aim of the present study was to test if the abundance, diversity (measured as average species number) and community structure of macrofauna associated with epiphytic algae on kelp stipes depend on physical stress from wave surge and habitat diversity, or if differences simply result from differences in habitat size. Results show that faunal diversity increased with wave exposure, mainly due to increasing wave stress and habitat diversity. Abundance was highest at medium wave exposed stations, and lowest at low exposure stations. However, the habitat structural diversity is high in kelp forests regardless of wave exposure, and a typical kelp forest fauna is associated with functional groups of epiphytic algae across different levels of wave exposure.

► The diversity of macrofauna associated to kelp increased with wave exposure.
► This was mainly caused by increasing wave stress and habitat diversity.
► A typical fauna is associated to kelp across different levels of wave exposure.