Seasonal variations in the grazing of Gammarus oceanicus, Idotea baltica, and Palaemon adspersus on benthic macroalgae

Abstract

Grazing of Gammarus oceanicus, Idotea baltica, and Palaemon adspersus on benthic macroalgae was studied in situ using small enclosures in Kõiguste Bay, N Gulf of Riga. Pilayella littoralis was the prime diet of the studied invertebrates. When its biomass declined in the field, invertebrate grazing on Fucus vesiculosus increased. The highest grazing rates were shown by I. baltica followed by G. oceanicus and P. adspersus. In general invertebrate grazing was high in summer, moderate in autumn, and low in spring.