Spatial variation in the abundance and growth of blue mussels along different gradients of wave exposure, depth and salinity

Abstract

Wave exposure, depth and salinity are the crucial factors in the abundance and growth of blue mussels Mytilus edulis in the Baltic Sea. The spatial variations in the mussel density, length and shell free biomass were studied in the West Hanko. The experiment aims to find out at which exposure and depth mussel density, length and biomass are maximized. The experiment assessed 3 levels of wave exposure and 3 depths among 9 sites. The results showed that the mussel densities and sizes were generally maximized from medium exposed to sheltered sites. At the same time, it was found that mussel density, length and biomass were maximized at 2 m and 4 m of depth. Physical stress from wave action and food concentration (microalgae) are the possible explanations for these findings. Salinity did not have any significant contribution to the variation in the mussel parameters studied, probably due to low range variation within the experimental locations of this study. It is concluded that sheltered sites at shallow depth own the most favourable condition for blue mussels. The results are useful for stakeholders interested in starting mussel farming aquaculture in the West Hanko coastal region.