Spatial distribution and growth of the common mussel Mytilus edulis L. in the archipelago of SW-Finland, northern Baltic Sea

Abundance, biomass, size distribution and growth of the common mussel, Mytilus edulis L. along a transect extending through the SW archipelago of Finland, northern Baltic Sea are described here for the first time. The parameters studied were found to vary according to environmental gradients extending from the inner to the outer archipelago. The lowest densities and biomass were found in the innermost archipelago. Most of the populations here consisted of small individuals between 4 to 6 mm (antero-posterior length), while in the middle and outer archipelago areas modal size was approximately twice as large. The average growth rate of mussels in the middle archipelago was higher than in all other areas. Very slow growing, or “dwarf” mussels were found in all areas studied, but these were most common in the outer archipelago

Growth and longevity of Mytilus edulis (L.) from northeast Europe

The growth of mussels, Mytilus edulis (L.), was studied in most of the northeastern part of their distribution. The growth, longevity and maximal size of molluscs from 24 wild populations and one cultured population located in the White Sea and the southeast part of the Barents Sea were compared. The 25 studied populations were combined in six clusters. The maximal longevity and the size of the mussels varied between 7 and 18 years and 25.5 and 77.7 mm, respectively. The geographical location of the population within the studied region did not affect either maximal longevity or maximal size, or the growth rate of mussels. However, these parameters were influenced by local habitat conditions, primarily connected with the position within intertidal and subtidal zones. Animals inhabiting the intertidal zone were characterized by relatively low growth performance, a short life span and a small size. The longest life span was typical for deep subtidal mussels, whereas the highest growth rate was recorded in the cultured population and in the upper subtidal habitats. Growth patterns of Mytilus edulis in the subarctic White and the Arctic southeast Barents seas are similar to those reported from other parts of the area of distribution. Therefore, growth was mostly determined by local environmental factors, including those related to vertical zonation, rather than by latitude/longitude and related temperature effects.

Growth and longevity of Mytilus edulis (L.) from northeast Europe

The growth of mussels, Mytilus edulis (L.), was studied in most of the northeastern part of their distribution. The growth, longevity and maximal size of molluscs from 24 wild populations and one cultured population located in the White Sea and the southeast part of the Barents Sea were compared. The 25 studied populations were combined in six clusters. The maximal longevity and the size of the mussels varied between 7 and 18 years and 25.5 and 77.7 mm, respectively. The geographical location of the population within the studied region did not affect either maximal longevity or maximal size, or the growth rate of mussels. However, these parameters were influenced by local habitat conditions, primarily connected with the position within intertidal and subtidal zones. Animals inhabiting the intertidal zone were characterized by relatively low growth performance, a short life span and a small size. The longest life span was typical for deep subtidal mussels, whereas the highest growth rate was recorded in the cultured population and in the upper subtidal habitats. Growth patterns of Mytilus edulis in the subarctic White and the Arctic southeast Barents seas are similar to those reported from other parts of the area of distribution. Therefore, growth was mostly determined by local environmental factors, including those related to vertical zonation, rather than by latitude/longitude and related temperature effects