A visual census of bivalve distributions in the saltwater lake Malo jezero (Mljet National Park, South Adriatic Sea)

Abstract

     A visual census of 3 epifaunal dwelling bivalve species was performed by SCUBA diving along four transect lines in a saltwater lake, Malo jezero (Mljet National Park), during the summer months (June to August), between 1998 and 2001. Significant differences in the distribution of Arca noae L. Pinna nobilis L., and Chlamys glabra (L.) were found with respect to depth and diving transects. Pinna nobilis was absent from depths greater than 15 m, whilst Chlamys glabra has disapeared from all transects in 2001. Pinna nobilis and Chlamys glabra were measured in situ and size distribution changes were noted with respect to 2000 to 2001 and 1999 and 2000, respectively. The survey method employed in this study was non-destructive and relatively simple to perform and therefore it can be easily applied for monitoring long-term in epifaunal bivalve distributions.