Studies on Baltic Sea mysids (original) (raw)

Mysid shrimps (Mysidacea, Crustacea) are efficient zooplanktivores in both marine and freshwater systems as well as lipid rich prey for many species of fish. Although some efforts have been made to study the role of mysids in the Baltic Sea, very few studies have been carried out in recent time and there are still knowledge gaps regarding various aspects of mysid ecology. This thesis aims to explore some of these gaps by covering a mixture of topics. Using multifrequency hydroacoustics we explored the possibility to separate mysids from fish echoes and successfully established a promising and effective method for obtaining mysid abundance/biomass estimates (paper I). An investigation of the current mysid community in a coastal area of the northern Baltic proper (paper II) demonstrated that the formerly dominant, pelagic mysid Mysis mixta had decreased substantially (textasciitilde50%) in favor for phytoplanktivorous, juvenile Neomysis integer and Mysis relicta sp. By examining diffe...