Facts & Figures
How does the coastal fish community change during the annual cycle?
Christina Henseler, Daniel Oesterwind | 01.06.2022
Scientists of the Thünen Institute are investigating the state of coastal fish along the coast of Schleswig-Holstein in the Baltic Sea. To do so, monthly samples were taken in 2021 to assess the coastal fish community at several sampling stations.
In total, 50 coastal fish species were documented including both bottom dwelling species, such as shorthorn sculpins and gobies, as well as fish occupying the water column like herring and mackerel. Species occurrence and composition displayed distinct differences throughout the course of the year.
From winter to March, shorthorn sculpins and the commercial species, cod and herring, dominated the catches. Although also present during other months, these groups clearly represented the most common species in the beginning of the year.
In spring, whiting and round goby occurred with increasing numbers. Round goby invaded the Baltic Sea as a non-native fish species and commonly leaves its deeper wintering areas in spring to occupy shallower coastal waters. Lesser sand eels, schooling fish burying themselves in sandy habitats, were caught numerously in very shallow areas in May.
From September until the end of the year, gobies clearly dominated the fish community based on their numbers. Several goby species were present in the catches including the sand-, common-, transparent- and the two-spotted goby.
Overall, species diversity was comparatively high in the coastal waters of Schleswig-Holstein displaying a dynamic occurrence of different fish species throughout the year.
As a next step, we will compare the composition of costal fish communities between different years to gain more detailed insights into long-term changes.