| Abstract [eng] |
Over the past two decades, abundance of three-spined sticklebacks (Gasterosteus aculeatus) have increased dramatically in the Baltic Sea. Although stickleback is a thoroughly studied species in terms of its behavioural and evolutionary ecology, its functional role and interactions within Baltic Sea is poorly known. The aim of this study was to get better understanding of ecological role of the three-spined stickleback in the Baltic Sea, with emphasis on feeding ecology and stock delineation. A considerable diet overlap and significant similarities in prey preferences between sticklebacks and clupeids (herring and sprat) in the Baltic Sea offshore was found, indicating a potential resource competition. By means of DNA metabarcoding, a highly diverse (>100 taxa) but selective diet of stickleback has been revealed at the coast. Morphological analysis contributed to the other studies on stickleback population differentiation in the Baltic Sea and showed that fish from the Curonian Lagoon have significantly higher number of body plates and deeper bodies, potentially indicating a response to higher predation pressure compared to the other areas studied (Bothnian Sea, Kalmar Sound, and Baltic Proper). Overall, results emphasize the need not to overlook the species, include stickleback into management plans and monitoring since it may affect many parts of both pelagic and benthic food webs, both offshore and at the coast. |
