Seasonal depth distribution and thermal experience of the non-indigenous round goby Neogobius melanostomus in the Baltic Sea: implications to key trophic relations

Abstract Native to the Ponto-Caspian region, benthic round goby ( Neogobius melanostomus ) has invaded several European inland waterbodies as well North American Great Lakes and Baltic Sea. The species is capable of reaching very high densities in ecosystems, with not only evidence for significant food-web effects on native biota habitats, but also negative implications coastal fishers. Although generally considered a species, it been shown that migrate deeper areas other lakes during cold season. Such seasonal movements may create new spatio-temporal ecosystem consequences systems. To seek depth distribution marine we compiled all available catch data Sea since its invasion until 2017. We furthermore related depths at capture each season ambient thermal environment. spend autumn winter significantly offshore compared spring summer months; few fish were captured < 25 m these colder months. Similarly, summer, > m. conditions which caught varied between seasons, being average 18.3 °C dropping low 3.8 Overall, sought within highest possible temperatures. spatial substantially overlaps main preferred prey (mussels) competitor food (flatfish), moderately predatory (perch), indicating thereby complex trophic interactions associated this invasion. Further investigations should aim quantifying web coupling different habitats migrations goby, both terms competitor, predator prey.