Alien species introductions in the eastern Gulf of Finland: current state and possible management options

Abstract

Recent studies showed that the eastern Gulf of Finland should be considered as a "hot spot" in the Baltic Sea area, taking into account the high rate of alien species introductions, the negative environmental impacts of established alien species, and rapidly increasing export-oriented shipping. At minimum, 14 new species have established in the eastern Gulf of Finland during the last two decades, including several invasive species. Alien species are playing an important role in the structural and functional organization of communities, specifically in the littoral zone, but this role has not been fully evaluated yet. Rapid development of new ports in the eastern Gulf of Finland will result in manifold increase in the volumes of discharged ballast waters, as well as in associated risk of new invasions of harmful aquatic species in the near future. Development of effective management options to control established nuisance species and to prevent or minimize the risk of new invasions is urgently needed.