Abstract

Coastal and regional sea ecosystems suffer from several human-induced stressors, including human mediated bioinvasions. The Baltic Sea is generally considered to be susceptible to invasions by non-indigenous species (NIS). Out of the total of 132 NIS and cryptogenic species recorded, 59% are currently established in at least one country surrounding the Baltic Sea. On average, each country currently hosts 27 such species with 15% of the established species being found in at least 50% of the countries. Benthic macroinvertebrates dominate, both among those recorded (48%) and established (59%) species. Shipping, deliberate stocking and natural spread of NIS previously introduced to the North Sea are the main introduction pathways, with considerable dynamics over time. Amongst the pathways responsible for the currently established species, shipping and natural spread strongly dominate. Substantial uncertainty in the information on introduction pathways (except for deliberate releases) hampers detailed analyses and poses major challenges for management. Spatio-temporal variability in the invasion dynamics reflects both the spatial differences in the main hydrographic conditions of the Baltic Sea as well as the availability of introduction pathways. We conclude that the Baltic Sea cannot be considered as a uniform waterbody in terms of the established introduced species and at least two major regions withdiffering hydrographic conditions and introduction pathways can be clearly distinguished. Due to the importance of natural spread of NIS from the North Sea, regional cooperation in bioinvasion management should be enhanced in the future.

Keywords

Baltic Sea; Non-indigenous and cryptogenic species; Deliberate and accidental introductions; Secondary spread; Taxonomic similarity

Published in

Biological Invasions
2017, Volume: 19, number: 3, pages: 799-813

SLU Authors

• Florin, Ann-Britt

  • Department of Aquatic Resources (SLU Aqua), Swedish University of Agricultural Sciences
    

Associated SLU-program

Coastal and sea areas


Sustainable Development Goals

SDG14 Conserve and sustainably use the oceans, seas and marine resources for sustainable development


UKÄ Subject classification

Ecology


Publication identifier

DOI: https://doi.org/10.1007/s10530-016-1316-x

Permanent link to this page (URI)

https://res.slu.se/id/publ/80545