Arctic Yearbook 2015 - Page 185

185 Arctic Yearbook 2015 transmission caused by microscopic pathogens (CAFF 2013). Additional research concentration in these areas may have high potential net benefits. Microorganism bio-invasions are a rather conspicuous feature of marine ecosystems overall, particularly because of the ballast water tanks which may carry hundreds of trillions (Society for General Microbiology 2008) of microorganisms on just a single tank or a hull can harbor whole ecosystems of microorganisms. The chances of their individual survival might be relatively low, but the increasing shipping activity in the Arctic increases the overall threat level. Fighting the challenge of microorganism invasions and managing them effectively has never been easy. One can argue that preventing introduction and new infestation would be an optimal solution but the limited amount of research to date does not allow strong conclusions (Burnett et al. 2008; Burnett, Pongkijvorasin & Roumasset 2012; Kaiser & Burnett 2010). Besides the general experience obtained so far, which indicates that particularly for marine ecosystems, preventing invasions has proved the most effective and economically viable way to mitigate their impacts (Carlton 2001; Williams et al. 2013), the diverse realm of Arctic invasions paves the way towards intensifying joint prevention efforts. Apart from the microorganisms discussed above, existing fears for future invasions are also informed by northward migrations in temperate waters and include species that range from the European green crab (Carcinus maenas) (deRivera, Steves, Ruiz, Fofonoff & Hines 2007), which as a voracious predator may pose a significant threat to Arctic marine life, to salmon (Nielsen, Ruggerone & Zimmerman 2013). Additionally to the above, other non-indigenous species have also been identified in Arctic and sub-Arctic waters but cannot yet be listed as confirmed invasions (Molnar, Gamboa, Revenga & Spalding 2008): Table 1: Suspected Arctic introductions Species name Binomial name Soft-shell clams Mya arenaria Hydroid Ectopleura crocea Naval shipworm Teredo navalis Higher Taxa Invertebrate Mollusc Ecoregion/ location of identification Invertebrate Cnidarian Invertebrate Mollusc Eastern Bering Sea Acartia copepod Acartia tonsa Invertebrate Arthropod Crustacean Zebra mussel Dreissena polymorpha Invertebrate Mollusc Kourantidou, Kaiser & Fernandez North and East Iceland Eastern Bering Sea East Greenland Shelf West Greenland Shelf Northern Grand Banks - Southern Labrador Northern Labrador Baffin Bay - Davis Strait White Sea Hudson Complex