AS1 Alien Baltic Sea species

This is a pressure indicator (DPSIR = drivers, pressures, state, impact, responses)

>> Background information


Altogether 23 alien species can be found from the Finnish part of the Baltic Sea. These species have arrived in the Baltic Sea assisted - intentionally or unintentionally - by man. Five of the species may be considered clearly harmful for original biodiversity and are classified as invasive alien species. Seven species are potentially invasive and 11 more alien species are not invasive or their impact is not known.

The number of alien species in the Finnish part of the Baltic Sea increased steadily troughout the 20th century until the 1980s. On average one new alien species was found per decade. Three new species were discovered during the 1990s and no less than 11 during the first ten years of the new Millennium .

The greatest number of alien species can be found in the southern sea areas where water is relavitely warm and salty. These circumstances are most suitable for southern salt water species. However, more than ten alien species can be found even in the northernmost parts on the Baltic Sea.

Invasive alien species

Bay Barnacle Balanus improvisus
Conrad's False Mussel Mytilopsis leucophaeata
Caspian Polyp Cordylophora caspia
American Polychaetes Marenzelleria spp.
Fishhook Waterflea Cercopagis pengoi

Potentially invasive species

Prussian Carp Carassius gibelio
Zebra Mussel Dreissena polymorpha
American waterweed Elodea canadensis
Chinese Mitten Crab Eriocheir sinensis
Tiger Sideswimmer Gammarus tigrinus
Round Goby Apollonia melanostomus
a Dinoflagellate Prorocentrum minimum
Sea Walnut* Mnemiopsis leidyi
Zuiderzee Crab Rhithropanopeus harrisii
Marine tubenose goby Proterorhinus marmoratus
Amur Sleeper Percottus glenii
a Bivalve* Corbicula fluminea
a Bivalve* Dreissena bugensis
an Amphipoda* Gmelinoides fasciatus
a Crustacean* Dikerogammarus villosus
a Crustacean* Pontogammarus robustoides

Other alien species

a planktonic Copepod Acartia tonsa
a muworm Boccardia redeki
Convergent Stoneworth Chara connivens
Common Carp Cyprinus carpio
a Crustacean Evadne anonyx
Bloody-red Mysid Hemimysis anomala
Rainbow Trout Oncorhynchus mykiss
a Crustacean Palaemon elegans
a Gastropod Potamopyrgus antipodarum
a Chironomid midge Telmatogeton japonicus
a Bryozoa Victorella pavida
This indicator will be checked when the national strategy for alien species in ready in the beginning 2011.
Prorocentrum minimum

Discuss this topic

Start the discussion »

Add comment

If you have trouble reading the code, click on the code itself to generate a new random code.

Your message will be sent for moderation. New comments are usually published on the next workday.

Hide comments