Most Unwanted: Asian clam
Corbicula fluminea
Habitat: Freshwater
Threat: Impact on benthic communities
Status: Potential
Corbicula fluminea or Asian Clam is a freshwater clam species that has become invasive in many parts of the world. At present this species is estimated to have caused millions of dollars of damage to industries based around freshwater systems. The clam is also known to cause the decline of native unionids. What is it?
Typically the species grows up to 25 mm in length but larger forms are know which can grow up to 50 to 65 mm. C. fluminea has a yellowish brown to black shell with concentric, evenly spaced ridges on the shell surface.
Potential impact
Like the zebra mussel, the Asian clam reaches high densities and colonises suitable substrates. It has similar impacts to the zebra mussel, competing with other species for food and space. Water based industries, such as hydroelectric power stations and water abstraction for household use may be faced with higher costs due to the clogging of intake pipes by this species. In the US one estimate from 1980 put the costs of correcting this problem at an estimated 1 billion dollars annually (ISSG). They can also negatively impact on sand/gravel abstraction.
Where is it from
China, Korea, southeastern Russia, and the Ussuri Basin
Where is it now
Widespread in Europe and the United States
How can it get here
Present in boat bilge water. Corbicula is used as live bait. C. fluminea is known as "pygmy" or "gold" clams in the aquarium trade. Juvenile clams can be carried in ballast water all over the world.
What you can do
Do not use Corbicula as bait.
Do not transfer water from one waterbody to another.
Do not bring Corbicula with you when you travel to Ireland.
Report all sightings.
Additional reading
Habitas Invasive Alien Species in Northern Ireland
