Invasive Species (Zebra Mussels)

Invasive Species

James Purcell

Freshwater

Zebra Mussel

Dreissena polymorpha

·         First recorded in Ireland in 1997

·         The species has spread rapidly throughout Irelands freshwater ecosystems, and significantly altered these habitats.

·         It has a striped shell, grow to 3-4cm, it attaches itself to hard surfaces and it is a filter feeder

Impacts of Zebra Mussels:
They can change nutrient cycles, filter out the microscopic plants called phytoplankton and zooplankton (which would impact the food chain), increase water clarity and increase plant growth, Change in fish populations can also occur where zebra mussels are present (colonize spawning grounds),
It has been noted in some lakes which previously had large population of roach previous to zebra mussels, showed a dramatic decline in numbers after the introduction of zebra mussels.
Zebra mussels can also block water intake pipes, for example at Killyhevlin water works, Enniskillen, £100,000 was needed to repair and modify due to zebra mussels.