Crabs invade Kejimkujik Seaside

It is native to Western Europe around England and France, but has rapidly been finding its way into coastlines in almost every continent.

Researchers at Kejimkujik Seaside are studying the effect the crabs are having in that area. One area they suspect is in the declining amount of eelgrass found in the estuaries.

“We’re trying to represent the natural ecosystems of Nova Scotia, and this gives us the opportunity to study how Nova Scotia is supposed to be,” said David Algar, Manager, Resource Conservation, Kejimkujik National Park and National Historic Site.

“We know that things are going on, for example our eel grass beds are declining, but also checking water quality. There are other possibilities like disease, pollutants in the water,” he added.

However they do know they have an invasive species on their hands.

Primarily the crab has traveled through ship’s ballasts and has gotten into other coastlines when they dump the water. It has so far proved very adaptable.

“Normally in a ecosystem species have co-existed together for a long time period, so there’s checks and balances that keeps the whole system running normally,” said Algar.

When a new species comes in, it can do pretty much whatever it wants, as long as nothing preys on it, he added.

Currently the crabs have no natural checks in Keji Seaside, although Algar noted that seagulls have been eating them.

Records of the Green Crab in Nova Scotia date back almost 50 years, but lately they have been getting attention due to their effect on the shellfish industry.

The crab preys on bivalves and other crustaceans, such as clams, oysters, mussels and even small fish.

Researchers at Keji Seaside are studying what effects they have in the estuary areas, one of their preferred habitats.

Within the next month they will be trapping Green Crabs.

“We want to know is it possible to trap this species and keep its population down to low levels that the natural habitat can handle,” said Algar.