The world's marine life is being redistributed, often without our knowing it, and sometimes with hazardous results. Non-native species are being deposited around the world in larval form, carried in the ballast water of freighters and tankers. Canada's coastline is not immune to the problem and is now home to several unintended species of marine life. Most are quite innocuous and for others the long term effects are unknown. But every once in a while a species arrives that creates a serious problem, such as the zebra mussel which has now infested the Great Lakes.

Recently, another species has arrived off the waters of British Columbia which could pose a serious threat. The Green Crab, originally from Europe is now found on both coasts of North America. It made it's first appearance on the Pacific coast in 1989 and since then has been moving steadily northward and has now been found off the west coast of Vancouver Island.

The Green crab has a voracious appetite for bivalves, and depending on how well it establishes itself along the coast, could represent a real threat to British Columbia's shellfish industry. Glenn Jamieson of the Pacific Biological Station says that the appearance of the Green crab "means a change in the whole coastal ecosystem."

By Doug Pemberton