sea life a worry
CanWest News Service
The ships entering Vancouver Harbour were officially hauling
cars and stereos, but below the waterline, they were also
carrying tiny stowaways from Asia and the U.S.
In a comprehensive study on life forms sailing into Canada's
western harbours, scientists have found that ballast tanks
are teeming with life. Researchers studying the water
in the tanks found dozens of different species of zooplankton
and small sea animals. In some instances, there were thousands
of creatures in every cubic metre of water taken on to
stabilize the ships. Some were well known species of flatworms
or clams. Others remain mysterious.
"We had no way of identifying what some of them
were," says Colin Levings, the federal fisheries
scientist who led the study, published this spring in
the Canadian Journal of Fisheries and Aquatic Sciences.
More than 200 alien species are already believed to have
taken up residence in Canadian waters, including the infamous
zebra mussels that have disrupted the Great Lakes' ecosystem.
Others, such as the Japanese varnish clam that appeared
on B.C. beaches a decade ago, appear to be relatively