Zebras sighted on Tiny Beaches

By Al Taylor

No, not the ones you see at the Elmvale Zoo or Wild Kingdom on television. They are striped, however, and that's where the similarity ends. These are Zebra Mussels which have invaded Georgian Bay over the past few years with a vengeance, and the fingernail shells have washed up on Tiny's beaches.

Residents have remarked on the vast numbers of shells observed on the beaches from Ossassane, Wymbolwood and Bluewater. We can expect to see a lot more of this.

So, where did they come from, and what can be done about it? Zebra Mussels arrived in Canada as stowaways in a ship's ballast water from Europe and were first noticed in the Lake St. Clair area in the early 1980's. Scientists believe that the North American Zebra came from the warmest portion of the zebra's range, the northern shore of the Black Sea, more specifically the lower Dnieper and Bug Rivers, near the Ukranian seaports of Kherson and Nikolayev. Zebras are believed also to have spread from there to the rest of Europe during the 19th century, including, Poland, Germany, Sweden and England.

A 1983 map of the zebra sightings in the Great Lakes showed three "hot spots" around Lake St. Clair area. Today, the map shows a vast infestation all through the Great Lakes, into the Muskokas, up the St. Lawrence, down through the Mississippi, and the surrounding States, to the Gulf !

Zebras attach to boats, anchors, travel in bilges and settle in new areas wherever they are introduced, whether it be fresh or saltwater.

These pests attach to anything in the water and can move around. Zebras that attach to it are killing native clams. I have seen 50 or more on one clam, and hundreds on tree branches brought up from 60 foot depths! They foul water intakes, and have cost millions to clean them off. Channel markers have sunk under their weight.

They are remarkable filters, with each zebra filtering a liter of water, removing everything in it, including PCV, plankton and contaminants. We have all heard that Lake Erie has experienced remarkable clarity as a result. Zebras are so numerous that Lake Erie is completely filtered once a day!

The immediate adverse abiotic affect is mussel biofouling, the build-up of zebra mussels on any surface, and the killing of native clams. When waterfowl birds eat zebra mussels, the result is elevated contaminants which lead to reproductive problems.

Predation by diving ducks, freshwater drum, carp and sturgeon have not had a sufficient impact and this is limited to warmer months when the Great Lakes are not frozen over.

The mussels’ tiny shells are also quite hazardous to swimmers as they are extremely sharp. In some areas it is recommended that children, and adults too, should wear protective footwear.

At this point nothing can be done to eradicate zebra mussels, and, without action, the zebra mussel will create a new balance of life in the Great Lakes, North America, and, the World.