Invasion of zebra mussels into the great lakes region. It"s a relatively recent invasion followed by a rapid spread across the region, and that it was a major cause for concern for both environmental and economic reasons. In hawkestone, ontario between orillia and barrie: The water has become much clearer as the quantity of particulate matter in the water column has been greatly reduced. This is one of the byproducts of the huge abundance of zebra mussels, whose filter-feeding activities cycle massive amounts of water every day. Beach shows no presence of zebra mussels because they have nothing to latch onto. Dock shows zebra mussel infestation, they collect on the side of the dock because they are protected from the water current and are able to latch on readily. Zebra mussel infestation is evident not because of their direct presence but because dead mussel shells wash ashore.