Signs of Change in Lake Champlain

Scientists studying Lake Champlain on the New York-Vermont border have noticed some recent, puzzling changes. Lakeshore residents and researchers were pleasantly surprised last summer when the thick, noxious blue-green algae blooms that have plagued the Mississquoi Bay near the Canadian border for a decade failed to occur. Water quality remained excellent all summer. Eric Smeltzer, the Vermont state government's lead lake scientist, analyzed changes in water temperature, transparency, phosphorus concentration and rainfall in his search for an explanation. None seemed strongly correlated with the sudden decline in algae. He did find that concentrations of nitrogen in the water were at nearly their lowest levels in a decade. In separate research; however, University of Vermont's Mary Watzin lined up evidence that other factors might help drive the rise and fall of blue-green algae. They include warmer water temperatures and an explosion of invasive white perch that eat the microscopic crustaceans that feed on algae. http://www.burlingtonfreepress.com/apps/pbcs.dll/article?AID=/20080109/NEWS02/801090322/1007

More recently, Vermont Fish and Wildlife biologists responded in early January to the first major die-off of alewives on Lake Champlain -- a discovery that indicates that the lake has undergone a significant infestation. Responding to phone calls from anglers, department personnel found tens of thousands of dead alewives. The biologists believe the fish kill is temperature-related, as the non-native species are not adapted to the cold winter lake temperatures. Similar alewife collapses have been seen in the Great Lakes. The invasive alewives were first found in Lake Champlain in 2005. http://www.burlingtonfreepress.com/apps/pbcs.dll/article?AID=/20080112/NEWS02/801120319/1007/NEWS05 

The Burlington Free Press, January 9 and January 12, 2008