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Going to the "edge" for wildlife

Research on colonial waterbirds at the top of Niagara Falls

Above the edge – the helicopter approaches the Canadian side of Niagara Falls / Julie Pollock, Canadian Wildlife Service

Lower the water level in the Niagara River – check. Make sure the wind conditions are right – check. Now, jump out of a helicopter after a harrowing landing near the precipice of Niagara Falls – check? It's another day in the service of wildlife for Canadian Wildlife Service researchers.

Since 1979, researchers have arrived each spring to study the colonial waterbirds nesting on a series of rocky islands just above the falls. Wildlife technicians and biologists work quickly, collecting 13 eggs from the nests of Herring Gulls. They also count the Herring Gull and Black-crowned Night-Heron nests for population censuses conducted in Canada and the United States.

One of the tiny, rocky islands that form the nesting colony / Julie Pollock, Canadian Wildlife Service

Researchers must move rapidly to vacate the islands by an appointed time, when Ontario Power Generation and New York Power Authority increase the flow rate of the river, a daily ritual to boost the visual appeal of the falls. Overnight, the flow rate is cut roughly in half and the excess is diverted to nearby generating stations.

Dr. D. V. (Chip) Weseloh leads the Great Lakes Herring Gull Egg Contaminants Monitoring Program (1974-2004), now in its 30th consecutive year. The program examines contaminants levels in the eggs of Herring Gulls and other colonial waterbirds from up to 15 sites throughout the Great Lakes and connecting channels. Field research is conducted in April and May.

Thirteen eggs are collected from each site and analyzed at the Canadian Wildlife Service laboratories in the National Wildlife Research Centre. The eggs are tested for approximately 100 compounds, including polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), dioxins and mercury.

Over the years, almost all chemical compounds have declined at egg sampling sites by at least 50 percent since they were first measured, and many have declined by more than 90 per cent. Early visible health effects in waterbirds have given way to more subtle health effects, but contaminants remain a concern. For example, a new family of chemicals – PBDEs, used widely as flame-retardants – has increased dramatically in Great Lakes gulls.

With the roar of the falls close and mist rising high all around, Dr. Weseloh and his team return to the helicopter and lift off above Niagara Falls. The birds begin to settle back on their nests. The team will return next spring to continue a 30-year tradition of tracking environmental contaminants in Great Lakes wildlife.

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