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Going to the "edge" for wildlife
Research on colonial waterbirds at the top of Niagara Falls
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.
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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