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Government guts gull study

Broadcast Date: Dec. 1, 1984

It's a quick, easy and inexpensive way to monitor contaminants in the Great Lakes — and it's about to get the axe. Eggs laid by herring gulls can show evidence of pollutants before water samples or fish do. By studying the eggs, scientists keep tabs on the health of the Lakes, wildlife and the people who live nearby. On CBC's Quirks and Quarks, Dr. Doug Hallett says he hopes a government decision to cut the study's funding will be reversed.

Government guts gull study

• The herring gull, a waterbird, is the most widely distributed gull in the Northern Hemisphere, and is found on all the Great Lakes.
• The omnivorous bird measures about 64 centimetres from bill to tail and is white with grey wings, pink legs and a yellow bill.
• Nesting spots are always very close to a body of water. Females typically lay three eggs each spring and will lay more to replace any lost early in the nesting season.

• Herring gulls and their eggs are good early indicators of chemical contamination because of the herring gull's position on top of the food chain. They eat larger fish, which eat smaller fish, which eat insects which feed on micro-organisms in the lake. The effect of bioaccumulation means that toxins present in water and small fish become magnified several times in the herring gull and are easily detected by scientists.

• There are several other reasons herring gulls make good study subjects: much is already known about the bird's biology and the effects of contamination on breeding habits and metabolism; they rarely migrate away from the Great Lakes; and their nesting practices make it easy to collect eggs without harming adults or chicks.
• Biologists collect just 13 eggs per year from each nesting colony.

• Over the years the herring gull study has revealed the presence of many different contaminants. Among them are DDE (a variant of the pesticide DDT), dieldrin (an insecticide), PCBs and dioxins.
• Levels of all contaminants in herring gulls has decreased greatly since the 1970s. The Canadian Wildlife Service attributes this to regulations limiting the manufacture and use of these contaminants.

• The Canadian Wildlife Service began the Great Lakes herring gull study in 1971 after a biologist noticed abnormally low numbers of herring gull chicks on Scotch Bonnet Island in Lake Ontario. Researchers had already noticed that birds in lakes Ontario and Michigan were heavily contaminated.
• After a public outcry, the herring gull study was not cancelled. It continues as of 2004 and is one of the longest-running bio-monitoring programs in the world.

Government guts gull study

Medium: Radio

Program: Quirks & Quarks

Broadcast Date: Dec. 1, 1984

Guest(s): Doug Hallett

Host: Jay Ingram

Duration: 3:40

Last updated:
Aug. 9, 2004