Surveillance monitoring lakes

In short, tire national surveillance monitoring net consists of 110 annually monitored reference or trend stations. In addition, 800 stations per year are monitored once every sixth year, which adds up to a total of 4910 monitored lakes in the six year monitoring cycle of the Water Framework Directive. 

Hebert C, Nordstrom R, Weseloh DV. 1999. A quarter century of environmental surveillance the Canadian Wildhfe Service s Great Lakes Herring Gull Monitoring Program. Environ Rev 7 147-166. 

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