The Year 2003 Great North American Secchi Dip-In

Press Release from the Kent State University,
Great American Dip-in Event Managers

The summer of 2003 marks the tenth year of the Great North American Secchi Dip-In. The Dip-In is an international effort in which volunteers produce a "snapshot" of the transparency of water in the United States and Canada. Sponsored by the North American Lake Management Society and the United States Environmental Protection Agency, the Dip-In is directed by Kent State University biologists, Dr. Robert Carlson and Professor David Waller, and KSU geographer, Dr. Jay Lee.

During the period from June 28 until July 13, 2003 more than 2,500 volunteers from more volunteer monitoring programs in the United States and Canada will measure transparency in their favorite lake, reservoir, river, or estuary. Most will use an instrument called a "Secchi disk", a flat, horizontal, black and white disk that is lowered from a rope into the water until it disappears. The disk itself is named after the Jesuit priest, Pietro Angelo Secchi, who used the disk more than 150 years ago. The depth the disk disappears is a measure of the transparency of the water.

Transparency is affected by the color of the water and by particles of silt or clay or small plants called algae, and therefore is a measure of some forms of pollution.

Carlson said that he wanted to find a way to produce a scientific picture of the water quality of the world's lakes. Such a project could only be done using the thousands of volunteers who routinely measure transparency in local volunteer programs. The Dip-In is really a chance for volunteers to think and contribute globally by taking a measurement in their local environment.

The previous Dip-In's have provided valuable information about water quality. The maps made each year have shown considerable regional differences in transparency. Lakes in the northern parts of the United States and in Canada typically have the clearest lakes, while lakes in agricultural regions of the Midwest have some of the smallest transparencies. Transparencies found during the Dip-In range from one inch to more than 65 feet. Almost 1,000 bodies of water have been monitored during the Dip-In for five or more years.

Equally valuable has been the information gleaned on the volunteer's perception of water quality. The Dip-In has found that opinions of water quality vary considerably from region to region. A person in Minnesota, Maine or Canada, for example, may think that a lake is degraded if the transparency is six feet while in other states, a lake with a transparency of only a foot may be considered beautiful. Carlson suggests that these regional differences mean that people become accustomed to the quality that they see every day. Most sobering may be the possibility that everyone grows up thinking that their environment is normal. Small changes in water quality may go unnoticed. Fortunately, there are volunteer monitors who record these changes in water quality year after year. Without their observations, our environment might change unnoticed.

For our part, we try to make the Dip-In more useful to you. We accept data from all sorts of turbidity instruments, not only Secchi disks, and last year we added temperature and pH. We are encouraging stream and estuary programs to participate. All nine years of Dip-In data are now available to anyone on our website. We list your program at our site and will be happy to advertise your volunteer events. We continue to add more volunteer methods to our methods section and are more than happy to post contributions or links by others. If you are having trouble with data archiving, we accept data all-year long which you can retrieve.

More information on the Great American Secchi Dip-In, including participating programs and state-by-state results for past Dip-Ins, is available on the World Wide Web at: http://dipin.kent.edu/

The LaMotte Company offers several devices for transparency measurement. Our secchi disk and turbidity tubes are used by many volunteer monitoring organizations.