News Releases - 2003

Local Lake Data Will Be Included in Great North American Secchi Dip-In

Springfield, Ill. -- Using flat metal disks attached to knotted lengths of rope, volunteers will gauge the transparency of the water in Lake Springfield Tuesday morning. The data they collect will then be blended into a “snapshot” of water clarity in lakes, rivers, reservoirs and estuaries being obtained by more than 2,500 volunteers in the U.S. and Canada as part of the 10th Great North American Secchi Dip-In.

The Dip-In originated with biologists at Kent State University and is sponsored by the North American Lake Management Society and the U.S. EPA. It takes its name from Secchi disks, flat horizontal metal plates painted with black and white quadrants. The devices were invented more than 150 years ago by a Jesuit priest, Pietro Angelo Secchi, who used such a disk to determine the transparency of water by lowering the disk into water and marking the depth at which it disappears from view. Distance is measured by equally spaced knots on the rope by which the disk is lowered. Some water bodies have been found to allow the disk to be seen at more than 65 feet; in some, it disappears at one inch.

Volunteers who regularly monitor water quality in Lake Springfield will meet at 10 a.m. Tuesday, July 8, at the boat ramp at the Vachel Lindsay bridge for this year’s Dip-In. Taking part will be Marcia Willhite, chief of the Bureau of Water at the Illinois EPA, and representatives of the City Water Light and Power Department and the IEPA’s Volunteer Lake Monitoring unit.

Water clarity is an important tool is measuring the health of a lake or other water body. Suspended sediments and a proliferation of algal scums and weeds indicate a water body with problems. Cloudy water makes it difficult for some aquatic life to see to feed. Weeds and algae make boating and swimming unattractive or even dangerous. Sedimentation can cover eggs or feeding grounds of some small aquatic creatures, hampering their survival.

Information collected will be submitted for inclusion with comparable results being taken between June 28 and July 13 in the U.S. and Canada.

Additional information about the Dip-In can be obtained on the web at www.dipin.kent.edu/