For Our Lakes & Rivers: Monitoring the Water
Left, students demonstrate taking a secchi disk reading and integrated water sample. Water monitoring is done by volunteers of all ages from students to retirees, and even groups of friends who get together to do water monitoring parties. (Photo courtesy of UW-Extension)
By Krista Olson
Wisconsin is home to over 13,000 lakes, and almost every lake is a special place for someone’s heart.
Unfortunately it isn’t possible for the state of Wisconsin to monitor each of these lakes, so the Citizen Lake Monitoring Network (CLMN) helps fill in the gaps to provide the state with needed data to understand trends. The effort involved in lake monitoring is a minimal, so this month we will look at what a typical CLMN volunteer may do:
Ice On and Off: Recording the “ice on” and “ice off” dates is valuable to show trends in climate change, or changes in the lake itself. It has been noted as a trend that “ice off” dates on Wisconsin lakes are becoming earlier over the last few decades, showing a trend of a warming climate.
Secchi Disk Monitoring: The black and white quartered disk provides information on water clarity, and can show trends of improvement or impairment in water quality. Secchi disk readings are done by lowering a weighted disc, attached to rope, into the water until it disappears from viewing. His measures water clarity, which tends to go though annual cycles of impairment or improvement.
Water Sample Monitoring: Three times a year a water sample is taken to measure the water quality of the lake. The first sampling is done two weeks after “ice off”, and the following samples are taken during the last weeks of June and July. The water samples are taken with an integrated sampler, which is a 6 foot PVC pipe with water stops and handles for sampling. Three pipe samples are taken, and then shipped to state labs in Madison for further testing. The trends of nutrients in the water show if the water body is experiencing an increase of nutrients, and the spring sample helps point to if there is a spring runoff nutrient overload.
Invasives Monitoring: When plants or animals are introduced to a new environment, there is always the risk that the newly- introduced species will overtake the natives and destroy habitat for all. While many fishermen are aware of invasives such as Eurasian Water Milfoil, Rusty Crayfish and the feared Asian carp, there are other future invasives that are first showing up in other states that may make their way into Wisconsin. As invasives spread, new plants such as Water Chestnut, Parrot Feather, and European Frog Bit are showing up in nearby states, and monitoring is needed to keep them from entering Wisconsin lakes. Invasives Monitors will watch a water body for unusual plants or animals, and if a new species is found a sample will be taken to the DNR or an RC&D for review. Early detection and removal is key to keeping an invasive plant or animal from taking over, and it is the watchful eyes of invasives monitors that provide early detection.
If you are interested in becoming a CLMN water monitor, there are many opportunities available. Contact your regional CLMN monitor by finding the correct contact at: http://dnr.wi.gov/lakes/contacts/Contacts.aspx?role=CLMN_EQ