CLWA completes second phase of aquatic weed survey
In August 2017 a team from the Water Quality committee of the CLWA completed the second phase of its comprehensive survey of Crystal Lake to update information on established native submerged plants, monitor invasives like Eurasian watermilfoil that are already present, and look for any new species that may have found their way into Crystal's waters. This year's surface-based investigation was supplemented by drone photography conducted by Zero Gravity Aerial. Both surface and drone components will be used again in 2018 to complete full coverage of Crystal Lake.
The 2017 survey focussed on the south shore and most of the west end of the lake. Less invasive Eurasian milfoil occurs in these areas than was found in the 2016 investigation of the east end of the lake, particularly at Beulah Beach. However, the drone survey showed that Eurasian milfoil is much more extensive than was expected. The survey also found that the most common weed in the lake is Chara.
The 2016 survey identified at least eighty sample sites, with Eurasian or hybrid watermilfoil the most common invasive. This plant was observed to be particularly prevalent around the boat launching sites in Beulah and at Mollineaux Road, which suggests the weeds are being carried from other lakes by visiting watercraft.
The CLWA Aquatic Weed Survey is being conducted under the auspices of the Michigan Cooperative Lakes Monitoring Program and is intended to update a study done in 2008. It aims to compare the amount and type of weeds and determine if beds are beginning or expanding and if treatment is needed. The identification and control of invasive species has been a long-time concern of the CLWA, leading to the construction of the boat washing station at the Mollineaux Road launch site in 2013. Dr. Jo Latimore of Michigan State University, who oversaw the launch of the survey in 2016, commented, "I've never had the pleasure of working with a more organized crew!"
According to CLWA board member Jim Hamp, who led the survey, “Invasive plants and animals can easily out-compete and dominate native communities of plants, fish, mussels and snails, and radically change the populations and health of the ecosystem of the lake. This is already happening in Crystal Lake, and we are working to reverse the impact.”
For more resources on invasive species, go to: http://crystallakewatershed.org/water-quality/invasive-species