didymo the fucking – or ‘rock snot’

The Michigan Departments of Environment, Great Lakes, Energy, and Natural Resources confirmed a report of didymo, a pesky freshwater algae, along the upper Manistee River in Kalkaska County. Also known as rocky mucus despite its coarse and woolly texture, didymus can grow into thick mats that cover the river bed.

The discovery of the Manisti River represents the first discovery of didymos in the Lower Peninsula. In 2015, extensive mats of didymo were found on the Michigan side of the Saint Mary River near Sault Ste. Marie on the Upper Peninsula.

“Didymo can be attached to fishing gear, wading gear, and other hard surfaces and transported to new waterways,” said Bill Keeper, an aquarist in EGLE’s Water Resources Division. “With each new discovery, it becomes important for people who fish, wade or boat to clean their boats and equipment, including waders, after each use.”

Anglers who have encountered infested streams in the western or eastern United States know that rocky mucus is more than just a nuisance.

“Dedemo has the potential to be a nuisance species in Michigan’s cold-water fisheries,” said Samuel Day, a water quality biologist for the Little Traverse Bay Bands of the Odawa Indians. “In contrast to the harmful algal blooms that plague the Great Lakes regions due to warm temperatures and excess nutrients, didimo flowers form in cool, low-nutrient streams that most people generally consider to be a wonderful, native habitat for trout. Didimo can become a problem when it thrives, clogging riverbeds and reducing It is a habitat of large invertebrates, which is an important food for fish.”

Didmo Mats in the River Manistee

Day, who studied didymo in the southeastern U.S. streams as a graduate student at Tennessee Technological University, discovered an algal bloom between the Three Mile Bend Landing and Sharon’s Road Bridge on the Upper Maneste River while fishing with a friend on November 14. Samples, his findings were sent to EGLE’s Water Resources Department, and then verified by Julian Heinlein, an aquatic ecologist and algal taxonomist at Great Lakes Environmental Center, Inc.

Since 2015, Michigan’s Invasive Species Grant Program has supported researchers at Lake Superior State University’s Center for Freshwater Research and Education in an extensive study of the occurrence of didymus in the waters of the St. It is increasing – a phenomenon that is observed all over the world.

The discovery of the Manistee River suggests that didymo’s distribution in Michigan waters may be more widespread than previously expected. LSSU’s ongoing efforts will help guide didymo’s research and management needs statewide.

Didymo, a microscopic diatom (a single-celled alga), may be present but not detected in some waterways until changes in water quality cause it to “bloom” or develop long stems, making them visible on hard surfaces downstream. Understanding the changes that lead to flowering may also help combat the species’ negative environmental influences.

Currently, there are no effective ways to eradicate didymosa once it has been established in a river or stream. To prevent the spread of didymo and other invasive aquatic species to new locations, it is essential for recreational users to clean, dry and dry the waders, equipment, and boats when leaving a stream.

  • Clean by removing mud and debris from all surfaces.
  • Drain water from all wells, wells and reservoirs.
  • Dry equipment for at least five days or sterilize it with hot water or a diluted bleach solution.
Amplification of cells and stalks Didymo

“Over the next few months, we will be working with partners to ensure that invasive aquatic species are tagged at access sites and spread the message of cleanup, drainage, and drought to the fishing community,” Kieber said. “We want to encourage local fly shops, fishing guides, and conservation groups to help by emphasizing the importance of decontamination equipment and equipment to protect these waters from didymo and other invasive aquatic species.”

If you notice a didemo in the water, either as small patches the size of a cotton ball or thick blankets of rope-like threads flowing in currents, take photos, note the location and report it using the Midwest Invasive Species Information Network, available online at MISIN.MSU.edu or as a phone app Intelligent Downloadable. The MISIN smartphone app will take a GPS location point if an on-site report is given; It will also allow you to upload photos with a report.

Find more information about didymo and how to get to know him at Michigan.gov/Invasives.

The Michigan Invasive Species Program is implemented collaboratively by the Department of Environment, Great Lakes and Energy, the Department of Natural Resources, and the Department of Agriculture and Rural Development.

/note to editors: The accompanying images are available below for download. Here are suggested captions and image credit information:

Hook: Didimo caught from the upper Manisti River with fishing gear. Image courtesy of Samuel Day, LTBB.

Slide: View of Didmo’s cells and stems through a microscope. Image courtesy of Samuel Day, LTBB.

Manistee: Didymo appears on pebbles in a dark brown Manistee River. Areas where thick growth peels off appear woolly and light, revealing a clean substrate underneath. Image provided by EGLE.

Threads: Didymo’s threads on a substrate in Saint Mary’s River. Image provided by EGLE.

Cell: A magnified single didmo cell. Image courtesy of Julianne Heinlein, Great Lakes Environmental Center, Inc. /

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