Minnesota lakes – Aquarius-Systems

Lake Minnewawa Restoration Shows Long-Term Benefits of Harvesting

Fri, 22 Dec 2023 19:20:27 +0000

In the 1970’s Lake Minnewawa in Minnesota was so choked with weeds that residents could no longer enjoy the lake as they once had. The water clarity and the phosphorous levels were awful. People would pull their docks out of the water in July because boating was impossible.

Save Minnewawa Association was formed in 1977 and they purchased their first aquatic vegetation harvester in 1982. Since the harvester has been in use, not only have the amount of weeds decreased, but the water clarity has significantly increased.

A big reason for this is because there are fewer weeds dying in the lake and decomposing in the bottom of the lake. Also, the weeds contain a huge amount of phosphorous which is being removed along with the weeds. The more phosphorous in a lake, the more algae growth, therefore the lower the water clarity.

The board has heard the suggestion of controlling the weeds by using chemicals instead of the weed harvester. The cost of the chemicals is very prohibitive though. It was $250,000 dollars and the lake had to be treated twice a year for the first 5 years; a price tag of a half million dollars. Compared to approximately $25,000 a year it takes to run the weed harvester.

Starry Stonewort Threat Growing in Minnesota Lakes

Tue, 20 Sep 2022 21:03:45 +0000

It’s only found in 14 Minnesota lakes at this point, but starry stonewort has the potential to cause lots of harm, and fast.

Recent research shows that the macroalgae has the potential to be the high-impact invader in Minnesota lakes that many already fear it is. It warrants the high prioritization that public agencies and many in the public are giving it.

Those are the conclusions of Carli Wagner, a graduate student with the Minnesota Aquatic Invasive Species Research Center, an interdisciplinary research center at the University of Minnesota.

Climate Impacts Starry Stonewort Spread in Minnesota Lakes

Thu, 02 Dec 2021 22:31:09 +0000

Starry stonewort was first discovered in Minnesota waters in Lake Koronis in 2015. It’s now found in 19 Minnesota waterbodies. Lake Koronis is helping researchers understand how a changing climate may influence this invasive and how we can better manage it.

Overall, the research showed year-to-year variability in the total biomass of starry stonewort. There were good years and bad years for it. Warm summers adversely affected its total biomass, while warmer winters appear to have allowed it it to expand its coverage area, according to the research.

While warmer summer temperatures could reduce the total biomass, the area of a lake bottom covered by starry stonewort tended to increase in the summers that followed warmer winters. In this way, water winter temperatures could be associated with greater spread of starry stonewort.

Much more needs to be learned, but the data can help find the most effective methods for controlling the invasive plant. In many of the infected lakes, Koronis included, mechanical harvesting and herbicide applications are being used to manage it.

Road Salt Helps Drivers but Harms Waterways and Drinking Water

Sun, 05 Feb 2017 18:31:07 +0000

Portland’s first snowstorm of the winter storm season hit mid-day prompting thousands of people to head home early. Unfortunately, roadways were clogged for hours leaving many to abandon their cars. Cautious motorists decided to stay home from work when the second snowstorm that left roadways icy for days. Portland is now looking at adding road salt to their arsenal to make road ways safer.

The city is concerned with the damaging effects of road salt. It would ultimately get washed into storm drains which flow to a sewer treatment plant. Will the salt corrode old metro-area pipes? It affects the roads, the steel in the bridges and the concrete and it affects your car. And, the salt that stays on the roads will eventually get washed into the environment.

Minnesota is beginning to see some of the environmental effects of road salt use. In the Twin Cities metro area, the level of salt (chloride) in 39 surface waters now exceeds water quality standards. An additional 38 surface waters are almost above the standard and many others remain untested. Data shows that salt concentrations are continuing to increase in both surface waters and groundwater across the state.

The fact is that it only takes one teaspoon of road salt to permanently pollute 5 gallons of water. Once in the water, there is no way to remove the chloride. At high concentrations, chloride can harm fish, aquatic plant life, groundwater and drinking water supplies.