In her 2016 master’s thesis research, South Dakota State University biologist conducted the first statewide assessment of South Dakota’s freshwater mussel population. Faltys’s team found live mussels in only a fifth of the 202 survey sites and shells in less than half. Faltys found only 17 of the 36 mussel species previously documented to inhabit South Dakota’s waterways.
Julie Bolding reports in South Dakota News Watch that industrial agricultural pollution is a major factor in this apparent decline in South Dakota’s freshwater mussel population:
Accelerating land-use changes — often tied to expansion of agriculture — lead to soil runoff, sedimentation and non-point pollution from manure, fertilizer and pesticides. Water clouded with clay, silt and other particles, including algae, can affect the fish hosts mussels rely on to reproduce. Increased sediment smothers mussels. Pesticides can poison them. Fertilizer runoff causes excessive algae growth that depletes oxygen.
Thirty-six percent of tested water in South Dakota rivers and streams has excessive amounts of total suspended solids, according to the 2020 South Dakota Integrated Report for Surface Water Quality Assessment prepared by the state. Suspended solids, which can include soil particles, can increase turbidity and water temperatures, decrease oxygen levels and generally degrade conditions for fish and other aquatic life [Julie Bolding, “Decline in Freshwater Mussels an Indicator of Poor River and Stream Health in South Dakota,” South Dakota News Watch, 2022.03.22].
Also contributing to the apparent decline in mussel population and species diversity is disruption of the natural flow of streams and rivers:
After poor water quality come physical barriers. Thousands of impoundments on tributaries restrict the natural volume and velocity of water that mussels need to reproduce. “Even dams as low as 1 meter in height have been found to inhibit the distribution of mussels as they can create unnatural sedimentation and flow regimes as well as cause barriers to fish host locality and movement, thus inhibiting the ability for successful mussel recruitment,” Faltys writes.
Perched culverts and other blockages to mussel larvae movement need to be adjusted so that mussel larvae and host fish can move beyond short stream segments. “It’s important to maintain that connectivity,” says Rich Biske, resilient waters director for the Nature Conservancy in South Dakota, North Dakota and Minnesota [Bolding, 2022.03.22].
Researcher Faltys suggests South Dakota work on restocking mussels and expanding buffer zones to restore their habitat in key waterways:
Faltys says options for conservation could include propagating young mussels of existing species and releasing them into streams with small populations, reintroducing species that once lived in certain streams, restoring mussel populations to historic levels and creating easements that would increase buffer zones to reduce sedimentation.
She identified the Big Sioux, James and Minnesota river basins as areas of high mussel diversity that would be optimal sites for mussel conservation. She recommends focusing on the Whetstone River in Roberts and Grant counties, Bios de Sioux River in Roberts County, Medary and Six Mile creeks in Brookings County, Split Rock Creek in Minnehaha County, Shue Creek in Beadle County, Lone Branch Creek in Hutchinson County, Cottonwood Creek in Jackson County and the James River in Hanson County [Bolding, 2022.03.22].
The Department of Agriculture (and Natural Resources) is trying to complement the state’s buffer strip tax incentive with its own Riparian Buffer Initiative to offer cash payments to get landowners to plant grass along designated streams in the Big Sioux River basin.
We could also preserve the diversity of mussel species by doing more to prevent the spread of invasive zebra mussels, which Bolding reports hog food and cluster on other mussels to prevent them from opening, but cranky Republicans on House Appropriations last month stymied Senate Bill 200, which would have spent $62,500 to build five boat cleaning stations that would have helped keep boaters from spreading zebra mussels. Instead, the Legislature passed Senate Concurrent Resolution 602 to “strongly encourage” the Executive Branch to fight the spread of zebra mussels and other invasive species and to report to the Legislature by August 1 on its “upgrade efforts”. The Legislature did pass a bunch of water project funding bills, including the $600-million Senate Bill 62, so maybe some of that money, which is mostly intended to build water pipes for thirsty communities, can be justified into broader water quality projects that will protect mussels and all the other species that depend on a healthy water ecosystem.
The death of the Missouri River ecosystem in South Dakota began with the European invasion, was accelerated by the Homestake Mining Company and sealed with the construction of the mainstem dams. Lake sturgeon prey on zebra mussels. Diving ducks like the Canvasback, Redhead, Bufflehead, Lesser Scaup and the Common Goldeneye feed on the invasive zebra mussels that have been plaguing the mainstem dams in the Missouri River since at least 2004 but they’re part of over a hundred species at risk to the South Dakota Republican Party.
South Dakota writer, Tom Lawrence calls it part of the “insanity of the Farm Bill.” Real conservatives at the Heritage Foundation have called for subsidy reform for years.
https://www.bhpioneer.com/local_news/danr-water-quality-study-shows-84-lakes-don-t-support-assigned-uses/article_4cec6ab6-a60c-11ec-8b15-7f3abc8ef425.html
I’m surprised SDSU let this research out to the public. I’ve heard from a mom that a daughter’s/son’s research such as this didn’t get published. (I did not double check her statement.) But there was a researcher who presented at the Big Sioux Water Conference a few years ago and was asked about tiling, etc who is no longer employed just like a biofilter expert who we used extensively in our pig fight. I would have wished that manure on tiled ground would have been addressed also. Wouldn’t that be a kick in the stomach to big ag?
Warnings of drought coming from the National Weather Service and US Army Corps of Engineers are prompting farmers to plant less corn. Ethanol being grown for motor fuel is produced by burning diesel fuel. How is that either conservative or sustainable? The number of acres in agroecosystems has tripled since the 1940s but ag practices like tiling have made soils unable to absorb rainfall creating elevated levels of salinity and concentrated animal feeding operations contribute to nutrient runoff.
larry kurtz
“Ethanol being grown for motor fuel is produced by burning diesel fuel.”
Huh? Reference?
Ending America’s dependence on so-called bridge fuels is an idea whose time has come. The Ogallala Aquifer, also called the Great Plains Aquifer, is being depleted at a far faster rate than its recharge flows and nearly all the groundwater sampled from it is contaminated with uranium and nitrates from industrial agriculture.
Nobody farms with gasoline powered equipment.
Mussels are the canary in the coal mine. Once water quality deteriorates its a long, long haul to bring it back to marginally acceptable levels. We are awash in manure and deadly chemicals.
Native species are canaries in thousands of human coal mines just like South Dakota has become.
Most East River lakes are already eutrophic manure holes filled with toxic algae and unable to even support fish populations so the Prairie Pothole Region is becoming increasingly threatened by the encroachment of industrial agriculture but more irrigation means pumping from depleted aquifers mainly recharged by the Prairie Pothole Region.