The Department of Agriculture (and Natural Resources) and Game Fish and Parks put out a reminder last week of Harmful Algal Blooms in several South Dakota lakes. Algae on lakes doesn’t just smell bad; it can produce microcystin, toxins from the decay of blue-green algae that can mess up your liver and kill your dog.
DA(NR) says algae bloom usually in July through September in “nutrient-enriched” lakes. Such is the term we use for ag-industrial pollution in the form of poorly applied chemical fertilizer and uncontained cow poop as “nutrients” that “enrich” our public waters.
The green-and-gold medal for nutrient enrichment so far this year goes to Lake Mitchell, where, according to the state’s supercool interactive map of Harmful Algal Blooms, a July 11 water quality test found 365 micrograms per liter of microcystin. The maximum allowable level of microcystin is 8 micrograms per liter.
Lake Madison gets silver with 115 µg/L on 7/14, just edging out bronze-medalist Mina Lake, which posted 114 µg/L on 6/30.
Eight lakes have blown hot for microcystin this summer and earned Harmful Algal Bloom notices. Here’s the full list with test dates and date of HAB notice:
- Lake Mitchell: 365 µg/L (tested 7/11, notified 7/25)
- Lake Madison: 115 µg/L (7/14, 8/17)
- Mina Lake: 114 µg/L (6/30, 7/25)
- Lake Hendricks: 86 µg/L (7/15, 8/17)
- Lake Herman: 66.8 µg/L (8/18, 8/27)
- Beaver Lake: 18.7 µg/L (7/29, 8/9)
- Lake Traverse: 16.3 µg/L (7/15, 8/17)
- Lake Poinsett: 9.9 µg/L (8/22, 8/30)
Congratulations to Lake County on being the only county to win two Harmful Algal Bloom notices this summer! Be sure to thank your local providers of all that nutrient enrichment for making these special notices possible.