Bad news for people, fish
Fly from Grand Forks to Minneapolis and notice the color of the hundreds of lakes en route. Many are blue and clear. Others are bright green, tainted by slimy surface layers of algae. The former, of course, is preferred, but the latter is becoming more common. Across the United States, algae woes are plaguing formerly clear lakes, many of which are heavily used for recreation and as a source for municipal drinking water. Among the latest is Lake Minnewaska, near Glenwood, Minn. The bloom on Minnewaska evidently isn’t widespread, and is just limited to a 1.5-acre area near the marina. But the algae — this variety is starry stonewort — can form dense mats that interfere with aquatic life and recreation. In south-central South Dakota, Lake Mitchell was besieged this summer by thick, slimy algae. It’s a stinky, gross mess and prompted health officials to issue warnings to recreational users of the lake. There, it’s annual occurrence. In Kansas, the Department of Health and Environment issued a public health warning this summer for at least 10 lakes due to harmful algae blooms. In New York, algae blooms have been reported on 113 lakes, ponds and rivers. Last year, the St. Lucie River in Florida was caked with a thick mat of algae, sparking national news coverage. The list could go on and on. The cause? Generally, it’s manmade — nutrients from human activities drain into watersheds and collect in slow-moving or still areas of water. Often, the cause is agricultural practices, from farm chemicals running off erodible land to livestock waste infiltrating watersheds. Sometimes, it might be caused by disrupting the natural flow of streams and rivers. It also can be caused by regular homeowners who live alongside water. The fertilizers and other chemicals they put on their lawns sometimes run directly into the water, feeding algae and promoting the blooms. And it can be caused from city waste — streets, commercial runoff, construction sites and the like. There are a few easy solutions. Waterside homeowners must understand the ramifications of the chemicals they use on their lawns and gardens, and local ordinances can help stem the flow of waste from cities into streams, rivers and lakes. Some groups add chemicals, such as alum, to combat algae growth, but that isn’t always effective. The best long-term solution — which is more time-consuming, costly and controversial — is better land management, including planting vegetative buffer strips between farmland and drainage areas and attention to reducing environmentally dangerous runoff. In Mitchell, S.D., city leaders have commissioned an outside entity to come study what, exactly, can be done about the problem. That initial step alone is costing more than $70,000, and more money — probably a lot more money — will be needed to actually begin a remedy, without a guarantee it will work. Yet without such steps, algae will continue to be a problem — in North Dakota, South Dakota, Minnesota and beyond — and that’s bad news for lakes, streams, people or wildlife.