02-07-1977 Planning Packet - Laserfiche WebLink

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GcnTal Inforwation .•• AX(a# ar6 sinipla and oftan microscopic plants that grow in lakao* ponds and straaaa. Like tha largar graan plants or "waads" of watara thay aanufactura by photogynthasis tha basic foods on which all aquatic lifa dapands* Algaa also giva off oxygon which halps to aarate tha water, but under conditions of unusually heavy growth may use up oxygen in water, especially at night, to tha detriment of aquatic life* I . • Thera are hundreds of kinds of algae but only a few aver become so abundant bhay are noticed by tha casual observer. Occasionally the kinds producing noticeable growth may become abundant enough to create a nuisance and interfere with use of the water* Such excessive growths are commonly called "blooms", "scums", and "moss". Chemical control of such algal growths is sometimes desirable. Nuisance growths of algae are of three general forms; (1) plankton alrae are minute, mostly microscopic, free-floating plants that cause water to become green and m^ produce blooms and scums; (2) filamentous algae appear as finely divided mosa<%ike tufts on the bottom or as floating masses or scums of hair-like strands, and (3) the muskgrasses typified by Chara which is a coarse, much branched, and often lime encrusted plant with a musky or fishy odor and which grows attached to the bottom* Tiny elliptical floating green pads are not algae but are duckweed. Plants with wide, grass-like or dissected leaves arc not algae but are higher plants or "water weeds". Treatment recommended for algae will usually have no effect on duckweeds and larger water weeds. Use of Chemicals in Water Nuisance growths of algae can usually be controlled by adding chemicals to the water in proper concentrations but such applications may be made only under pexmiit from the Commissioner of Natural Resources. An application form for such a permit cm be obtained by writing to the Technical Services Section, Division of Game and Fish, Department of Natural Resources, 390 Centennial Building, St. Paul, Minnesota, 55155* Chemicals for algae control should not be purchased for use on public waters without first having obtained a permit or consulting with the Department of Natural Resources* The costs of algae control projects muj»t be paid by the benefited property owners. However, Minnesota Statutes 1')d1, Section lll.ol authorizes cities, villages, boroughs and towns to levy taxes for this purpose. Control of Plankton Al»ie Plankton algae are ol many kinds’but those causing blooms in summer are usually blue-green algae. Blue-greens arc a natural growth of fertile waters but sometimes become overabundant because of man*s activities. These may impart a uniform blue- green or greenish color to the water or appear scattered through it as tiny green flakes or dots. Guch flakes or dots are colonics of microscopic algae. The sudden appearance of a bloom means that algal cells have risen to the lake surface and accumulated in the upper iew foet of water. If very abundant, blue-green alrac may f- ' meeurnttlmte Growth tho wator. from adjace carp and bv Lorgoi i^ore weed algae may i Plank’ for not mo: sulphate d Amounts us treated* is greatoe of copper where the used in wc per acre « upon the li The coppei ctable affli copper ca: adkaline possible. Ther method it Commercia scatterin smaller 1 use the \ (1) (2) (3) (4!