Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)


Wildlife Management


Concentrations and loads of nutrients transported through the Lake Poinsett system were monitored from April 1, 1970 to April 1, 1971. An annual 2.07x 10~ m3 surface discharge into Lake Poinsett transported 1.66 x 104 kg (PO4) phosphorus, 1.28 x 104 kg nitrate nitrogen, and 3.90 x 104 kg organic carbon. The Big Sioux River-Dry Lake system contributed 63% of the phosphorus, 45% of the nitrate nitrogen, and 43% of the organic carbon load. The remaining portion entered Lake Poinsett from the Lake Albert drainage. Of the annual load of nutrients transported into Lake Poinsett, 33% of the nitrate nitrogen load, 40% of the organic card load, and 70% of the phosphorus load was retained by the lake or lost by ways other than water discharge. Average annual phosphorus concentrations decreased through the system from 1.9 mg/l (PO4) in the Big Sioux River of 0.22 mg/l (PO4) in Lake Poinsett. Soluble inorganic phosphorus constituted 71% of the total phosphorus which entered Lake Poinsett and comprised 50% of the phosphorus in the lake. The average annual concentration of nitrate nitrogen in Lake Poinsett was 0.52 mg/l. Average annual organic carbon concentrations increased through the system from 12.27 mg/l in the Big Sioux River to 18.40 mg/l in Lake Poinsett. Nutrient concentrations in Lake Poinsett, relative to the needs of aquatic plants in the lake, are in a state of super-saturation. The advanced degree of eutrophication in Lake Poinsett is ascribable to the large annual nutrient load entering and retained by the lake.

Library of Congress Subject Headings

Marine ecology -- South Dakota -- Lake Poinsett
Lake Poinsett (S.D.)


Includes bibliographical references (pages 61-62)



Number of Pages



South Dakota State University


No Copyright - Non-Commercial Use Only