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THE SUMMER STANDING CROP OF SUBLITTORAL AND PROFUNDAL BENTHOS IN LAKE ITASCA, MINNESOTA 1
Author(s) -
Cole Gerald A.,
Underhill James C.
Publication year - 1965
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.4319/lo.1965.10.4.0591
Subject(s) - profundal zone , standing crop , fauna , littoral zone , eutrophication , benthos , environmental science , ecology , chironomus , biomass (ecology) , hydrology (agriculture) , biology , chironomidae , geology , larva , benthic zone , nutrient , geotechnical engineering
Lake Itasca, Minnesota, is eutrophic with a clinograde oxygen profile. The profundal and sublittoral bottom fauna is dominated by Chironomus plumosus and Chaoborus punctipennis. Procladius sp. and Palpomyia sp. are next in abundance. Pisidium and oligochaetes, especially, are rare. From 27 Ekman dredge samples taken from depths of 5.5–10.2 m in the north arm during the period 10–22 July 1964, a total macrobenthic fauna of 16,165,300/ha in the sublittoral zone and 14,843,570/ha in the profundal zone was estimated. The total formalin weights were 418.8 kg/ha and 265.3 kg/ha in the sublittoral and profundal zones, respectively; for the entire area sampled this amounted to 300.3 kg/ha. The peak of the biomass was 567.5 kg/ha at the sublittoral‐profundal boundary. Over 90% of the weight was contributed by C. plumosus. Lake Itasca may be the third richest lake in the United States in bentbic standing crop.