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Blue-green algae toxicity in Black Lake, Kootenai County, Idaho. Research technical completion report Item Info

Increasing occurrences of explosive growths or blooms of blue-green alqae in lakes throughout the western United States have been linked to recreational use, sewage inputs, and non-point runoff associated with agriculture and grazing. In certain instances these blooms produce a toxin which can be lethal to fish, aquatic invertebrates, mammals and humans. Black Lake in northern Idaho has experienced massive late summer and fall growths of a toxic algae, Nostoc commune. At times, demonstrated fatal toxicity to cattle and small mammals has resulted in three of the last four years. Since little is known of the exact environmental conditions required to cause toxicity, environmental and phytoplankton parameters were monitored throughout the lake durinq summer and fall, 1984. Although conditions seemed favorable, and other blooms were intermittent through the summer-fall 1984, Nostoc did not develop to bloom proportions and toxicity did not occur. Algal assay results showed that algal growth potential ranged in the very productive range of -1 9.60 to 12.16 mg dry weight 1 /14 days for the late summer-early fall period. The limiting nutrient switched from phosphorus to nitrogen during the fall months, also indicating the potential for a Nostoc bloom. All indicators showed that Black Lake was highly productive in 1984 despite the absence of a toxic Nostoc bloom. Water transparency ranqed from 0.8 to 3.4 m, averaging 1.2 m from June to October. pH values went as high as 8.2, with the total absence of CO2 in some of the littoral areas. Dissolved oxygen values were at super saturated levels throughout most of the sampling reqime. Diatoms (Fragilaria sp., Melosira sp., and Asterionella sp.) dominated the phytoplankton composition with Nostoc only showing up in early August. Chlorophyll 11 a11 values correlated with phytoplankton trends, with highs of 15 to 31 mgl-1, and lows of 0 to 5 mgl-1. The fact that Black Lake is clearly eutrophic, and that the potential for a blue-green bloom was present but did not materialize, may possibly be explained by two factors ... climatoloqical trends and stratification pattern. The absence of a well developed hypolimion along with excessive cloudiness and lack of a protacted calm, bright, and warm fall may have accounted for the lack of a toxic bloom in Black Lake during 1984.

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Title:
Blue-green algae toxicity in Black Lake, Kootenai County, Idaho. Research technical completion report
Authors:
Kann, Jacob; Falter, Michael C.;
Date Created (ISO Standard):
1985-09
Description:
Increasing occurrences of explosive growths or blooms of blue-green alqae in lakes throughout the western United States have been linked to recreational use, sewage inputs, and non-point runoff associated with agriculture and grazing. In certain instances these blooms produce a toxin which can be lethal to fish, aquatic invertebrates, mammals and humans. Black Lake in northern Idaho has experienced massive late summer and fall growths of a toxic algae, Nostoc commune. At times, demonstrated fatal toxicity to cattle and small mammals has resulted in three of the last four years. Since little is known of the exact environmental conditions required to cause toxicity, environmental and phytoplankton parameters were monitored throughout the lake durinq summer and fall, 1984. Although conditions seemed favorable, and other blooms were intermittent through the summer-fall 1984, Nostoc did not develop to bloom proportions and toxicity did not occur. Algal assay results showed that algal growth potential ranged in the very productive range of -1 9.60 to 12.16 mg dry weight 1 /14 days for the late summer-early fall period. The limiting nutrient switched from phosphorus to nitrogen during the fall months, also indicating the potential for a Nostoc bloom. All indicators showed that Black Lake was highly productive in 1984 despite the absence of a toxic Nostoc bloom. Water transparency ranqed from 0.8 to 3.4 m, averaging 1.2 m from June to October. pH values went as high as 8.2, with the total absence of CO2 in some of the littoral areas. Dissolved oxygen values were at super saturated levels throughout most of the sampling reqime. Diatoms (Fragilaria sp., Melosira sp., and Asterionella sp.) dominated the phytoplankton composition with Nostoc only showing up in early August. Chlorophyll 11 a11 values correlated with phytoplankton trends, with highs of 15 to 31 mgl-1, and lows of 0 to 5 mgl-1. The fact that Black Lake is clearly eutrophic, and that the potential for a blue-green bloom was present but did not materialize, may possibly be explained by two factors ... climatoloqical trends and stratification pattern. The absence of a well developed hypolimion along with excessive cloudiness and lack of a protacted calm, bright, and warm fall may have accounted for the lack of a toxic bloom in Black Lake during 1984.
Subjects:
cyanophyta phytoplankton toxicity
Location:
Black Lake; Coeur d'Alene River
Latitude:
47.45
Longitude:
-116.66
Collection:
Coeur d'Alene Basin
Series:
Water for Idaho
IWRRI number:
198508
Rights:
Rights to the digital resource are held by the University of Idaho. http://www.uidaho.edu/
Publisher:
University of Idaho
Contributing Institution:
University of Idaho
Type:
Text
Format:
application/pdf
Cataloger:
wbv
Date Digitized:
2012

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Preferred Citation:
"Blue-green algae toxicity in Black Lake, Kootenai County, Idaho. Research technical completion report", Idaho Waters Digital Library, University of Idaho Library Digital Collections, https://www.lib.uidaho.edu/digital/iwdl/items/iwdl-cda_kann_1985.html
Rights
Rights:
Rights to the digital resource are held by the University of Idaho. http://www.uidaho.edu/
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