ISSN:
1573-5117
Keywords:
Saline lakes
;
Nodularia spumigena
;
Pyramid Lake
;
phytoplankton periodicity
;
remote sensing
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Magnitude and long-term periodicity of summer-autumn blooms of the nitrogen-fixing cyanobacterium, Nodularia spumigena, were characterized for hyposaline Pyramid Lake, Nevada, from Landsat MSS band 3 film negatives. Predicted lakewide mean chlorophyll a concentrations for Landsat overpasses during the July–October Nodularia bloom season ranged from 27 to 72 mg m−3 with an overall average concentration of 32 ± 7 mg m−3 between 1972 and 1986. Nodularia blooms were usually annual events. Blooms were not observed on Landsat images in only three of 15 years (1973, 1980, 1982) and midsummer calcium carbonate whitings occurred in two of these years (1973, 1980). Magnitude of Nodularia blooms was highly variable among years and ‘very large’ blooms, where maximum mean chlorophyll a concentration exceeded one standard deviation of the 15 year overall mean (〉 39 mg m−3) appeared in 1974, 1975, 1977, 1979, 1984, 1985 and 1986. Very large early-July blooms always occurred during or following years of above average fluvial discharge to Pyramid Lake (1984–1986) and were associated with meromixis produced by the large influx of freshwater. Several problems arise using Landsat remote sensing to estimate magnitude and periodicity of scum-forming blue-green algal blooms. These complications may reduce accuracy and precision of phytoplankton biomass estimates made from Landsat images. Nevertheless, Landsat remote sensing enabled us to quantify relative bloom magnitude with limited collection of ground-based data and at a large-scale temporal and spatial resolution not possible using alternative methodologies.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00026947
