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The Prevalence of Cyanobacteria: A historical perspective from lake sediment

Publication number Date Published
19-03-011June 2019
VIEW NOW: The Prevalence of Cyanobacteria: A historical perspective from lake sediment (Number of pages: 13) (Publication Size: 778KB)

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Author(s) Hobbs, W. and S. Wong
Description Anderson Lake in Jefferson County, Washington experiences annual cyanobacteria blooms that produce high concentrations of the neurotoxin, anatoxin-A. As a result, the lake has been closed over the summer for recreation each year since cyanotoxin monitoring began in 2006. The goal of this project was to understand whether cyanobacteria have been a dominant part of the lake phytoplankton historically. We collected a lake sediment core, established sediment ages using radioisotopes, and analyzed the sediment intervals for fossil algal pigments.

The pigment analysis recorded a diverse cyanobacteria community extending back to at least the mid-1700s. Measured pigments in the sediment representing filamentous (canthaxanthin) and colonial cyanobacteria (myxoxanthin), in addition to general cyanobacteria pigments (zeaxanthin and echinenone), were compatible with observations of modern cyanobacteria blooms. The accumulation of cyanobacteria pigments increased dramatically from ~1900–1970 while there was farming occuring on the shore of the lake. In 1969 a state park was established around the lake and within ~10 years the cyanobacteria productivity had returned to historical levels. This decreasing trend in cyanobacteria productivity (rate of production/accumulation) could be in response to reduced nutrient inputs once agricultural activities ceased and/or hydrologic alteration of the lake outlet due to construction of a road just prior to when the park was established.
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Keywords sediment sampling, sediment core, toxin, toxics, toxics monitoring, lakes, sediment, lake, cyanobacteria, algae, cyanotoxin, pigment
WEB PAGE Toxics studies
DATA Environmental Information Management (EIM) #WHOB008


Quality Assurance Project Plan: Prevalence and Persistence of Cyanotoxins in Lakes of the Puget Sound Basin