Data will be available in open file reports within a year of collection. Data are also placed in Division databases or databases associated with the Ecosystem Program when the databases are available. If the periphytic algae is attached to submerged aquatic plants, the plant stems are cut and the whole unit of plant and periphytic algae is collected. Periphyton samples are air-dried in the laboratory in a laminar flow hood to maintain a stream of filtered air across them. Whole samples from each site are ground and aliquants are removed for analysis.
Total mercury is determined by cold vapor absorption spectroscopy.
Methylmercury and other organomercury compounds are extracted using supercritical fluid carbon dioxide and quantitated using liquid chromatography with electrochemical detection. No warrantees are implied or explicit for the data.