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  Surface Water and Ecology - Algae  



PhotographBenthic algae, or periphyton, are algae attached to the bottoms of streams as opposed to freely floating in the water. Three types of benthic algal samples may be collected: a Qualitative Multihabitat (QMH) sample, a quantitative Richest-Targeted Habitat (RTH) sample, or a quantitative Depositional Habitat (DTH) sample. Qualitative samples are collected to provide a list of algal species found at a site. Quantitative samples are collected to provide actual abundances of species found in selected habitats at a site and allow computation of measures or metrics. The QMH sample is intended to represent algal species from as many different types of habitats as possible. The RTH sample is intended to represent the habitat with the greatest diversity of species, usually a riffle. The DTH sample is collected from shallow areas along the edges of the stream where sediment has been deposited. Data on species, their abundances, their pollution tolerance and other environmental preferences, allow computation of metrics for water quality assessment in a manner similar to that used for invertebrates and fish. One group of algae, the diatoms, has been used for decades in assessing water quality in the US and around the globe.

Benthic algae samples (RTH and DTH) were collected once annually from the four surface-water trends sites in Cycle II: Popple River , Duck Creek, Lincoln Creek, and Milwaukee River . Samples for RTH, DTH and QMH were collected from these same sites in Cycle I, and an examination of potential trends between Cycle I and Cycle II data may yield valuable information on changes in water quality at these sites.

Low Phase - Cycle II

During low phase (starting in 2005), benthic algal sampling will be limited to one RTH sample collected once annually from the Popple River site.


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Surface Water