User:Rugtata/Oligosaprobe

Oligosaprobes are organisms that inhabit oligosapropic zones, defined as clear freshwater bodies, with no or only slight organic matter pollution and high dissolved oxygen (DO) content; this characteristic stems from decomposition of organic runoff with high biochemical oxygen demand, decreasing concentrations of dissolved oxygen. This is further refined as streams whose "oxidation and mineralization processes are complete, and the organic content is low." Such classification derives from analysis of the pollutive impact from untrreated wastewater.

Common aquatic communities that indicate that a water zone is oligosaprobic are the chlorophyta, (Draparnaldia gromerata), the Rhodophyta community, the Vaucheria sessilis community, and the Phormidium innudatum community. Their presence is attributable due to the presence of pollutation-sensitive bacterial species thriving alongside other baterical species more adapted to pollution, and competing for limited organic pollutants in oligosaprobic waters.

Although classifications define oligosaprobic water to be only slightly polluted by organic matter, varying methods of classifying bodies of water as oligosapropic exist. One methodology, based on DIN 38410, places the saphobic index at 1.0 to 1.5 and defines the following:

"Water sections with pure water that is always more or less saturated with oxygen and low in nutrients; low bacteria content; moderately densely colonised, mainly by algae, mosses, flatworms and insect larvae; if cool in summer, spawning grounds for salmonids."

Another method is based on the ASPT score (Average Score Per Taxon), calculated with the BMWP  score divided by  the number of families counted for the BMWP score. There, the score's range to deem a body of water oligosaprobic is generally somewhat below the number of families tallied for a particular study.