Saprobic System

Abstract

In regard to the bioactivity of waters, the saprobity represents the sum of all metabolic processes that are in contradiction to primary production (sapro-, a prefix meaning ‘decayed’ or ‘rotten’, from Greek sapros meaning ‘putrid’). In simple terms, saprobity is a biological state of the waters induced by pollution of water with decomposable organic substances. Intensive decomposition (decay) processes result in lower oxygen contents, which can be tolerated by organisms to a different extent. Consequently, different degrees (intensities) of pollution give rise to different biocoenoses. The saprobic system is used to evaluate the degree of such water pollution by means of a taxonomic and quantitative analysis of all components of the respective biocoenosis from prokaryotes, lower algae, and protozoans to higher plants and vertebrates (mostly fishes). Assigning a locality to the respective class of saprobity is based on a concrete value of the saprobic (also saprobe, saprobial) index. The saprobic index is most frequently expressed by the following formula: S = ∑ i = 1 n A i ⋅ s i ⋅ g i ∑ i = 1 n A i ⋅ g i where i is a taxon, n represents the number of taxa, A i is the abundance of a taxon found or collected, s i equals the saprobic value of the taxon in question, and g i is the indication weight of the taxon.