Saprobity

In 1902, the botanist R. Kolkwitz and zoologist M. Marsson proposed a system of biological analysis of water quality, which later became classical. The researchers proposed to give the two main groups of representative antagonist organisms the name saprobionts (from the Greek. Sapros - rotten) for the inhabitants of wastewater and katarobionts (from the Greek. Katharos - clean) for organisms that inhabit exclusively pure waters. By saprobity, the authors understood the ability of organisms to develop with a higher or lower content of organic pollutants in water. In 1908-1909 Kolkwitz and Marsson published extensive lists of representative plant and animal organisms, which were subsequently replenished many times and updated. ^[2]

Saprobionts were divided into three groups:

• Organisms of wastewater proper - polysaprobionts (p-saprobes)
• Organisms of heavily polluted waters - mesosaprobionts (two subgroups - α-mesosaprobes and β-mesosaprobes)
• Lightly Polluted Organisms - Oligosaprobes (o-saprobes)

To assess the degree of pollution of water bodies with organic substances, the authors established four pollution zones: poly-, α-meso, β-meso and oligosaprobic.

• The polysaprobic zone is characterized by an abundance of unstable organic substances and products of their anaerobic decomposition, a significant amount of protein compounds. Free oxygen is almost absent, as a result of which biochemical processes are reducing in nature. Hydrogen sulfide, carbon dioxide, methane, ammonia accumulate in water. The main population is saprophytic bacteria , the number of which reaches many hundreds of millions of cells in 1 ml of water. The number of species that live in polysaprobic waters is small, but they develop in huge numbers.
• The α-Mesosaprobic zone is close to polysaprobic in the nature of biochemical processes, but free oxygen is already present here; hydrogen sulfide and methane are absent.
• The β-Mesosaprobic zone differs from the previous ones by the predominance of oxidative processes over reduction ones. Due to the intense photosynthesis of numerous plants in summer, the waters are oversaturated with oxygen.
• The oligosaprobic zone is completely free from contamination and is usually oversaturated with oxygen. The population is most diverse in terms of species, but quantitatively significantly poorer than in previous zones.

From the above characteristics of the saprobity zones, it follows that as the water quality deteriorates, the taxonomic composition of hydrobionts becomes poorer, while the number of individual species increases and can be huge in the polysaprobic zone.

The current system of indicator organisms is not universal for all continents; it is most applicable in the European part of the Palearctic . Moreover, the original meaning of the term “saprobity”, as the ability of organisms to dwell in waters polluted with organic substances, has been lost due to the widespread prevalence of industrial pollution over domestic wastewater, which was originally used to construct the Kolkwitz-Marsson system, but despite this, the term continues to be used in the sense of general pollution.

In Russia, the Pantle-Bucca saprobity index is used, calculated by the formula S = Σ (sh) / Σ (h), where s is the indicator significance of the form (s: = 1 - oligosaprobes, = 2 - alpha-mesosaprobes, = 3 - beta- mesosaprobes, = 4 - polysaprobes); h is the relative number of individuals of the species (h: = 1 - random finds, = 3 - frequent occurrence, = 5 - mass development). At S = 4.0-3.5 - polysaprobic zone, = 3.5-2.5 - mesosaprobic zone, = 2.5-1.5 - mesosaprobic zone, = 1.5-1.0 - oligosaprobic zone, = 0.5-0 - xenosaprobic waters.

V.Yu. Zakharov in his Methodological Guide (1997) provides a calculation of saprobity using the modified Pantle-Bucc formula for several series of observations (for example, saprobity indices for several groups of organisms from a single collection point):

Goodnight and Whitley Index. Goodnight and Whitley on the sanitary condition of rivers are judged by the ratio of oligochaetes to other bottom dwellers: a river in good condition - oligochaetes is less than 60% of the total number of all bottom organisms, in a dubious state - 60-80%, heavy pollution - more than 80%.

Zaner (1964) assesses water quality by the absolute numbers of Tubifex tubifex and species of the river. Limnodrilus:

Bioindication

• R. Kolkwitz, M. Marsson: Ökologie der pflanzlichen Saprobien . In: 'Berichte der Deutschen Botanischen Gesellschaft,' Band 26a, S. 505-519. ( 1908 ).
• R. Kolkwitz, M. Marsson : Ökologie der tierischen Saprobien. Beiträge zur Lehre von der biologischen Gewässerbeurteilung . In: 'Internationale Revue der gesamten Hydrobiologie und Hydrographie,' Band 2, S. 126-152. ( 1909 ).
• Galtsova V.V., Dmitriev V.V. Workshop on water ecology and monitoring the status of water systems. St. Petersburg, 2007