MOSCOW, December 28. /TASS/. Experts of the Russian Academy of Sciences' Siberian Branch following a biodiversity expedition offer new methods to assess impacts on the Arctic waters - not by changes in biomass, but by indicators living in the waters, the expedition's press service told TASS.
"The anthropogenic impacts on the Arctic waters must be assessed not by biomass rates or even by its decline, as it keeps growing, but by the species diversity, by indicating species. The current methods to calculate damage to water biology resources are based on damage compensation from declining biomasses," the press service quoted Mikhail Gladyshev, Deputy Director of the Institute of Biophysics (the Russian Academy of Sciences' Siberian Branch) as saying.
The expedition participants have identified what species could be indicators of significant impact around Norilsk. Their presence means the ecology situation is bad and requires rehabilitation works. The experts have also identified reference species, which, if appear after rehabilitation works, prove those works were successful, the press service added.
Arctic waters contain little feed and are low-productive. They are known for low biomass and small reproduction at all food chain links - from microalgae to fish, scientists said. However, results of the studies, which began in the early 21st century, show that heavy metals pollution of Arctic lakes may cause the effect, where microalgae and other food chain links have higher productivity and biomass keeps growing.
"Clearly, in analyzing any ecology damage and, most importantly, rehabilitation options, we must rely not on the biomass amount, but on quality specifications of the water system, namely on the species structures as a biodiversity component," the scientist said. "In other words, scientists should identify the organisms which provide growth and development of the unique Arctic fish species, which have the most valuable nutritional properties for humans and which are the golden gene pool for aquaculture."
The unified system of contaminants' allowable safe limits for all the Russian climate zones does not mind the specifics of Arctic lakes on the Taymyr Peninsula. Those lakes are located in a specific ore bearing geology zone with the naturally high reference shares of heavy metals in the water. These levels are much higher than the allowable limits for fishery reservoirs, the press service said.
In assessing impacts on such lakes, scientists suggest using not chemical limits, but biological indicators, or rather indicating species, which need to be identified for every ecoregion.
Most valuable fish
Arctic lakes, which do not have much fish, need to be assessed in terms of species and ascending to them food chain links, the scientists insist. Boganida char (endemic to Russia), which is called "the most useful fish in the world", was chosen as a standard. This fish contains a record-high amount of polyunsaturated omega-3 fatty acids. These substances are responsible for the cardiovascular and nervous systems, skin's youth and beauty, for prevention of brain degenerative processes and for prevention of obesity.
Boganida char is found only in the protected Dog Lake on the Taymyr Peninsula. Fishing is outlawed there. At the same time, there are quite successful projects for breeding Boganida char in aquaculture.
The food chain link to the "most useful fish in the world" is planktonic crustacean, while the most undesirable inhabitant is planktonic rotifer.
The basic biodiversity survey continues the work, which the Norilsk Nickel Company (Nornickel) and the Russian Academy of Sciences’ Siberian Branch began in 2020. Since the Great Norilsk Expedition, this work has extended into another three regions. The survey’s purpose is to identify Nornickel’s impact zones and to assess biodiversity in areas of Nornickel’s operations. The research results will be used in building out a corporate biodiversity management system and biodiversity monitoring and conservation programs.