TASS, December 25. Results of the survey of insects and invertebrates, living on the bottom of reservoirs, show significant oil contamination in the Bezymyannyi Brook, the Daldykan and Ambarnaya Rivers only near the power plant in Norilsk, where fuel spilled in May, the Great Norilsk Expedition, organized by the Russian Academy of Sciences’ Siberian Branch, said in its final report.
“The presence and domination at all the test stations, with the exception for the Bezymyannyi Brook, the Daldykan and Ambarnaya Rivers, of larvae of caddisflies, chironomids, freckles and amphipods, which normally would disappear after an oil contamination, proves there has not been significant oil contamination of those aquatic ecosystems,” the report reads. “On the contrary, the domination of oligochaetes, registered in the Bezymyannyi Brook, the Daldykan and Ambarnaya Rivers, is absolutely similar to well-known consequences from oil spills and thus proves the power plant’s accident did have an impact on the bottom communities in those rivers.”
The expedition’s participants have taken 13 samples of bottom sediments. Soils with signs of oil pollution are characterized by a poor species composition with a high number of forms that are resistant to pollution, and in case of a strong contamination the entire community is affected, the scientists said.
“The hydrobiology studies, conducted as the pollutants were coming, allow us to assess the ecosystem’s stability under stressful conditions, to identify self-purification processes,” the experts said. “In the studied water bodies, specialists have found 36 species of higher-ranking invertebrates, which are widely represented in the Arctic.”
In bottom communities the dominating role remains with representatives of dipterous insects, which have more opportunities for settlement during the ground-air stage of development. The greatest species diversity was observed among dipterous insects of the Chironomidae family. There are four groups of the Oligochaeta organisms, three groups of mollusks, two of larvae of caddisflies. The remaining groups of invertebrates are represented by single examples.
“Since larvae of caddisflies are a group, which is most sensitive to oil contamination, and they are usually the first to disappear in case of an accidental spill, their presence in the Pyasina River proves there has not been a significant oil contamination in the said river,” the report reads. “The smallest amount of bottom fauna was registered in the sources of the Daldykan River and near Cape Golyi of Lake Pyasino.”
Expedition to Taimyr
The Siberian Branch of the Russian Academy of Sciences for the first time over recent years has sent to the Taimyr Peninsula, at the invitation of Nornickel, a big scientific expedition to conduct a large-scale survey of the area. Scientists will use the expedition’s results to present nature-friendly solutions and suggestions for industrial companies, working in the Arctic.
The expedition’s key points were watersheds of the Rivers Pyasina, Norilka and Ambarnaya, and Lake Pyasino. In August, experts from 14 research institutes of the Academy of Sciences’ Siberian Branch collected samples of soils, plants and sediments and later began tests at the institutes’ labs.