Preliminary Estimates of Low-Frequency Sound Effect on Sea Animals in the Eastern Arctic.

For many years, the economic exploitation of the Arctic was confined to fishery and aquatic mammals hunting. Such activities being performed by all coastal countries lead to a considerable decrease in number of all kinds of fish and whales. Even the supplies of the regional basic fish species were depleted. This caused a serious disbalance of the ecological system: the number of bird's colonies was decreased, the food supplies of aquatic mammals was changed, which was followed by moving of seal herds from Greenland to the coast of Norway; certain changes occurred in the migration distribution, behaviour, and reproduction of the white whale. Currently, there is no whale-fishery for most of the whale species in the Barents Sea, hunting harp seals is strictly regulated, and the white whale-fishery is forbidden. The Arctic ecological system is highly sensitive, and, therefore, the intensive works carried on in the Barents Sea and aimed at oil and gas prospecting, drilling, extraction, and transportation (the shelf at the South and South-West side of the Kolguev island, the Shtokmanskoe deposit) may be a serious trouble. The ecological safety of this industry is usually evaluated with relation to possible accidents and the impact they may have on the ecosystem due to oil spills and other chemical pollutants. Acoustical sea pollution due to the seismic prospecting, boring, bore-hole exploiting, oil pumping, and intense large-capacity navigation is assumed to be harmless. But the long-term consequences of powerful low-frequency acoustic field effects, both on individual species of the ecosystem and on the ecosystem as a whole, are little studied. The recent data (part 2.4 of this report) on the visual and reproductive system impairments in fish call for the extension of research on the monitoring of the acoustic pollution.