Summary of Working Paper No. 53-1996

II.4.1 & II.4.4: The Marine Invertibrates, Fish and Coastal Zone Features of the NSR Area.

By Lars-Henrik Larsen, Rune Palerud, Harvey Goodwin, Akvaplan-niva, Tromsų, Norway, and Boris Sirenko, Zoological Institute, St.Petersburg, Russia.

The WP presents the information collected and included in the INSROP database by the three Subprogram II Projects II.4.1 Marine and Anadromous fish and Invertebrates, II.4.4 The Coastal Zone and II.4.5 Large River Estuaries and deltas. The projects have been carried out by Akvaplanniva and Zoological Institute St. Petersburg (ZISP). The paper presents the outline and extent of data coverage, and presents examples of the data collected during phase I of INSROP. In addition to the authors, the data collection has been performed by a number of scientists of Zoological Institute. N.V. Chernova, O. Kudersky, V. Khlebovich, A. Neyelov and A. Golikov are greatly acknowledged for their constructive contributions to this work.

A description of the invertebrate communities and fish resources is given, with special emphasis put on the processes and links between the Valued Ecosystem Components (VECs) selected by Subprogramme II. Correlations between environmental parameters and distribution of selected animal groups are presented, to illustrate the potential for further analyses which the stored data offer. The Kara Sea, Laptev Sea, East Siberian Sea and the Chukchi Sea are some of the least explored and mapped areas of the world. The number of known species of benthic invertebrates along the NSR decreases from west to east. This is partly a result of the harsher arctic environmental conditions eastward along the Siberian coast. East of the Laptev Sea, the influence of Pacific species is gradually increasing. A limited number of surveys have been carried out in the eastern parts of the NSR Thus, even though the projects have recorded information on more than 2000 different species of plants, invertebrates and fish, the data coverage is still fragmentary.

Invertebrates are the food source for animals at higher trophic levels, such as fish, which are in turn preyed upon by birds and seals. Invertebrates are also eaten directly by mammals and birds. The information on biomass of potential prey organisms and the feedpreferences of marine mammals can thus be used for mapping of particularly rich areas, not only rich in invertebrates, but also potential feeding areas for marine mammals.

The fish fauna of the NSR area is as sparsely mapped as the invertebrate fauna, and only a few quantitative investigations covering parts area have been performed by Russian scientists. The marine fish fauna is too sparse and so difficult to access that no commercial fishing is taking place in the open parts of neither of the four seas, except for the westernmost area of the Kara Sea, and occasionally in the Bering Strait. The fishery of the Arctic seas is restricted to the rivers and estuaries, where the main species caught are anadromous whitefish (Coregonids). Eight species of this family have been recorded, from which 6 species make up 70 to 90 % of the total recorded landings from the area. These species are Coregonus nasus (Broad Whitefish, Chir), C. autumnalis (Omul), C. muksun (Muksun), C. peled (Peled (a freshwater species)), C. sardinella (Siberian cisco) and C. lavaretus (Humpback Whitefish). In the paper, data on whitefish landings are presented to illustrate the extent of the fishing activities in different areas. Data on landings of other species and the checklist of species recorded from the area are available from the INSROP database. The statistics on landings have been provided by the State Institute of Lake and River Fisheries (GOSNIORKH).

For the Kara Sea area, data on landings of the most important fish species were collected from the Ob Bay, the lower Yenisei river, the Pyasina and the Taymyrskaya rivers. The data indicate a significant decline in landings of whitefish in all four areas. This tendency is most evident in the western parts of the NSR area (Kara Sea), compared to the eastern parts For example has the landings of whitefish from the Ob Bay has suffered a 42 % reduction during the period 19901994. In the lower Yenisei river, the decline was 35 % during the same period. Compared to the average landings of the period 198185, the recorded landings of whitefish from Ob Bay in 1994 make up only 46 % of the landings recorded ten years earlier.

Human settlements along the NSR area comprise a large variety of communities, from small villages and camps of nomadic groups of indigenous people to large communities with several tens of thousands of inhabitants concentrated around a harbour, a factory or a mineral resource. Even though more than 1100 permanent human settlements exist in the Siberian North the area is among the least populated in the world. The selection of human settlements as a VEC in the present context is based on the fact that not only indigenous, but also people of Russian or other former Soviet heritage are dependent on the natural resources of this remote and climatic harsh region. Although reindeer herding, fur hunting and fishing are most common among the indigenous populations, fishing and furhunting is also important trades for people of nonindigenous heritage.

The report also contains an example of remote sensing of environmental features of the NSR area. During the ice melting season, an enormous increase in water flow of the Siberian rivers occur. The water level can increase with several tens of meters in rivers like Yenisey. As a consequence, large inland areas surrounding the lower parts of the rivers become inundated and may be affected, should an accidental oil spill take place during that period. The extent and location of inundated riverine areas in the lower Yenisei valley were mapped by use of satellite images; two NOAA Advanced Very High Resolution Radiometer (AVHRR) images covering the same river area were superimposed on each other, one from the spring flow period, and one from summer. Unfortunately it was not possible to find two useful images from the same year, due to frequent cloud cover of the area. As a result, an image from the 25th June 1988 and another from the 29th July 1994 were used. The images were subsectioned, radiometrically calibrated and geometrically corrected. The nearinfrared channel (channel 2) which generally provides the best discrimination between land, water and clouds was used.

Anyone interested in further information or data on these subjects presented in the report is encouraged to contact either the authors or the INSROP secretariat at Fridtjof Nansens Institute.