Ecotoxicological assay of seawater quality on the western Kamchatka shelf

Ecotoxicological assay of seawater quality along the shelf of West Kamchatka, including the areas of oil and gas deposits, was conducted in the summer of 2014. Temperature and salinity conditions were usual for summer season, as well as the field of density currents. For introduction of modern and representative bioassay methods in practice of environmental monitoring in the regions of oil and gas production and transportation, embryogenesis of sand dollar Scaphechinus mirabilis was used for biotesting. The stations with high number of the embryos and larvae abnormalities had mosaic distribution - this effect may be connected with shipping of fishing and merchant vessels

Assessment of ecological state for the north-eastern shelf of Sakhalin Island: hydrochemical analysis and bioassay

Results of ecological monitoring in the coastal waters at north-eastern Sakhalin are presented. Spatial patterns of water temperature, salinity, dissolved oxygen content, and concentrations of inorganic phosphate and silicon are described, geostrophic currents are calculated. Abnormalities of early embryogenesis are revealed for the sand dollar Scaphechinus mirabilis in the water sampled both at the coast and in the oil-producing areas but not in the areas distanced from the oil wells. Possible influence of natural environments and anthropogenic factors on marine biota in the area of monitoring is discussed: the abnormalities at the coast are possibly caused by low salinity, but those ones in the oil-producing areas have no any natural reasons, so far as salinity, temperature and nutrients concentration in these areas are the same as in the open-waters with normal results of the bioassay. Thus, anthropogenic impact on marine biota is detected for the areas of continued oil and gas production on the northeastern shelf of Sakhalin Island

Results of multidisciplinary survey in the Laptev Sea in August-September, 2015

Data on oceanographic conditions and species composition of plankton, benthic and demersal fish and invertebrates are presented, obtained in the complex survey over the external shelf of the Laptev Sea in August-September 2015. The zooplankton abundance was low, with only local increases up to 400 mg/m3. Species diversity of fish and nekton invertebrates in the bottom trawl catches was low, too: 26 fish species and 2 species of cephalopods. Mean biomass of fish was estimated as 4.3 t/km2 (in total 132. 103 t within the surveyed area of 30,500 km2). All fish species were distributed sparse. Arctic cod was the most abundant and occurred over the whole surveyed area, with large-sized fish dominating at the bottom and medium-sized (9-15 cm) fish - in the pelagic layer, other commercial species were greenland halibut and deepwater redfish caught on the continental slope. Bottom invertebrates in trawl catches were presented by 6 species of shrimp and 12 taxonomic groups of different rank, with predominance of starfish, brittle stars and sponges; gastropods were represented by 11 species, with Neptunea heros dominating by mass (42 %). Macrobenthos in samples of the bottom sampler was presented by 20 taxonomic groups, with predominance of polychaetes, bivalves and sipunculoids

Results of complex surveys in the East Siberian Sea in August 2015

Data on oceanographic conditions, composition of plankton communities, benthic and demersal fish and invertebrates in the southern East Siberian Sea are presented by results of the complex survey conducted in August 2015, The bottom trawl survey assessed 10 species of fish and 3 species of jellyfish with total biomass 1900 t. Arctic cod Boreogadus saida dominated absolutely in the benthic ichthyocenose (60.6 % of the total biomass). Besides, 3 species of shrimps, 1 crab species, 4 species of gastropods, and 6 other taxonomic groups of macrobenthos including starfish and isopods were found in trawl catches, with the average biomass of macrobenthos 41.7 kg/km2. In the bottom samples of macrobenthos, 12 taxonomic groups were presented, with predominance of bivalves, polychaetes, isopods, and amphipods (summary 95 % of the total biomass)