Том 42, № 3 (2016)

Complex studies were carried out in the southern part of Onega Bay (White Sea) in the summer seasons of 2003–2006 and 2011–2013. These studies revealed the dynamics of oil pollution of the water area after an accidental fuel oil spill in September 2003 and its long-term adverse effects on organisms of different trophic levels of the coastal ecosystem (benthos, fish, and sea mammal populations) in the most polluted southeastern part of the bay. The deterioration of the status of the top trophic-level white whale population (a decrease in numbers) and the accumulation of oil hydrocarbons in tissues of benthic organisms are described.

The data on the abundance and distribution of sea birds and waterfowl at the coast of southern Primorye and distribution diagrams of the sea ducks along the surveyed coast in winter season are given. The dependence of the presence of the birds in certain coastal areas on the winter ice condition was revealed.

The species composition, period of occurrence, density, and distribution of the larvae of burrowing shrimp of the infraorders Gebiidea and Axiidea in Amursky and Ussuriysky bays (Sea of Japan) were studied in May–October 2008. Larvae of eight species of this group were found in plankton samples. The period of occurrence of larvae in the bays was longest in Upogebia major and Nihonotrypaea petalura (4 and 3 months, respectively). Zoeae of the rest of the species occurred in the plankton for no more than 2 months, indicating a single larval hatching during the reproductive season. The average density of gebiidean and axiidean larvae was low and reached the highest values (4 ind./m³) in June in Amursky Bay and in July in Ussuriysky Bay; their contribution to the total density of decapod larvae was not above 18%. In general, larvae of the family Upogebiidae dominated in Amursky Bay and larvae of the Callianassidae were predominant in Ussuriysky Bay. The zoeae of U. major (up to 37 ind./m³) and Nihonotrypaea makarovi (up to 46 ind./m³) were most numerous. Larvae of the family Axiidae were recorded only in very low numbers in both bays.

The histological organization and ploidy levels of the digestive gland cells in 34 species of prosobranch gastropod mollusks that belong to the subclasses Patellogastropoda, Vetigastropoda, and Caenogastropoda (orders Littorinimorpha and Neogastropoda) were investigated using histochemical methods and cytophotometry of nuclear DNA. Two general types of differentiated cells, viz., digestive and basophilic (secretory-calcium), were identified in the epithelium of the digestive tubules. In Vetigastropoda and Neogastropoda species, all the cells are mostly diploid. In representatives of Patellogastropoda and Littorinimorpha, the digestive cells are diploid as well, but basophilic cells of many species reach polyploidy levels of 4–8c and in some species, even 4–8–16c. Cases of somatic polyploidy in basophilic cells are considered as adaptive modifications of histogenesis associated with the peculiarities of the environment (intensified metabolism in osmotically tolerant Littorina and Lottia species), the duration of ontogenesis (the short life cycle in Lacunida species), and a specific diet.

The lifecycle of the Bacillus sp. 1839 cultivated during a long period on solid and liquid Youschimizu-Kimura medium was investigated, and then bacteria and spores were studied by light and transmission electron microscopy. Sporulation in this strain is distinguished by engulfment of forespore by mother cell. In the liquid medium, bacteria have the decondensed nucleoid and the loose granular component of cytoplasm; bacteria and spores are generally smaller; the outer coat of spores includes 2 concentric rings. On the solid substratum, the nucleoid is condensed, and the cytoplasmic region is extensive and dense; a longer cultivation stimulates transition of vegetative cells into the spore form; spores have a thicker outer coat with 3–5 rings. On the solid substratum, sporulation in Bacillus sp. 1839 is spontaneous, without additional stimulation; spores have a larger diameter and thicker layers than those in the liquid medium. This research contributes to the current understanding of biotechnological tetrodotoxin production from a bacterial raw material.

The seasonal dynamics of diarrhetic shellfish poisoning (DSP) toxins in the digestive gland of the mussel Crenomytilus grayanus (Dunker, 1853) from Peter the Great Bay in the Sea of Japan have been studied. Toxins in the form of 4-bromomethyl-7-methoxycoumarin derivatives have been analyzed using high-performance liquid chromatography (HPLC) with fluorometric detection. This method allows the determination of the quantitative and qualitative composition of individual toxins. All the C. grayanus samples contained DSP toxins, but their concentration varied substantially during the year. The highest concentration was recorded from the mussels collected in May; the lowest concentration was recorded in February. The toxins were represented predominantly by dinophysistoxin-2; in July-September and December, okadaic acid was detected. An assumption has been made about the relationship between the potential producers of DSP toxins in the waters of the Peter the Great Bay and the dynamics of these toxins in tissues of C. grayanus. The HPLC method, as an alternative to the enzyme-linked immunosorbent assay, was used to assess the quantitative and qualitative composition of DSP toxins in seafood for the first time in the Russian Federation. This method can be recommended for the routine monitoring of toxins conducted by the controlling organizations of the Russian Federal Service for Veterinary and Phytosanitary Surveillance.

The spatial distribution of epifauna in the Far Eastern Marine Reserve was examined using a remotely operated vehicle. The abundance and distribution patterns of the sea stars Patiria pectinifera, Distolasterias nipon, and Asterias amurensis, as well as those of brittle stars, the black sea cucumber Cucumaria japonica, the sea urchin Strongylocentrotus intermedius, the ascidian Halocynthia aurantium, hermit crabs, and the Japanese scallop Mizuhopecten yessoensis were determined in the South Section of the Reserve. The average biomass of five dominant epifaunal species ranged from 51.0 to 87.4% of the average biomass of the softbottom communities.

A formula to calculate the area of samples that would provide the necessary level of completeness for a species richness survey of a cenosis has been deduced. The model is based on a stochastic differential equation that describes random fluctuations in species abundance and on the assumption that a Poisson distribution of individuals in space occurs. The calculations are illustrated based on the example of the littoral polychaete taxocene in Vityaz Bay of Possiet Bay of the Sea of Japan.

The finding of the shortfin lizardfish Saurida microlepis Wu et Wang, 1931 in Peter the Great Bay of the Sea of Japan makes a contribution to the ichthyofauna of the Russian waters with a new family Synodontidae.