Distribution of echinoderms and their larvae in the southwestern Peter the Great Bay, Sea of Japan

Based on results of processing planktonic and benthic samples collected in 1996 and 1997, a spatial distribution of echinoderms in the bottom and of their larvae in the plankton were collated for the water area of the Southern region of the Far Eastern State Biosphere Marine Reserve. Some correlation between distributions of the adult and larval sea star Asterias amurensis in July was revealed. At the same time, there was no correlation between distributions of larvae and adult individuals of the brittle star Ophiura sarsi and sea urchin Echinocardium cordatum, which are most abundant in the area. The size structure of bottom populations of the brittle stars O. sarsi and Amphiodia fissa in the studied area was assessed. The correlation coefficient between the distribution of young-of-the-year and the population density was 0.47 in O. sarsi and 0.74 in A. fissa respectively, which implied a selective settling of larvae of those species in areas inhabited by adult brittle stars. Recruitment of bottom populations from 1996 spawning was 5% in O. sarsi and 3.3% in A. fissa.     

Nemertean larvae of the ototyphlonemertidae family in the plankton of Peter the Great Bay, Sea of Japan

Larvae of two nemertean species,Ototyphlonemertes (O.) martynovi Chernyshev, 1993 andOtotyphlonemertes (Norenburgia) sp., found in the neritic plankton of Peter the Great Bay, the Sea of Japan are described. The larvae of both species had two statocysts and a pair of eyes, but differed in the number of statoliths and in their tactile cirri. Changes of some traits during ontogenesis are discussed.     

The Meroplankton of Amurskii Bay (Peter the Great Bay,Sea of Japan)

Russian Journal of Marine Biology - The composition and seasonal dynamics of meroplankton in Amurskii Bay (Sea of Japan) were studied for the first time. The total survey period exceeded two years....     

The current state of resources of commercial gastropod species,family Buccinidae,in Peter the Great Bay,sea of Japan

Dynamics of the resources of commercial gastropod species, family Buccinidae (B. bayani bayani, B. verkruzeni, N. bulbacea, N. constricta, N. lyrata lyrata, and N. polycostata), in Peter the Great Bay were analyzed based on the results of trawl surveys in 1998–2008. The overall buccinid biomass was shown to have increased since 2004, after pot fishing for gastropods was ceased. However, some structural changes in the proportions of buccinid species in Peter the Great Bay were recorded during that period.     

Pollution in Peter the Great Bay, Sea of Japan, and its biological consequences

This review summarizes information published in the 1980s–1990s about anthropogenic pollution in Peter the Great Bay, the largest of the bays in the northwestern part of the Sea of Japan. The coastal zone of the bay occupies about 12% of the area of Primorskii Province and is the most heavily populated. The bulk of the human settlements, the seaports of Vladivostok and Nakhodka, railways, industrial enterprises, and developed agriculture are located in the coastal zone. Sewage waters containing multicomponent mixtures of polluting agents of both mineral and organic origin are discharged into the coastal waters of the bay. This paper presents information about the concentration of major classes of polluting agents (oil hydrocarbons, polychlorinated hydrocarbons, surfactants, heavy metals, and radionuclids) in the water and bottom sediments of the bay. The results of physico-chemical and biogeochemical investigations performed in the 1970s–1990s justify considering Zolotoi Rog Bay, Bosfor Vostochnyi Strait, Nakhodka Bay (especially its innermost portion, around the harbor of Nakhodka), and Amurskii Bay to be the most polluted areas in Peter the Great Bay. The information about the biological consequences of pollution in these water areas is briefly reviewed.     

New Data on Rotifers of Peter the Great Bay,Sea of Japan

The first records of 11 species of rotifers from Peter the Great Bay (Sea of Japan) are reported. Of these, Synchaeta grimpei, Aspelta clydona, Encentrum algente, and E. graingeri are the first records for the Pacific Ocean. Synchaeta pacifica and S. posjetica described from Peter the Great Bay by Chaga (1984) are considered as nomen dubium.Original Russian Text Copyright ¢ 2005 by Biologiya Morya, Chernyshev.     

Fouling of hydrotechnical structures in western Peter the Great Bay, Sea of Japan

We studied the fouling of piers and quays in Amurskii and Pos’et bays, the Sea of Japan. The main fouling communities and groupings were identified. They were usually dominated by bivalves, the musselMytilus trossulus and the oysterCrassostrea gigas. The exotic speciesBalanus improvisus was found to naturalize in the fouling on the hydrotechnical structures of the Amurskii Bay. The qualitative composition of the fouling of the structures examined was compared using cluster analysis.     

Morphology of gametes in sea urchins from Peter The Great Bay,Sea of Japan

The fine structure of the gametes in six sea urchin species of the Sea of Japan was studied. The sperm in Strongylocentrotus nudus, S. intermedius, Echinocardium cordatum, Scaphechinus mirabilis, Sc. griseus and Echinarachnius parma are species-specific. The conical head and symmetrically disposed ring-shape mitochondrion are common to regular sea urchin sperm cells. S. nudus is characterized by the bulb-shaped head of the sperm; S. intermedius, by a bullet-shaped one. The sperm spearhead and small amount of post-acrosome material are common to irregular sea urchins; the sperm width: length ratio varies for different species, with the highest for Sc. mirabilis. The sperm of Sc. griseus is characterized by two lipid drops in the middle part of sperm. Asymmetrical mitochondrion disposal is usual for E. parma. Actin filaments are found in the postacrosome material in the sperm of heart-shaped sea urchins. The differences in the fine structure of sperm in cosmopolitan species Ech. cordatum inhabiting the Sea of Japan and coastal areas of the Northeast Atlantic may bear record to the complex existence of species Ech. cordatum. The fine structure of sperm is unique for each of the studied families, Strongylocentrotidae, Scutellidae, and Loveniidae. The eggs of all the species are characterized by vitelline and jelly-like membranes. The vitelline membrane is formed by cytoplasm protrusions; the area between them is filled with fibrillar material. The jelly-like membrane is formed by fibrillar material associated with apical parts of microvilli of the vitelline membrane. The irregular sea urchins Sc. griseus, Sc. mirabilis and E. parma are characterized by chromatophores situated in the jelly-like membrane, with the highest abundance in Sc. mirabilis.     

Biochemical markers of commercial fish adaptation in estuaries of Peter the Great Bay (the Sea of Japan)

The results of the comparative study of molecular biomarkers of oxidative stress and biotransformation of some representatives of the families Cyprinidae and Mugilidae from estuaries of rivers which enter Peter the Great Bay are presented. The haarder mullet Liza haematocheila is used as an indicator species for monitoring the degree of environmental pollution. The basic values of biochemical parameters in different organs of haarder mullet and their seasonal variations have been determined. A significant increase in the concentration of glutathione and activity of glutathione-S-transferase in fish from the Razdolnaya River has been found on the basis of the comparison of the functional state of haarder mullet in estuaries of the Razdolnaya and Amba rivers, which differ in the degree of anthropogenic load.     

Spawning of the sea ravenHemitripterus villosus in Peter the Great Bay, Sea of Japan

The spawning habits of the sea ravenHemitripterus villosus were investigated by scuba diving at shallow rocky bottom sites around Bolshoi Pelis Island (Peter the Great Bay, Sea of Japan). Spawning occurs in September, when the surface water temperature drops. The optimum spawning temperature is 17–18°C. The fish density in nest sites reaches 120/300 m². The mean individual fecundity is about 10000 eggs. Over 35% of the egg masses ofH. villosus are eaten by echinoderms, primarilyPatiria pectinifera andStrongylocentrotus nudus. Since fecundity is relatively low and parents do not take care of the egg masses, predation can strongly affect the abundance of this species.     

Karyotype of sculpin,Myoxocephalus stelleri from Peter the Great Bay, Sea of Japan

We studied the karyotype of the frog sculpinMyoxocephalus stelleri Tilesius (Cottidae) from Peter the Great Bay: 2n=40; NF=46. In the series of two-armed chromosomes, there is a pair of large submetacentric ones, while there are two pairs of large subtelocentric chromosomes in the one-armed series. Ag-NOR staining revealed nucleolus organizer regions in the short arms of two pairs of subtelocentric chromosomes that differed in size. We found neither differences between male and female karyotypes nor variability of any type. The karyotype ofM. stelleri is compared with that of the short-spined sea scorpionM. scorpius.     

The Larvae of Unarmed Nemerteans in Peter the Great Bay (Sea of Japan)

Nemertean pilidia belonging to the groups magnum, pyramidale, gyrans, recurvatum, and auriculatumwere found in Peter the Great Bay. Pilidium auriculatumis probably a little-known ribbon worm of the family Hubrechtiidae, which has never before been found in the Sea of Japan. Larvae of two species of the order Archinemertea were also found.     

Allozyme variability of the gastropodTegula rustica from Peter the Great Bay, Sea of Japan

Eight polymorphic loci were surveyed in three samples of the gastropodTegula rustica collected in a clean area of Peter the Great Bay and in three samples from a heavily polluted area of the bay. Macrospatial, microspatial, and temporal differences in allele frequencies and heterozygosity were found at some of the loci; however, the genetic similarity among the samples was very high. It is concluded that allozyme variability at the surveyed loci ofT. rustica cannot be used in pollution monitoring of Peter the Great Bay.     

Foraging conditions of planktotrophic larvae of echinoderms in the southwestern part of Peter the Great Bay of the Sea of Japan

Foraging of planktotrophic larvae of echinoderm common species in the Peter the Great Bay (Sea of Japan) was estimated on the basis of distribution of phyto- and meroplankton. The diversity and abundance of phytoplankton in the studied area in summer months were shown (141 algae species; abundance—up to 743000 cells/m³; biomass—more than 2.7 g/m³ of fresh weight). It was found that in Peter the Great Bay the diet of echinoderm larvae depended on their feeding behavior, duration of their pelagic stage, and abundance and size composition of phytoplankton, included up to several micrograms of fresh algae per larva.     

Fauna of Sponges (Porifera) of Peter the Great Bay,Sea of Japan

A complete list of sponges of Peter the Great Bay (northwestern Sea of Japan) is presented comprising 40 species belonging to 27 genera, 19 families, 9 orders, and 2 classes. Information is presented about the biogeographical composition of sponge fauna of the bay, the depths of their habitats, and their substrates.Original Russian Text Copyright ¢ 2005 by Biologiya Morya, Khodakovskaya.     

Salinity Tolerance of Some Teleost Fishes of Peter the Great Bay, Sea of Japan

Salinity tolerance in some marine teleost fishes was studied. Based on a comparison of sexually mature specimens in the summer season, the investigated species can be arranged in the order of decreasing capability for hyperosmoregulation into the following series: the Far Eastern dace Trybolodon brandti, the haarder Mugil soiuy > the frog sculpin Myoxocephalus stelleri > the snowy sculpin M. brandti > the plain sculpin M. jaok > the masked greenling Hexagrammos octogrammus > the pipefish Syngnathus acusimilis. The adult Far Eastern dace and the haarder showed high salinity tolerance and fully adapted to fresh water. Sculpins and the masked greenling usually occur only in seas or brackish water, but they were capable of enduring fresh water for a long time. Unlike them, the pipefish, which is also a euryhaline fish and occurs in river estuaries and brackish bays, perished in fresh water within 1 h. Representatives of the genus Myoxocephalus show between-species differences in salinity tolerance, which allows them to colonize extensive near-shore areas of the sea and to occupy specific ecological niches.     

Reproduction Peculiarities of Plain Sculpin Myoxocephalus jaokin Peter the Great Bay, Sea of Japan

We performed observations in the spawning grounds of the plain sculpin. We found that the spawning of this species in Peter the Great Bay begins in December and takes place along the coast. The egg clutches are guarded by the males.     

Seasonal dynamics and spatial distribution of epiphytic dinoflagellates in Peter the Great Bay (Sea of Japan) with special emphasis on Ostreopsis species

Studies of epiphytic dinoflagellates in Peter the Great Bay, Sea of Japan in 2008–2011 revealed the presence of 13 species. Five of the species are known as potentially toxic: Amphidinium carterae, A. operculatum, Ostreopsis cf. ovata, O. cf. siamensis and Prorocentrum lima. The maximum species richness and abundance of epiphytic dinoflagellates were observed in autumn (from September to October). Ostreopsis spp. were most widely distributed and predominated, amounting to 99% of the total density of dinoflagellates. Multi-year seasonal dynamics of Ostreopsis spp. in Peter the Great Bay showed that these cells appear as epiphyton in August after maximum warming of surface waters (22–24 °С) and disappear in early November, when the water temperature decreases below 7 °С. Ostreopsis spp. proliferation occurred in September, when the water temperature was 17.2–21.0 °C. The highest densities of Ostreopsis spp. were recorded on September 9, 2010 on the rhodophyte Neorhodomela aculeata – 230 × 10³ cells g⁻¹ DW or 52 × 10³ cells g⁻¹ FW. The spatial distribution of epiphytic dinoflagellates was investigated in the near-shore areas of Peter the Great Bay during the second half of September 2010 to evaluate the role of hydrodynamic conditions. Epiphytic dinoflagellates were not found in sheltered sites having weak mixing hydrodynamics. However, the abundances of Ostreopsis spp. were significantly higher at sites having moderate turbulence compared to biotopes experiencing strong wave action. Densities of Ostreopsis spp. were not significantly different on macrophytes with branched thallus of all taxonomic divisions. However, the average cell densities of Ostreopsis spp. on green algae with branched thallus were significantly higher than on green algae having laminar thallus.