Benthic foraminifera at a scallop aquaculture site in Minonosok Bay,the sea of Japan

The species composition and distribution of benthic foraminifera at a scallop aquaculture site in shallow Minonosok Bay (southern Primorye) were studied. Ninety-three species of benthic foraminifera were found in Minonosok Bay in 1998 and 83 species in 2000; representatives of the families Elphidiidae, Discorbidae, Trochamminidae, and Ataxophragmiidae dominated. In 1998, the calcareous species Cribroelphidium frigidum was most abundant; in 2000, calcareous Protelphidium asterotuberculatum and arenaceous species Trochammina inflata and Eggerella advena were dominant. The effect of scallop cultivation on the distribution of benthic foraminifera was local. The species composition and population density of foraminifera directly under scallop cages were decreased, compared to areas of the bay where there were no mariculture operations.     

The efficiency of Yesso scallop (<Emphasis Type="Italic">Mizuhopecten yessoensis</Emphasis>) aquaculture in Ussuri Bay (Sea of Japan)

Data on cultivation of the Yesso scallop, Mizuhopecten yessoensis, in Ussuri Bay are summarized. The sea-based farms that are established in the shallow waters at depths of 2–18 m differ in the area occupied by their facilities and the hydrodynamic characteristics. A farm with a complex structure (collectors, cages, and bottom cultures) operates in the semi-enclosed Sukhodol Bay. In the other two bays, mostly bottom facilities for ranching scallop and sea cucumber are used. The local scallop broodstocks were formed by introducing juveniles from Posyet Bay. As a result, at least 20 million scallop spat were collected in these three bays from 2000 to 2014. The total yield of market-size scallops was approximately 216 tons, of which over 111 t were obtained in Sukhodol Bay, 70 t in Ilmovaya Bay, and 35 t in Malye Kushi Bay. Analysis showed that the potential for the development of this type of aquaculture in the region was limited. The mean long-term value of the spat density was not higher than 200 spat per collector and did not increase throughout the period of operation of the farms. Thus, farmers had to increase the number of collectors to obtain the required quantity of scallop seed. Some years were unfavorable for harvesting juvenile scallop at all of the farms along the eastern coast of Ussuri Bay. The environmental conditions in these waters are not optimal for Yesso scallop cultivation by the extensive method.     

Summer distribution of the purplegray sculpin <Emphasis Type="Italic">Gymnocanthus detrisus</Emphasis> (Cottidae) in Waters of Primorsky Krai,Sea of Japan

Results of trawl catches show that in the summer period, in the waters of Primorsky Krai, Russia, Sea of Japan, the purplegray sculpin Gymnocanthus detrisus occurs at depths of 20 to 411 m, preferring the range 80–250 m. The temperature of the species’ habitat varies from 0.8 to 8.6 ° C, and the optimal one is 1.2–2.2 °C. G. detrisus occurs at the preferred depths more frequently in the southern area—the Peter the Great Bay, which is more favorable for foraging; in the area of North Primorsky Krai it was found both at greater and lesser depths. The latter is probably determined by the more limited spreading of waters with unsuitable temperatures for the species there. The body size of the purplegray sculpin grows with depth. Juveniles avoid depths over 200 m, where inflow of low-temperature waters is recorded. G. detrisus, which inhabits waters of Primorsky Krai, is represented mainly by females; the proportion of males exceeds that of females only in the 21–27 cm size group. This may be related to the lower growth rate in males after maturation as compared to females.     

Long-Term Variation of Polychaete Bioerosion of the Scallop Mizuhopecten yessoensis from the Northwest Part of the Sea of Japan

The bioerosion of shells of the Japanese scallop Mizuhopecten yessoensis by endolithic organisms over the last few decades and millenia in areas close to the main sources of organic pollution in Peter the Great Bay was studied. It was established that the occurrence of Japanese scallop shells damaged by borers increased over 2500 years practically from 0 up to 96% in the northern part of the bay at Mys Peschany Cape, which is subject to the impact of the Pazdol'naya River drain. The bioerosion of the Japanese scallop shells has increased considerably over the last two decades in the coastal zone, near the center of the city of Vladivostok, at one of the main sources of the city's wastewater discharge. Thus, in 4-year old individuals 33.0 ± 2.9% of upper valves were eroded on average in 1982; in 1998 it was already 68.3 ± 6.4%. In Reinike strait, that is, at some distance from the mouth of Razdol'naya River and from the main discharge sources of polluted waters of Vladivostok, the shells of the Japanese scallop were eroded to a lesser extent than in the population from the coastal region near the city. However, a significant increase in the degree of bioerosion of the scallop shells was observed over one-and-a-half decades: in 1987 in 4-year scallops 2.3 ± 0.3% of the area of the upper valve was eroded on average, and in 1999 that parameter increased and became 32.6 ± 3.4%. In the western part of Peter the Great Bay near Furugelm Island, which is located 20 km away from the mouth of the Tumannaya River, the degree of bioerosion of scallop shells had also increased significantly over the last 30 years. The increase in the degree of bioerosion of the shell is connected to a gradual increase in the content of organic substances in the bottom sediments. This is a factor favorable for the development of bacteria and phytoplankton, which is a food source for polychaetes—the basic shell boring symbionts of the Japanese scallop.     

Population Dynamics of the Japanese Scallop <Emphasis Type="Italic">Mizuhopecten yessoensis</Emphasis> (Bivalvia) Under Conditions of Enhanced Hydrodynamics

A population of the Japanese scallop, Mizuhopecten yessoensis, found in the open area of Peter the Great Bay (Sea of Japan), which was not protected against southeastern summer monsoons, has been studied. Specimens of different ages, from 1 year old to 11 years old, were found in the population. According to a provisional estimation, the total reserve of the Japanese scallop in the population reached 30 000 specimens. After strong typhoons, up to 6 000 specimens were stranded along the shoreline. Even after repeatedly occurring typhoons observed during one particular summer season, the population of M. yessoensis remained rather stable, although its age structure demonstrated both uneven annual recruitment in the population and different survival rates in different generations. Specimens of the highly productive generation of 1999 constituted the bulk of the bottom population and coastal wreckage. At older ages, the probability for the Japanese scallop to be stranded during a storm decreases significantly.Original Russian Text Copyright ¢ 2005 by Biologiya Morya, Silina, Latypov.     

Parasite fauna of the snakehead Channa argus warpachowskii from Primorsky Krai

Parasite fauna of the snakehead Channa argus warpachowskii was studied in water bodies of Primorsky Krai. Thirty-one parasite species were recorded in this host from the studied area according to original and literary data. Most part of these species are host-specific parasites of snakehead originated from Chinese-Indian region or parasites having a wide host range and able to infest almost all freshwater fishes. Moreover, three brackishwater species of parasites were found in the fishes introduced into the rivers of the southern part of Primorsky Krai. The causes of this invasion are discussed.     

The Meiobenthos in the Area of Japanese Scallop Cultivation in Minonosok Bay (Peter the Great Bay,Sea of Japan)

In Minonosok Bay, in a region of long-term industrial mariculture of mollusks, a steady biohydrochemical complex with increased organic matter content has been formed, in which the meiobenthos community was represented by a rather complete set of taxonomic groups of low population density. There were 16 groups (order, class) of the meiobenthos revealed, and the greatest population density was recorded in the central part of the bay under installations with suspended mollusks, (333000 ind./m²). Nematodes dominated in the eumeiobenthos; however, crustaceans prevailed in the bottom water layer and sediments at stations with increased oxygen content. Bivalves and gastropods dominated in the pseudomeiobenthos. Correlation analysis has revealed the dependence of the population density of the total meiobenthos and eumeiobenthos on the type of ground. There were 42 nematode species revealed; Axonolaimus seticaudatus, Enoplolaimus medius, Daptonema sp., Paracomesoma sp., and Oncholaimium paraolium dominated. Three nematode taxocens were discriminated by dominating species in the population density and results of cluster analysis of the data. Detritivorous nematodes prevailed in all types of ground. A correlation was found between the index of species diversity of nematodes and the content of organic carbon in the ground.     

Commercial rearing of the sea cucumber <Emphasis Type="Italic">Apostichopus japonicus</Emphasis> in Peter the great bay: Methodical peculiarities and results of the work of a mariculture farm in Sukhodol Bight

Methodical approaches to commercial rearing of sea cucumber at mariculture farms in Peter the Great Bay in the Sea of Japan are discussed. This includes two basic phases, viz., intermediate rearing of underyearlings in cages and sea ranching. The survival rate of juvenile sea cucumbers during intermediate rearing in cages in Sukhodol Bight (Ussuri Bay) was shown to depend on the body size and rearing density of the juveniles and its value varied from 35 to 82%. The survival rate of two-year-old juveniles on artificial reefs reached 85%. Monitoring studies of the bottom sites showed that for the entire period of functioning of the farm, 8 years, a sea cucumber colony with the average distribution density of 1.5 inds/m² was formed on an area of about 30 ha. The harvest of the commercial production of sea cucumbers purchased at hatcheries can be calculated taking the survival rates of juveniles during the first years of their life into account. The calculation of the production of juvenile sea cucumbers picked by collectors was based on an appraisal of the current state of their aggregation (abundance, biomass, and size structure) with use of conservation protection measures (the allowable harvest rate of 6.4%).     

Effects of intensive scallop mariculture on macrobenthic assemblages in Sishili Bay, the northern Yellow Sea of China

To elucidate the effects of scallop mariculture on the macrobenthic community in a moderate energy system, bimonthly samples from four transects along a distance gradient in Sishili Bay, the northern Yellow Sea of China, were investigated. Differences in macrobenthic community structure along the distance gradient were evaluated using univariate and multivariate analyses. The AZTI’s Marine Biotic Index (AMBI) and multivariate-AMBI analyses indicated that the macrobenthic community suffered little disturbance from the scallop culture. Consistently, the results of two-way analysis of similarities demonstrated that macrobenthic communities showed no difference along the distance gradient, but were significantly affected by the sampling months and transects. This conclusion was also confirmed by other univariate and multivariate analyses. The concentration of total organic carbon was 17.27 ± 6.05 mg g^?1, which is below the dangerous threshold of 35 mg g^?1 toxic to benthic fauna. Combined results revealed that no detectable effects on the macrobenthic community were caused by intensive and long-term scallop culture in this moderate energy system. This is likely due to the influence of local hydrodynamics and it is recommended that intensive scallop farming be located in areas with strong tidal or current flows.     

Invertebrate drift in the piedmont part of the Kedrovaya River (Primorsky Krai,Russia) in warm season

Diurnal dynamics of invertebrate drift in the Kedrovaya River (Primorsky Krai, Russia), which flows in the zone of influence of the monsoon climate, has been studied. It has been shown that drifting invertebrates tend to shift from a predominantly daytime drift pattern to a distinguished nocturnal drift pattern during the frost-free period. The ratio of the total number of nighttime migrants to the total number of daytime migrants increased with every subsequent month. It has been proposed that the degree of light contrast between day and night can be significant in the regulation of nocturnal drift intensity.     

Life cycle of the trematode Echinochasmus spinosus Odhner, 1911 (Echinostomatidae) in the natural conditions of Primorye

Life cycle and developmental stages of the trematode Echinochasmus spinosus Odhner, 1911 are described. As it was established experimentally, in the conditions of Primorsky Krai circulation of the trematode involves first intermediate host, mollusk Parafossarulus spiridonovi, and the second one, freshwater fishes. Adult worms were reared in chicken.     

Effect of the mariculture of the Japanese scallop on foraminifera assemblages in Alekseev Bight, Sea of Japan

The species composition and population densities of foraminifera were studied in scallop farming grounds in Alekseev Bight (Amurskii Bay, Sea of Japan). Ninety-one species of foraminifera were identified; members of the Elphidiidae, Discorbidae, and Ataxophragmiidae were numerically dominant. When the scallop mariculture farm was in operation, the species composition of foraminifera in farming grounds was impoverished and their population densities were an order of magnitude lower than at more distant locations. Between 1988 and 1995, after the liquidation of the farm, the species diversity and population density of foraminifera in farming grounds increased, while there was a general decline of the foraminifera population in the bay. The highest density and species diversity of foraminifera occurred on coarse silty sand and small silty pebbles, and the lowest species diversity was found on silty sediment.     

桑沟湾养殖生态系统健康综合评价

桑沟湾是我国北方以筏式养殖利用为主的典型海湾,来自养殖的压力对海湾生态系统和养殖自身的健康发展产生了影响.利用《海洋养殖生态系统健康综合评价:方法与模式》建立的方法,对桑沟湾这一养殖生态系统的健康进行了综合评价.结果表明:桑沟湾养殖生态系统受到中等程度的压力,主要来自较高的养殖密度、较大的养殖面积和陆源营养盐的输入;生态系统状态等级为较好,其中水交换、水体环境和底质环境均为较好;自然生物群落状态为中等;生态系统响应中的养殖病害问题和养殖产品质量问题为中等.总体评价,桑沟湾养殖生态系统健康勉强达到较好水平,控制养殖密度和规模等措施是改善桑沟湾生态系统健康的必要途径.     

Macrofouling of the Scallop Mizuhopecten yessoensisin the Polluted Area of Amursky Bay, Sea of Japan

The fouling structure of the Japanese scallop was studied in Amursky Bay near Vladivostok. Fifty-six species of hydrobionts were identified. Barnacles prevailed in biomass and population density, and algae dominated in the number of species. The change in the dominant barnacle species observed in the fouling was caused, apparently, by the reproductive strategy of Hesperibalanus hesperius, which is more labile than that of Balanus rostratus, and by the anthropogenic impact on the ecosystem of the bay. The fouling was marked by bivalve and sea anemone species resistant to silting and pollution. The main groups of epibionts were classified as suspension feeders, and as selective detritophages that are characterized by their type of feeding. The total infestation of shells of the Japanese scallop by boring polychaetes and the depressed condition of most mollusks and algae evidenced the unfavorable ecological situation in the area surveyed.     

象山港日本对虾增殖放流的效果评价

日本对虾是中国近海重要的增殖品种,2010年象山港分两批次放流日本对虾苗种约1.67亿尾。通过对放流苗种存活状况、洄游分布、生长特性及回捕情况的跟踪调查,对象山港日本对虾的增殖效果做出初步评价。结果表明:(1)日本对虾放流苗种在8月中旬成为补充群体,集中于港区底部进行索饵育肥;9月中旬,第1、2批放流苗种的平均体长分别达到95.4 mm和71.4 mm,成活率分别约为0.79%和1.06%;10月上旬,随着港区水温降低,增殖苗种资源量锐减。(2)协方差分析表明:日本对虾增殖群体和自然群体的体长-体重关系存在显著性差异,增殖群体的体征状况明显优于自然群体。(3)日本对虾放流苗种在港区主要为桁杆拖虾和地笼网渔业所利用,在港区滞留期间,回捕率约为0.25%。总结发现:栖息地破坏及放流苗种的过早利用是制约象山港日本对虾增殖效果的重要因素,优化增殖策略、保护港区生态环境应是今后港区增殖工作的重点。     

The polymorphism in the promoter region of metallothionein 1 is associated with heat tolerance of scallop Argopecten irradians

Metallothioneins (MTs), a superfamily of cysteine-rich proteins, perform multiple functions, such as maintaining homeostasis of essential metals, detoxification of toxic metals and scavenging of oxyradicals. In this study, the promoter region of a metallothionein (MT) gene from Bay scallop Argopecten irradians (designed as AiMT1) was cloned by the technique of genomic DNA walking, and the polymorphisms in this region were screened to find their association with susceptibility or tolerance to high temperature stress. One insert–deletion (ins–del) polymorphism and sixteen single nucleotide polymorphisms (SNPs) were identified in the amplified promoter region. Two SNPs, − 375 T–C and − 337 A–C, were selected to analyze their distribution in the two Bay scallop populations collected from southern and northern China coast, which were identified as heat resistant and heat susceptible stocks, respectively. There were three genotypes, T/T, T/C and C/C, at locus − 375, and their frequencies were 25%, 61.1% and 13.9% in the heat susceptible stock, while 34.2%, 42.1% and 23.7% in the resistant stock, respectively. There was no significant difference in the frequency distribution of different genotypes between the two stocks (P > 0.05). In contrast, at locus − 337, three genotypes A/A, A/C and C/C were revealed with the frequencies of 11.6%, 34.9% and 53.5% in the heat susceptible stock, while 45.7%, 32.6% and 21.7% in the heat resistant stock, respectively. The frequency of C/C genotype in the heat susceptible stock was significantly higher (P < 0.01) than that in the heat resistant stock, while the frequency of A/A in the heat resistant stock was significantly higher (P < 0.01) than that in the heat susceptible stock. Furthermore, the expression of AiMT1 mRNA in scallops with C/C genotype was significantly higher than that with A/A genotype (P < 0.05) after an acute heat treatment at 28 °C for 120 min. These results implied that the polymorphism at locus − 337 of AiMT1 was associated with the susceptibility/tolerance of scallops to heat stress, and the − 337 A/A genotype could be a potential marker available in future selection of Bay scallop with heat tolerance.     

Comparison of fungal complexes of Japanese scallop Mizuhopecten yessoensis (Jay, 1856) from different areas in the Peter the Great Bay of the Sea of Japan

Mycological investigation of the Japanese scallop Mizuhopecten yessoensis (Jay) (Bivalvia) from different areas of the Peter the Great Bay (Sea of Japan) was conducted. Isolates from internal organs of M. yessoensis scallop comprise 72 species of filamentous fungi from 30 genera of ascomycetes, anamorphic fungi, and zygomycetes. Species richness of filamentous fungi—fungi of the genera Aspergillus, Penicillium, Cladosporium, and Chaetomium—in the internal organs of bivalve mollusks increases in polluted coastal waters.     

Biological consequences of organic pollution of nearshore marine ecosystems in the Russian waters of the Sea of Japan

The process of the inflow and accumulation of organic matter in the bays and bights of the Russian coast of the Sea of Japan was evaluated. Changes in the composition and structure of marine communities that take place in certain water bodies of Primorsky Krai were shown using the author’s own material and literature data. The rating of water bodies by the degree of the anthropogenic transformation of biocenoses as a result of the accumulation of organic matter was performed.     

Distribution of the Yesso Scallop, <Emphasis Type="Italic">Mizuhopecten yessoensis</Emphasis> (Jay, 1857) (Bivalvia: Pectinidae) in the southern part of the Far Eastern Marine Reserve

The current status of the Yesso scallop, Mizuhopecten yessoensis, population has been studied in waters of the southern part of the Far Eastern Marine Reserve. The maximum population densities of this species observed in Kalevala Bay in 2007 and 2015 were 0.50 and 0.56 ind./m², respectively. In the bays and off the semi-open shores, the mean population density was higher than in open waters. The number of Yesso scallops in the studied part of the reserve (1.3 million ind.) is equivalent to that in 2007 (1.2 million ind.); the difference between the population density values in 2007 and 2015 is statistically insignificant at the 5% level of significance. The total number of M. yessoensis in Peter the Great Bay is estimated at 4 million ind.; at least one-quarter of the population inhabits the southern part of the reserve.     

Nosogeographical estimation of the territory of Primorsky Krai based on the analysis of spatial and temporal structure of the incidence of infectious diseases

Nosogeographic estimation of the territory of Primorsky Krai has been carried out on the base of the long-term data on spatial distribution of the incidence of infectious diseases. Analysis of the complex maps of the zoning allow us to say, that the territory of the region is rather clearly differentiated by the groups of infections.