Intertidal Communities of Severnyi Bay (Northern Sakhalin Island)

The paper describes the composition, structure and vertical distribution of intertidal communities in Severnyi Bay (the northern extremity of Sakhalin Island).     

Microbian Indication of Pollution of the Coastal Zone of the Sea of Okhotsk and Avacha Bay

The results of microbiological analysis of a number of microorganisms of various ecological–trophic groups in plankton microbial communities of some water areas of the Sea of Okhotsk and Avacha Bay are presented. The data were compared to the hydrochemical parameters (temperature, salinity, BOD₅, dissolved oxygen, phosphates, organic phosphate, detergents) determined simultaneously. The microbian indication method is used for express assessment of water pollution of the surveyed areas. The data demonstrated that Avacha Bay was subjected to heavier anthropogenic impact than the water areas of the ports of Kholmsk and Magadan.     

New Data About Seasonal Distribution and Migrations of Whales and Dolphins in the Sea of Okhotsk

This paper presents new data about the seasonal distribution of whales and dolphins in the Sea of Okhotsk including the ice period. Even under the most severe ice conditions, the migrating species of whales and dolphins may be encountered in the Sea of Okhotsk. In all seasons the density of cetaceans is higher in the eastern part of the sea, which is more abundant in fish.     

Distribution,Feeding, and Some Physiological Parameters of the Pacific Herring from the Gizhigin and Okhotsk Populations in the North Part of the Sea of Okhotsk in the Spring Season

The distribution of the Pacific herring of various sizes from the Okhotsk and Gizhigin-Kamchatka populations is discussed. The dependence of herring food composition on the condition of the plankton community is demonstrated. In the spring season the feeding rate of juveniles and fattening adult herring depended on the degree of its fatness and on the maturity of the gonads in the prespawning period.     

Preliminary investigation of Okhotsk Sea ice algae; taxonomic composition and photosynthetic activity

Okhotsk Sea pack ice from Shiretoko in northern Hokkaido, sampled in March 2007, contained microalgal communities dominated by the centric diatoms Thalassiosira nordenskioeldi and T. punctigera. Domination by this genus is very unusual in sea ice. Communities from nearby fast ice at Saroma-ko lagoon were dominated by Detonula conferavea and Odontella aurita. Average microalgal biomass of the Okhotsk Sea pack ice (surface and bottom) was 1.59 ± 1.09 μg chla l⁻¹ and for fast ice (bottom only) at nearby Saroma-ko lagoon, 16.5 ± 3.2 μg l⁻¹ (=31.1 ± 5.0 mg chla m⁻²). Maximum quantum yield of the Shiretoko pack ice algal communities was 0.618 ± 0.056 with species-specific data ranging between 0.211 and 0.653. These community values are amongst the highest recorded for sea ice algae. Rapid light curves (RLC) on individual cells indicated maximum relative electron transfer rates (relETR) between 20.8 and 60.6, photosynthetic efficiency values (α) between 0.31 and 0.93 and onset of saturation values (E _k) between 33 and 91 μmol photons m⁻² s⁻¹. These data imply that the pack ice algal community at Shiretoko was healthy and actively photosynthesising. Maximum quantum yield of the Saroma-ko fast ice community was 0.401 ± 0.086, with values for different species between 0.361 and 0.560. RLC data from individual Saroma-ko fast ice algal cells indicated relETR between 55.3 and 60.6, α values between 0.609 and 0.816 and E _k values between 74 and 91 μmol photons m⁻² s⁻¹ which are consistent with measurements in previous years.     

夏季鄂霍茨克海公海区狭鳕渔场环境特征

根据鄂霍茨克公海区狭鳕资源声学评估调查资料,研究了狭鳕分布状况及渔场环境特征,并分析了狭鳕行动分布与环境的关系．结果表明,8月公海区狭鳕密集群位于55°N以北、水深小于500m的海域,其主要分布水层在150～300m之间;调查期间狭鳕只为索饵群体,主要摄食太平洋磷虾,狭鳕密集区一般也为太平洋磷虾高密度分布区;8月公海区水温跃层大致在0～50m之间,强度为0．25℃     

The First Finding of the Actinia Synandwakia hozawai in the Sea of Okhotsk

The finding of the actinia Synandwakia hozawai in the coastal waters of northern Sakhalin (Sea of Okhotsk) suggests a wider range of this species, which was previously only known to inhabit the coastal waters of eastern Japan. Data are presented on the morphology of the S. hozawai specimen from the Sea of Okhotsk and the types of its nematocysts.     

Autotomy and regeneration of limbs in the male blue king crabParalithodes platypus from the Bering Sea and the Sea of Okhotsk

Limb loss and the frequency of regeneration was investigated in the male blue king crabParalithodes platypus collected in the Sea of Okhotsk and the Bering Sea. TheP. platypus population in the Bering Sea is characterized by an anomalously high proportion of crabs with missing limbs, which is largely due to the intensive fishing. The present approach to the exploitation of the Bering Sea population, in which large intact crabs are removed and injured crabs are left to recover to the normal state, may result in a decline in the reproductive potential of this population as early as this coming year.     

First Record of Ulca bolini (Pisces: Hemitripteridae) in the Southeastern Part of the Sea of Okhotsk

This paper presents data on the first record of Ulca bolini. The fish was caught at a depth of 280–300 m in the Sea of Okhotsk off the Kuril Islands (Prostor Bay, Iturup Island). It was 60 cm in fork length (FL) and 7 kg in weight.     

Living benthic foraminifera of the Okhotsk Sea: Faunal composition, standing stocks and microhabitats

Live (Rose Bengal stained) benthic foraminifera were investigated in surface sediment samples from the Okhotsk Sea to reveal the relationship between faunal characteristics and environmental parameters. Live benthic foraminifera were quantified in the size fraction > 125 µm in the upper 8 cm of replicate sediment cores, recovered with a multicorer at five stations along the Sakhalin margin, and at three stations on the southwestern Kamchatka slope. The stations are from water depths between 625 to 1752 m, located close or within the present Okhotsk Sea oxygen minimum zone, with oxygen levels between 0.3 and 1.5 ml l^- 1. At the high-productivity and ice-free Kamchatka stations, live benthic foraminifera are characterized by maximal standing stocks (about 1700-3700 individuals per 50 cm²), strong dominance of calcareous species (up to 87-91% of total live faunas), and maximal habitat depths (down to 5.2-6.7 cm depth). Vertical distributions of total faunal abundances exhibit a clear subsurface maximum in sediments. At the Sakhalin stations, which are seasonally ice-covered and less productive, live benthic foraminifera show lower standing stocks (about 200-1100 individuals per 50 cm²), lower abundance of calcareous species (10-64% of total live faunas), and shallower habitat depths (down to 2.5-5.4 cm depth). Faunal vertical distributions are characterized by maximum in the uppermost surface sediments. It is suggested that 1) lower and strongly seasonal organic matter flux, caused by the seasonal sea ice cover and seasonal upwelling, 2) lower bottom water oxygenation (0.3-1.1 ml l^- 1), and 3) more pronounced influence of carbonate undersaturated bottom water along the Sakhalin margin are the main factors responsible for the observed faunal differences. According to species downcore distributions and average living depths, common calcareous species were identified as preferentially shallow, intermediate and deep infaunal. Foraminiferal microhabitat occupation correlates with the organic matter flux and the depth of the oxygenated layer in sediments.     

Specific Biological Traits of Males of the Blue Crab Paralithodes platypusin the Northeast Part of the Sea of Okhotsk

Data on body size, composition, and mass; peculiarities of molting; and number and seasonal migrations of males of the blue king crab Paralithodes platypusfrom the northeast part of the Sea of Okhotsk are presented. It was found that the main aggregations of juveniles (up to 65% of the total number) are located in the south of the population area. Males molt once every two years, and the relative number of groups molting in alterating years was equal. Mass molting was observed at the end of June and July. Mass migration of males to shoals occurred in June, and their return occurred in October.     

Distribution of the Eelpout Lycodes soldatovi(Pisces: Zoarcidae) over the Continental Slope of the Sea of Okhotsk

The eelpout Lycodes soldatovi was found at depths of 153 to 1005 m in the Sea of Okhotsk; however, it usually inhabits the depth range of 400 to 800. The mean and maximum abundance and the biomass of this species were 198.5 and 1037 individuals per km² and 173.7 and 1275 kg/km², respectively. In view of the data on the distribution of young fish (up to 30 cm in total body length) and the reports on the absence of Lycodes larvae, a hypothesis was developed that this species spawns predominantly in the waters off western Kamchatka and eastern Sakhalin at the depth range of 700 to 900 m. Large individuals (>50 cm) exhibit higher migratory activity and are more tolerant of environmental conditions. That is why they are encountered throughout the distribution area of this species, even in subzero temperature areas. Lycodes soldatovi seems to be a typical inhabitant of the Sea of Okhotsk, except for the waters off the South and Central Kuril Islands and the Pacific waters off the North Kuril Islands.     

The size composition of the pelagic eggs of walleye pollack <Emphasis Type="Italic">Theragra chalcogramma</Emphasis> in spawning areas of the northern Sea of Okhotsk

The data on the size composition of the pollack developing eggs of walleye pollack collected in the northern Sea of Okhotsk in 2001 during mass spawning are given. The eggs caught in western Kamchatka and in Shelikhov Bay had the greatest diameter; they were somewhat less in the northern Okhotsk Sea area; and the smallest eggs were found in eastern Sakhalin. The clinal variability of the size composition of walleye pollack eggs was observed in the northern Sea of Okhotsk, and in the western and eastern parts it had a local pattern. Parameters such as spawning female size composition, temperature, and salinity, as well their influence on the size composition of eggs, were considered.Original Russian Text Copyright © 2004 by Biologiya Morya, Ovsyannikov.     

Coccolithophore (–CaCO3) flux in the Sea of Okhotsk: seasonality, settling and alteration processes

Coccolithophore fluxes were determined in the Sea of Okhotsk using samples from a 1 year experiment (12 August 1990 to 12 August 1991) with sediment traps at 258 and 1061 m depth. A special study was made on Coccolithus pelagicus, using fragmentation and the degree of etching, as indicators of transport mechanisms. A Corrosion Index for C. pelagicus is developed. The coccolithophore flux pattern at 258 m depth was characterised by a strong seasonality, with flux peaks during autumn 1990 (late November to early December) and spring 1991 (March). The assemblage consisted almost entirely of the two species C. pelagicus and Emiliania huxleyi. During autumn, coccolithophore transportation to 258 m depth mainly occurred within cylindrical fecal pellets and marine snow aggregates of silicoflagellates, and through agglutination on tintinnids. Grazing caused severe fragmentation of coccoliths and disintegration of coccospheres. Marine snow aggregates contained many intact coccospheres of C. pelagicus. During spring, coccolithophores were probably removed from the euphotic zone by the ballast effect of sinking diatoms. The coccolithophore flux peak in spring occurred immediately after the ice had retreated from the trap station, and the trapped assemblage included coccoliths of subtropical species. These features indicate drifting from an ice-free location to the south or east.The coccolith and coccosphere flux at 1061 m was respectively 7 and 12 times lower than at 258 m depth, and maximum fluxes were recorded 2 months later. Increasing carbonate dissolution from 258 to 1061 m depth is expressed in the coccolithophore–CaCO₃ flux reduction of 82%, and in the increasing percentage of etched coccoliths of Coccolithus pelagicus from 32 to >90%.     

Evaluation of the Effect of Light Intensity on the Measurement of the Photosynthetic Rate in Plankton Microalgae by the Chlorophyll Fluorescence Method

The use of relative variable fluorescence (RVF) of chlorophyll, as measured in the presence of Diuron, an inhibitor of electron transfer, for the estimation of the photosynthetic activity of plankton microalgae was analyzed under a wide range of light intensities in the PAR region. Oxygen evolution rates (estimated by the method of light and dark bottles and the amperometric method), RVF, and chlorophyll a concentration were measured in parallel in natural algal cenoses and microecosystems. When the previously used regression equation, in the form A = b(F/F_d)C_chlI, where A is O₂ evolution rate (g/(m³ h), F/F_d is RVF (relative units), C_chl is chlorophyll a concentration (mg/m³), and I is light intensity (W/m²), was verified in the PAR region, we observed a nonlinear dependence of the correction coefficient b on I, which can be described by the formula b = 6.227 × 10³I. This result agrees with the hypothesis that chlorophyll a fluorescence quenching comprises photochemical (qQ) and energy (qE) components. On the basis of the energy model, we determined the upper limit b_max = 0.003 for light intensity range I< 4.4 W/m² and the lower limit b_min = 0.0003 for I = 400 W/m².     

Comparative Characterization of the Microbial Community in Two Species of Sponges from Sea of Japan Using Fatty Acid Markers

The fatty acid composition of total lipids in two species of sponges (Halichondria panicea and Clathria pennata) inhabiting the same biotope in the Sea of Japan was examined. More than 80 fatty acids (FAs) were found for each species of sponges. Of them, 61 fatty acids were identified for H. panicea and 54 for C. pennata. The relative content of most FAs was less than 1%. The contribution of symbiotic microorganisms to the total fatty acids was higher in H. panicea than in C. pennata. Bacterial symbionts and microeukaryotes were found among the microorganisms associated with the sponges. The contribution of prokaryotic organisms was equal (7.8%) for both species of sponges, but the fatty acids were characteristic of different taxonomic groups of bacteria. The proportion of microeukaryotic fatty acids in the total lipids of H. panicea (19.6%) was two times that of C. pennata (10.1%).     

Filamentous fungi of the submarine soils of the Sakhalin Gulf (Sea of Okhotsk)

This study examines the biodiversity of submarine-soil filamentous fungi in Sakhalin Gulf for the first time. A total of 82 species of fungi belonging to 35 genera were isolated and identified. Of these, representatives of Anamorphic fungi were predominant. All species identified were facultative marine fungi, except one, Acremonium fuci, which was known until now only from marine habitats. The qualitative and quantitative structure of submarine-soil fungal assemblages of the eastern part (Amur River plume) and the western part (continental shelf) of Sakhalin Gulf was studied.     

An Examination of Cell Volume in Dominant Phytoplankton Species of the Central and Southern Adriatic Sea

The phytoplankton biomass expressed as total cell volume is often of doubtful value due to cell size and volume variations in the organisms present. Cell volume calculations for 95 phytoplankton species and volume-frequency diagrams for 25 dominant species were analyzed for the Adriatic Sea. Recommendations for more precise work dealing with phytoplankton cell volume and biomass are given. Temporal variations in the average microplankton cell volume are presented and discussed.     

<Emphasis Type="Italic">Magadania skopetsi</Emphasis>, a new genus and species of Zoarcidae (Teleostei: Perciformes) from the Sea of Okhotsk

A new genus and species of zoarcid fish, Magadania skopetsi, is described on the basis of 17 specimens (83.4–115.9mm SL) from the intertidal zone of the northern coast of the Sea of Okhotsk, near Magadan, Russia. This species differs from other known zoarcid genera and species by having the following combination of characters: suborbital bones 5, the suborbital canal with 6–8 small pores; first epibranchial fan-shaped; palatopterygoid series reduced; supraoccipital broadly contacting exoccipital; posttemporal ventral ramus weak; upper lip continuous at symphysis; palatine teeth, pelvic fins and scales present; lateral line configuration mediolateral, incomplete, absent on posterior half of body; vertebrae 18–22+78–83=97–104. The closest genus cannot be determined cladistically except that the species is a member of the subfamily Gymnelinae. During the spawning season, M. skopetsi lives under stones near the outer marginal area of the intertidal zone.     

2008年夏季南海北部浮游植物群落结构特征分析

根据2008年8月15日—2008年9月7日南海北部调查期间所获得的网采浮游植物资料,对该海域的4个断面共计13个站位的浮游植物群落结构特征进行了研究,包括种类组成、丰度、分布、多样性以及浮游植物群落结构与环境因子之间相关关系等基本状况。本次调查共鉴定出浮游植物4门53属169种(含变种和变型),主要以暖水性、广温性和广布性种为主,其中硅藻门(Bacillariophyceae)37属114种,占总种数的67.4%,甲藻门(Pyrrophyta)12属50种,占总种数的29.6%,蓝藻门(Cyanophyta)2属3种及金藻门(Chrysophyta)2属2种等。浮游植物丰度平均值为18.06×104cells/m3,其中硅藻丰度平均值为55.72×106cells/m3,甲藻丰度平均值为0.81×106cells/m3。调查区域内的优势种包括铁氏束毛藻(Trichodesmium thiebautii),洛氏角毛藻(Chaetoceros lorenzianus),柔弱菱形藻(Nitzschia delicatissima),红海束毛藻(Trichodesmium erythraeum)和菱形海线藻(Thalassionema nitzschioides)。藻类为聚类分析(UPMGA)将站点大致上分为4个生态区(珠江口生态区,吕宋海峡区,琼东上升流区和18°N断面区),结果表明,在地理位置上分布比较相近的站点具有较高的群落结构组成相似性。