Succession of Fouling Communities on an Artificial Substrate of a Mussel Culture in the White Sea

The pattern of development of a fouling community, based on research data on their formation in the mussel culture in the White Sea is presented. The succession may come to an end either by the mussel community or by the community of Styela rustica, which is analogous to the natural epitbenthic biocenosis of Laminaria saccharina. It also might develop with the deletion of some stages. The presence of the mussel phase is not necessary in the development of fouling. The final stage of the fouling development is determined, apparently, by hydrological conditions.     

Long-Term Changes in Shallow-Water Fouling Communities of the White Sea

The replacement of an ascidian (Styela rustica L.) fouling community by a blue mussel (Mytilus edulis L.) community was described for the White Sea. The alternation of populations of these two species takes place in fouling communities developing in the upper 3- to 5-m layer of water. The life span of each type of fouling probably depends on interannual climate fluctuations.     

Fouling Communities of Hydrotechnical Constructions in Nakhodka Bay (Sea of Japan)

The fouling of mooring facilities in Nakhodka Bay, Sea of Japan, has been studied. The main fouling communities have been distinguished dominated by green algae Enteromorpha linza and Ulva fenestrata, brown algae Laminaria japonica and Costaria costata, a hydroid Obelia longissima, a polychaete Pseudopotamilla occelata, cirripede barnacles Balanus crenatus and Semibalanus cariosus, a bivalve mollusk Mytilus trossulus, and an ascidian Halocynthia aurantium. The naturalization of some species-invaders in the fouling of mooring facilities in Nakhodka Bay has been registered, namely hydroids Laomedea flexuosa and Clytia languida, a polychaete Pseudopotamilla occelata, and a bryozoan Bowerbankia gracilis.     

The Influence of Salinity on Early Ontogeny of the Mussel Mytilus edulisand the Starfish Asterias rubensfrom the White Sea

The influence of increased and decreased salinity on early larvae of the mussel Mytilus edulisL. and the starfish Asterias rubensfrom the White Sea is studied. Fertilized egg cells, embryos, larvae, and yearlings of the two species were compared. Salinity tolerance changes with the stage of development of mussels and starfish. Morphological changes occurring in eggs and embryos exposed to extremely high and low salinities are reported.     

Comparative Study of Microbial Communities from Cultured and Natural Populations of the Mussel Mytilus trossulus in Peter the Great Bay

The 525 strains of heterotrophic bacteria isolated from natural and cultured populations of the mussel Mytilus trossulus and the surrounding seawater were identified to a genus level on the basis of phenotypic analysis and the fatty acid composition of cell lipids. Gram-negative isolates were dominated by six genera of the family Enterobacteriaceae and by the genera Pseudoalteromonas, Vibrio, Photobacterium, Cytophaga/Flavobacterium/Bacteroides, Pseudomonas, and Moraxella. Gram-positive isolates were mainly represented by the genus Streptomyces. The taxonomic compositions of natural and cultured populations of the mussel M. trossulus in Peter the Great Bay were similar.     

Effect of the Spatial Orientation of a Substrate on the Formation of Early Fouling Communities in the White Sea

The formation of early fouling communities developing under different spatial orientations of substrates and various lighting conditions was studied during a field experiment. The algal predominance on the sunlit upward-oriented sides and the animal predominance on the shaded downward-oriented sides are the consequence of two processes: (1) competitive displacement of animals from the sunlit sides by algae; (2) preferential colonization of the shaded downward-oriented sides of the substrates by animals.     

Dynamics of a biofouling community in finfish aquaculture: a case study from the South Adriatic Sea

Biofouling is one of the challenges that can strongly affect the finfish farm economy. Although several studies on biofouling in aquaculture have been conducted in the Mediterranean Sea, they focused on specific taxa or were limited to a particular period of sampling. The present study investigated for the first time the development, composition and variation in a biofouling community in a finfish farm with immersion time, season and depth. The results indicate that all these factors influence biofouling succession and recruitment. Moreover, the species that had a crucial role in structuring the community and in the farm cleaning activities were the ascidian Styela plicata and the bivalve Mytilus galloprovincialis. Compared with the literature data, the results highlight the heterogeneity in the composition of the biofouling present in the Mediterranean Sea. Moreover, such knowledge of the biofouling community could provide important information about management efforts and the costs that farmers will face when siting new fish farms.     

Growth Characteristics of the Common Mussel Mytilus edulis from the White Sea

We studied the following growth indices of the White Sea mussels Mytilus edulis: shell length, total weight, soft tissue weight, and shell weight. The coefficients of allometric relationships between the indices were determined. Age-related changes in the indices could be approximated by the Bertalanffy equation. The maximum age of mollusks in the studied population equaled 13 years (with the maximum shell length of 66.2 mm). Growth rate of littoral mussels in the region of Umba Settlement (Northern Kandalaksha Bay) was lower as compared to those published for other littoral White Sea populations (Chupa Bay).     

Life History of the Barnacle Balanus Amphitrite Darwin and Its Role in Fouling Communities of Peter the Great Bay, Sea of Japan

The life history of the barnacle Balanus amphitrite Darwin and its role in fouling communities of Golden Horn Bay (Peter the Great Bay), which is subjected to thermal pollution, were studied. The warm-water B. amphitrite occurs as a common minor species on operational vessels and waterworks in Peter the Great Bay, where it was brought by ocean-going ships operating on Russia–Japan lines. Even in the conditions of the higher temperature regime of Golden Horn Bay, the reproductive season of B. amphitrite is confined to the summer and autumn months. The adult individuals brought by ships in summer produce 2–3 generations of larvae. The development of larvae and their settling on the substrate occurs from August to October within a broad temperature range from 22.5 up to 12°C. Even in the low temperatures of Golden Horn Bay the larvae attain a greater size than those in tropical and subtropical waters. The juveniles have time to reach maturity and to produce their own progeny, but most often they perish with winter drop in the water temperature. It was shown that in Peter the Great Bay there is dependent population of B. amphitrite inhabiting the anthropogenic substrates only in the warm season: water works, idle vessels, and operational offshore vessels. The water temperature is the limiting factor of successful acclimation of that species.     

A comparative study of the pumping activity of some fouling animals from the White Sea

The pumping activity of the bivalve Mytulus edulus, Hiatella arctica, and solitary ascidian Styela rustica from the White Sea has been studied. The dependence of the pumping activity on the mass and size of animals has been analyzed. It was shown that the mussel is the most active filter-feeder, that the least value of the pumping activity has been registered for H. arctica, and that S. rustica occupies an intermediate position according this index. The results obtained are examined in connection with the competitive relationship of the animals in the fouling community.     

Subtidal Underwater Rock Communities of the White Sea: Structure and Interaction with Bottom Flow

The taxonomic composition and quantitative characteristics of typical subtidal rock communities of the White Sea (biocenosis of Laminaria and biocenosis of Lithothamnion and the sponges Polymastia arctica) were studied. The hydrodynamic activity of the near-bottom water layer within and beyond the communities was estimated using the plaster structures technique. A comparative analysis of our results and the literature data revealed three main types of interactions between the benthic community and the water flow: turbulation of the water flow (mussel banks), smoothing of turbulent pulsations (Laminaria community), and an insignificant effect on the water flow (community of Lithothamnion and sponges).     

Yeast Communities Associated with Diptera of the White Sea Littoral

Microbiology - Relationship between symbiotic yeast and Diptera insects are studied mainly on fruit flies (Drosophilidae). Evolutionary experiments showed that changes in the composition of the...     

Fauna associated with detached kelp in different types of subtidal habitats of the White Sea

The fauna, associated with Laminaria and other largebrown macroalgae was studied by using SCUBA anddredging in two different types of underwater habitatsof the White Sea.In shallow water fjords and bays, with a depth of nomore than 30–40 m, detached kelp (mainly Laminaria saccharina, L. digitata and Alaria esculenta) formed large accumulations. One ofthese benthic accumulations, which has existed morethan 20 years, was studied. It covers about2000 m², and is about 2 m thick. The upper layerof the accumulation of fronds is characterized by highturbulence and is well aerated. The lower layer ischaracterized by anoxic conditions. Mats of sulphurbacteria were not observed, although fronds in themiddle layer were covered by layers of cyanobacteria.About 50 species of macroinvertebrates were found,mainly species that are normally associated withliving kelp, such as the detritivorous species Ophiura robusta and Gammarus oceanicus, and fewspecies that are specific inhabitants of organic-richbiotopes in the White Sea such as Capitellacapitata, Ophryotrocha irinae and Nebaliabipes. It was remarkable that in the shallow waterbasins of the White Sea, the process of decompositionof brown algae in the sublittoral takes place withoutsea urchins, and no other macrofaunal form plays anecological role in the mechanical breakdown of theplant substratum, even not in the large accumulationsof detached kelp.Along the open rocky shoreline, communities associatedwith dead detached kelp were situated at a depth of60–90 m, 40–50 m below the belt of living kelp. Inthis deep zone, no macroinvertebrates typical of thekelp community in the photic zone were found. Duringthe passage from the shoreline to the deeper benthiccommunity, where sea urchins were dominant, all plantdebris became fragmented. These deeper benthiccommunities appeared to be the zone for decompositionof the detached kelp.     

Byssus production rate of the White Sea blue mussel <Emphasis Type="Italic">Mytilus edulis</Emphasis> (Linnaeus, 1758) in the presence of metabolites of some hydrobionts

The byssus production of the blue mussel Mytilus edulis L. was studied in the laboratory in the presence of the metabolites of the following animals: a predator (a starfish Asterias rubens L.) and several species competing with the mussel in White Sea fouling communities (a bivalve Hiatella arctica L. and a solitary ascidian Styela rustica L.). The byssus threads and attachment plaques produced by each mussel per day were counted. The number of byssus threads and plaques was smallest in pure sea water and in the presence of metabolites produced by conspecific individuals.     

Sublittoral Protistan Communities of the Shores of the Sea of Cantabria (Bay of Biscay)

The composition of the protist communities of three coastal areas of the Sea of Cantabria were studied, and the seasonal variation of the larger groups of these organisms described, with respect to the productivity. Also, the annual dynamics of consumption and degradation of organic matter achieved by the ciliate species were analyzed.     

枸杞岛养殖贻贝中诺如病毒污染情况调查与分析

为了解养殖场内贻贝的诺如病毒（Norovirus,NoVs）污染情况和基因型分布特点,分别于2019年4月和9月在浙江省舟山市枸杞岛后头湾和龙泉村贻贝养殖场近岸和远岸区域进行贻贝样本采集及诺如病毒检测,共检测670只贻贝样本,诺如病毒阳性率约9.9%（66/670）。离人类活动区域较近的贻贝,诺如病毒阳性率占总阳性率的72.7%（48/66）,远岸的贻贝诺如病毒阳性率占总阳性率的27.3%（18/66）。共检测到6种诺如病毒基因型,分别为GI.3（36.4%）、GI.4（19.7%）、GII.12（18.2%）、GII.17（13.6%）、GII.3（10.6%）和GII.2（1.5%）。研究表明,枸杞岛养殖场中诺如病毒污染率较高,涉及基因型较多,人类活动对养殖场内贻贝中诺如病毒的富集量具有一定影响。     

Mutual effects of several fouling organisms of the White Sea (<Emphasis Type="Italic">Mytilus edulis,Styela rustica</Emphasis>, and <Emphasis Type="Italic">Hiatella arctica</Emphasis>) on their growth rate and survival

The mutual effects of several fouling species (the bivalves Mytilus edulis and Hiatella arctica and a solitary ascidian Styela rustica) on their growth rate and mortality were studied through field experiments. The interactions between S. rustica and H. arctica appeared to be the least antagonistic. In contrast, the mussel was the most “aggressive” species with regard to both competitors. It was observed that the ascidians died, because they were intensively braided and gummed up with the byssus threads of the mussels. However, in some cases the intraspecific competition was stronger than the interspecific one.     

Mussel culture in a changing environment: the effects of a coastal engineering project on mussel culture (Mytilus edulis L.) in the Oosterschelde estuary (SW Netherlands)

To evaluate the effects of a large scale coastal engineering project on the mussel (Mytilus edulis) bottom culture in the Oosterschelde estuary (S.W. Netherlands), mussel growth and production in the period 1980–1990 are studied in relation to food supply and the hydrodynamic conditions. Due to the construction of a storm-surge barrier and two additional dams, the risk that mussels are swept away by high current velocities decreased, resulting in an increase of the area in the Oosterschelde potentially suitable for mussel culture and in food availability now being more important as a limiting factor. For the Oosterschelde, a clear relation between mussel growth, stock sizes, and phytoplankton dynamics has been demonstrated. The meat yield of mussels landed in autumn — which is an index for growth rate — seems to be determined by the phytoplankton production in the preceding summer. In years with dense bivalve stocks, phytoplankton production and meat yields are relatively low. It is concluded that an increase of the mussel biomass cultured can result in a reduction of the primary production and, consequently, in a deterioration of the growing conditions for suspension-feeders in the estuary. This conclusion is supported by model calculations. An expansion of mussel culture in the new Oosterschelde is therefore dissuaded. Apart from primary production and stock sizes, food supply for mussels on culture lots appeared to be controlled by the horizontal advection of phytoplankton between and within the tidal channels. An observed decline in mussel landings from certain areas is attributed to the reduced mixing energy of the estuary in relation to the present distribution of the lots over the estuary. Production figures from the experimental lots, established in 1988 in the newly available areas, demonstrate that the yield of mussels can be enhanced by relaying culture lots towards the areas where the phytoplankton is produced. It is expected that by redistributing the culture lots, without expanding the biomass cultured, the carrying capacity of the Oosterschelde for mussel culture can be maintained.     

楚科奇海及白令海大型底栖生物初步研究

1999年夏季在楚科奇海、白令海采用30 cm×30 cm箱式取样器,取得16个站位大型底栖生物定量样品。经分析研究有大型底栖生物92科164种,其中多毛类、软体动物和甲壳动物种数最多,占总种数的88.41％,三者构成北极楚科奇海和白令海大型底栖生物的主要类群。优势种有独毛虫属一种(Tharyx sp.) 、齿吻沙蚕属一种(Nephtys sp.)、囊叶齿吻沙蚕(Nephtys caeca)、平滑胡桃蛤(Ennucula tenuis)、短吻状蛤(Nuculana pernula pernuloides)、拟猛钩虾属一种( sp.)、日本沙钩虾(Byblis japonicus)和萨氏真蛇尾(Ophiura sarsii)等。楚科奇海和白令海大型底栖生物平均生物量为111.83 g/m²,平均栖息密度为2538个/m²。生物量和栖息密度均以多毛类和软体动物占多数。楚科奇海和白令海大型底栖生物有5个群落类型：Ⅰ. 梯额虫(Scalibregma inflatum)-紫轮参(Polycheira rufescens)-结栉盖蛇尾(Stegophiura nodosa)群落, Ⅱ. 拟单指虫(Cossurella sp.)-平滑胡桃蛤-鳞甲钩虾(Lepidepecreum sp.)群落, Ⅲ. 缩头竹节虫(Maldane sarai)-葛氏希泊钩虾(Hippomedon gorbunovi)-萨氏真蛇尾群落, Ⅳ.齿吻沙蚕(Nephtys sp.)-平滑胡桃蛤-日本沙钩虾-戈芬星虫(Golfingia sp.)群落和白令海群落, 即索沙蚕(Lumbrineris fragilis)-户枢蛤(Asthenothaerus sp.)-太平洋方甲涟虫(Eudorella pacifica)-革囊星虫(Phascolion sp.)群落。楚科奇海的群落Ⅰ、群落Ⅱ和白令海各群落结构相对稳定;楚科奇海群落Ⅲ和群落Ⅳ出现一定扰动。