Feeding ecology of the tufted puffin (<Emphasis Type="Italic">Lunda cirrhata</Emphasis>) and the horned puffin (<Emphasis Type="Italic">Fratercula corniculata</Emphasis>) in the northern Sea of Okhotsk

The feeding of tufted puffin and horned puffin nestlings was studied on two islands of Tauyskaya Bay of the Sea of Okhotsk: at Talan Island in 1999–2004 and 2006 and Umara Island in 1994 and 1996–1997. The composition of the puffin diet during the breeding season was determined. The main fish species in the diet were determined and the seasonal and annual dynamics of the occurrence of the items was analyzed. Comparative data on biological characteristics, such as the size, weight and age of the fish caught by these birds, as well as the size and composition of food samples, were collected. Differences between the age groups of fish in the diets of the two puffin species were revealed. Conditions for forming of seabird feeding base in Tauyskaya Bay were described.     

Composition and seasonal fluctuations of the ichthyoplankton community in a shallow tidal channel of Cadiz Bay (S.W. Spain)

The composition and seasonal variation of the ichthyoplankton community in a shallow tidal channel in Cadiz Bay was studied for 5 years (1984 1988), taking fortnightly samples with a conical tide-strained net (0.5 mm mesh). Thirty-nine species belonging to 21 families of teleosts were caught. Four species ( Pomutoschistus microps Kroyer, Atherina hoyeri Risso, Liza rumuda Risso and Lizu a lira Ia Risso) totalled more than 90% of the annual ichthyoplankton abundance. Three species, assumed to be permanent residents, dominated the number offish (837%), and were represented by all their developing stages; 26 species (66.7%) were temporary residents, contributing 17.2% to the total abundance and were represented only by early developing stages; the remaining 10 species were classified as rare. Monthly numbers of species and individuals showed seasonal variation with a main annual peak in spring and in late spring-early summer, respectively. The diversity (H') and evenness (S) indices of this community were low (0.13 to 1.83 and 0.03 to 0.71. respectively), with higher values in winter and late summer, and both were significantly correlated with the log-transformed density of temporary residents (r = 0.43 and 0.41, respectively; P<0.0l) and permanent residents (r=−0.75 and −0.79, respectively; P<0.01). Multivariate classification analysis of samples revealed that similar cyclical changes were taking place in the structure of this ichthyoplankton community every year; three periods could be differentiated: (1) a cool period of low fish density but relatively high diversity; (2) moderate temperature and salinity with high numbers of species and density but low diversity and (3) a warm period of moderate diversity and fish density.     

Comparative characteristics of the ichthyoplankton of lagoon lakes of the south-eastern part of Sakhalin

Ichthyoplankton surveys are made in lagoon water bodies of the south-eastern part of Sakhalin (the Vavai-Chibisan system of lakes, Lake Tunaicha, Lake Izmenchivoe) from April until November 2002–2007. Comparative characteristics of ichthyoplankton complexes in the ice-free period is given. In the investigated lagoon lakes, differences in the species composition of the ichthyoplankton by the number and time of appearance of the maxima of abundance of eggs and larvae are noted, and also related to morphological structure and hydrological conditions of water bodies. In lagoon lake Izmenchivoe with a salinity not less than 26‰, the eggs and larvae of marine fishes only takes place while, in Vavai-Chibisan lakes, that of freshwater fishes only takes place. In brackish lake Tunaicha, the lowest number of fish species reproduce. In the Vavai-Chibisan system and in Lake Izmenchivoe, one maximum of abundance of ichthyoplankton in June is recorded and, in Lake Tunaicha, two maxima (the highest in June and less expressed in August) are recorded. Irrespective of the species composition, the ichthyoplankton complexes of lagoon lakes have general traits determined by hydrological conditions of water bodies and by their general origin and geographic situation: prevalence of eggs and larvae of low boreal fish species, the maximum species diversity in the late spring-early summer, and decrease of abundance in cooler years.     

Retrospective analysis of the marine flora of Vostok Bay,Sea of Japan

A general list of the flora of Vostok Bay (Sea of Japan) compiled on the basis of original and literature data includes 161 species, among them 25 green algae, 42 brown algae, 90 red algae, and 4 species of seagrass. In the period from 2000 to 2004, 114 species of macrophytes (19 green algae, 29 brown algae, 63 red algae, and 3 species of seagrass) were found in Vostok Bay; 19 species of algae were first records for this bay. On the whole, the flora of Vostok Bay is dominated by warm-water species, among which Asian low-boreal species occupy the leading position. The flora of Vostok Bay is changing under the influence of global climatic and local anthropogenic factors. In recent years, there is a tendency for the proportion of warm-water species to increase. The local anthropogenic influence on the flora of Vostok Bay has caused changes in the species composition of plant communities.     

Testing the enemy release hypothesis: trematode parasites in the non-indigenous Manila clam <Emphasis Type="Italic">Ruditapes philippinarum</Emphasis>

Knowledge of temporal variation in nearshore Laurentian Great Lakes fish assemblages is important for understanding species–habitat associations, how abiotic and biotic influences vary temporally, and when sampling should occur. Using spring and fall seining data from Lake Erie beaches, we compared day and night fish assemblages and tested for differences among sampling periods. Beaches were utilized by a diverse collection of Lake Erie basin fishes (one-third of known species). During all sampling periods, catches were dominated by cyprinid species (53–91%), and by invertivores and planktivorous fishes. Diel differences were detected in abundance, species richness and assemblage structure. Multivariate analyses (canonical analysis of principal coordinates) indicated that season had a larger influence on fish assemblage structure than diel period. Given observed temporal variation in assemblage structure, studies of Laurentian Great Lakes beach fishes should be restricted to a single time period (e.g. day-time spring sampling), or adopt sampling designs that permit diel period and season to be included as factors in analyses. Second, the large seasonal variation in assemblage composition combined with higher night species richness indicates that night sampling during both spring and fall would be the most efficient and comprehensive approach for beach fish inventory. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. Handling editor: J. Trexler     

Species composition and distribution of summer ichthyoplankton in Chupa Estuary (Kandalaksha Bay of the White Sea)

On the basis of ichthyoplankton surveys performed in July 2002 and June 2004–2005 in Chupa Estuary and adjacent waters of Kandalaksha Bay, species composition and distribution of eggs and larvae of fish were studied. Early stages of development of seven fish species were found in the composition of ichthyoplankton. The bulk of abundance of ichthyoplankton was formed of Clupea pallasii marisalbi larvae. It was shown that the sites of aggregation of larval C. pallasii marisalbi from June to July are constant and located in the central and preestuarine areas of Chupa Estuary. Possible routes of their passive migrations within Chupa Estuary and the adjacent water area of Kandalaksha Bay are considered. It is suggested that the drift of larvae beyond the estuary proceeds slowly, and after hatching they can long stay in the estuary concentrating in its central and preestuarine areas.     

Distribution of ichthyoplankton in the eastern Peter the Great Bay,Sea of Japan,in June and July of 2007

Comparison of the results of ichthyoplankton surveys conducted at 97 stations in the eastern part of the Peter the Great Bay of the Sea of Japan, in June–July 2007 with the similar research data of the 1950s shows that at present, as was the case 50 years ago, flatfish eggs belonging mainly to the yellowfin sole Limanda aspera and brown sole Pleuronectes herzensteini prevail in the local ichthyoplankton (up to 86%). The highest concentrations of these species’ eggs were recorded in the Vostok Bay and Strelok Bay. The spawning activity of flatfish in 2007 is found to be lower than in the mid 1900s, but the significance of the eastern part of the Peter the Great Bay for flatfish reproduction remains large. The importance of long-term monitoring in this area, which is being subjected to steadily growing anthropogenic impacts, is also proven.     

Distribution and seasonal changes in fish abundance in the estuary of the Razdol’naya River (Peter the Great Bay), Sea of Japan

The distribution and seasonal dynamics of fish abundance in the estuary of the Razdol’naya River (Peter the Great Bay) depending on several abiotic factors are considered. It is established that fish biomass increases with an increase in salinity and decrease in water temperature (both in space and time). Freshwater stenohaline species dominate in the upper part of the estuary, semianadromous and freshwater euryhaline species dominate in the middle part, and semianadromous and marine species dominate in the lower part. The seasonal succession of ichthyocenosis includes two periods: warm (May–October) and cold (November–April). The warm period is characterized by a low biomass (4–10 g/m²) and maximum species richness (22–29 species) against the background of a decrease of the penetration into the estuary of high-saline waters and an increase in the water discharge, turbidity, and temperature. Freshwater species dominate in catches, and subtropical migrants appear. In the cold period, species richness is minimal (2–12 species), and biomass is, on the contrary, very high (on average, 71–374 g/m²); water temperature and discharge are minimal. In catches, the proportion of semianadromous and marine species is maximum.     

Subtidal macrobenthos communities of Vostok Bay (Sea of Japan) under conditions of anthropogenic impact

Quantitative samples of the macrobenthos were collected in May, July, and October–November from 2000 to 2002 in Vostok Bay, Sea of Japan. The main characteristics of the subtidal macrobenthos communities are described. The present study shows that the rocky bottom communities of Vostok Bay have changed little over the past 30 years. Changes have occurred in the structure of soft bottom communities and phytocenoses. Analysis of the macrophytes species composition and the value of the floristic coefficient suggest a currently moderate anthropogenic load on Vostok Bay.Original Russian Text Copyright © 2004 by Biologiya Morya, Galysheva.     

Summer Ichthyoplankon in Onega Bay of the White Sea: Species Composition and Spatial Distribution

Data on the species composition and distribution of ichthyoplankton in Onega Bay of the White Sea are presented for June–July 2007, 2010–2012, and 2015–2016. In the ichthyoplankton, the specimens of the early developmental stages of 21 fish species were registered; the larvae of the White Sea herring Clupea pallasi marisalbi, capelin Mallotus villosus, and Pacific sand lance Ammodytes hexapterus were the most abundant. It is shown that the northwestern and southeastern zones, distinguished in Onega Bay by hydrophysical parameters, also differ in species composition and in ichthyoplankton abundance.     

Composition, structure and distribution of the ichthyoplankton in a Mediterranean coastal lagoon

The species composition and assemblage structure of the ichthyoplankton from the Mar Menor Lagoon in south‐east Spain are given. The fish larvae were sorted from zooplankton samples collected at 20 stations with a plankton net (50 cm mouth diameter and 500 μm mesh) during 36 surveys between February and December 1997. A total of 39 575 fish larvae representing 14 families, 22 genera and 36 species were identified. Gobiidae was the most dominant family (77·0%) followed by Blenniidae (19·4%) and Atherinidae (1·3%). The most abundant species were Gobius niger and Gobius paganellus , which accounted for 42·7 and 19·3% of the total respectively. These species were followed in order of relative abundance by Pomatoschistus marmoratus (13·9%), Parablennius pilicornis (9·4%), Lipophrys pavo (7·7%), Atherina boyeri (1·3%) and Parablennius tentacularis (1·3%). The high species diversity (2·0–2·8 bits individual⁻¹ for the annual diversity spectra at each sampling station) reflected a diverse assemblage of species. The main commercial species in the lagoon (Sparidae and Mugilidae) were poorly represented among the ichthyoplankton and they probably enter the lagoon on the bottom as recruits. Chlorophyll a concentration in the water column was the main factor explaining the seasonal variation in larval abundance. Spatial distribution of larvae was related to hydrographical circulation patterns in the lagoon and the movement of marine‐spawned larvae through the channels connecting the lagoon with the Mediterranean Sea.     

Seasonal and interannual variation of the ichthyoplankton off the coast of Northern Morocco

Changes in the qualitative and quantitative composition of the ichthyoplankton off the coast of Northern Morocco (36–28° N) are analyzed in different seasons of 1994–2008. Pelagic eggs and larvae of over 80 fish species belonging to 57 families are recorded. In cold periods at the Morocco coast, there is maximum spawning of fish belonging to the subtropical (Mediterranean-Atlantic) fauna, the dominant of which are European pilchard Sardina pilchardus, common scad Trachurus trachurus, and Atlantic mackerel Scomber japonicus. In warm periods, in addition to the aforementioned species, the ichthyopankton often comprises eggs and larvae of fish form the tropical fauna. Among the latter are round sardinella Sardinella aurita and West-African mackerel T. trecae dominate. The spawning biomass of principal commercial fish is also calculated by the quantity of eggs laid by females.     

Seasonal dynamics and grazing rate of zooplankton in Yueqing Bay, China

The species composition, biomass, abundance, and species diversity of zooplankton were determined for samples collected from August 2002 to May 2003 from 14 stations in Yueqing Bay, China. Phytoplankton growth rate and microzooplankton grazing rate were obtained by using the dilution method developed by Landry and Hassett. The spatial and temporal variations of zooplankton and its relationship with environmental factors were also analyzed. The results showed that the zooplankton in the Yueqing Bay could be divided into four ecotypes, namely coastal low saline species, estuary brackish water species, offshore warm water species, and eurytopic species. A total of 75 species of zooplankton belonging to 56 genera and 17 groups of pelagic larva were identified in the Yueqing Bay. The coastal low saline species was the dominant ecotype in the study area, and the dominant species were Labidocera euchaeta, Acartia pacifica, Acrocalanus gibber, Pseudeuphausia sinica, and Sagitta bedoti among others. There was considerable seasonal variation in zooplankton biomass and abundance in the surveyed areas. The peak biomass appeared in August, descending in November and in May, and the lowest biomass appeared in February. Similarly, the highest abundance of zooplankton was observed in August, with the abundance descending in the following months: May, November, and February. There were similar horizontal distribution patterns for the biomass and the abundance of zooplankton. They both increased from the upper to the lower bay in February and May, but decreased from the upper to the lower bay in August. Biomass and abundance were evenly distributed in the Yueqing Bay in November. Moreover, there was marked seasonal variation in the species diversity of zooplankton, which conformed to the abundance of zooplankton. Results of the dilution experiments indicated that there was grazing pressure of microzooplankton on phytoplankton in the Yueqing Bay throughout the year though the rate of microzooplankton grazing on phytoplankton varied seasonally. Phytoplanktons were growing at 0.26–2.07/d and grazed by microzooplankton at a rate of 0.15–0.48/d in different seasons. __________ Translated from Acta Ecologica Sinica, 2005, 25(8): 1853–1862 [译自: 生态学报, 2005, 25(8): 1853–1862]     

Species composition,seasonal dynamics of quantities and spatial distribution of hydromedusae (Cnidaria: Hydrozoa) in Vostok bay of the Sea of Japan

Hydromedusae (Cnidaria: Hydrozoa) are one of the most common and widely spread plankton organisms. Due to their low quantities in the plankton and complicated species identification, they are poorly observed in zooplankton research works, especially in the Northwestern part of the Sea of Japan. The subjects of the present work are the seasonal dynamics of the spatial distribution and abundance of hydromedusae that inhabit Vostok bay (Peter the Great bay of the Sea of Japan), which were observed from April to November in 2002–2004. The timing of mature specimens was studied for different species. Eighteen species were found. Of these, Coryne sp., Tiaropsis multicirrata (Sars, 1835) and Neoturris breviconis (Murbach et Shearer, 1903) are the first records for Peter the Great Bay; the last two species are the first records for the Northwestern part of the Sea of Japan.     

Species composition and distribution of free-living marine nematodes in Vostok Bay, Sea of Japan

The qualitative and quantitative composition of free-living marine nematodes have been studied in Vostok Bay (Peter the Great Bay, Sea of Japan). It is found that the population density of nematodes in the bottom sediments of Vostok Bay shows an uneven distribution. The mean population density equaled 56800 ± 23400 specimens/m². A correlation has been revealed between the population density of nematodes and the substrate type. Altogether, 85 species of nematodes have been found; they were dominated by Sabatieria palmaris, Rhabdodemania orientalis, Araeolaimus parvibulbosus, Oncholaimium paraolium, Doryolaimopsis peculiaris, and Metachromadora itoi. Six taxocenoses of nematodes were distinguished, taking into account the species dominating in the population density and using cluster analysis of the obtained data. The dominating trophic assemblage of nematodes was “scrapers.” In general, the species composition of nematodes in Vostok Bay is characterized by the relatively great similarity with that in other areas of Peter the Great Bay (Sea of Japan).     

Abundance,growth and grazing loss rates of picophytoplankton in Barguzin Bay,Lake Baikal

The abundance, growth, and grazing loss rates of picophytoplankton were investigated in August 2002 in Barguzin Bay, Lake Baikal. Water samples for incubation were taken once at a near-shore station and twice at an offshore station. Contributions of picophytoplankton to total phytoplankton were high (56.9–83.9%) at the offshore station and low (5.8–6.8%) at the near-shore station. The picophytoplankton community in the offshore station comprised mainly phycoerythrin (PE)-rich cyanobacteria, with eukaryotic picophytoplankton being less abundant. In contrast, as well as PE-rich cyanobacteria and eukaryotic picophytoplankton, phycocyanin (PC)-rich cyanobacteria were found in the near-shore station. At the offshore station, growth and grazing loss rates on 25 August were 0.56 and 0.43 day⁻¹, respectively, and on 29 August, 0.69 and 0.83 day⁻¹, respectively. At the near-shore station, growth and grazing loss rates were 1.61 and 0.70 day⁻¹, respectively. These results show that there is a difference in the abundance, composition, and ecological role in the microbial food web of picophytoplankton between the near-shore and the offshore areas in Barguzin Bay.     

Seasonal variation of microbial eukaryotic community composition in the large,shallow, subtropical Taihu Lake,China

Microbial eukaryotic community (0.8–20 μm) composition and its seasonal variation were investigated in large, shallow, subtropical Lake Taihu located in Southeast China. The water samples were collected monthly from August 2006 to July 2007 at two sites distantly located in Meiliang Bay and Lake Center, which differed strongly in their trophic status and sediment resuspension. The microbial eukaryotic community compositions (MECC) were measured using denaturing gradient gel electrophoresis (DGGE) of PCR-amplified eukaryotic 18S rRNA gene fragments. Seasonal variations were related to environmental factors by means of redundancy analysis (RDA) in order to reveal the most important regulating factors. At both sites, the structures and Shannon–Wiener indices of the microbial eukaryotic communities displayed apparent seasonal variations, which were significantly related to environmental variables. There were significant intrahabitat differences in environmental factors regulating MECC, as well as in the seasonal dynamics of the two sites during the study period. At Meiliang Bay, the variations of total phosphorus concentration and cladocera abundance had the most profound impacts on the microbial eukaryotic community composition, while at Lake Center, the total nitrogen concentration and conductivity were most influential. Our results suggest that the DGGE method is a cost-effective way to analyze the seasonal dynamics of MECC and their interaction with environmental variables, which will provide new insights into the diversity and dynamics of MECC.     

Ichthyoplankton in the plankton community of the western sector of the Black Sea in October 2005

Data on the numbers, species composition, and spatial distribution of ichthyoplankton, mesoplankton, and jelly-bodied microplankton in the western sector of the Black Sea in October 2005 are presented. A decrease in the predatory impact of the comb jellyfish Mnemiopsis leidyi on mesoplankton is recorded, which promoted the formation of favorable trophical conditions for larval fish survival. In the 1990s in the study area, the proportion of larvae with empty stomachs reached 80–90%; in October 2005, all the studied larvae were with food.     

青岛崂山青山湾人工鱼礁区及附近海域鱼卵仔稚鱼种类组成与数量分布

为研究人工鱼礁对产卵鱼类的诱集效果和庇护效应,2014—2015年对青岛崂山青山湾海域人工鱼礁区及附近海域鱼卵和仔稚鱼的种类组成和数量分布进行了水平和垂直拖网调查. 2014年春、夏、秋3个季节的7个航次调查中,共采集鱼卵7306粒、仔稚鱼52尾,隶属于4目9科11属12种;2015年同期进行的13个航次调查中,共采集鱼卵10373粒、仔稚鱼159尾,隶属于6目11科14属15种.2年间鱼卵和仔稚鱼样品均以鲈形目数量最多,鲽形目次之,其中鱼卵样品中仅有少鳞鱚和短吻红舌鳎构成优势种;仔稚鱼样品以少鳞鱚优势度最高,但不存在仔稚鱼优势种.鱼卵和稚鱼的高优势度物种的季节间演替明显.春、夏、秋季鱼类浮游生物群落Margalef丰富度指数、Shannon多样性指数和Pielou均匀度指数平均值均较低,说明该海域鱼类浮游生物群落结构稳定性较低.2年间所采集物种对应的成鱼平均营养级分别为3.71和3.78,均属第三营养级中的低级肉食性鱼类,绝大多数为暖温种,无冷温性种类,表现出明显的暖温带特点.综合分析认为,人工鱼礁区鱼类浮游生物群落的多样性相对较高,这与鱼礁区流速和流场特征及复杂的空间异质性有关.     

Oceanographic and lunar forcing affects nearshore larval fish assemblages from temperate rocky reefs

The influence of oceanographic features and moon phases on ichthyoplankton assemblages in a temperate nearshore rocky reef off El Quisco Bay, central Chile, was assessed during austral spring–summer 2015–2016 using Bongo nets. Wind direction was predominantly south-west, and ocean temperature increased gradually during the study period, fluctuating between 11.6°C and 17.7°C. A relatively cold period (from late September to early December, 12.42?±?0.64°C) was distinguished from a relatively warmer phase (from mid-December to February, 13.56?±?1.08°C). Nearshore ichthyoplankton was composed of 13,700 individuals, belonging to 43 taxa. Larval Strangomera bentincki (Clupeidae) were collected in high numbers between late September and late October with peaks during full moon and first quarter (maximum?=?734 ind. 100?m^?3); larval Engraulis ringens (Engraulidae) was most abundant between late October and late December 2015, with peaks during the third quarter and full moon. Principal Component Analysis of ichthyoplankton data explained more than 44% of total variance and showed the influence of cold/warm periods in the structuring of larval fish assemblages. Water temperature had more influence than lunar phase in the structure and composition of nearshore fish larvae off central Chile. We conclude that larval fish assemblages found in nearshore waters change on a seasonal scale by differences in the reproductive activity among species, and that lunar phase exerts a low, but significant effect on the abundance of fish larvae, but this variability is species-specific.