73 research outputs found
Structure of mesozooplankton community in the Barents Sea and adjacent waters in August 2009
No full textDvoretsky, Vladimir G., Dvoretsky, Alexander G. (2013): Structure of mesozooplankton community in the Barents Sea and adjacent waters in August 2009. Journal of Natural History 47 (31-32): 2095-2114, DOI: 10.1080/00222933.2013.772670, URL: http://dx.doi.org/10.1080/00222933.2013.77267
Figure 5 in Structure of mesozooplankton community in the Barents Sea and adjacent waters in August 2009
No full textFigure 5. Mesozooplankton biomass (a: mg dry mass m−3 ± standard error; b: g dry mass m−2 ± standard error) within different water masses in the upper 100-m layer in the Barents Sea and adjacent waters in August 2009. MCW, Murmansk coastal waters; AW, Atlantic waters; AWF, Atlantic waters (frontal zone); BW, Bear Island waters; SCW, Svalbard coastal waters; ArW, Arctic waters.Published as part of Dvoretsky, Vladimir G. & Dvoretsky, Alexander G., 2013, Structure of mesozooplankton community in the Barents Sea and adjacent waters in August 2009, pp. 2095-2114 in Journal of Natural History 47 (31-32) on page 2107, DOI: 10.1080/00222933.2013.772670, http://zenodo.org/record/519743
Abundance of pteropods distribution near Novaya Zemlya in the eastern Barents Sea in August 2006
No full textAbundance of pteropods distribution near Novaya Zemlya in the eastern Barents Sea in August 200
Coastal Mesozooplankton Assemblages during Spring Bloom in the Eastern Barents Sea
No full textMesozooplankton play an important role in Arctic shelf ecosystems as a trophic link and a key food source for many larval fish species. The distribution of mesozooplankton in the eastern Barents Sea was studied along a 500 nautical mile-long transect in May 2016 during the spring bloom. Mesozooplankton were sampled using a Juday net hauled from the surface to the bottom at 12 stations. We found good correspondence between the distribution of water masses and mesozooplankton assemblages. Mesozooplankton abundance (mean 73·103 individuals m−2) in Novaya Zemlya coastal water was dominated by Copepoda ova and nauplii, Thyssanoessa spp. nauplii and Oithona similis. Parasagitta elegans and Calanus finmarchicus comprised most of the total mesozooplankton biomass (mean 0.9 g dry mass m−2) in that water mass. A second assemblage (mean abundance 171·103 individuals m−2) was associated with the colder Barents Sea water, with Oithona similis, Copepoda nauplii, Fritillaria borealis and Cirripedia nauplii being the most numerous. In that water mass, C. finmarchicus, Metridia longa, Cirripedia nauplii and Calanus glacialis contributed most to the total biomass (mean 3 g dry mass m−2). The dominance of young stages of Copepoda and a high proportion of meroplankton were typical of spring mesozooplankton assemblages. The spatial distribution of mesozooplankton abundance and biomass was strongly correlated with latitude, longitude and chlorophyll a concentration, which together explained 10% of the total variance in mesozooplankton density. The present investigation is a baseline study for the assessment of the spring mesozooplankton assemblage in the eastern Barents Sea, and for an evaluation of the possible impact of future environmental changes on the Arctic shelf marine ecosystem
Distribution of Calanus species off Franz Josef Land (Arctic Barents Sea)
No full textAbstractThe spatial distribution of Calanus species was examined near Franz Josef Land archipelago in August 2006 and 2007. Surface and bottom water temperatures exceeded the average multiannual values. Calanus species dominated the total mesozooplankton abundance and biomass, accounting for 818±178individualsm−3 (mean±SE) and 803±163mgwetweight(WW)m−3, respectively, in 2006. In 2007, the values were much lower (153±29individualsm−3 and 192±17mgWWm−3, respectively), reflecting the weaker influence of warm Atlantic water that year. Calanus glacialis dominated the Calanus populations, contributing 95% and 60% of the biomass in 2006 and 2007, respectively. Older copepodite stages (CIV–CV) predominated in the C. finmarchicus (69% and 76%, respectively) and C. hyperboreus populations (80% and 77%, respectively), whereas young copepodites (CI–CIII) were predominant in C. glacialis (45% and 59%, respectively). A clear negative relationship between the average water temperature and the total Calanus biomass was observed in 2006, whereas a positive correlation between these parameters was observed in 2007. The distributions of three Calanus species off Franz Josef Land were mainly associated with hydrological conditions and circulation patterns
Summer mesozooplankton community of Moller Bay (Novaya Zemlya Archipelago, Barents Sea)
No full textNovaya Zemlya Archipelago is the eastern boundary of the Barents Sea. Theplankton of this region have been less intensively studied than thoseof other Arctic areas. This study of the mesozooplankton assemblage of Moller Bay was conducted in August2010. The total mesozooplankton abundance and biomass ranged from 962to 2980 individuals m-3 (mean ± SD: 2263 ± 921 indiv.m-3) and from 12.3 to 456.6 mg dry mass m-3 (mean ± SD:192 ± 170 DM m-3) respectively. Copepods and appendicularians werethe most numerous groups with Oithona similis, Pseudocalanusspp.,Acartiaspp., Calanus glacialis and Oikopleura vanhoeffennibeing the most abundant and frequent. Mesozooplankton abundance tendedto decrease with depth, whereas an inverse pattern was observed for the totalbiomass. Total mesozooplankton biomass was negatively correlated with watertemperature and positively correlated with salinity and chlorophyll aconcentration. Comparison with previous data showed significant interannualvariations in the total zooplankton stock in this region that may be due todifferences in sampling seasons, climatic conditions and the distribution ofpotential food sources (phytoplankton and seabird colonies)
Copepod Assemblages in A Large Arctic Coastal Area: A Baseline Summer Study
No full textTo provide a baseline description of copepod assemblages in the Pechora Sea, an estuarine area with great economical and ecological importance, we conducted a survey during the summer season. A total of 24 copepod taxa were identified in the study, with Acartia longiremis, Calanus finmarchicus, Centropages hamatus, Copepoda nauplii, Eurytemora affinis, Oithona similis, Pseudocalanus spp., and Temora longicornis being the most numerous. The high diversity (Shannon index = 2.51 ± 0.06), density (18,720 ± 3376 individuals m−3) and biomass (89 ± 18 mg dry mass m−3) of copepods were revealed. Populations of common small copepod taxa were dominated by the young stages, indicating spawning, while older copepodites prevailed among medium- and large-sized species, showing that their reproduction occurred before our survey. Cluster analysis indicated three groups of stations that mainly differed in the abundance of particular species. There were clear associations between copepod assemblages and environmental variables. Statistical analyses showed significant correlations between copepod abundance and water temperature or sampling depth, while other factors had a lesser influence. Our results suggest a strong effect of local circulation and currents on the spatial pattern of the copepod assemblages in the study area. This study may be useful for future biomonitoring in the south-eastern Barents Sea
Winter Epibiotic Community of the Red King Crab Paralithodes camtschaticus in Sayda Bay (Barents Sea)
No full textThe species composition of epibiotic communities on red king crab was investigated in Sayda Bay, Russia, during November of 2015 and 2016. The community consisted of 12 species in total. Among epibionts, the barnacle Balanus crenatus was most prevalent (67.0%), while the amphipod Ischyrocerus commensalis was the most frequent symbiont (77.3%). Infestation levels in May–June 2005 and September 2004 were higher, as a larger proportion of small crabs without fouling species were present during those seasons. The lower infestation intensities recorded for other common associated organisms during winter can be attributed to their increased mortality due to unfavorable temperature conditions. The localization of epibionts and symbionts were related to larval settlement patterns of attached species and feeding behavior of mobile species. Monthly growth increments for I. commensalis and B. crenatus were estimated at 2 mm in body length and 1.35 mm in basal diameter, respectively. Size-at-age data for epibionts can aid in the age determination of large male crabs that may skip an annual molt
Biological Aspects, Fisheries, and Aquaculture of Yesso Scallops in Russian Waters of the Sea of Japan
No full textScallops are bivalve filter-feeding mollusks that can attain a large size and have great importance in terms of their ecological roles and commercial value. Overfishing has led to a decrease in scallop stocks worldwide, leading to intense development of the aquaculture industry. The latter is well-established in Asian countries in the East Sea and Sea of Japan. In this paper, we summarized information regarding the biology, stock dynamics, and fishery of yesso scallops inhabiting Russian waters of the Sea of Japan. This species has relatively rapid growth rates and reaches a marketable size of 100 mm in shell height at age 3–5 years. In Russian waters, the total commercial stock of yesso scallops in 2021 was estimated at 2784 t. Commercial fisheries have been banned since 2020 due to the depletion of natural stocks as a result of illegal fishing and overexploitation. The total allowable catch for yesso scallops has been set at 3 t for monitoring and recreational purposes. The cultivation of the scallops includes spat collection, spat intermediate culture, and final grow-out on the seafloor or in suspended cages. In the past decade, this industry has demonstrated rapid growth and currently accounts for >16,000 t per year. Environmental fluctuations and epizootics seem to be the most important challenges for the scallop aquaculture sector in the Sea of Japan
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