The relationship between occurrence of invasive bryozoan <Emphasis Type="Italic">Pectinatella magnifica</Emphasis> (Leidy 1851) and parameters of the aquatic environment in the Biosphere Reserve Třeboňsko (Czech Republic)

In the period from 2012 to 2014, twenty localities with a varying density level of the invasive bryozoan Pectinatella magnifica were investigated in the T?eboň region. These localities included water bodies ranging from eutrophic-hypertrophic fishponds to mesotrophic-oligotrophic flooded sandpits. The aim of the study was to investigate and compare the water bodies’ physical, hydrochemical and hydrobiological parameters. Control localities (localities with absence of P. magnifica) were found to be significantly different from localities with occurrence of P. magnifica in most of the measured parameters. Also shown was that P. magnifica tends to form colonies in localities showing above-average qualitative parameters within the T?eboň region: balanced oxygen and pH regime, low concentration of suspended solids (Secchi depth over 1 m) and nitrogen forms (mean TN 1.5 mg L^?1), chlorophyll-a mean concentration 54 µg L^?1, and zooplankton mean density 117 ind L^?1 and biomass 2 mg of wet weight L^?1. Furthermore, P. magnifica was also found in brown humic waters. While the sites with P. magnifica occurrence are often mesotrophic flooded sandpits and fishponds under nature protection, fishponds for recreational use, and those with low intensity of fishery management (without formation of massive cyanobacterial water blooms, oxygen regime fluctuations, etc.), localities unoccupied by invasive bryozoans are mostly strictly eutrophic-hypertrophic, semi-intensified, carp fishponds.     

The onset of invasion of bryozoan <Emphasis Type="Italic">Pectinatella magnifica</Emphasis> in South Bohemia (Czech Republic)

Pectinatella magnifica is an invasive freshwater bryozoan with ability to produce large colonies reaching a capacity of up to several tens dm³. In the Protected Landscape Area and Biosphere reserve Třeboňsko the bryozoan was first found in 2003 in one mesotrophic sandpit. The species gradually spread to many other sites around the Třeboň area and at most of these locations its occurrence has invasion properties. Pectinatella expanded to some other sandpits, fishponds without intensive pisciculture. Pectinatella colonies are found mainly on submerged branches of willow trees. The differences between biomass in transects with the occurrence of shrub willow and biomass in transects without their presence were statistically significant in the total biomass weight and the number of colonies. The average weight of several colonies did not differ. The most important parameter affecting the occurrence was the low trophy of water. The water temperature is evidently an important factor affecting the seasonal dynamics of occurence. Differences in nitrogen and phosphorous content between the water outside and inside the colonies were statistically significant. The colonies also accumulate other elements, including microelements.     

Experimental cultivation of the invasive freshwater bryozoan <Emphasis Type="Italic">Pectinatella magnifica</Emphasis>

The freshwater bryozoan Pectinatella magnifica (Leidy, 1851) is an invasive species in many countries all over the world. Although native to North America, it has been found in many countries of Europe and Asia. Pectinatella magnifica forms the largest colonial masses from all recently known bryozoan species. Culturing this organism in an aquarium has never been achieved for more than few days so far. Colonies from laboratory culture are important for various studies on its biology and life cycle of this species in experimental conditions. Young colonies successfully hatched from germinating statoblasts of P. magnifica in the laboratory and were maintained over eight weeks. Moreover, this was the first time when the compound colonies of this species were carried from its natural habitat to the laboratory, into a special aquarium system, and kept alive for more than three weeks. In both experiments the physicochemical parameters of the water (temperature, concentration of dissolved oxygen, electrolytic conductivity and pH) and changes in weight of compound colonies of P. magnifica in laboratory conditions were checked. The results found in this study are essential for understanding the invasiveness of this species and identifying methods for elimination of its ecological risks because these are closely resembling those of other invasive species.     

Trepostome bryozoans from the Zahořany Formation (Upper Ordovician) of Loděnice,Prague Basin,Czech Republic

Three trepostome bryozoan species are described from the Upper Ordovician Zaho?any Formation of Loděnice, Prague Basin, Czech Republic. One genus is new—Lodenicella gen. nov. One species is described in open nomenclature. The described fauna contains ramose colonies or ramose branched projections from encrusting tubular-shaped colonies which inhabited shallow environment with moderate wave energy and significant influx of clastic material.     

Typha productivity in a Texas pond: Implications for energy and nutrient dynamics in freshwater wetlands

Above-and below-ground biomass of Typha angustifolia L. was sampled monthly for 18 months from a small Texas pond. Maximum above-ground biomass was 2559±284 g AFDW (ash-free dry weight) m⁻² in 1983 and 2895±217 g AFDW m⁻² in 1984. Peak below-ground biomass for these 2 years was 2506±278 g AFDW m⁻² and 2314±226 g AFDW m^t-2, respectively. Stepwise multiple linear regression analyses revealed that mean above-ground biomass accrual was related to duration of growing season, cumulative precipitation, cumulative degree days and/or cumulative pan evaporation. The same was not true for below-ground biomass increases. Analysis of covariance revealed that the rates of above-ground biomass production were not significantly different (F test, p < 0.05) between the 1983 and 1984 growing seasons. Below-ground biomass turnover times for 1983 and 1984 were 2.47 and 1.21 years, respectively.     

Do mute swan (Cygnus olor) grazing, swan residence and fishpond nutrient availability interactively control macrophyte communities?

The mute swan (Cygnus olor Gmelin) is one of the largest herbivorous waterbirds in the world. Its population increased dramatically over the last decades in Western Europe, leading to concerns about its potential impact on aquatic ecosystems. Indeed, swan consequences on fishponds remain poorly investigated, although fishpond animal communities and economic value both largely depend on aquatic macrophytes. We carried out an experiment in the Dombes region (Eastern France) with 96 exclosures on 24 fishponds. Our aim was to assess the impact of swan grazing on aquatic macrophyte presence, abundance and community structure (diversity and evenness) during the growing season (April to July). We also considered the potential effect of swan stay (i.e. number of swan days ha⁻¹) and nutrient availability on macrophyte depletion. Swan grazing negatively affected the presence and abundance (% cover) of macrophyte beds, particularly at high swan density. No significant effect on dry biomass was found. Furthermore, swan grazing negatively affected community structure, suggesting that mute swan promoted the dominance of a few species in macrophyte communities. Whatever the macrophyte variable considered, nutrient availability in fishponds did not affect macrophyte depletion rate. It is speculated that both the repeated use of the same fishponds by birds and their expansion within the landscape may lead to more acute and broader consequences for macrophyte beds over the longer term.     

Growth of Phragmites australis and Phalaris arundinacea in constructed wetlands for wastewater treatment in the Czech Republic

Common reed (Phragmites australis) and reed canarygrass (Phalaris arundinacea) are two most commonly used plant species in constructed wetlands for wastewater treatment in the Czech Republic. Growth characteristics of both plants (biomass, stem count, and length) have been measured in 13 horizontal sub-surface flow constructed wetlands since 1992. The results revealed that while Phalaris usually reaches its maximum biomass as early as during the second growing season, Phragmites usually reaches its maximum only after three to four growing seasons. The maximum biomass of both species varies widely among systems and the highest measured values (5070 g m⁻² for Phragmites and 1900 g m⁻² for Phalaris) are similar to those found in eutrophic natural stands. The shoot count of Phragmites decreases after the second growing season while length and weight of individual shoots increases over time due to self-thinning process. Number of Phalaris shoots is the highest during the second season and then the shoot count remains about the same. Also the shoot length remains steady over years of constructed wetland operation.     

Abiotic and biotic factors affecting zooperiphyton development in a waterflow of a cooling water pool

The study is concerned with invertebrates populating riffle stones in a cooling water pool. It was shown that the invertebrate community is dominated by Oligochaeta of the genus Naididae in abundance, and Plumatella emarginata bryozoans, in biomass. The study revealed the following: (1) in communities with biomass >100 g/m² abundance and biomass are affected by roughness and lightness of the substrate; (2) bryozoan biomass and Oligochaeta abundance correlate.     

Heterotrophic microorganisms and viruses in the water of the Gorky reservoir during a period of anomalously high water temperature

During the anomalously hot summer of 2010, the water temperature in the Gorky reservoir reached 27–33°C. Pronounced cyanobacterial blooms occurred in the limnetic part of the reservoir. The average values for bacterioplankton abundance (11.58 ± 1.25 × 10⁶ cell/mL), biomass (886 ± 96 mg/m³), and production [169 ± 32 mg C/(m³ day)] were twice as high as in the year with temperatures comparable to long-term average values. These parameters were higher in the limnetic part than in the river one. The abundance (4.86 ± 0.75 × 10³ cell/mL) and biomass (138 ± 9 mg/m³) of heterotrophic nanoflagellates were 2.3 and 1.7 times higher, respectively, than in years with regular temperature regimes. The average number of plank-tonic viral particles (N _v) in 2010 was 48.89 ± 9.54 × 10⁶ particles/mL, while virus-induced bacterial mortality (VMB) accounted for 26.9 ± 4.6% of the bacterial production. The N _v and VMB values in the limnetic part of the reservoir were, respectively, 1.5 and 1.8 times higher than in the river one.     

Littoral diatoms as indicators for the eutrophication of shallow lakes

The littoral zone of shallow water bodies in the Czech Republic has been studied quite consistently at several fishponds. The use of algae, especially diatoms, for the monitoring of the state of lotic freshwater also has a long tradition. The main objective of the presented paper is to validate the feasibility of the use of littoral periphyton comunities for the biomonitoring of standing waters. At the investigated sites, littoral periphytic diatoms were studied together with selected enviromental variables (pH, conductivity, nutrients – especially total phosphorus) on three types of natural substrates (epilithon, epiphyton, epipelon). The evaluation of the diatom community was performed on the basis of the checklists of algal indicator species published by authors from the Czech Republic, Austria and the Netherlands. The data were subjected to statistical software NCCS 2000 (GLM Anova and ``Ward's minimum'' variance cluster analysis). Littoral periphytic diatoms appear to be good indicators of the fishpond water quality. The selected substrates show non-significant differences therefore the average values from all substrates were used. The best indicatory system for evaluation of Czech fishponds was van Dam's index.

     

Field inoculation with arbuscular-mycorrhizal fungi overcomes phosphorus and zinc deficiencies of linseed (Linum usitatissimum) in a vertisol subject to long-fallow disorder

Background and aims

Long-fallow disorder is expressed as exacerbated deficiencies of phosphorus (P) and/or zinc (Zn) in field crops growing after long periods of weed-free fallow. The hypothesis that arbuscular-mycorrhizal fungi (AMF) improve the P and Zn nutrition, and thereby biomass production and seed yield of linseed (Linum usitatissimum) was tested in a field experiment.

Methods

A factorial combination of treatments consisting of ± fumigation, ±AMF inoculation with Glomus spp., ±P and ±Zn fertilisers was used on a long-fallowed vertisol. The use of such methods allowed an absolute comparison of plants growing with and without AMF in the field for the first time in a soil disposed to long-fallow disorder.

Results

Plant biomass, height, P and Zn concentrations and contents, boll number and final seed yield were (a) least in fumigated soil with negligible AMF colonisation of the roots, (b) low initially in long-fallow soil but increased with time as AMF colonisation of the roots developed, and (c) greatest in soil inoculated with AMF cultures. The results showed for the first time in the field that inflows of both P and Zn into linseed roots were highly dependent on %AMF-colonisation (R²?=?0.95 for P and 0.85 for Zn, P?<?0.001) in a soil disposed to long-fallow disorder. Relative field mycorrhizal dependencies without and with P+Zn fertiliser were 85 % and 86 % for biomass and 68 % and 52 % for seed yield respectively.

Conclusions

This research showed in the field that AMF greatly improved the P and Zn nutrition, biomass production and seed yield of linseed growing in a soil disposed to long-fallow disorder. The level of mycorrhizal colonisation of plants suffering from long-fallow disorder can increase during the growing season resulting in improved plant growth and residual AMF inoculum in the soil, and thus it is important for growers to recognise the cause and not terminate a poor crop prematurely in order to sow another. Other positive management options to reduce long fallows and foster AMF include adoption of conservation tillage and opportunity cropping.     

Industrial and post-industrial habitats serve as critical refugia for pioneer species of newly identified arthropod assemblages associated with reed galls

Gravel-sand river terraces were nearly eliminated from central European landscape by river channelization. Monotypic stands of common reed (Phragmites australis) growing on such terraces are often stressed by drought, which makes them vulnerable to Lipara spp. (Diptera: Chloropidae) gallmakers. Although Lipara are considered ecosystem engineers, only fragmentary information is available on the biology of their parasitoids and inquilines. We analyzed the assemblages of arthropods (Arachnida, Collembola, Dermaptera, Psocoptera, Thysanoptera, Hemiptera, Raphidioptera, Neuroptera, Coleoptera, Diptera, Lepidoptera and Hymenoptera) that emerged from 17,791 Lipara-induced galls collected in winter from 30 reed beds in the Czech Republic, 15 of which were situated at (post)industrial sites (gravel-sandpits, tailing ponds, limestone quarries, colliery dumps, and reclaimed lignite open-cast mines) and 15 were in near-natural habitats (medieval fishponds, and river and stream floodplains). The Chao-1 estimator indicated 229.3 ± 18.1 species in reed galls at (post)industrial and 218.1 ± 23.6 species at near-natural sites, with the Sørensen index reaching only 0.58. We identified 18 red-listed species and four new species for the Czech Republic (Gasteruption phragmiticola, Echthrodelphax fairchildii, Haplogonatopus oratorius and Enclisis sp.), representing mostly obligate (64 %) or facultative (9 %) reed specialists. We propose that Lipara gall-associated assemblages undergo a long-term cyclic ecological succession. During first 10 years after reed bed formation, only Lipara spp. and several other species occur. During next decades, the reed beds host species-rich assemblages with numerous pioneer species (Singa nitidula, Polemochartus melas) that critically depend on presence of prior disturbances. Middle-aged reed beds (near medieval fishponds) are prevalently enriched in common species only (Oulema duftschmidi, Dimorphopterus spinolae). Habitats with the longest historical continuity (river floodplains) host again species-rich assemblages with several rare species that probably require long-term habitat continuity (Homalura tarsata, Hylaeus moricei). Landscape dynamics is thus critical for the persistence of a full spectrum of reed gall inquilines, with (post)industrials serving as the only refugia for pioneer species ousted from their key nesting habitats at once cyclically disturbed gravel-sand river terraces.     

Relationships between environmental factors and vegetation in nutrient-enriched fens at fishpond margins

Vegetation-environment relationships were investigated in fens of the T?eboň basin (Czech Republic), which are enriched by nutrients and calcium from intensively managed and limed fishponds to test the hypothesis of altered gradient structure after long-term nutrient enrichment in fens. Water-table depth, pH, conductivity, N-NH ₄ ⁺ , N-NO ₃ ^? , PO ₄ ^3? , total P, SO ₄ ^2? , K⁺, Ca²⁺, Mg²⁺ and Fe were measured four times in 30 vegetation plots of 16 m² during the 2004 vegetation season. Both constrained and unconstrained ordination (DCA, CCA) were used to relate environmental factors to the species composition of the vegetation. The relationships among particular factors were revealed using PCA. Four fen vegetation types obtained by TWINSPAN classification were compared with measured factors using repeated measures ANOVA. Vegetation types differed significantly in water-table depth, water pH and Ca²⁺, Mg²⁺, K⁺, and N-NO ₃ ^? content. The concentration of major nutrients fluctuated noticeably during vegetation season and displayed large variation within vegetation types. Temporarily the concentration of different nutrients reached extremely high values. However, high nutrient supply has not altered the gradient structure of the vegetation. Water pH and water-table depths were found to be two major determinants of species variation in fishpond-margin fens, as in the majority of other environments studied throughout the Northern Hemisphere. Species richness of both vascular plants and bryophytes was partly explained by pH. However, the extent of variation in total mineral richness and potassium concentration were the next two most important variables determining bryophyte species richness. Water in flooded poor-fen vegetation, directly affected by water from limed fishponds, had calcium and magnesium concentration similar to fishpond water. The calcium concentrations of about 20 mg l^?1 in typical poor-fen vegetation have no analogy in the ecological literature. High phosphorus level presumably buffers the effect of calcium by enhancing bryophyte biomass depositing superfluous calcium. In conclusion, extremely high long-term nutrient supply to fishpond-margin fens have not altered gradient structure, but shifted chemical limits of plant communities.     

CO2 flux in alpine wetland ecosystem on the Qinghai-Tibetan Plateau, China

Using the CO₂ flux data measured by the eddy covariance method in the northeast of Qinghai-Tibetan Plateau in 2005, we analyzed the carbon flux dynamics in relation to meteorological and biotic factors. The results showed that the alpine wetland ecosystem was the carbon source, and it emitted 316.02 gCO₂ · m⁻² to atmosphere in 2005 with 230.16 gCO₂ · m⁻² absorbed in the growing season from May to September and 546.18 gCO₂ · m⁻² released in the non-growing season from January to April and from October to December. The maximum of the averaged daily CO₂ uptake rates and release rates was (0.45 ± 0.0012) mgCO₂ · m⁻² · s⁻¹ (Mean ± SE) in July and (0.22 ± 0.0090) mgCO₂ · m⁻² · s⁻¹ in August, respectively. The averaged diurnal variation showed a single-peaked pattern in the growing season, but exhibited very small fluctuation in the non-growing season. Net ecosystem exchange (NEE) and gross primary production (GPP) were all correlated with some meteorological factors, and they showed a negatively linear correlation with aboveground biomass, while a positive correlation existed between the ecosystem respiration (R_es) and those factors.     

Phenotypic Switching in Biofilm-Forming Marine Bacterium Paenibacillus lautus NE3B01

Biofilm-forming marine bacterium Paenibacillus lautus NE3B01 was isolated from a mangrove ecosystem, Odisha, India. This isolate formed a swarming type of colony pattern on the solid culture medium with 0.5–2 % agar. Phase contrast microscopy study of a growing colony of P. lautus on solid media and swarming pattern revealed the existence of two phenotypically distinct cells (i.e. cocci and rods) across the colonies. However, in actively growing planktonic culture, only rod-shaped cells were observed. Biofilm growth studies (crystal violet assay) with the isolate showed significant biofilm formation by 6 h, and the detachment phase was observed after 18 h. Biofilm parameters (such as total biomass, roughness coefficient, biofilm thickness, etc.) of 24-h-old P. lautus biofilm were studied by confocal scanning laser microscopy (CSLM). The CSLM study showed that P. lautus formed a biofilm with an average thickness of 14.8 ± 2.6 μm, a high roughness coefficient (0.379 ± 0.103) and surface to bio-volume ratio (4.59 ± 1.12 μm²/μm³), indicating a highly uneven topography of the biofilm. This also indicates that the 24-h-old biofilm is in dispersal phase. Scanning electron microphotographs of P. lautus also supported the existence of two distinct phenotypes of P. lautus. The current findings suggest that P. lautus has two vegetative phenotypes and to decongest the overcrowded biofilm the bacterium can switch over to motile rods from nonmotile cocci and vice versa.     

Peculiarities of summer phytoplankton spatial distribution in Onega Bay of the White Sea under local hydrophysical conditions

The species composition and phytoplankton biomass, concentrations of chlorophyll “a” (Chl) and nutrients in the surface water layer, and accompanying hydrophysical conditions were studied in Onega Bay of the White Sea in June 2015. The temperature and salinity of surface water layer and the water column stability varied greatly in the bay. The nutrients' concentrations exceeded the limiting threshold necessary for the phytoplankton development. The phytoplankton abundance was relatively low, averaged as 13.46 ± 9.00 mg C/m³ (total phytoplankton biomass), 0.78 ± 0.43 mg/m³ (concentration of chlorophyll “a”), and 0.18 ± 0.27 mg C/m³ (picophytoplankton biomass). The highest phytoplankton biomass has been registered along the frontal zones. Three phytoplankton communities that differed significantly in their structure have been found.     

Seasonal succession of the travertine‐forming desmid Oocardium stratum

The calcifying Conjugatophyte Oocardium stratum occurs exclusively in spring‐associated limestones (SAL) with active meteogene limestone deposition. The macroscopic colonies of Oocardium stratum form hemispherical, pinhead‐like structures with a diameter of 0.5–2.0 mm. As its autecology is still poorly understood, we focused on the seasonal development of Oocardium stratum and linked environmental factors to its abundance. The study was conducted in a rivulet in Lunz/See (Austria) for 16 months on a weekly (growing season) to monthly (winter season) basis. Oocardium colonies were found throughout the whole year, with maximum abundance during the mid‐summer months July and August. Repeated macro‐mapping of three SAL sites measuring 750 cm² each showed a maximum Oocardium cover of around 30% in August; two smaller peaks developed in early summer and late autumn with ~10% cover. Diatom mats dominated by Cymbella excisiformis occurred in spring, autumn and winter, with more than 75% cover. The seasonal change between Oocardium and diatoms in limestone‐precipitating springs causes a typical sequence pattern of limestone layers. Redundancy analysis revealed water temperature and bicarbonate content as the main structuring factors; these control the occurrence and growth of Oocardium, reflecting season as a background variable. Optimum growth conditions for Oocardium were an alkalinity around 4.7 meq · L^?1 and a water temperature around 13°C. Site openness, nitrate and dissolved carbon dioxide were inversely related to Oocardium biomass, the opposite for diatoms. Other environmental factors such as total ions or soluble reactive phosphorus had no significant influence on Oocardium stratum abundance.     

Water quality parameters and tipping points of dragonfly diversity and abundance in fishponds

Fishponds are often enriched with nutrients in order to increase phytoplankton and zooplankton populations to support fish production. This eutrophication often leads to a global decrease of biodiversity. This biodiversity shift may be identified by a tipping point, the value of an environmental parameter above which a significant change of species richness and abundance occurs. A total of 110 eutrophic to highly eutrophic fishponds were studied in two areas in France to investigate parameters governing dragonfly species richness and species abundance by determining tipping points. Parameters investigated were chlorophyll a (CHL), water transparency, total N (TN), total P (TP), aquatic plant richness and coverage, adult dragonfly richness and abundance, and fish harvest. A high species richness of dragonflies was found in fishponds, with a total of 34 species, including six species of conservation concern. Dragonfly richness and abundance was shown to be negatively influenced by higher degrees of eutrophication. A high diversity of dragonflies occurred in the fishponds with CHL concentrations below 127 µg/l, water transparency above 67 cm, TN concentrations below 2.30 mg/l, and a fish harvest smaller than 253 kg/ha. A minimum of 5% of aquatic plant cover and the presence of a minimum 9 aquatic plant species seem to promote the richness and abundance of dragonflies. According to tipping points, 19 dragonfly species could be determined as indicator species for water quality in fishponds.     

Fish fauna and fisheries of large European rivers: examples from the Volga and the Danube

The role of herbivores in regulating aquatic plant dynamics has received growing recognition from researchers and managers. However, the evidence for herbivore impacts on aquatic plants is largely based on short-term exclosure studies conducted within a single plant growing season. Thus, it is unclear how long herbivore impacts on aquatic plant abundance can persist for. We addressed this knowledge gap by testing whether mute swan (Cygnus olor) grazing on lowland river macrophytes could be detected in the following growing season. Furthermore, we investigated the role of seasonal changes in water current speed in limiting the temporal extent of grazing. We found no relationship between swan biomass density in 1 year and aquatic plant cover or biomass in the following spring. No such carry-over effects were detected despite observing high swan biomass densities in the previous year from which we inferred grazing impacts on macrophytes. Seasonal increases in water velocity were associated with reduced grazing pressure as swans abandoned river habitat. Furthermore, our study highlights the role of seasonal changes in water velocity in determining the length of the mute swan grazing season in shallow lowland rivers and thus in limiting the temporal extent of herbivore impacts on aquatic plant abundance.     

Estimated copepod production rate and structure of mesozooplankton communities in the coastal Barents Sea during summer–autumn 2007

The southern Barents Sea is considered to be the most productive area in the Arctic Ocean; however, there are no assessments of daily production rates in the coastal waters. During the summer and autumn of 2007, we investigated the variation of mesozooplankton community structure relative to environmental conditions at 12 coastal stations. Copepods dominated the total zooplankton biomass and abundance during both periods. Diversity indices and the total biomass of zooplankton communities differed significantly between the two seasons. Cluster analyses revealed two distinct groups of stations which were associated with Ura Bay and the adjacent open sea, respectively. Daily production rates of the copepod species examined were calculated using three methods based on: (1) a temperature-dependent equation and (2) two multiple regressions that consider temperature, body weight, and chlorophyll a concentration. Significant seasonal differences for daily production rates were found using all three model equations (p?<?0.05): 358?±?188–1,775?±?791 versus 198?±?85–1,584?±?559?μg?dry?mass?m^?3?day^?1. Results of principal components analyses demonstrated that the abundance and biomass of herbivorous species were related to variation in chlorophyll a concentration while the abundance and biomass of other species (omnivorous copepods and Ctenophora) were related mainly with water temperature and salinity. Mesozooplankton biomass was higher during this study relative to previous studies. Computed copepod production rates were higher compared with other Arctic seas confirming a high productive potential of the coastal southern Barents Sea.