Daria Martynova | Russian Academy of Sciences, Zoological Institute (original) (raw)

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Papers by Daria Martynova

Research paper thumbnail of Feeding of the Mass Species of the White Sea Copepods

Oceanology

Selected quantitative characteristics of the feeding of the mass species of the White Sea copepod... more Selected quantitative characteristics of the feeding of the mass species of the White Sea copepods such as Acartia bifilosa (Giesbrecht, 1882), Centropages hamatus (Lilljeborg, 1853), and Temora longicornis (O.F. Müller, 1792) were examined, and their relationships with selected biotic and abiotic factors were determined. The rates of filtration and ingestion for all three species of copepods reliably depended on the species to which the copepod belongs and on its maturity stage. The ingestion rate ranged from 1.17 0.60 10frame03 mg dry weight/ind./h (copepodites CI–CIII, A. bifilosa) to 8.59 0.43 10frame13 mg dry weight/ind./h in the C.hamatus females. The filtration rate was from 0.21 0.08 (copepodites CII–CIII of T. longicornis) to 2.03 1.13 ml/ind./h (C. hamatus females). The light conditions have a reliable effect on the rate of ingestion. High values of the rate are observed when C. hamatus and T. longicornis feed in dark containers. A. bifilosa demonstrates the same relations...

Research paper thumbnail of Copepod faecal pellets in the White Sea: experimental and in situ studies

Oceanology

Size and weight characteristics of pellets produced by the mass White Sea copepod species Acartia... more Size and weight characteristics of pellets produced by the mass White Sea copepod species Acartia bifilosa (Giesorecht, 1882), Centropages hamatus (Lilljeborg, 1853), and Temora longicornis (O.F. Müller, 1792) are estimated. The pellet length and width vary from 97 to 168 and 13 to 23 µm, respectively. The average volume and weight range from 0.013 mm3 and 0.3 10–3 mg to 0.067 mm3 and 1.1 10–3mg in A. bifilosa (the CIII copepodite stage) and C. hamatus females, respectively. The pellet length-to-width ratio varies from 7.45 to 8.78. The pellet length and volume increase with the prosoma length in the relevant copepod individual. The pellet dry weight depends on its volume. The subsidence rate of pellets averages 2.5 m/h. The duration of pellet formation is a few tens of minutes, decreasing during onthogenesis. The highest rates are noted for A. bifilosa. The faecal pellet flux varies during the season and within separate areas, depending on the structure of pelagic community in the ...

Research paper thumbnail of Tab. 1: Chupa Inlet, Kandalaksha Bay of the White Sea. Population density of the dominant boreal copepod species and daily pellet carbon flux

Data on the zooplankton community structure, gut evacuation rate and carbon content of zooplankto... more Data on the zooplankton community structure, gut evacuation rate and carbon content of zooplankton faecal pellets were used for assessing the contribution of zooplankton to vertical carbon fluxes in the White and Kara Seas. The results revealed strong regional and seasonal variations of pellet carbon input related to differences in structure and dynamics of the zooplankton communities in the regions studied. In the deep regions of the White Sea, maximum daily pellet carbon flux from the 0-50 m layer was observed in the spring. It reached 98 mg Corg m-2 day-1 and coincided with a strong predominance of the large arctic herbivorous copepod Calanus glacialis in the surface layers. In summer and fall, it decreased by 1 to 2 orders of magnitude due to migration of this copepod to its overwintering depths. In contrast, in the shallow coastal regions, the pellet production was low in spring, gradually increased during summer and reached its maximum of 138 mg Corg m-2 day-1 by late summer t...

Research paper thumbnail of Spatial variability of the species composition, abundance, and productivity of the phytoplankton in the white sea in the late summer period

Oceanology, 2011

The species composition, cell concentration (N), and biomass (B) of the phytoplankton, as well as... more The species composition, cell concentration (N), and biomass (B) of the phytoplankton, as well as the chlorophyll a (Chl a) concentration, primary production (PP), and the concentrations of the dissolved inorganic micronutrients (phosphorus, silica, nitrogen as nitrite), were estimated for Kandalaksha Bay (KB), Dvina Bay (DB), and the basin (Bas) of the White Sea in August of 2004. The micronutrient

Research paper thumbnail of Adaptation strategies of copepods (superfamily Centropagoidea) in the White Sea (66°N)

Polar Biology, 2009

Seasonal dynamics of major biochemical features were studied for three abundant egg-diapausing co... more Seasonal dynamics of major biochemical features were studied for three abundant egg-diapausing copepods Acartia biWlosa, Centropages hamatus and Temora longicornis, in the White Sea (66°N), between June 2002 and September 2002. Dry weight (DW) and prosome length varied from 0.54 g ind ¡1 and 0.163 § 0.012 mm (A. biWlosa, CI) to 9.58 § 0.72 g ind ¡1 and 1.135 § 0.167 mm (C. hamatus, females). C org and N org content reached up to 5.91 § 0.44 and 1.23 § 0.09 g ind ¡1 (C. hamatus, females). Protein and lipid content varied greatly from 31.8 to 67.3% DW and from 8.7 to 42.6% DW, respectively. These species show somewhat diVerent biology compared to species at lower latitudes. The copepods use lipid stores to survive during short-term food shortage (e.g. in autumn) and successfully complete their life cycle. In the isolated White Sea during last post-glacial period, species probably evolved some special biochemical features (especially wax esters presence). Food quality demands and long ice coverage are possible factors limiting early development of species in spring.

Research paper thumbnail of Effects of food quality on naupliar development in Calanus glacialis at subzero temperatures

Marine Ecology Progress Series, 2011

... 2010). This life history strategy is consid-© Inter-Research 2011 · www.int-res.com *Email: d... more ... 2010). This life history strategy is consid-© Inter-Research 2011 · www.int-res.com *Email: daase@npolar.no Effects of food quality on naupliar development in Calanus glacialis at subzero temperatures Malin Daase1, 2,*, Janne E. Søreide1, Daria Martynova3 ...

Research paper thumbnail of Scale-dependent effects of climate on two copepod species, Calanus glacialis and Pseudocalanus minutus, in an Arctic-boreal sea

Marine Ecology Progress Series, 2012

Climate-driven changes in the phenology and composition of plankton affect ecosystem structure an... more Climate-driven changes in the phenology and composition of plankton affect ecosystem structure and function, but knowledge about such changes is limited by the scarcity of highquality, high-resolution, long-term monitoring data. Using a high-resolution observation series from the White Sea, spanning > 50 yr, we explored how water temperature and salinity influenced 2 key copepod species, Calanus glacialis and Pseudocalanus minutus. The results of the analysis depended critically on the temporal and life-stage resolution of the analysis. Copepod biomass was negatively correlated with salinity, but not correlated with temperature, when using annually aggregated data. However, salinity showed very small effects at a monthly resolution, failing to support a causal effect of salinity. On the other hand, temperature did show effects: in warm years, the biomass of C. glacialis increased earlier in spring and declined earlier in autumn. Analysis of stage-resolved data revealed a new level of complexity. The increase of biomass in spring at warmer temperatures mainly consisted of young life stages, whereas the decrease in autumn was mainly caused by reductions in older life stages. Temperature affected the phenology of several life stages of P. minutus, but not its total biomass, implying that climate effects on different life stages cancelled each other out. We argue that such climate-driven fluctuations in zooplankton phenology and age structure are likely to influence the role of the zooplankton as predators, competitors and prey, but that these effects of climate could remain unnoticed when using the coarser resolution of many sampling programs.

Research paper thumbnail of Light-dependent behavior of abundant zooplankton species in the White Sea

Journal of Plankton Research, 2010

Research paper thumbnail of Every species is good in its season: Do the shifts in the annual temperature dynamics affect the phenology of the zooplankton species in the White Sea?

Hydrobiologia, 2013

ABSTRACT We hypothesize that shifts in the annual pattern of the environmental parameters may aff... more ABSTRACT We hypothesize that shifts in the annual pattern of the environmental parameters may affect the phenology of the zooplankton especially in temperate and polar areas. Five species (cold-water: Calanus glacialis, warm-water: Centropages hamatus, Temora longicornis, Acartia longiremis, and Evadne nordmanni) were tested with regard to the annual pattern of the water temperature using the dataset of 50-year-long monitoring in the White Sea (1961–2010). The hydrological summer duration increased by 20 days during the last 50 years, as it has been tracked by an earlier warming up of 0–10-m water layer in spring. Calanus glacialis responded to these changes by the appearance of CI copepodites earlier in the season. We suggest that the earlier start and longer period of ice melt may cause a longer phytoplankton bloom and thus may promote better trophic conditions during the period of Calanus reproduction and its early development. In contrast to cold-water C. glacialis, the phenology and abundance of warm-water copepods have not changed significantly. Both the timings of autumn cooling and average summer temperature remained relatively stable since the beginning of observations resulting in steady conditions during the reproductive period of warm-water species. Prolongation of summer had no effect on their reproduction.

Research paper thumbnail of Contribution of zooplankton to vertical carbon fluxes in the Kara and White seas

Polarforschung, 2005

zeigen, dass sowohl im Weißen Meer wie in der Karasee der Kotballen-Kohlenstoff des Zooplanktons ... more zeigen, dass sowohl im Weißen Meer wie in der Karasee der Kotballen-Kohlenstoff des Zooplanktons bis zu 30 % des Kohlenstoff-Flusses in bestimmten Jahreszeiten ausmachen kann.

Research paper thumbnail of Seasonal abundance and feeding patterns of copepods Temora longicornis, Centropages hamatus and Acartia spp. in the White Sea (66°N)

Polar Biology, 2011

We have studied the seasonal dynamics of abundance and feeding characteristics of three species o... more We have studied the seasonal dynamics of abundance and feeding characteristics of three species of calanoid copepods (Acartia spp., Centropages hamatus and Temora longicornis) in the White Sea from the surface water layer (0-10 m), in order to assess their role in the pelagic food web and to determine the major factors governing their population dynamics during the productive season. These species dominated in the upper water layer (0-10 m) from June through September, producing up to 3 generations per year. Data on the food spectra revealed all species to be omnivorous; but some inter-and intraspecific differences were observed. Generally, copepods consumed diatoms, dinoflagellates and microzooplankton. The omnivory index 'UC' (i.e., fatty acid unsaturation coefficient) varied from 0.2 to 0.6, which implied ingestion of phytoplankton. The different degree of selectivity on the same food items by the studied species was observed, and therefore, successful surviving strategy with minimal overlapping could be assumed. In total, the populations of the three studied copepod species grazed up to 2.15 g C m -2 day -1 and released up to 0.68 g C m -2 day -1 in faecal pellets. They consumed up to 50% of particulate organic carbon, or up to 85% of phytoplankton standing stock (in terms of Chl. a), and thus played a significant role in the transformation of particulate organic matter. Seasonal changes in abundance of the studied species depended mostly on water temperature in the early summer, but were also affected by food availability (Chl. a concentration) during the productive season.

Research paper thumbnail of Feeding of the Mass Species of the White Sea Copepods

Oceanology

Selected quantitative characteristics of the feeding of the mass species of the White Sea copepod... more Selected quantitative characteristics of the feeding of the mass species of the White Sea copepods such as Acartia bifilosa (Giesbrecht, 1882), Centropages hamatus (Lilljeborg, 1853), and Temora longicornis (O.F. Müller, 1792) were examined, and their relationships with selected biotic and abiotic factors were determined. The rates of filtration and ingestion for all three species of copepods reliably depended on the species to which the copepod belongs and on its maturity stage. The ingestion rate ranged from 1.17 0.60 10frame03 mg dry weight/ind./h (copepodites CI–CIII, A. bifilosa) to 8.59 0.43 10frame13 mg dry weight/ind./h in the C.hamatus females. The filtration rate was from 0.21 0.08 (copepodites CII–CIII of T. longicornis) to 2.03 1.13 ml/ind./h (C. hamatus females). The light conditions have a reliable effect on the rate of ingestion. High values of the rate are observed when C. hamatus and T. longicornis feed in dark containers. A. bifilosa demonstrates the same relations...

Research paper thumbnail of Copepod faecal pellets in the White Sea: experimental and in situ studies

Oceanology

Size and weight characteristics of pellets produced by the mass White Sea copepod species Acartia... more Size and weight characteristics of pellets produced by the mass White Sea copepod species Acartia bifilosa (Giesorecht, 1882), Centropages hamatus (Lilljeborg, 1853), and Temora longicornis (O.F. Müller, 1792) are estimated. The pellet length and width vary from 97 to 168 and 13 to 23 µm, respectively. The average volume and weight range from 0.013 mm3 and 0.3 10–3 mg to 0.067 mm3 and 1.1 10–3mg in A. bifilosa (the CIII copepodite stage) and C. hamatus females, respectively. The pellet length-to-width ratio varies from 7.45 to 8.78. The pellet length and volume increase with the prosoma length in the relevant copepod individual. The pellet dry weight depends on its volume. The subsidence rate of pellets averages 2.5 m/h. The duration of pellet formation is a few tens of minutes, decreasing during onthogenesis. The highest rates are noted for A. bifilosa. The faecal pellet flux varies during the season and within separate areas, depending on the structure of pelagic community in the ...

Research paper thumbnail of Tab. 1: Chupa Inlet, Kandalaksha Bay of the White Sea. Population density of the dominant boreal copepod species and daily pellet carbon flux

Data on the zooplankton community structure, gut evacuation rate and carbon content of zooplankto... more Data on the zooplankton community structure, gut evacuation rate and carbon content of zooplankton faecal pellets were used for assessing the contribution of zooplankton to vertical carbon fluxes in the White and Kara Seas. The results revealed strong regional and seasonal variations of pellet carbon input related to differences in structure and dynamics of the zooplankton communities in the regions studied. In the deep regions of the White Sea, maximum daily pellet carbon flux from the 0-50 m layer was observed in the spring. It reached 98 mg Corg m-2 day-1 and coincided with a strong predominance of the large arctic herbivorous copepod Calanus glacialis in the surface layers. In summer and fall, it decreased by 1 to 2 orders of magnitude due to migration of this copepod to its overwintering depths. In contrast, in the shallow coastal regions, the pellet production was low in spring, gradually increased during summer and reached its maximum of 138 mg Corg m-2 day-1 by late summer t...

Research paper thumbnail of Spatial variability of the species composition, abundance, and productivity of the phytoplankton in the white sea in the late summer period

Oceanology, 2011

The species composition, cell concentration (N), and biomass (B) of the phytoplankton, as well as... more The species composition, cell concentration (N), and biomass (B) of the phytoplankton, as well as the chlorophyll a (Chl a) concentration, primary production (PP), and the concentrations of the dissolved inorganic micronutrients (phosphorus, silica, nitrogen as nitrite), were estimated for Kandalaksha Bay (KB), Dvina Bay (DB), and the basin (Bas) of the White Sea in August of 2004. The micronutrient

Research paper thumbnail of Adaptation strategies of copepods (superfamily Centropagoidea) in the White Sea (66°N)

Polar Biology, 2009

Seasonal dynamics of major biochemical features were studied for three abundant egg-diapausing co... more Seasonal dynamics of major biochemical features were studied for three abundant egg-diapausing copepods Acartia biWlosa, Centropages hamatus and Temora longicornis, in the White Sea (66°N), between June 2002 and September 2002. Dry weight (DW) and prosome length varied from 0.54 g ind ¡1 and 0.163 § 0.012 mm (A. biWlosa, CI) to 9.58 § 0.72 g ind ¡1 and 1.135 § 0.167 mm (C. hamatus, females). C org and N org content reached up to 5.91 § 0.44 and 1.23 § 0.09 g ind ¡1 (C. hamatus, females). Protein and lipid content varied greatly from 31.8 to 67.3% DW and from 8.7 to 42.6% DW, respectively. These species show somewhat diVerent biology compared to species at lower latitudes. The copepods use lipid stores to survive during short-term food shortage (e.g. in autumn) and successfully complete their life cycle. In the isolated White Sea during last post-glacial period, species probably evolved some special biochemical features (especially wax esters presence). Food quality demands and long ice coverage are possible factors limiting early development of species in spring.

Research paper thumbnail of Effects of food quality on naupliar development in Calanus glacialis at subzero temperatures

Marine Ecology Progress Series, 2011

... 2010). This life history strategy is consid-© Inter-Research 2011 · www.int-res.com *Email: d... more ... 2010). This life history strategy is consid-© Inter-Research 2011 · www.int-res.com *Email: daase@npolar.no Effects of food quality on naupliar development in Calanus glacialis at subzero temperatures Malin Daase1, 2,*, Janne E. Søreide1, Daria Martynova3 ...

Research paper thumbnail of Scale-dependent effects of climate on two copepod species, Calanus glacialis and Pseudocalanus minutus, in an Arctic-boreal sea

Marine Ecology Progress Series, 2012

Climate-driven changes in the phenology and composition of plankton affect ecosystem structure an... more Climate-driven changes in the phenology and composition of plankton affect ecosystem structure and function, but knowledge about such changes is limited by the scarcity of highquality, high-resolution, long-term monitoring data. Using a high-resolution observation series from the White Sea, spanning > 50 yr, we explored how water temperature and salinity influenced 2 key copepod species, Calanus glacialis and Pseudocalanus minutus. The results of the analysis depended critically on the temporal and life-stage resolution of the analysis. Copepod biomass was negatively correlated with salinity, but not correlated with temperature, when using annually aggregated data. However, salinity showed very small effects at a monthly resolution, failing to support a causal effect of salinity. On the other hand, temperature did show effects: in warm years, the biomass of C. glacialis increased earlier in spring and declined earlier in autumn. Analysis of stage-resolved data revealed a new level of complexity. The increase of biomass in spring at warmer temperatures mainly consisted of young life stages, whereas the decrease in autumn was mainly caused by reductions in older life stages. Temperature affected the phenology of several life stages of P. minutus, but not its total biomass, implying that climate effects on different life stages cancelled each other out. We argue that such climate-driven fluctuations in zooplankton phenology and age structure are likely to influence the role of the zooplankton as predators, competitors and prey, but that these effects of climate could remain unnoticed when using the coarser resolution of many sampling programs.

Research paper thumbnail of Light-dependent behavior of abundant zooplankton species in the White Sea

Journal of Plankton Research, 2010

Research paper thumbnail of Every species is good in its season: Do the shifts in the annual temperature dynamics affect the phenology of the zooplankton species in the White Sea?

Hydrobiologia, 2013

ABSTRACT We hypothesize that shifts in the annual pattern of the environmental parameters may aff... more ABSTRACT We hypothesize that shifts in the annual pattern of the environmental parameters may affect the phenology of the zooplankton especially in temperate and polar areas. Five species (cold-water: Calanus glacialis, warm-water: Centropages hamatus, Temora longicornis, Acartia longiremis, and Evadne nordmanni) were tested with regard to the annual pattern of the water temperature using the dataset of 50-year-long monitoring in the White Sea (1961–2010). The hydrological summer duration increased by 20 days during the last 50 years, as it has been tracked by an earlier warming up of 0–10-m water layer in spring. Calanus glacialis responded to these changes by the appearance of CI copepodites earlier in the season. We suggest that the earlier start and longer period of ice melt may cause a longer phytoplankton bloom and thus may promote better trophic conditions during the period of Calanus reproduction and its early development. In contrast to cold-water C. glacialis, the phenology and abundance of warm-water copepods have not changed significantly. Both the timings of autumn cooling and average summer temperature remained relatively stable since the beginning of observations resulting in steady conditions during the reproductive period of warm-water species. Prolongation of summer had no effect on their reproduction.

Research paper thumbnail of Contribution of zooplankton to vertical carbon fluxes in the Kara and White seas

Polarforschung, 2005

zeigen, dass sowohl im Weißen Meer wie in der Karasee der Kotballen-Kohlenstoff des Zooplanktons ... more zeigen, dass sowohl im Weißen Meer wie in der Karasee der Kotballen-Kohlenstoff des Zooplanktons bis zu 30 % des Kohlenstoff-Flusses in bestimmten Jahreszeiten ausmachen kann.

Research paper thumbnail of Seasonal abundance and feeding patterns of copepods Temora longicornis, Centropages hamatus and Acartia spp. in the White Sea (66°N)

Polar Biology, 2011

We have studied the seasonal dynamics of abundance and feeding characteristics of three species o... more We have studied the seasonal dynamics of abundance and feeding characteristics of three species of calanoid copepods (Acartia spp., Centropages hamatus and Temora longicornis) in the White Sea from the surface water layer (0-10 m), in order to assess their role in the pelagic food web and to determine the major factors governing their population dynamics during the productive season. These species dominated in the upper water layer (0-10 m) from June through September, producing up to 3 generations per year. Data on the food spectra revealed all species to be omnivorous; but some inter-and intraspecific differences were observed. Generally, copepods consumed diatoms, dinoflagellates and microzooplankton. The omnivory index 'UC' (i.e., fatty acid unsaturation coefficient) varied from 0.2 to 0.6, which implied ingestion of phytoplankton. The different degree of selectivity on the same food items by the studied species was observed, and therefore, successful surviving strategy with minimal overlapping could be assumed. In total, the populations of the three studied copepod species grazed up to 2.15 g C m -2 day -1 and released up to 0.68 g C m -2 day -1 in faecal pellets. They consumed up to 50% of particulate organic carbon, or up to 85% of phytoplankton standing stock (in terms of Chl. a), and thus played a significant role in the transformation of particulate organic matter. Seasonal changes in abundance of the studied species depended mostly on water temperature in the early summer, but were also affected by food availability (Chl. a concentration) during the productive season.