Values Of Zooplankton Biomass Research Articles

Conditions for carp growing in feeding ponds of the Yaniv fishery

The article presents the results of research on the ecological conditions of carp farming in feeding ponds, which were carried out on the basis of the fishery “Yaniv”, which is part of PrJSC “Lviv Regional Fish Production Plant”. The research was carried out during the vegetation period of 2019 in accordance with the methods adopted in hydrobiology and fish farming. The hydrochemical state of the studied reservoirs and their biotic component, in particular zooplankton and zoobenthos, were analyzed. The results of studies of water quality of feeding ponds of the fishery “Yaniv” show that the hydrochemical parameters during the study period in the vast majority were within the maximum permissible concentrations set for fish farms; sometimes were registrated some indicators which slightly exceeded the normative limits, in particular permanganate oxidation, nitrites, phosphates, chlorides. The study of the natural forage base by zooplankton and zoobenthos revealed that the values of development of the studied aquatic organisms corresponded to the limits of development, which are characteristic of the ponds of the studied type of the Forest-Steppe zone. The values of zooplankton biomass in the experimental ponds were in the range of 5.3–12.5 g/m3. The dynamics of zooplankton development in feeding ponds shows its maximum development in early summer and some decrease in the second half of the vegetation season. In general, the basis of its biomass was consisted of Cladocera (Daphnia magna Straus, Bosmina longirostris, Daphnia cucullata Sars, Ceriodaphnia quadrangula OF Müller, Moina rectirostris Leydig), representatives of Copepoda (Thermocyclops crassus Fischer), Calanoida (Diaptomus castor Jurine, Eudiaptomus coeruleus Fischer) and Rotatoria (Brachionus diversicornis Daday, B.calyciflorus Pallas, Filinia longiseta Ehrb., Keratella cochlearis Gosse). Cladocera and Copepoda made the largest contribution to biomass, while Rotatoria had almost twice less share of total biomass. Indicators of zoobenthos biomass in ponds were in the range of 4.9–6.8 g/m2. The maximum development of benthic organisms was observed in late spring. The basis of biomass of zoobenthos was mainly consisted of insect larvae and oligochaeta.

Latitudinal variations of zooplankton community structure and productivity in the Barents sea (summer 2013)

The Barents Sea is regarded as one of the world’s most unique regions with its high summer productivity. However, there were a few studies dealing with estimation of daily secondary production in the Barents Sea. The aim of the present study was to conduct an investigation of the pelagic mesozooplankton assemblage in the Barents Sea, to calculate daily production levels of mesozooplankton and to analyze the relationship between the community structure and environmental drivers.Structure of zooplankton communities was investigated within the main water masses of the Barents Sea in the summer 2013 (June–July). Calanus finmarchicus presented as copepodites IV–V dominated in terms of the total zooplankton abundance and biomass in Murmansk Coastal Water and Atlantic Water. Spring phase of zooplankton succession cycle was found in Arctic Water where Copepoda nauplii were the most abundant and Calanus glacialis dominated by zooplankton biomass. Zooplankton of the Barents Sea Water had features of spring and summer phases of zooplankton succession cycle. Spatial variations in the zooplankton distribution were associated with hydrological conditions and phytoplankton density. Maximum of the mean zooplankton biomass was registered in Atlantic Water (30,7 mg dry mass/m3) while the minimum was found in Barents Sea Water (5,4 mg dry mass/m3). Calculated daily production of zooplankton ranged from 0,01 to 1,57 mg dry mass/m3per day. Total zooplankton stock for the study area of 281 000 km2was estimated to be > 740 000 t of dry mass. The obtained values of zooplankton biomass and stock were considerably lower than in previous years, which are probably connected with higher predator pressure — grazing of zooplankton by capelin and other predators as well as with possible climatic influence.

Estimaciones de la biomasa zooplanctónica en la Bahía de Tumaco durante junio 2009 a junio 2010, Pacífico colombiano

Biomass was measured by wet weight and dry weight of zooplankton samples collected in the Bay of Tumaco. Sampling was conducted during june 2009 – june 2010 and for four climatic periods. The highest average wet biomass and dry biomass were recorded in June 2009 and the lowest values in September 2009. Significant differences in the values of wet and dry biomass between sampling months. Taking into account the climatic periods the highest values were average during both wet to dry wet biomass to dry biomass, the lowest values were recorded during the wet to dry wet biomass and the wet period dry biomass. The four climatic periods showed no significant variations in the values of zooplankton biomass by wet weight but did show significant differences in the values of zooplankton biomass by dry weight.

General Limnology of Lakes Near Cook Inlet, Southcentral Alaska

ABSTRACT Data from lakes on the Kenai Peninsula (n = 111) and in the Matanuska-Susitna Valley (n = 108) show that lakes near the Cook Inlet, Alaska are moderately stained, with low turbidity and are predominately oligotrophic with a potential for phosphorus limitation. In both locations measures of salinity (as measured by conductivity) and pH were heterogenous and tied to hydrologic flowpaths. Overall, seepage lakes had lower pH, salinity, alkalinity, Ca, Mg and Si than drainage lakes. In our data set, both seepage and drainage lakes on the Kenai had lower alkalinity, Ca, and Si than corresponding lake types in Mat-Su. Most zooplankton biomass (ZB) measurements in the Cook Inlet lakes were <100 μg L−1 and over one-third were <10 μg L−1. Values of ZB were low relative to empirical models and did not increase with lake trophic state. Each of these lakes supports a fish community and the well-known effects of food web structure via grazing by planktivorous fish likely account for the observed ZB values. Environmental measurements and their patterns match earlier studies and collectively describe extant features of lake resources in this region of the southern boreal forest in southcentral Alaska.