Zooplankton Production

Zooplankton constitute important food item of many omnivorous and carnivorous fishes. The study was conducted with an aim to study the zooplankton production including physico-chemical parameters with an emphasis to the existing management practices taken by the operators. The study was carried out in a culture and a non-culture pond of Rajshahi University campus was carried out from September, 2004 to February, 2005. Monthly fluctuations of some physico-chemical parameters were noted. The ponds showed alkaline in nature with moderate bicarbonate alkalinity. Diurnal change of water temperature, free CO2 and dissolved Oxygen were also studied. Four groups of zooplankton were identified, of which copepods (1260 units/l and 973.33 units/l in pond-1 and pond-2 respectively) were most dominant. A total of 9 genera of zooplankton were identified of which Cyclops (68.25% and 60.28% of total copepods) was most abundant in both ponds. Total zooplankton showed positive correlation with pH, carbonate alkalinity (CO3) and bicarbonate alkalinity (HCO3) in both ponds and DO, carbon dioxide (CO2) in pond-1. Present findings indicated that the culture pond showed better result than that of the non-culture pond regarding zooplankton production. Key words: Zooplankton, culture pond, non-culture pond, physico-chemical parameters. Â doi:10.3329/ujzru.v27i0.1951 Univ. j. zool. Rajshahi Univ. Vol. 27, 2008 pp. 35-41

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Zooplankton Production and Planktivore Consumption in Lake Pend Oreille, Idaho

Northwest Science ◽

10.3955/0029-344x-81.3.215 ◽

2007 ◽

Vol 81 (3) ◽

pp. 215-223 ◽

Cited By ~ 2

Author(s):

Lance R. Clarke ◽

David H. Bennett

Keyword(s):

Zooplankton Production

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Particle-Size-Conversion Efficiency and Contaminant Concentrations in Lake Ontario Biota

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f83-048 ◽

1983 ◽

Vol 40 (3) ◽

pp. 328-336 ◽

Cited By ~ 50

Author(s):

Uwe Borgmann ◽

D. M. Whittle

Keyword(s):

Particle Size ◽

Body Size ◽

Conversion Efficiency ◽

Food Chain ◽

Lake Ontario ◽

Dry Weight ◽

Growth Efficiency ◽

Fish Production ◽

The Relationship ◽

Zooplankton Production

The particle-size-conversion efficiency (log food consumption/production divided by log predator prey size ratio) is shown to be directly related to the relationship between the concentration of persistent contaminants accumulated primarily through the food chain and body size for organisms in pelagic ecosystems. The difference between particle-size-conversion efficiency for biomass and that for the contaminant gives the slope of the relationship between log contaminant concentration and log body size. This provides a useful theoretical framework for analyzing contaminant concentrations in aquatic biota without the need for specifying trophic level but still incorporating the idea of food chain accumulation. Concentrations of PCB, DDT, and mercury were examined in aquatic organisms from Lake Ontario, ranging in size from zooplankton to large salmonids (a 108 -fold range in dry weight). The slope of the double log plot of concentration versus weight varied from 0.20 to 0.22 for PCB and DDT and was approximately equal to 0.13 for mercury. This indicates that mercury is accumulated less efficiently through the food chain than PCB or DDT. After correcting for incomplete uptake and retention of the contaminant, an estimate of particle-size-conversion efficiency for biomass of about 0.26 was obtained, which agrees reasonably well with previous estimates obtained from growth efficiency experiments and analysis of particle-size spectra. These calculations indicate that potential fish production in Lake Ontario is ~ 120-fold lower than zooplankton production (for fish averaging 108-fold larger in body size as compared to zooplankton).Key words: particle-size-conversion efficiency, PCB, DDT, mercury, zooplankton production, fish production

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Zooplankton production in the Bay of Quinte 1975–2008: relationships with primary production, habitat, planktivory, and aquatic invasive species (Dreissena spp. and Cercopagis pengoi)

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/cjfas-2012-0162 ◽

2012 ◽

Vol 69 (12) ◽

pp. 2046-2063 ◽

Cited By ~ 3

Author(s):

Ora E. Johannsson ◽

Kelly L. Bowen

Keyword(s):

Fish Community ◽

Abundant Species ◽

Ratio Method ◽

Nutrient Level ◽

General Context ◽

Cercopagis Pengoi ◽

Community Shifts ◽

Zooplankton Production ◽

Changing Light ◽

Trophic Range

The Bay of Quinte, a long, shallow, high-phosphorus system in Lake Ontario, spans a trophic range from eutrophic (upper Bay) to meso-oligotrophic (mouth). Phosphorus control (PC) and the invasion of dreissenid mussels and Cercopagis pengoi have influenced its biology and environment. We elucidated the principal drivers behind zooplankton production in the Bay from pre-PC times to the present (1975–2008). Production of abundant species was calculated using the egg-ratio method. Production estimates were improved by determining system-specific production/biomass (P/B) relationships for rarer species. Planktivory governed zooplankton production initially, likely preventing a response to PC. With changes in the fish community, zooplankton production increased. Thereafter, the principal drivers were the structure and size of the fish community, shifts in the predatory arena associated with changing light penetration, temperature, and addition of C. pengoi — all within a general context of nutrient availability. Dreissenid impacts were indirect. Interactive variables combining measures of predation, nutrient level, light, and temperature were the best at accounting for variability in zooplankton production.

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Aspects of Estimating Zooplankton Production from Phytoplankton Production

Journal of the Fisheries Research Board of Canada ◽

10.1139/f69-025 ◽

1969 ◽

Vol 26 (2) ◽

pp. 199-220 ◽

Cited By ~ 49

Author(s):

C. D. McAllister

Keyword(s):

Growth Rate ◽

Primary Productivity ◽

Secondary Production ◽

Relative Effect ◽

Plant Production ◽

Phytoplankton Production ◽

Continuous Grazing ◽

Different Types ◽

Phytoplankton Growth Rate ◽

Zooplankton Production

Primary productivity and zooplankton data from Ocean Station P are used to compare estimates of phytoplankton and herbivore production calculated on the assumption of continuous grazing by the animals with estimates obtained on the assumption of three different types of nocturnal grazing. Effective plant production, that corrected for the effects of grazing on the size of the phytoplankton stock and hence on the magnitude of the plant respiratory loss, was less than the measured production and was least under the assumption of continuous grazing. The small differences in effective production resulting from the choice of different grazing schemes resulted in large differences in estimates of secondary production. The relative effect of assuming different grazing schemes on the estimate of secondary production varied markedly with zooplankton respiration and with the phytoplankton growth rate.

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The consumption of zooplankton by early life stages of fish in the North Sea

ICES Journal of Marine Science ◽

10.1093/icesjms/fsm156 ◽

2007 ◽

Vol 64 (9) ◽

pp. 1650-1663 ◽

Cited By ~ 20

Author(s):

Michael R. Heath

Keyword(s):

North Sea ◽

Early Life ◽

Life Stages ◽

Early Life Stages ◽

The North ◽

The North Sea ◽

Zooplankton Consumption ◽

Zooplankton Production ◽

Fish Early Life Stages

Abstract Heath, M. R. 2007. The consumption of zooplankton by early life stages of fish in the North Sea. – ICES Journal of Marine Science, 64: 1650–1663. Previous work has shown that during the 1970s, fish and carnivorous macrozooplankton together consumed ∼22 gC m−2 year−1 of mesozooplankton, principally copepods. Consumption declined to ∼17 gC m−2 year−1 during the 1990s, mainly because of a reduction in fish production. The zooplankton production required to meet this demand seems to be approximately accounted for by estimates of new primary production, but there are additional sinks for zooplankton production attributable to predation by, for example, gelatinous species. Additionally, the consumption of zooplankton by early life stages of fish is difficult to assess and could be larger than implied by the earlier analysis. Here, the role of fish early life stages in zooplankton consumption is re-assessed, and found to be approximately double that previously estimated. Some 28% of the zooplankton consumption by fish is now estimated to be attributable to early life stages, resulting in an estimate of zooplankton consumption by the fish community as a whole 14% higher. Taken overall, the consumption of zooplankton production by fish and other planktivorous predators is now estimated to be 19–25 gC m−2 year−1.

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