Zooplankton biomass

In comparison, our measurements of epilimnetic zooplankton biomass over the study period (3540 mg/m2), combined with Scavia s (7) weight-specific zooplankton regeneration rate of 1.7 xg of P/mg per day, give a flux of —800 mg of P/m2. These estimates of phosphorus excretion rates are similar to our carbon-based phosphorus demand. 

Figure 14 Relationship between the fatness of anchovy in October and the weight of zooplankton food, as grams available to each gram of fish. The zooplankton biomass is computed from the summed concentration (as mg nr3 x 300 km3) the volume of the Sea of Azov, and is applied to the long-term average yield for anchovy.

Thus, a change in zooplankton biomass follows the law described by the following differential equation ... 

Hemandez-Leon, S., Almeida, C., Gomez, M., Torres, S., Montero, I., and PortiUo-Hahnefeld, A. (2001). Zooplankton biomass and indices of feeding and metabolism in island-generated eddies around Gran Canaria. J. Mar. Syst. 30, 51-66. 

Feeding and growth rates, egg production and hatching success, and fecal pellet production are affected by both quantity and quality of food supply (Abou Debs, 1984 Besiktepe and Dam, 2002 Frost, 1972 Tang and Taal, 2005). Changes in food quality can create a mismatch in stoichiometry between predator and prey (Sterner and Hessen, 1994) and effect all of the above parameters, as well as body N content, and ultimately zooplankton production and biomass. In fact the nutritional status of phytoplankton (N cell quotas), not the phytoplankton biomass, may be the major bottom-up determinant of zooplankton biomass (Hessen, 1992 Sterner and Hessen, 1994) except in periods of low food availability (Jonasdottir et al., 2002). 

With the growth and death rates given by Equations 25 and 26, respectively, the source term for herbivorous zooplankton biomass is given by Equation 24. The conservation of mass equation which describes the behavior of Z, is given by Equation 2, with Z, as the dependent variables replacing Pj and SZj replacing SPj as the source terms. 

The conservation of mass principle is applied to the nutrients being considered in the same way as it has been previously applied to the phytoplankton and zooplankton biomass within a volume segment. The number of mass conservation equations required is equal to the number of nutrients that are explicitly included in the growth rate formulation for the phytoplankton. For the sake of simplicity, the formulation for only one nutrient is discussed below. 

In the previous sections, the equations for phytoplankton and zooplankton biomass and nutrient concentration within one volume element have been formulated. The resulting equations are an attempt to describe the kinetics of the growth and death of the phytoplankton and zooplankton populations and their interaction with the nutrients available. The form of the equations for the volume V are as follows ... 

Baars, M.A. and Oosterhuis, S.S. (1997) Zooplankton biomass in the upper 200 m in and outside the seasonal upwelling areas of the western Arabian Sea, in Pelagic Biogeography ICoPBII Proceedings of the Second International Conference (eds A.C. Pierrot-Bults and S. van der Spoel), IOC/UNESCO, Paris, pp. 39-52. 

Mathew, K.I., Naomi, T.S., Antony, G., Vincent, D., Anilkumar, R. and Solomon, K. (1990) Studies on zooplankton biomass and secondary and tertiary production of the EEZ of India, in Proceedings of First Workshop of Scientific Results, FORV Sagar Sampada (ed. K.I. Mathew), Central Marine Fisheries Research Institute, Cochin. 

Burd, B.J. and Thomson, R.E. (1994) Hydrothermal venting at Endeavour Ridge effect on zooplankton biomass throughout the water column. Deep-Sea Research I, 41, 1407-1423. 

Quantitative estimates of the global distribution and biomass of zooplankton are extremely difficult. The routine net sampling techniques probably fail to collect a considerable proportion of the microzooplankton which could itself equal the biomass of the net zooplankton (Pomeroy, 1974). Zooplankton biomass data were summarised for various oceanic and coastal waters by Raymont (1966). It is striking that Mullin (1969) in his survey of the production of zooplankton in the ocean does not himself venture any global estimate. 

Productivity/biomass ratios are strongly dependent both on temperature and food supply. Mullin s (1969) review contains a summary table in which the season and location of the measurements are recorded total production estimates in the literature vary between 4.9 and 70 (or 234) mg C m day" . Moreover, this review draws attention to the many dubious approximations, assumptions, mistakes and ambiguities that are not uncommon in this literature (Crisp, 1975). Russian investigators (Bogorov, Moiseev, Vinogradov) estimated the zooplankton biomass in the world oceans at 1.6 to 1.9 X 10 t C (as cited in De Vooys, 1979). In the FAO atlas of the living resources... 

Areas with high, moderate and low phytoplankton production roughly coincide with areas rich, moderate and poor in zooplankton biomass (Bogo-rov et al., 1968 Section 6). Zooplankton exhibits by far the largest biomass and production of all marine animal groups considered (viz. zooplankton, zoobenthos, nekton Table VIII). 

Goutx, M. and Saliot, A., 1980. Relationship between dissolved and particulate fatty acids and hydrocarbons, chlorophyll a and zooplankton biomass in Villefranche Bay, Mediterranean Sea. Mar. Chem., 8 299—318. 

The zooplankton biomasses vary in different areas and seasons. The spatial zooplankton biomass decreases from south to north the average biomasses in the north, middle area and south are 28.8, 31.7, and 74.3 mg/m, respectively. The highest value is found in summer, followed by spring, and the lowest value is in winter. In spring, the average biomasses in the north, middle area, and south are 12.9, 14.3, and 134.7 mg/m , respectively. In summer, the average biomasses in the north, middle area, and south are 50.1, 45.4, and 27.1 mg/m, respectively. In autumn, the average biomasses in the north, middle area, and... 

Xu ZL, Chao M, Chen YQ (2004) Distribution characteristics of zooplankton biomass in the East China Sea. Acta Oceanol Sin 26(3) 93-101 (in Chinese with Enghsh abstract)... 

Consecutive cruise data along three transects (added to four transects since 2003) in the southern Yellow Sea (SYS, Fig. 3.16), maintained by the YS Environmental Cooperative Research between China and Korea, were used. The research concerned marine physics, chemistry, geology, biology, and environment. The cruise data included the ocean temperature (T), salinity (5), plankton biomass (chlorophyll a concentration and zooplankton biomass, etc.) and biogenic elements. 

Carbon fixed production of zooplankton through zooplankton biomass could be undertaken from the following procedures. Firstly, the dry weight for a zooplankton unit is calculated ... 

Fig. 3.73. Horizontal distribution of the chlorophyll a ( lg/L), plankton cell density (xlO cells/L), and zooplankton biomass based on wet weight (mg/m ) in the surface seawater of the SYS (Zhang et al., 2007) (With permission from Elsevier s Copyright Clearance Center)...

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