. The Composition of sea-water : comparative and descriptive oceanography. Seawater -- Composition. SECT. 4J THEORY OK FOOD-CHAIN RELATIONS IN THE OCEAN 443 sary to assume a maximum limit for assimilation, which was set at 8% of the animals' weight per day, otherwise the rate of increase would have been too rapid during the spring flowering. The limitation was qualitatively realistic although empirically derived, because it is well known that herbivores at such times eat more than they can digest. Carnivorous predation was attributed to Sagittae and was proportional to their number, although t
. The Composition of sea-water : comparative and descriptive oceanography. Seawater -- Composition. SECT. 4J THEORY OK FOOD-CHAIN RELATIONS IN THE OCEAN 443 sary to assume a maximum limit for assimilation, which was set at 8% of the animals' weight per day, otherwise the rate of increase would have been too rapid during the spring flowering. The limitation was qualitatively realistic although empirically derived, because it is well known that herbivores at such times eat more than they can digest. Carnivorous predation was attributed to Sagittae and was proportional to their number, although they were not the sole predators. A predation coefficient and the death rate were determined statisti- cally. The results, shown in Fig. 2, were moderately realistic, but the empirical elements made the analysis less acceptable than the phytoplankton treatment. Assimilation. Fig. 2. Seasonal cycle of zooplankton on Georges Bank, (a) Summation of growth pro- cesses. Upper curve is the postulated seasonal cycle of the coefficient of assimilation. From it the coefficients of respiration, predation and natural death are successively subtracted. The remainder, the lowest curve, is the estimated rate of change of the zooplankton population, (b) Dots represent observed zooplankton population; the smooth curve is a theoretical seasonal cycle obtained by approximate integration of the rate curve in (a). The equations that have been described transformed the Volterra theory into a promising ecological tool, but an important aspect of the theory was lost, namely the mutual dependence of equations (1) and (2). Fleming postulated an arbitrary rate of zooplankton increase, and the writer used observational data. Ecologists recognize the existence of this mutual dependence in nature. Zoo- plankton growth depends on the quantity of phytoplankton available, and conversely, grazing affects the phytoplankton concentration. Also, the animals and bacteria release inorganic nutrients that influence p
Size: 1663px × 1503px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollectionameri, bookcollectionbiodiversity
