X
Contents
2.3.3.2 Ks Calculative Method .................................... 54
2.3.3.3 Conversion from Daily Rates to the Whole Basin
and Annual Primary Production. . . . . . . . . . . . . . . . . . . . . . . . . . .. 61
2.4
Faults in the Radiocarbon Method and Problems
in its Calibration ......................................... 64
2.5
Use of the Radiocarbon Method to Determine Primary
Production by Benthic Hydrophytes and Their Associations. . .. 74
2.5.1 General Principles in the Use of 14C - Methods .............. 76
2.5.2 Experimental Vessels and Enclosures ....................... 78
2.5.3 Preparation of Working Solution of 14C - Carbonate .......... 82
2.5.4 Incubation Procedures .................................... 85
2.5.5 Estimation of Radioactivity in Plant Material ................ 94
2.5.6 Calculation of Results; Comparison with Alternative Methods .. 97
3
Radioisotopic Methods for the Study of Nutrition in Aquatic
3.1
3.2
3.3
3.3.1
3.4
3.4.1
3.4.2
3.4.3
3.4.4
3.5
3.5.1
3.5.2
3.5.3
3.5.4
3.5.5
3.5.6
3.5.7
3.5.7.1
3.5.7.2
3.6
3.6.1
Animals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 100
Introduction. Alternative Methods .......................... 100
General Principles ....................................... 104
Preparation of Labeled Food .............................. 107
Labeling Algae and Plant Detritus .......................... 107
Analyses of Basic Values Needed for the Calculation
of Intensity and Efficiency of Nutrition ...................... 112
Estimation of Cr • • • • • • • • • • • • • • • • • . • • • • • • • • • • • • • • • • • • • • • • • 112
Determination of Radioactivity in Consumers' Bodies (Ra)
115
Determination of Radioactivity of Respired CO2 and Feces .... 118
Estimation of the Inverse Specific Radioactivity
of CO2 Respired by Labeled Animals (Cq) . . . . • • • • • . . . . • • • • • • 119
Use of 14C for Assessment of Nutritional Problems
in the Ecology and Physiology of Aquatic Animals . . . . . . . . . . .. 120
Assessing the Duration of Digestion ........................ 121
Assessing Comparative Rates of Food Ingestion
and Assimilation ......................................... 121
Radiocarbon Estimation of the Relative Rate of Respiration ... 126
Evaluation of Food Spectrum and Selectivity . . . . . . . . . . . . . . . .. 127
Dependence of Nutrition Rate upon Food Concentration ...... 129
Experimental Evaluation of Other Factors Influencing
Nutrition Rate ........................................... 132
Determinating Filtration Rates in Filter Feeders .............. 135
General Considerations ................................... 135
Technique for Fr Determination ............................ 136
Measurements of Absolute Rates of Feeding,
Food Assimilability, and Respiration ........................ 138
General Considerations ................................... 138