CHAPTER 2 GROSS ACTIVITY Dl PLANTS, SOIL, CORAL, ALGAE AND WATER At the tine of their collectica in the field plent, soil, coral end elzze samples were placed in individual plasticbags for ehiprent to USERDL. 2.1 Fater secples vere collected in l-liter polyethylene bottles. Frocedures at the Leboratcry The edible portions of the food plants were separated froa the in- edible portions with every preccution being taken to ensure a low probability of cress-conteciination. Weiched ensples of the food vere dried at 110% end then ashed in a mffle furnace at 590°C. The esh wos transferred to tared alucinun planchets, veiched and prepared for counting. Samples of supporting plent syste:s and grass were prepared in the sace feshion. Fresh water 6a:cles were acidified and the entire sample evaporated to dryness. The resifue wes taken up in water end the slurry transferred to & planchet for drying, weighing ard counting. The ectivity wes isolated fraa ocean vater satples ly (a) buffering vith TH,C1 to hold ragresiua in solution, ena (b) precipitating the natural caleiun with-Tra,C03. ‘the resulting flock wes allowed to cettle overnight and the bulk of th2 suparmct.at was removed by suction or decentation. to lustroié tubes ard centrifuced. The remaining slurry wes tronsferrad The preeciritete wos washed ooce with vater, transferred to on elurinun plioncket and dried at n0°%. Anolyais of the supernatants frou the more active sacples showed that reccvery of activity by precipitation ron fron ® to 30 rer cect. Soll and lagoon bottan gilt samples vere dried and mounted in