都市下水の養殖ノリの生育に及ぼす影響に関する研究 ＩＩ 養殖ノリの生育に及ぼす都市下水処理水の影響評価のための培養法について

Abstract

The effect of effliuents from municipal sewage treatment plants on the growth of Porphyra yezo-ensis was studied by comparing the shaking culture method with the static culture method. Emuents examined were sampled before chlorination, and Provasoli's enriched seawater(PES) was used as a control. To clarify the differences in effects between shaking and static cultures on the growth of Porphyra thalli, the thalli length and the absorption spectra of living thalli were measured every second day. The number of dead or diseased cells in a thallus were observed under a microscope followed by erythrosine staining after 10 to 12 days from the start of the culture. The ranges of relative length of the thalli (1.8-4.9 and 1.3-2.1) were obtained after 10 days in effluents, with a salinity of 31‰ by shaking or static cultures, respectively. The maximum relative length of thalli (5.8) was obtained after 10 days in a fortyfold diluted PES medium, with a salinity of 31‰ by shaking culture. The shaking culture method showed a higher sensitivity than the static culture method for other aspects examined regarding the effect of the effluent on the growth of Porphyra thalli.