Analysis of factors controlling responses of an aquatic microcosm to organic loading
- 50 Downloads
The changes in the numbers of individuals of the constituent species and ammonia concentrations in 6 subsystems (Bacteria, bacteria-Cyclidium, bacteria-Aeolosoma, bacteria-Chlorella, bacteria-Cyclidium-Chlorella, bacteria-Aeolosoma-Chlorella) of an aquatic microcosm were examined after the addition of organic substance (peptone) at both the young and mature stages of succession. Organic loading led to decreases in the numbers of bacteria and Aeolosoma after temporary increases in their numbers and an oscillation in the numbers of Cyclidium but the densities of these populations were maintained at constant values in the presence of Chlorella. When organic substance was added at a young stage where the photosynthetic activities of algae were high, invertebrates, especially Aeolosoma, were damaged by unionized ammonia which was formed as the pH value increased. In contrast, organic loading at the mature stage enhanced the population densities and biomasses of all constituent species.
Key wordsAeolosoma aquatic microcosm Chlorella Cyclidium organic loading
Unable to display preview. Download preview PDF.
- Kurihara, Y., 1978. Studies of the interaction in a microcosm. Sci. Rep. Tohoku Univ. 37: 161–177.Google Scholar
- Parsons, T. R. & J. D. H. Strickland, 1963. Discussion of spectrophotometric determination of marine-plant pigments, with revised equations for ascertaining chlorophylls and carotenoids. J. mar. Res. 21: 155–163.Google Scholar
- Sagi, T., 1966. Determination of ammonia in sea water by the indophenol method and its application to the coastal and off-shore waters. Oceanogr. Mag. 18: 43–50.Google Scholar
- Shikano, S. & Y. Kurihara, 1985. Community responses to organic loading in a microcosm. Jap. J. Ecol. 35: 297–305.Google Scholar
- Tabata, K., 1962. Toxicity of ammonia to aquatic animals with reference to the effect of pH and carbon dioxide. Bull. Tokai. Reg. Fish Res. Lab. 34: 67–74. (in Japanese with English summary)Google Scholar
- Watanabe, A., 1960. List of algal strains in collection at the Institute of Applied Microbiology, University of Tokyo. J. Gen. Appl. Microbiol. 6: 283–292.Google Scholar