| 摘要 |
PROBLEM TO BE SOLVED: To suppress accumulative increase in a concentration of nitric acid in circulated seawater and to efficiently raise marine animals by circulating seawater purified through a specific seawater-purifier layer and seaweeds for treating inorganic salts and by making the seaweeds serve as bait for the marine animals. SOLUTION: The method of this invention is to raise marine animals by circulating seawater purified through a seawater-purifier layer 2a comprising polychaetes such as a sea urchin 1 treating castings from and leftover bait by the marine animals, and seaweeds 3 for treating inorganic salts along with making the seaweeds serve as bait for the marine animals. The seawater-purifier layer 2a is fibrous materials and Marphysa sanguinea 2 dwelling therein. The water tank system for raising the marine animals preferably has a marine animal-raising area 1a communicating with the seawater-purifier layer 2a and the seaweed-growing area 3a accepting the seawater purified through the seawater-purifier layer 2a, where the area 1a and the area 3a are communicating with each other. |
