| 摘要 |
Basic materials for mussel cultivation, i.e. mussel seedlets, are caught by nets or ropes. These nets or ropes function as substrates and by nature the mussel larvae settle upon them. As the larvae grow they are harvested as mussel seed and sown out on cultivation ground where they are further developed. There are many types and varieties of mussel seed catchment installations. The nets used hang in the correct position in the water column. This operative process is obtained by heavy duty polyethylene tubes (diameter 314 mm) closed in a watertight manner and set under air pressure. The total length of these tubes is approximately 126 meters. So that this length can be easily handled during installation and removal (both once a year), a construction has been conceived whereby it is possible to fold the tube into three parts, preferably each of 42 meters. Each part tube is individually made watertight and set under pressure. In the inner end of each part is one tube with a diameter of approximately 25 centimeters, which projects to an extent of 40 centimeters. Over this is fixed a piece of flexible hose of some 2 meters length. The same applies at the other outer end. In the outer end of the tube is a fixture point, where by means of a closure a line is attached, which is also fixed to the other outer end. This produces a completely rigid hinged movement. |
