| Abstrakt: |
Frequent occurrences of typhoons invading cage culture farms and causing the death or escape of all the farming fish result in substantial losses for farmers in our country and abroad. Before a typhoon hits Taiwan, fishermen who use round submersible cage farming will submerge the cage to a depth of about 20 meters to avoid the effects of strong currents and waves on the sea surface. Typhoons are prevalent in Taiwan during the summer and fall. However, the fisherman are unaware of the depth changes of the cage. In this study, 9 depth sensors and an Acoustic Doppler Current Profiler were attached to a small round submersible cage with a diameter of 16 m and a net depth of 8 m in order to detect the change in the cage's depth in different parts, as well as the speed and direction of current during the typhoon that struck Taiwan. The cage can maintain a stable depth when there is no typhoon, but when the current speed exceeds 20 cm/s, its volume ratio will decrease and it will float to the surface. When the center of the Meranti Typhoon passes through the culture farm, the current speed exceeds 30 cm/s for approximately three hours, with a maximum speed of 41.6 cm/s that is maintained for approximately half an hour. The deformed cage is floated from a depth of 20 meters to a depth of 5 to 8 meters. The center of the Malakas Typhoon did not pass through the culture farm, but it caused the cage to float upwards and the mesh to become severely deformed, resulting in a reduction in breeding space. This research may provide the cage culture industry with references for the technological development of the anti-strong flow cage, cage structure fixation, and underwater anchor to reduce fish culture mortality. [ABSTRACT FROM AUTHOR] |
