Impacts of fishing on coral reefs
Takafumi Arimoto
Tokyo University of Fisheries
4-5-7, Konan, Minato-ku, Tokyo 108-8477, Japan
Coral reefs are well recognized as important buffer areas for global warming issues, and as nursery areas for the diversed ecosystems of the tropical zone. Destructive fishing practices such as the use of explosives and toxins have been criticized and prohibited. Environmentally friendly fishing technologies for coral reef areas need to be suggested to replace the conventional destructive practices. For this purpose, a case study for evaluating the impacts of fishing activities on the environment and the biodiversity of coral reef areas in the Ryukyu Islands, Japan, is outlined as a key to minimize impacts by establishing sustainable fisheries.
The fishing gear and methods used in the Sekisei Coral Lagoon, Ishigaki Island, were surveyed by boarding the fishing operations and interviewing the fishermen. The catch species and size, together with the by-catch/discards species, were recorded during the onboard fishing trials. Long-term catch data for several types of fishing gears were also obtained for the later analysis. The type and size classification of fishing boats in this area was also surveyed both from the statistic data and fishing port inspections. The fishing gear and methods of set-net, trammel net and fish pot are described here with special attention to the typical fishing practices by the diving operations in this region.
For suggesting the alternatives to these fishing gear and methods, the evaluation of the conventional activities from the view point of impacts can be the first step. Here in this paper, the direct evaluation was challenged by onboard and diving inspections of the capture process for the concerned fishing practices, to check the physical benthic damage by the gear, by-catch and discards, and the catch composition diversity. Further analysis on the fishing impact will be required with comparisons among the localities in the wide tropical areas. On this respect, the comparative/ comprehensive approach will be the key solution, both from the ecological and economical analysis including the infra-structure of fishing ports, fish market, technological level of fishing gear and boats, together with the balancing with the recent move of eco-tourism in the coral lagoon.
