418
Destruction and Recovery of Reef Systems, Reef and Man
(Munro and Williams 1985; Table 6.8). Presently, the annual catch of fish on
reefs could be evaluated to be between 0.6-1 x 10 6 t, which comprises
about 1.5% of the total world catch. Reef filshery provides 50 to 90%
of necessary proteins for ca. 50-70 million people inhabiting tropical
coasts.
Among the reef fish communities subjected to fishery only 1-3% of adult
specimens has weights over 200 g. They comprise about 50% of the total
biomass of fish on a reef. Among them up to 90% middle-sized fish:
acanthurids, caesionids, mugilids, goat fish, and sardines (Table 6.8). The
fish catch on reefs depends much upon the kinds of fishing gear and fishery
techniques employed. In an optimal case they should be suitable for
catching variously sized groups of fish, being at the same time the least
destructive. In particular, successful fishery on reefs of the Philippines is
ensured by the wide use of gill nets. The overcatch and degradation of fish
resources at Tonga and the Marianas were caused by the use of destructive
methods- toxic substance and explosives for fishery, and by the overcatch of
large predators with line fishing. In areas of active commercial fishery the
degradation of resources becomes habitual. For example, fish and
crustacean resources of reefs off Florida and Guam were undermined by
poorly regulated amateur fisheries. It is precisely amateur fishermen and
sportsmen who violate fish stocks on reefs, eliminating mostly large
predatory fish, which have a low growth rate and thus overcome overfishing
very slowly. Significant damage to stocks of reef fish is made by mass catch
with trawls of middle and average planktivore fish for bait by tuna
fishermen. In many reef regions destructive methods of fishery are
employed, e.g. explosives, ichthyocides and various other toxicants, which
severely damage the whole reef communitiy (Campbell 1977). The same
destructive impact is made by the booming amateur and sportive fishery in
regions of mass tourism and near cities, where spear hunters and amateurs
are literally devastating the reefs.
The negative consequences of these events are also obvious. For
example, in the central GBR the number of objects of amateur fishing, like
marlins, reef trout (Plectroponus) , emperors (Lutjanus sebae), sweet-lips
(Lethrinus chrysostomus) , groupers (Epipephelus) , as well as the average
sized fish significantly decreased. Moreover, the amateur and sportive catch
exceeds the commercial catch threefold. On the east coast of Queensland
75000 motor boats of amateur fishermen were registered in 1979. The trade
in reef fish for aquaria became a multimillion dollar business. Their export
in the Philippines and Taiwan contzibutes a significant part to the total
export of these countries. On the Philippines alone about 20000 hundred
weights of aquarium fish are exported annually. For fishing them besides gill
nets and traps also cyanide and ichthyocides are employed which damage
the reef fauna. For this business the most beautiful and rare species of reef
fish are decimated, e.g. Centropyge bispinosus, Pomacanthus imperator,
Euxiphippos sextriatus, and Pygolites diacanthus. This trade severely
Destruction and Recovery of Reef Systems, Reef and Man
(Munro and Williams 1985; Table 6.8). Presently, the annual catch of fish on
reefs could be evaluated to be between 0.6-1 x 10 6 t, which comprises
about 1.5% of the total world catch. Reef filshery provides 50 to 90%
of necessary proteins for ca. 50-70 million people inhabiting tropical
coasts.
Among the reef fish communities subjected to fishery only 1-3% of adult
specimens has weights over 200 g. They comprise about 50% of the total
biomass of fish on a reef. Among them up to 90% middle-sized fish:
acanthurids, caesionids, mugilids, goat fish, and sardines (Table 6.8). The
fish catch on reefs depends much upon the kinds of fishing gear and fishery
techniques employed. In an optimal case they should be suitable for
catching variously sized groups of fish, being at the same time the least
destructive. In particular, successful fishery on reefs of the Philippines is
ensured by the wide use of gill nets. The overcatch and degradation of fish
resources at Tonga and the Marianas were caused by the use of destructive
methods- toxic substance and explosives for fishery, and by the overcatch of
large predators with line fishing. In areas of active commercial fishery the
degradation of resources becomes habitual. For example, fish and
crustacean resources of reefs off Florida and Guam were undermined by
poorly regulated amateur fisheries. It is precisely amateur fishermen and
sportsmen who violate fish stocks on reefs, eliminating mostly large
predatory fish, which have a low growth rate and thus overcome overfishing
very slowly. Significant damage to stocks of reef fish is made by mass catch
with trawls of middle and average planktivore fish for bait by tuna
fishermen. In many reef regions destructive methods of fishery are
employed, e.g. explosives, ichthyocides and various other toxicants, which
severely damage the whole reef communitiy (Campbell 1977). The same
destructive impact is made by the booming amateur and sportive fishery in
regions of mass tourism and near cities, where spear hunters and amateurs
are literally devastating the reefs.
The negative consequences of these events are also obvious. For
example, in the central GBR the number of objects of amateur fishing, like
marlins, reef trout (Plectroponus) , emperors (Lutjanus sebae), sweet-lips
(Lethrinus chrysostomus) , groupers (Epipephelus) , as well as the average
sized fish significantly decreased. Moreover, the amateur and sportive catch
exceeds the commercial catch threefold. On the east coast of Queensland
75000 motor boats of amateur fishermen were registered in 1979. The trade
in reef fish for aquaria became a multimillion dollar business. Their export
in the Philippines and Taiwan contzibutes a significant part to the total
export of these countries. On the Philippines alone about 20000 hundred
weights of aquarium fish are exported annually. For fishing them besides gill
nets and traps also cyanide and ichthyocides are employed which damage
the reef fauna. For this business the most beautiful and rare species of reef
fish are decimated, e.g. Centropyge bispinosus, Pomacanthus imperator,
Euxiphippos sextriatus, and Pygolites diacanthus. This trade severely