Reef Fishery
419
devastated their populations in numerous places in S.E. Asia (Lubbok and
Polunin 1975; Albadejo and Corpuz 1981).
Among the important accompaying phenomena of reef fishery the
siquaterra disease should be mentioned. This disease is caused by the
consumption of poisonous fish (Banner 1976). It is especially widespread on
the Marshalls, on Tuamotu and the Society Islands, where it injures 5 to
20% of local populations (Bagnis et al. 1988). On the atoll Hao (Tuamotu)
43% of the local people died due to siguaterra in 1969. The signs of
siquaterra are fever reflexes, loss of reflexes, muscle pains and convulsions.
Recovery takes several months. The initial source of the toxin seemed to be
some toxic microalgae. Fish concentrate it in their bodies. Siguarotoxin has
been isolated from fish meat. Its specific feature is thermostability. It
survives even boiling and is present also in cooked fish. Its appearance in
fish seems to be unpredictable. Many fish traded at certain periods might
contain this toxin. But in some of them it happens to be present more often.
Among these are the medium-sized and large perchiform fish (Lutjanus
bohar, Symphorus nematophorus) and mackerels. Siguaterra seriously
affects not only the health of people, but it harms also fishery, because the
fishermen, afraid of this disease, often avoid some valuable and harmless
fish too (Lewis et al. 1988).
Besides fish, a large quantity of invertebrates are also taken on reefs. The
most sought after among them are the molluscs Lambis, Strombus, Trochus,
large Voluta, Cassis, Murex, Tridacna, Pinna, Pteria - the pearl shell,
Cardium, and Pecten (Salvat 1981b; Wells 1981). The meat of molluscs is
used by local people as food and as fodder for pigs. The shells are utilized as
lime material for construction or for the making of souvenirs, buttons and
various adornments. The catch of such edible molluscs like Strom bus (S.
luhuanus) Trochus (T. niloticus) , Tridacna and Pteria species in some reef
regions has reached many thousand tonnes. Only from the Tuamotu atolls
since 1810 about 100000 t of pearl shells alone have been exported. By the
beginning of our century their stocks were devastated in this area. On many
reefs also the rich populations of Tridacna and of the edible holothurians
were exterminated (Dahl 1981; Sal vat 1981a,b). The same happened to
many common and even rare species of gastropods, especially cowries and
conids, caught for selling to tourists and collectors. The catch of cowries
alone on the Philippines reefs was estimated to be near 100 t. The total
export of souvenir shells in 1970 was close to 4500t, the total volume of
their world trade amounting to about 20 X 10 3 t (Helsinga 1981; Wells
1981). The data on catch of holothurians were given above (d. Se.ct. 5.5.5).
The annual catch of the spiny lobster Palinurus argus on Florida reefs is
valued at 10 million dollars. On the Pacific reefs the lobster P. ornatus is
extensively fished.
The corals are taken from reefs for souvenirs and for the ornamentation
of marine aquaria. The value of the annual trade of corals only from the
Philippines in 1977 was about 3 million dollars (Johannes 1975, 1978b;
419
devastated their populations in numerous places in S.E. Asia (Lubbok and
Polunin 1975; Albadejo and Corpuz 1981).
Among the important accompaying phenomena of reef fishery the
siquaterra disease should be mentioned. This disease is caused by the
consumption of poisonous fish (Banner 1976). It is especially widespread on
the Marshalls, on Tuamotu and the Society Islands, where it injures 5 to
20% of local populations (Bagnis et al. 1988). On the atoll Hao (Tuamotu)
43% of the local people died due to siguaterra in 1969. The signs of
siquaterra are fever reflexes, loss of reflexes, muscle pains and convulsions.
Recovery takes several months. The initial source of the toxin seemed to be
some toxic microalgae. Fish concentrate it in their bodies. Siguarotoxin has
been isolated from fish meat. Its specific feature is thermostability. It
survives even boiling and is present also in cooked fish. Its appearance in
fish seems to be unpredictable. Many fish traded at certain periods might
contain this toxin. But in some of them it happens to be present more often.
Among these are the medium-sized and large perchiform fish (Lutjanus
bohar, Symphorus nematophorus) and mackerels. Siguaterra seriously
affects not only the health of people, but it harms also fishery, because the
fishermen, afraid of this disease, often avoid some valuable and harmless
fish too (Lewis et al. 1988).
Besides fish, a large quantity of invertebrates are also taken on reefs. The
most sought after among them are the molluscs Lambis, Strombus, Trochus,
large Voluta, Cassis, Murex, Tridacna, Pinna, Pteria - the pearl shell,
Cardium, and Pecten (Salvat 1981b; Wells 1981). The meat of molluscs is
used by local people as food and as fodder for pigs. The shells are utilized as
lime material for construction or for the making of souvenirs, buttons and
various adornments. The catch of such edible molluscs like Strom bus (S.
luhuanus) Trochus (T. niloticus) , Tridacna and Pteria species in some reef
regions has reached many thousand tonnes. Only from the Tuamotu atolls
since 1810 about 100000 t of pearl shells alone have been exported. By the
beginning of our century their stocks were devastated in this area. On many
reefs also the rich populations of Tridacna and of the edible holothurians
were exterminated (Dahl 1981; Sal vat 1981a,b). The same happened to
many common and even rare species of gastropods, especially cowries and
conids, caught for selling to tourists and collectors. The catch of cowries
alone on the Philippines reefs was estimated to be near 100 t. The total
export of souvenir shells in 1970 was close to 4500t, the total volume of
their world trade amounting to about 20 X 10 3 t (Helsinga 1981; Wells
1981). The data on catch of holothurians were given above (d. Se.ct. 5.5.5).
The annual catch of the spiny lobster Palinurus argus on Florida reefs is
valued at 10 million dollars. On the Pacific reefs the lobster P. ornatus is
extensively fished.
The corals are taken from reefs for souvenirs and for the ornamentation
of marine aquaria. The value of the annual trade of corals only from the
Philippines in 1977 was about 3 million dollars (Johannes 1975, 1978b;