Anthropogenic Impacts
411
Palau, Solomons, Hawaii, French Polynesia and E. Samoa were seriously
damaged. The military dredged reefs for passage through them, crushed
them by ships and anchors, polluted them with various wastes and rubble,
and bombed them with explosives to kill fish. Major destruction of reefs and
the radioactive contamination of reef fauna for hundreds of square
kilometers were the conseqences of nuclear tests on the atolls Bikini,
Enivetok and Moruroa. Destruction was aggravated by the appearance of
diving equipment, boat motors and air communication. Within a short time
the collection of shells, corals and also of reef fish for aquaria became a kind
of industry, promoted by the development of marketing and monetary
systems in reef regions and countries. All these developments caused the
rapid devastation of many reefs (Endean 1976).
The tourist boom of the last two decades became an importamt factor
harmful to reefs (Sudara 1988; Bell and Gabric 1991) as it turned into a
large-scale business. Thousands of hotels and recreation centers house been
constructed for tourists. The wastes discharged from them are a main source
of pollution on numerous reefs (Fraizier et al. 1985). Hordes of tourists
wander on reef flats, trampling down everything that lives (Kay and Liddle
1984). They fish, collect shells and corals and buy them from local people.
As a consequence, in regions of intensive tourism, the populations of many
molluscs, gorgonians, asteroids, pencil urchins and corals seem to be
diminishing. Among them were key species of the reef ecosystems, such as
the large predatory gastropods Melo, Charonia, and Cassis. Their price
during the tourist boom rose and they became objects of extensive
collection. For example, the populations of Charonia tritonis abundant on
reefs of the GBR at the beginning of the 1970s has been practically
extinguished. Now this mollusc has disappeared from this area. The same
happened in many other places. In 1970 on the market of Suva over 1000
species of Charonia were being sold at the same time. As mentioned above,
it was just the extermination of this key species that most probably triggered
the Acanthaster plague.
Trampling about on reefs tourists destroy the populations of ramose
corals. For example, on the Wistari reef (GBR), which has been often
visited by tourists, the bottom cover by these corals quickly decreased from
41 to 8% (Kay and Liddle 1984). In places of massive tourism reef suffer
also from mechanical damage by anchors, anchor chains and motor
propellers of numerous excursion boats and ships (Rogers 1985; Smith
1985). Tourists - amateur fishers employing modern equipment, including
scuba apparatus and spear rifles destroyed on many reefs the populations of
large predatory fish like groupers, sweetlips, and reef cods (Dahl 1985).
Overfishing endangers also the populations of beautiful reef fish, which are
caught for aquaria, like butterfly and angel fish (Lubbok and Polunin 1975).
A world trade in corals has been set up, which undermines their populations
in the Philippines, Thailand, Australia, Taiwan, and French Polynesia
(Wells 1981; Gomez 1982).
411
Palau, Solomons, Hawaii, French Polynesia and E. Samoa were seriously
damaged. The military dredged reefs for passage through them, crushed
them by ships and anchors, polluted them with various wastes and rubble,
and bombed them with explosives to kill fish. Major destruction of reefs and
the radioactive contamination of reef fauna for hundreds of square
kilometers were the conseqences of nuclear tests on the atolls Bikini,
Enivetok and Moruroa. Destruction was aggravated by the appearance of
diving equipment, boat motors and air communication. Within a short time
the collection of shells, corals and also of reef fish for aquaria became a kind
of industry, promoted by the development of marketing and monetary
systems in reef regions and countries. All these developments caused the
rapid devastation of many reefs (Endean 1976).
The tourist boom of the last two decades became an importamt factor
harmful to reefs (Sudara 1988; Bell and Gabric 1991) as it turned into a
large-scale business. Thousands of hotels and recreation centers house been
constructed for tourists. The wastes discharged from them are a main source
of pollution on numerous reefs (Fraizier et al. 1985). Hordes of tourists
wander on reef flats, trampling down everything that lives (Kay and Liddle
1984). They fish, collect shells and corals and buy them from local people.
As a consequence, in regions of intensive tourism, the populations of many
molluscs, gorgonians, asteroids, pencil urchins and corals seem to be
diminishing. Among them were key species of the reef ecosystems, such as
the large predatory gastropods Melo, Charonia, and Cassis. Their price
during the tourist boom rose and they became objects of extensive
collection. For example, the populations of Charonia tritonis abundant on
reefs of the GBR at the beginning of the 1970s has been practically
extinguished. Now this mollusc has disappeared from this area. The same
happened in many other places. In 1970 on the market of Suva over 1000
species of Charonia were being sold at the same time. As mentioned above,
it was just the extermination of this key species that most probably triggered
the Acanthaster plague.
Trampling about on reefs tourists destroy the populations of ramose
corals. For example, on the Wistari reef (GBR), which has been often
visited by tourists, the bottom cover by these corals quickly decreased from
41 to 8% (Kay and Liddle 1984). In places of massive tourism reef suffer
also from mechanical damage by anchors, anchor chains and motor
propellers of numerous excursion boats and ships (Rogers 1985; Smith
1985). Tourists - amateur fishers employing modern equipment, including
scuba apparatus and spear rifles destroyed on many reefs the populations of
large predatory fish like groupers, sweetlips, and reef cods (Dahl 1985).
Overfishing endangers also the populations of beautiful reef fish, which are
caught for aquaria, like butterfly and angel fish (Lubbok and Polunin 1975).
A world trade in corals has been set up, which undermines their populations
in the Philippines, Thailand, Australia, Taiwan, and French Polynesia
(Wells 1981; Gomez 1982).