A guide for planners and managers - IUCN

166 MARINE AND COASTAL
PROTECTED AREAS
Johannes (1975) states that fringing reefs “are self-repairing breakwaters which
permit the continued existence of about 400 atolls and numerous other low tropical
islands, as well as preserve thousands of miles of continental coastlines.” Entire
island archipelagos owe their existence to the reef-building processes of past millennia
and the protective role of living sea-level reefs. In the Indian Ocean, for example, 77
percent of the isolated islands and island archipelagos are built exclusively of reef
depositions, and 18 percent have coral islands in addition to the principal island type
(Figure II-5). The Maldives Archipelago alone comprises 20 atolls and about 2,000
coral islands. Coral islands are valuable for tourist sites, permanent settlement,
plantations (notably coconut and papaya), and a refuge for fishermen in stormy
weather, temporary bases for itinerant fishermen, and recreation areas. They also provide
sanctuaries to a number of species, including seabirds and turtles.
FIGURE II-5.
A satellite-eye view of Salomon Atoll (Indian Ocean) as digitally
interpreted by computer graphing. Notice the characteristic ringlike
reef on which islands form, the central lagoon, and the sheer seaward
slope of atolls.
In summary, coral reefs
are utilized for subsistence,
income generation, research,
and recreation. Their uses can
be classified as either extractive
or non-extractive. Extractive
uses include the harvest of edible
species (fishes, crabs, lobsters,
snails, clams, octopus, sea
cucumbers, sea urchins, and
turtles), the harvest of ornamental
products (pearls, coral,
echinoderms. molluscs, and
turtles), and the harvest of industrial
products (bulk coral,
sponges. and giant clams). Nonextractive
uses include recre-
ation, science and education, tourism, and shore protection. Cesar (1996), Cesar et al.
(1997), and Spurgeon and Aylward (1992) have attempted economic valuation of these
reef products and services.
1.3 Threats from Human Activities
Coral reefs are in trouble from both natural and human causes. The literature
abounds with many cases of damage from careless development (see, for example,
Bryant et al., 1998; Endean, 1976; Johannes, 1975; Salvat, 1974, 1978, 1987a;
UNEP/IUCN, 1988; Wells and Hanna, 1992; Wilkinson, 1998). Specific examples are
discussed in the following paragraphs.
After the mining of coral reefs on high energy shorelines on the east coast of
Sri Lanka (Figure II-6) the shoreline eroded, causing trees and coconut palms to fall