A guide for planners and managers - IUCN

260 MARINE AND COASTAL
PROTECTED AREAS
5. Bonaire: Calculating Carrying Capacity
The coral rich waters surrounding Bonaire in the Netherlands Antilles Marine Park
are a major tourist attraction and all have been designated the Bonaire Marine
Park (BMP). However, the steady increase in the number of divers visiting BMP
caused concern about diver impacts and the sustainability of the coral based resource.
The World Bank commissioned a study of the situation in 1991.
Fortunately, an extensive reef-mapping project conducted in 1981/82 provided
good baseline data for comparison with the 1991 situation. The study focussed on a
comparison of two heavily dived sites and one moderately dived site. Comparison of
available 1981/82 estimates of coral cover with 1991 found that the percentage of live
coral cover was significantly lower in the heavily dived sites, but not in the moderately
dived site.
An informed assumption was made that the decrease in coral cover observed
at the two heavily dived sample sites was not acceptable and exceeded the scenic carrying
capacity of those particular sites. “Unacceptable” impact was found more at 100 m
to 260 m from fixed mooring buoy locations. Dive statistics showed that the impact
becomes unacceptable when a site receives over 5,000 dives per year.
The total “diveable” coastline was estimated at 52 km, and with moorings
spaced 600 m apart, the Park could have a total of 86 dive sites. At 4,500 dives per
year per site there could be 387,000 dives per year. Making corrections for unevenness
of use of the various sites, the maximum carrying capacity was set at about 200,000
dives per year. Concurrent with Bonaire’s recommended total tourist limit of 40,000
divers (of a total of 100,000 total tourists) the 200,000 dive limit would allow 5 dives
per visitor.
An important lesson learned is that for the use of marine resources for tourism
to be sustained, tourism interests must be warned early on that resource use may have
to be limited at some stage. It is essential to assess carrying capacity at an early stage
of development and to refine the assessment later.
Source: Tom v’ant Hof, in Coastal Seas, The Conservation Challenge. Blackwell
Science, Oxford. 1998. 134 pp.
E-Mail Contact: vanthof@megatropic.com