Unexpected relationships between coral reef health and socio-economic pressures in the Philippines: reefbase/RAMP applied

Abstract

The paper analyses variables hypothesized to affect the health of coral reefs. These variables include fishing pressure as measured by fisher density and land-based human activities as indicated by population, relative wealth, waste disposal and aspects of land use. Findings indicating that the healthiest coral reef areas are characterized by higher fisher densities as well as greater increases in population density were, at first, surprising. In retrospect, the results fit perfectly with human ecological theory; where possible, people tend to migrate from resource-poor to resource-rich areas. Any synchronic analyses of the interrelationships between the condition of aresource and associated population size or density will probably be confounded by the dynamics of the populations dependent on the resource. Hence, there is a need to account for this dynamic when researching anthropogenic effects on coral reefs. The findings also indicate that less-healthy reefs are found in areas with a higher percentage of land devoted to permanent crops; this appears to be related to observed high levels of runoff from permanent crops.