Implications of resource management in La Parguera, Puerto Rico (The)

A recent rezoning of La Parguera, southwest Puerto Rico, as a tourist zone has resulted in an imbalance between development and appropriate resource management. Development associated with tourism is destroying the sub-tropical dry forest and adding pressure on the marine resources through increased boat traffic and marine structures. Declining water quality and benthic community health are two of the impacts seen in La Parguera associated with these land use changes. This study is three-fold. First, I evaluated the effect of houseboats on the benthic community. By comparing seagrass vigor under houseboats and in control areas, the houseboats were not found to be damaging seagrasses through shading nor were they reducing water quality. In fact, these boats may have positively impacted the localmarine system by creating an artificial reef environment. However, it was found that seagrass beds had significantly decreased in all areas since the last quantitative benthic study in 1979. Second, I examined the effect of land use changes on water quality. Declining water quality is a concern to the local town's people who depend on the resource. Elevated chlorophyll-a concentrations indicated a source of nutrients entering near the waste treatment facility. Total suspended solids were significantly higher in reas near new development as compared to upstream and downstream sites (31.78 mg/l). Boat ramps were a point source for this material as well as trace metals. Third, I examined the distribution of seagrass beds near La Parguera. Seagrass beds were reduced or absent near development, and where they were found elevated epiphyte loads were associated with reduced productivity. Sediment composition was not significantly different in areas devoid of seagrasses, suggesting that seagrass might be able to recolonize if other impacts were reduced. Lower water quality and seagrass vigor in areas near recent development suggest that the changes in local zoning and lack of planning have measurably contributed to reduced water quality. Rapid changes in la nd use in La Parguera without consideration for best management techniques to control stormwater and nutrient runoff is causingdeterioration of water quality, and, in turn, deterioration of the benthic community of this marine system.