Inorganic nutrients, photosynthetic pigments, and zooplankton species richness and species diversity in the surrounding waters of urban Kralendijk, Bonaire

Excess nutrients as a result of agricultural, urban, and industrial runoff are major causes to increases in plankton. Coral reefs are nutrient poor environments to begin with; therefore any increase in inorganic nutrients could potentially alter the balance of these ecosystems. Bonaire is suffering from nutrient input in the coastal waters and said trends are expected to increase in subsequent years. Zooplankton diversity and species richness, photosynthetic pigments, water properties and nutrients were measured at two different sites in Kralendijk, Bonaire. The most common taxonomic groups at each site were copepods and siphonophores. The difference in mean turbidity between the two sites was statistically significant (ttest; n = 14; p = 0.002). Excessively turbid water can be explained by an increased plankton population but also by sediment runoff from events such as coastal construction. A possible trend was found between number of zooplankton individuals, chlorophyll a, turbidity, and ammonia nitrogen concentration. This trend could indicate abnormal amounts of runoff entering the waters surrounding Bonaire. Not only is marine management necessary, but also an additional terrestrial aspect to monitor in the form of wastewater and watershed management. Zooplankton taxonomic groups identified during this study could be used as indicators of reef ecosystem health, reproduction success of organisms with planktonic larvae, or predator-prey impact studies such as with pelagic predators of zooplankton. Overall, this study shows important indicators of management for urban areas on Bonaire, but could also contribute to future ecological studies on zooplankton population dynamics around the Caribbean.

This student research was retrieved from Physis: Journal of Marine Science XVIII (Fall 2015)19: 1-9 from CIEE Bonaire.

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