A lack of sufficient wastewater treatment practices on the island of Bonaire, Dutch Caribbean suggests that contaminated groundwater seepage or runoff could be impacting the health of the coastal habitats and fringing reefs that surround the island. Bonaire does not monitor the health of its coastal waters, although effects of pollution have been observed. This study aims to learn more about the coastal water quality at three stations along the coast of the city of Kralendijk, Bonaire. Both indicator bacteria (coliform bacteria, Escherichia coli, and enterococci) and polychaete assemblages were monitored. IDEXX ColilertTM and EnterolertTM test kits were used to monitor bacteria levels in samples taken over a five-week study period. Polychaetes were identified to the family level from soft sediment samples. Polychaete family abundance, richness, and diversity were compared between stations. Grain size of the soft sediments at each station was measured. Polychaete assemblages varied between stations, but not enough data was gathered to eliminate the possibility of unexpectedly large grain size differences in explaining this variability. Typical water samples from each station showed narrow variability within U.S. Environmental Protection Agency standards for indicator bacteria levels. Two outliers occurred. The Marina station experienced a wider variance in all bacteriological indicator levels than the other two stations, and all surface stations experienced a significant spike in enterococci levels after a heavy rainstorm. If elevated enterococci levels consistently occur during heavy rainstorms, this could present a
Seagrass beds are globally declining due to human activities in coastal areas. We here aimed to identify threats from eutrophication to the valuable seagrass beds of Curaçao and Bonaire in the Caribbean, which function as nursery habitats for commercial fish species. We documented surface- and porewater nutrient concentrations, and seagrass nutrient concentrations in 6 bays varying in nutrient loads. Water measurements only provided a momentary snapshot, due to timing, tidal stage, etc., but Thalassia testudinum nutrient concentrations indicated long-term nutrient loads. Nutrient levels in most bays did not raise any concern, but high leaf % P values of Thalassia in Piscadera Bay (0.31%) and Spanish Water Bay (0.21%) showed that seagrasses may be threatened by eutrophication, due to emergency overflow of waste water and coastal housing. We thus showed that seagrasses may be threatened and measures should be taken to prevent loss of these important nursery areas due to eutrophication.