Christmas tree worms (Spirobranchus giganteus) as a potential bioindicator species of sedimentation stress in coral reef environments of Bonaire, Dutch Caribbean

The effect of land-based pollution on Bonaire’s coral reef ecosystem has not been well-quantified. Observations of the coral reefs of Bonaire show a great abundance of the polychaete Spirobranchus giganteus. This study investigated whether S. giganteus is sensitive to the environmental stress caused by wastewater pollution and therefore could be used as a bioindicator species of pollution in coral reef health assessments. Pollution indicators were assessed through the analysis of water samples, concentrating on the levels of ammonia, nitrate, nitrite and phosphate, sediment levels, and fecal contamination. To allow for comparison between differing levels of water pollution, six different sites were chosen with various levels of expected pollution impact by their proximity to resorts. Abundance of S. giganteus and coral reef cover at these sites were analyzed through transects at different depths. No significance was found between S. giganteus density and nutrient levels or fecal contamination. This study found a significant positive correlation (r² = 0.936) between S. giganteus density and sedimentation rates, suggesting the possible use of S. giganteus as a bioindicator of sedimentation_stress_on_coral_reefs.

This student research was retrieved from Physis: Journal of Marine Science IX (Spring 2011)19: 20-30 from CIEE Bonaire.