Caribbean sponges

Sponges are important to reef health, fulfilling a number of structural and functional roles. Despite the wide range of functions they provide, limited research on sponges has been conducted. Their ability to filter the water column of nutrients is essential to keeping the water around reefs clean. Coral reef diseases are becoming more widespread due to multiple factors such as pollution and eutrophication. This study assessed the possible relationship between sponge abundance and disease prevalence in Bonaire, Dutch Caribbean, by using 10 m x 2 m belt transects photographed into 1 m x 1 m quadrats. Per transect, 10 randomly selected photographs were analyzed using Image J to find the total area of sponges and live and diseased coral. Less than 1% disease was found at the study sites because the majority of the coral in the quadrats was partially or completely dead. No correlation was found between disease and sponge coverage. However, a significant correlation was found between percent sponges and live coral coverage. Although there was no correlation found between sponge cover and disease prevalence, the relationship between live coral and sponge is of particular importance for reef health monitoring across the Caribbean.

This student research was retrieved from Physis: Journal of Marine Science X (Fall 2011)19: 35-39 from CIEE Bonaire.

Sponges are sessile marine organisms that have developed efficient defense mechanisms against microbial pathogens. These organisms are one of the most promising sources of antibiotic pharmaceutical products derived from the ocean. As human infectious microorganisms evolve to become more resistant to our current antibacterial medications, the medical community has developed an increased interest in the use of sponges for novel medications. This study aims to provide a basis for the collection of sponges to be used for pharmaceutical purposes. Sponges have shown variation in antimicrobial compounds due to changes in their environment, such as increased temperature or depth. This study analyzed variation in antibacterial properties based on proximity to a pollution source. Samples of three Caribbean sponges, Pseudoceratina crassa, Aplysina archeri, and Holopsamma helwigi, were taken from areas of low relative pollution and high relative pollution, caused by the presence of an adjacent drainage ditch. Sponge extracts were used to create antibacterial assays to test the inhibition of each sponge species at each site toward bacteria derived from the human mouth. Two of the three species, P. crassa and A. archeri, were found to inhibit bacteria, while H. helwigi showed no inhibition. Pseudoceratina crassa and Aplysina archeri taken from an area of high pollution showed greater inhibition levels than samples from areas of low pollution. Pseudoceratina crassa from both sites inhibited significantly less bacteria than A. archeri. These results suggest that sponges from high-pollution areas might be more useful than those from low-pollution areas in the production of pharmaceutical products.

This student research was retrieved from Physis: Journal of Marine Science XVI (Fall 2014)19: 38-47 from CIEE Bonaire.