CHEMICAL ANALYSES OF SURFACE SEDIMENTS IN PROXIMITY TO A SOAKAWAY IN WARWICK PARISH, BERMUDA AND IMPLICATIONS TO RESIDENT AMPHIBIANS

Bermuda, a 53.2 km² group of islands atop a carbonate reef platform in the Sargasso Sea of the Atlantic Ocean, has an alarming rate of amphibian abnormalities and growth defects compared to those on the U.S. mainland. This study seeks to compliment and expand on the Bermuda Amphibian Project’s work by analyzing contaminants in sediments from a soakaway site in Warwick Parish. The contaminants in focus are polycyclic aromatic hydrocarbons (PAHs) and heavy metals, produced by the combustion of petroleum in vehicles on the islands. These contaminants, which can bio-accumulate through the porous skin of amphibians as they metamorphose and grow are thought to be the cause of the biological issues in amphibians on Bermuda. It is hoped that this investigation will add to the accumulated data set focusing on ground water contamination and ways it can be remediated to protect the wildlife that exists on Bermuda.

Samples from four locations, increasing in distance from the soakaway and at depths of 0.03, 0.30, 0.60 and 0.90 m were collected. From these samples, heavy metals were analyzed using inductively coupled plasma emissions spectrometry (ICP-ES). Each sediment sample went through a multi-step extraction process to simulate fresh and anoxic water and find total metals. Polycyclic aromatic hydrocarbons were analyzed using gas chromatography-mass spectrometry (GC-MS). The PAHs analysed are the 16 listed on the U.S. EPA priority pollutant list. The data analysis then focuses on trends of depth and distance from the soakaway, as well as a comparison to contaminant concentration in amphibian tissue from nearby localities.