Tar contamination on beaches in Curaçao, Netherlands Antilles

Abstract

Tar pollution on Curaçao beaches was monitored at 10 stations around the island on monthly visits for 14 months. Accumulated tar at stations in coastal areas susceptible to tar pollution (the wave-exposed northeast coast and the industrial, central south-west coast) averaged 954 ± 779 g m −1 (SD), excluding the most grossly polluted study site. Two wave-sheltered southwest coast beaches lying outside the industrial zone yielded no tar at any time. The beaches of the northeast coast, and those of the industrial zone of the south-west coast (oil terminals and refining) differed in terms of the level and temporal pattern of tar influx, as well as in the physical nature of tar contamination. On north-east coast beaches the average monthly influx of new and residual tar to clean beach transects amounted to 127 ± 471 g m −1 month −1. Lowest influx rates were in October–December, corresponding largely with the main rainy season. Highest influx rates were in January–May, corresponding with a period of more easterly, longshore winds. On beaches of the central south-west coast, the average monthly influx of tar amounted to 53 ± 193 g m −1 month −1, while the temporal pattern suggested periodic fluctuation of influx throughout the year. The occurrence of rubble beaches, which have been largely solidified by oil contamination, is indicative of the impact of occasional significant spills which have affected the central southwest coast.