The impact of oily discharges on the meiobenthos of the North Sea

Abstract

From the Abstract: “The discharge of drilling cuttings, contaminated with oil-based drilling mud, was found to strongly modify meiofaunal densities within 800 m of the Beryl A Platform. Nematode densities are strongly reduced in the vicinity of the platform and it is thought that the impact on this infaunal taxon may be due to slow degradation within the sediment of toxic fractions of the diesel base of the drilling mud. By contrast copepod densities were greatly enhanced in one survey and the difference in impact is considered to be due to the epibenthic habit of the species involved, enabling them to flourish in conditons of high food or low predation and competition or all three. The species involved seem typical members of meiofaunal communities of organically enriched sediments. Some improvement in meiofaunal densities throughout the period 1984–85 is thought to be possibly the result of a switch from diesel-based to low-toxicity drilling muds. It is concluded from these and other studies that hydrocarbon discharges into the North Sea are unlikely to be causing extensive damage to meiofaunal communities.”