Environmental monitoring of offshore oil and gas drilling discharges - A caution on the use of barium as a tracer

Commonly used methods for extracting barium from marine sediments are inefficient when high concentrations of barium sulphate are present in samples. Comparative data on sea-bed barium concentrations around a single exploration well are presented to highlight the influence of different extraction methods which can result in 2-3 order of magnitude differences in levels recorded. This suggests that in many monitoring studies the value of barium as a tracer of discharged drilling wastes and thus as an aid to the interpretation of survey data is reduced, The environmental management implications of these findings are explored and a holistic and more collaborative approach to environmental effects monitoring is advocated. Copyright (C) 1996 Elsevier Science Ltd