The Ba/Ca record of coral from Weizhou Island: Contributions from oil-drilling muds and the winter monsoon

Oil exploration and drilling activities are known to have catastrophic effects on marine environments and ecosystems, yet full understanding of these effects is hindered by sparse observations in many areas of the world. We present annual and bimonthly records of coral Ba/Ca from Weizhou Island in Beibu Gulf in the northern South China Sea (SCS) - the largest oilfield in the SCS. On interannual timescales, a significant increase in Ba/Ca ratios is associated with high barite consumption used for oil exploration and drilling activities. On seasonal timescales, a strong winter monsoon signal is seen in the skeletal Ba/Ca records. Our data provide a long-term and continuous on-site record for oil exploration and drilling activities that can be used for offshore oil management. Furthermore, our approach offers a means to study the influence of oil-related activities on the marine environment when no oil exploration and drilling records are available.

Automated summary

This study examines the impact of oil exploration and drilling activities on marine environments using coral samples from Weizhou Island in the northern South China Sea. The analysis of Ba/Ca ratios in the coral provides insights into the effects of oil exploration and drilling activities, as well as natural signals such as the winter monsoon.