Impact of oil and gas production activities on cohesive sediment and biological adaptation
Chen, M.; Wartel, S.; Fiers, F. (2011). Impact of oil and gas production activities on cohesive sediment and biological adaptation, in: Hun-Wei Lee, J. et al. Asian and Pacific Coasts 2011. Proceedings of the 6th International Conference on APAC, Hong Kong, 14-16 December 2011. pp. 1062-1069. http://dx.doi.org/10.1142/9789814366489_0126 In: Hun-Wei Lee, J.; Ng, C-O (Ed.) (2011). Asian and Pacific Coasts 2011. Proceedings of the 6th International Conference on APAC, Hong Kong, 14-16 December 2011. World Scientific: Singapore. ISBN 978-981-4366-48-9. 2153 pp., more |
| Abstract | The potential impacts of oil and gas production activities on marine environment and ecological habitats are of growing concerns. This study presents the effect of oil and gas production activities induced mud contamination on meiobenthic community, and the interactions between meiobenthic and cohesive sediments in the Campeche Shelf, Yucatan, Mexico. The meiobenthic community has potential merits in environment monitoring, because it is not affected by physical disturbance to the same degree as macrofauna, and is more stable than macrofauna but with a shorter generation time, and moreover, its life cycle is spent entirely within the sediment. The field investigations and data analyses showed that one of the key factors seriously affecting the study area is the deposition of a cohesive clay layer, bentonite, introduced from the oil production sites. The occurrence of such bentonite clay significantly changed the natural sediment granulometry as observed in the grain-size frequency distribution where a narrow peak in the size fractions between 2 and 4 µm was predominant. Such peak occurred frequently in the area surrounding the oil production sites. Contrary to what may be expected, the increase of clay content had no influence or even had a negative influence on the density of nematodes. The nematode to copepod ratio normally would increase when the content of fine fractions increases (or with decreasing particle size). However this study showed that the nematode-copepod ratio increased with the decreasing clay content. The observed contradistinctions may be explained by the deposition of bentonite clay that was artificially imported to the study area by oil and gas production activities and caused a lagged impact on the meiobenthic community. This study showed that the interactions between meiofauna and cohesive sediments as an indicator can give valuable information on environmental changes and provide a better understanding of the impact of oil and gas production activities on the marine benthic realm. |
|
