Effects of drilling fluids on reef corals: A review
Dodge RE and Szmant-Froelich A. 1985. Effects of drilling fluids on reef corals: A review. Pages 342-364. In Duedall IW, Kester DR, Park PK (ed). Energy Wastes in the Ocean. John Wiley and Sons, Inc.. New York
This chapter reviews research on the effects of drilling fluid on reef building, or hermatypic, corals. Experiments have shown that the burial of corals in drilling fluid, or mud, caused mortality and that certain drilling fluids applied as slurries could not be removed by corals. Under field conditions, however, slurries were removed with the assistance of natural currents, but appeared to cause lowered growth rates in treated specimens. Certain species showed behavorial stress symptoms after 96-h exposure to 0.100 ml liter^-1 of chilling fluid (0.100 ml of the fluid in I liter of seawater) and exposure to 1.000 ml liter- 1 caused mortality in 65 h for three of seven species tested. A chronic 6-week exposure to 0.100 ml liter^-1 of drilling fluid caused an 84% decrease in calcification, a 40% decrease in respiration, reductions in gross photosynthesis (26%), nitrate uptake (28%), ammonium uptake ( 49%), and feeding, as well as some death. Other studies showed that average linear skeletal growth also decreased. A field assessment of a reef, several years after drilling, indicated a 70-90% reduction in foliose, branching, and platelike corals within ,a 115 m X 85 m ellipse around the drilling sits. Detrimental effects on corals, as extrapolated from the limited information on effects, seem probable within a minimum distance of 100 m from the source
- Type
- Book Chapter
- Authors
- Dodge, Richard; Szmant-Froelich, Alina
- Units
- BUIS
- Keywords
- Animal Behavior, Biochemistry, Composition, Coral Reefs, Ecology, Ecosystems, Mortality, Physiology, Sedimentation, Sessile