Coral as Environmental BioIndicators: Ecological and Morphological Effects of Gasoline on Gorgonian Corals, Leptogorgia virgulata

Oil spills are the most common sources of pollution in marine ecosystems occurring worldwide, causing problems not only for benthic and pelagic organisms but also for terrestrial species that feed on marine organisms. Coral, more so than many other organisms, are sensitive to tiny changes in the marine environment, which makes them an excellent bioindicator of changing environmental conditions. In this study, Leptogorgia virgulata located in the Aransas Pass ship channel, Port Aransas, Texas was examined to determine the level of gasoline (10 ppm, 50 ppm, and 100 ppm) this species could tolerate. Our experimental research compared both coral-tips (the youngest and most rapid growing part of gorgonian corals) to the coral-bases (the older part of these coral) of L. virgulata. Affects were characterized by determining the number of sclerites sloughed off over seven days (168 h). Comparative analysis between treatments show that gasoline has a significant negative consequence, damaging coral tissue over time (ANOVA, p=0.008; ?=0.05). Similarly, the sensitivity of tips to bases was significantly different (ANOVA, p=0.003; ?=0.05). The coral-bases sloughed more cells and sclerites than the coral-tips indicating greater sensitivity to the gasoline treatments. This study also showed that at low concentrations, environmental managers may have as much as 48 h to mitigate the effects of a petroleum spill. Any clean-up not completed beyond that period of time will cause massive death to the coral L. virgulata and associated inhabitants, including potentially important sport fishes known to associate with these benthic fauna.