ASSESSMENT OF THE TOXICITY OF KUWAIT CRUDE-OIL ON THE PHOTOSYNTHESIS AND RESPIRATION OF SEAGRASSES OF THE NORTHERN GULF

Photosynthetic and respiratory responses of leaf tissues of the seagrasses Halophila ovalis, H. stipulacea, and Halodule uninervis exposed for 12-18 h to unweathered Kuwait crude oil were measured using an oxygen electrode system to assess the possibility of acute toxicity. Leaf tissues were incubated in natural seawater (control treatment) or in the water-soluble fraction of a 1% (weight:volume) solution of Kuwait crude oil in seawater (oil treatment). Photosynthesis vs. irradiance (PI) responses exhibited typical light-saturation kinetics. One-way analysis of variance detected no significant treatment effects on the PI characteristics: alpha, P(max), I(k), or I(c). Respiration rates were also not significantly affected by short-term exposure to the oil treatment. In addition, no significant among-species differences in PI characteristics or respiration were detected, possibly reflecting the low metabolic state for these subtropical species during Leg II sampling when water temperatures were 16-19-degrees-C. These results support our observations that the Gulf War oil spill primarily impacted intertidal communities rather than the submergent plant communities of the northern Gulf region.