THE DEVELOPMENT OF BIOREMEDIATION FOR OIL SPILL CLEANUP IN COASTAL WETLANDS: PRODUCT IMPACTS AND BIOREMEDIATION POTENTIAL

Abstract

ABSTRACT Although bioremediation for oil spill cleanup has received considerable attention in recent years, its satisfactory use in the cleanup of oil spills in the wetland environment is still questionable and generally untested. We have initiated a multidisciplinary experimental program to evaluate the use of both microbial seeding and fertilizer as means of enhancing oil biodegradation in coastal salt marshes. We are utilizing controlled greenhouse experiments as well as field trials to test the efficacy and ecological safety of these enhanced biodegradation methodologies. This paper summarizes the overall scope of the study and presents some preliminary findings concerning marsh plant response to the bioremediation agents. We shall report on the results of the first year of this three-year investigation. Sods of marsh (soil and vegetation intact), approximately 30 cm in diameter and 25 cm deep, collected from the inland zone of a Spartina alterniflora dominated salt marsh in south Louisiana were used in a greenhouse experiment to identify the effects on plant and soil responses of the following treatments, with and without oil: seeding product, fertilizer product, and control (no product). Mesocosms were sampled for petroleum hydrocarbon chemistry to identify and quantify the degree of oil biodegradation, soil microbial response to determine the effect of the bioremediation products on the microbial communities that are performing the oil biodegradation, soil chemistry to determine the effect of the bioremediation products (such as nutrients, soil reducing conditions, and soil toxins) on those factors that limit the growth of microbes and plants, and plant response to evaluate the effects of the oil and products on plant vigor and growth. This paper presents selected plant responses that demonstrated that the bioremediation products tested had no adverse impact on plant growth. Additionally, soil respiration was increased by fertilizer, but not microbial, application.