HYDROCARBONS IN BIOTURBATED SEDIMENTS

SEDIMENT PROFILE PHOTOGRAPHY HAS PROIDED OCENOGRAPHERS WITH AN IMPORTANT NEW SOURCE OF SPATIAL INFORMATION ABOUT BIOLOGICAL AND SEDIMENTOLOGICAL STRUCTURES AND PROCESSES. WE PROPOSE TO EXPLORE THE POSSIBLILITY OF DETERMINING THE VERTICAL DISTRIBUTION OF PETROLEUM CONTAMINANTS IN BULK SEDIMENTS BY IN-SITU UV VIDEO PROFILE IMAGING. WE WILL DETERMINE EFFECTIVE EXCITATION AND EMMISSION WAVELENGTHS BY MEASURING EMMITTED FLUORESCENCE INTENSITIES OF UN- CONTAMINATED SEDIMENTS AS WELL AS PREPARED HYDROCARBON- SEDIMENT MIXTURES WITH A HIGH RESOLUTION VIDEO CAMERA ATTACHED TO AN EPIFLUORESCENCE MICROSCOPE. THESE VIDEO IMAGES WILL BE DIGITIZED AND MEASURED TO DETERMINE THE THRESHOLD CONCENTRATION REQUIRED TO ELICIT DETECTABLE FLUORESCENCE. WE THEN PROPOSE TO APPLY THIS IMAGING TEHCNIQUE TO LABORATORY TANK MICROCOSMS CONTAINING POPULATIONS OF THE POLYCHAETE CAP INTRODUCED HYDROCARBONS TO MEASURE THE RATE AND DEPTH OF DOWNWARDS MIXING (BIOTURBATION) OF CONTAMINATED SEDIMENTS. CONCENTRAION GRADIENTS, AS MEASURED BY DIGITIZED VIDEO IMAGES, WILL BE VERFIED BY GC ANALYSIS OF THE SEDIMENTS. SHOULD THE UV HYDRCARBON IMAGING AND MEASUREMENT TECHNIQUE PROVE FEASIBLE IN THE LABORATORY (PHASE I), RESEARCH TO VERIFY THIS TECHNIQUE IN THE FIELD WILL BE PROPOSED (PHASE II). A RECONNAISANCE TECHNIQUE WITH THE ABILITY TO DETECT HYDROCARBON CONTAMINATION IN-SITU WOULD GREATLY FACILITATE COST-EFFECTIVE MONITORING OF MARINE AND LACUSTRINE SEDIMENTARY ENVIRONMENTS.