Shoreline Surveys at the Exxon Valdez Oil Spill: The State of Alaska Response
ABSTRACT The state of Alaska needs information on the shoreline impacts of the Exxon Valdez incident to determine the linear extent of affected shoreline and the degree of oil penetration into the beach versus surface coverage, to assist the shoreline treatment effort, and to monitor oil persistence. Three principal methods were used to obtain data. Low-altitude helicopter surveys were made repeatedly during the first months of the incident to define shoreline impacts as heavy, moderate, light, and “no observed oiling.” A total of 140 ground stations in Prince William Sound, and over 60 stations in the Kenai and Kodiak areas, were set up to make specific measurements of surface coverage, oil penetration, and oil thickness along a topographic profile. An extensive (more than 1,400 km) walking survey was mounted after the 1989 treatment season to determine the extent of oil remaining and to guide the 1990 cleanup effort. More than 160 km of shoreline remained moderately to heavily oiled in the three regions at the end of 1989. Collected data were entered into the Alaska Department of Environmental Conservation geographic information system to enable map production, database queries, and report creation. On an as-needed basis, data derived from these surveys were presented to the state on-scene coordinator, other state and federal agencies, and the cleanup operation.