Prince William Sound Long-Term Environmental Hydrocarbon Monitoring Program

This dataset contains hydrocarbon chemistry data from sediments, intertidal mussels, and passive sampling devices from Prince William Sound and the North Gulf of Alaska to document hydrocarbon levels, source, and persistence from 1993 through 2021 (ongoing). These data are contained in three csv-formatted tabular data files: LTEMP_1993-2021, LTEMP Locations_Master, Passive Sampling 2016-2021 . The main dataset (LTEMP 1993-2021) contains concentrations of aliphatic and aromatic hydrocarbons and selected petroleum biomarkers in sediments and intertidal mussels collected at multiple stations (described in LTEMP Locations_MASTER) at varying annual intervals. The Passive Sampling 2016-2021 dataset reports the Cfree seawater concentrations of aromatic hydrocarbons, petroleum biomarkers, and oxygenated hydrocarbons (not all years) at select locations around Prince William Sound. Deployment and retrieval sites for passive samplers are listed in the LTEMP Locations_MASTER sheet. PWSRCAC was formed following the Exxon Valdez oil spill to advise Alyeska Pipeline Service Company and the public on issues related to oil spill prevention and response and mitigation of the environmental impacts of terminal and tanker operations. As part of this mission, PWSRCAC began monitoring petroleum hydrocarbons in the marine waters of the Port of Valdez, greater Prince William Sound, and the Gulf of Alaska. This hydrocarbon monitoring program, known as the Long-Term Environmental Monitoring Program (LTEMP), aims to determine and understand the environmental effects of oil compound concentrations attributable to the operations of the Valdez Marine Terminal (Terminal) and associated tankers, and lingering concentrations of oil from the 1989 Exxon Valdez oil spill. The program aims to assess ongoing and legacy pollution sources and possible contributions from the Terminal and tankers to the local marine environment. These samples are analyzed by contracted partner laboratories. Opportunistic sampling of spill events both reported and unreported are also found in the dataset.