The Deepwater Horizon (DWH) oil spill was unprecedented in extent and duration, and affected marine natural resources, including sea turtles, throughout the northern Gulf of Mexico. Consequently, US federal and state Trustees documented and quantified oil exposure and resulting injuries to sea turtles under the DWH Natural Resource Damage Assessment. At-sea rescue operations focused on surface-pelagic juvenile sea turtles, which were especially at risk to oil exposure within oceanic convergence zones, and provided direct observations of the degree that turtles in this young life stage were exposed to DWH oil. In contrast, locations of larger neritic juvenile and adult turtles were documented during aerial surveys, but because these turtles were not captured, their oiling status could not be directly evaluated. Both the rescue operations and aerial surveys were able to observe only a small fraction of sea turtles within the vast spill footprint. We developed a spatio-temporally explicit approach that used direct observations of oiled surface-pelagic juvenile sea turtles and satellite-derived surface oil distributions to statistically estimate the probabilities of oil exposure for all sea turtles that were present within the area of the DWH spill, but whose oiling status was unknown. Our results enabled an expansion of exposure and injury quantification across the entire DWH spill area and period. This approach was conceptually straightforward and used common geospatial and statistical techniques, making it applicable to other situations in which the full extent of oil exposure for marine natural resources must be estimated from an incomplete sample.

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The complexities of remediation and restoration of abandoned mine lands with acid mine drainage require cost effective investigations that are coupled with in situ parameter measurements and monitoring, sometimes in near real-time. Off-the-shelf as well as innovative, state-of-the-art instrumentation and equipment can be readily adapted to site characterization and monitoring, and can be linked to various digital data transmission technologies for remote sites lacking power and easy access. Data, once received, can be readily displayed on web sites or incorporated into a GIS. At the Elizabeth and Ely abandoned mine sites in Vermont, we have employed various types of instrumentation to monitor surface and ground water hydrology, meteorology and water chemistry, depending on the application. To characterize temporal variations in drainage sources and metal loading during spring runoff at Ely Mine, we used Hydrolab data sondes for in situ measures of water temperature, conductivity and pH at 20-minute intervals. For laboratory chemical analyses, we obtained water samples at timed intervals automatically using an ISCO suction sampler in conjunction with water level measurements using a pressure transducer in a calibrated weir. Stage, along with air and water temperatures and rainfall, were measured at 5-minute intervals and stored on a Campbell data logger powered by a battery charged by solar panels. At the Elizabeth Mine, acid mine discharge and various water quality parameters are monitored continuously at five remote sites, three near the points of discharge of seeps from tailings. Data are stored on Campbell data loggers and periodically transmitted via radio to a cell phone for transmission and rapid graphical display on a web site. In addition, we used ISCO samplers triggered by intense rainfall to collect water samples in 15-minute intervals, allowing us to characterize the total storm loading during summer thunderstorms.