In August 2007, as part of the NOAA National Marine Fisheries Service (NMFS) West Coast Groundfish Bottom Trawl Survey, we examined the biomass of demersal organisms in a known hypoxic area off the Oregon coast. Although observed each summer, the intensity of hypoxia has varied annually (2002)(2003)(2004)(2005)(2006)(2007) with the greatest temporal and spatial extent noted in 2006. In 2007 we identified the geographic extent of the hypoxic zone and sampled 17 stations along two depth contours (50 and 70 m) within the area. A Sea-Bird SBE 19plus equipped with a dissolved oxygen (DO) sensor was attached to the bottom trawl to monitor oxygen concentration during each tow. Bottom DO concentrations at all stations were hypoxic with means along the tow tracts ranging from 0.43 to 1.27 mL L )1 . Total catch per unit effort (ln CPUE, kg hectare )1 ) and species diversity (number of species, N) were significantly and positively related to oxygen concentration along the hypoxic gradient. In addition, CPUE (natural log-transformed) for eight fish species and five benthic invertebrate species were significantly and positively related to bottom oxygen concentration within the hypoxic region. Condition factors for five fish species, as well as Dungeness crab (Cancer magister) increased with increased bottom oxygen levels along the hypoxic gradient. Historical catch (2003)(2004)(2005)(2006) within the hypoxic zone indicates that biomass was significantly lower in 2006, the year with the lowest bottom DO levels, relative to other years.

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The Northwest Fisheries Science Center (NWFSC) and the Pacific Islands Fisheries Science Center (PIFSC) are collaborating with researchers at Woods Hole Oceanographic Institution (WHOI) to develop the SeaBED autonomous underwater vehicles (AUV) to overcome the challenges in surveying fish in inaccessible habitats.Traditional survey techniques such as bottom trawls are of limited applicability in such areas due to the rocky, rugose terrain. Fish in marine protected areas must also be surveyed using non-lethal methods. Furthermore, monitoring deeper coral reefs are difficult since many important habitats are below depths that can be surveyed by divers. Hover-capable bottom-tracking AUVs offer a unique tool that is appropriate for work in such areas. We present preliminary results from two surveys: one of deep water corals on a mesophotic coral reef near Guam and another of demersal fishes on rocky reefs off southern California. We discuss some developments needed to utilize this tool for future routine surveys and assessments.