ME70 Water Column Sonar Data Collected During SH1709

Many species of rockfishes live in complex rocky habitats, have been over-fished, and are difficult or impossible to accurately survey using conventional bottom-trawl gear. Our ability to count these species in rocky habitats and to delineate the distribution and extent of these habitats is critical to the estimation of absolute abundance of these species for stock assessments. To that end, NMFS is pursuing the Untrawlable Habitat Strategic Initiative (UHSI) field research in the Southern California Bight. Associated with the goals of the UHSI, NMFS also recognizes the need for more high-resolution mapping of the seafloor in order to delineate and quantify rockfish habitats. Research planned for October 2017 on the B. Shimada represents year-2 of the UHSI project in Southern California. We are using the results from our year-1 study off the R. Lasker in October 2016 in Southern California to inform the experiments we will conduct in this second year from the B. Shimada . We also will continue our plan to map the seafloor at priority sites in and around the Channel Islands. During this mission, we will 1) rendezvous with R/V Velero IV (contracted through NMFS) and use NMFS’s Seabed autonomous underwater vehicle (AUV) as part of an underwater experiment to observe and quantify the behavior of rockfishes in reaction to mobile survey vehicles; 2) acquire high-resolution bathymetric data around the northern Channel Islands using the vessel’s ME70 sonar; 3) survey rockfishes and habitats visually using the AUV; 4) deploy and retrieve small drop cameras to observe fishes on the seafloor. This is a multi-year collaboration among researchers from the NMFS SWFSC, NWFSC, SEFSC, and AFSC, and complements ongoing similar surveys being conducted in the Gulf of Mexico as well as ongoing seafloor mapping and habitat surveys being conducted by NOAAs Channel Islands National Marine Sanctuary. The results of this mission will lead to more accurate estimates of demersal fish populations and associated habitats in deep-water, thereby supporting NOAA’s objectives to achieve sustainable fisheries and improve our understanding of marine ecosystems. Our findings will improve stock assessments of species in untrawlable habitats, and will assist in the interpretation and understanding of the use of deepwater habitats by demersal fishes.