Master of Science (M.S.)
Moss Landing Marine Laboratories
Based on multibeam bathymetry, multibeam backscatter datasets, Remotely Operated Vehicle (ROV) observations and sediment grab data collected in the San Juan Archipelago and Georgia Basin region, sedimentary bedforms including sediment waves, ripples and ripples overlying waves were identified and characterized as habitat for fishes and invertebrates according to the deep-water classification scheme for marine benthic habitats by Greene et al. (1999). Analysis of long term bathymetric survey data in a GIS suggests that sediment waves were dynamic and influenced by modern physical oceanographic processes. Direct observational data collected in the sediment wave fields revealed that sediment waves were poorly sorted and composed of both fine-grained sediment (sand) and coarse-grained sediment (cobbles, pebbles and coquina). Density, percent composition and distribution of fishes and invertebrates, specifically in San Juan Channel, were calculated. Pacific sand lance (Ammodytes hexapterus) had high percent composition values among the observed fishes in both the mixed and sand substrates. Spot prawns (Pandalus platyceros) dominated the gravel, mixed sediment and sand substrates. There were significant density differences for individuals in the families Hexagrammidae and Scorpaenidae, but there were no significant density differences for the remaining fish or invertebrates observed in both the sand wave and non-sand wave areas. Percent composition varied between gravel, mixed sediment, rock and sand substrates; however, based on Chi-squared analyses, there were significant differences detected among varying substrate types in both sand wave and non-sand wave transects which suggests that species occurrences are not independent of habitat types.
Lopez, Holly Linda, "Characterizing sedimentary bedforms as habitat for fishes and invertebrates in the San Juan Archipelago, Washington, USA, and the Georgia Basin, British Columbia" (2007). Capstone Projects and Theses. 78.