Groundfish habitat associations on the “lost reefs” of the Monterey Bay National Marine Sanctuary; implications for conservation and management

Management of marine ecosystems requires accurate, quantitative, and spatially explicit information on species distributions at scales that are relevant to the management process. The “lost reefs” comprise an understudied area in 30 to 40 meters depth that lie between shallow waters, surveyed extensively via SCUBA, and deeper waters, which are surveyed using submersibles. Major ecological and management-based questions concerning fish assemblages of the “lost reefs” remain unresolved, including: (1) spatial and temporal variability in abundance, size distributions, and community structure and (2) microhabitat associations, including ontogenetic movements between shallow and deep zones. To address these questions, diver-held stereo video is coupled with underwater visual census techniques and Digital Elevation Models to evaluate species abundance, richness and microhabitat associations in the “lost reefs”. To date, this research has been conducted in the Carmel Canyon of the Monterey Bay National Marine Sanctuary (MBNMS). Preliminary analyses suggest that community assemblages are highly variable among depths and seasons, and that species associate differently to habitat variables such as bathymetric features, slope, and rugosity. Habitat suitability models created from this data will be used to improve spatial management strategies for the MBNMS by combining them with existing MPA maps to assess the effectiveness of previously established protected zones. Data and analyses from this project will aid in adaptive management by contributing to the MBNMS’s Site Characterization, Condition Report, and the new Sanctuary Management Plan. Video records from this project will contribute to the permanent imagery archive for use in answering long-term questions and for public outreach.