Use of manned submersible and autonomous stereo-camera array to assess forage fish and associated subtidal habitat

Forage fish and associated with particular benthic habitats (e.g., rockfishes, sand eels, lances) may be particularly difficult to assess through standard survey methodologies. Stereo-cameras, video, automated visual data serve as useful complementary tools provide insight into the dynamics of these species. Visual methods used not only estimate abundance distribution, but also inform important biological metrics life history attributes. We explored application Pacific lance (Ammodytes personatus), a forage sediments, using combination directed observations from manned submersible quantitative analysis fixed image footage obtained stereo-camera. This research provides better understanding how in situ might complement other abundance, habitat, behavior. were compared collected via sampling physical extraction at same site year. Submersible provided new insights on conditions habitat. confirmed wavefield morphologies previously identified multibeam acoustic imagery measured attributes relevant oceanography water column above this habitat feature. informed light penetration, diurnal cues for seasonal progression diel vertical migration foraging. schooling dynamics, behavioral attributes, including avoidance response disturbance aggregation presence artificial light. Quantitative stereo-camera center-edge north-south transects determined that length distribution was relatively uniform throughout Estimates measurement error stereo-cameras calculated correction factors identified. Mean lengths estimated specimens closely matched, though variance measurements far greater. reduced when filtering basis orthogonal position or incidence angle relative camera. Our presence, movement within habitats. applications, opportunities, constraints observation-based methods, use submersibles stereo-cameras.