Towards Quantifying Avoidance and Attraction of Reef Fish to Mobile Video Survey Platforms

The NMFS Untrawlable Habitat Strategic Initiative (UHSI) team conducted a multi-tiered field experiment to evaluate tools and methods appropriate for estimating sampling efficiency of camera systems mounted on stationary-arrays, ROV, AUV, and towed vehicles to count fish within a measureable sampling path. We observed species specific responses of attraction and displacement relative to the transiting vehicles.  Abundance of scamp (Mycteroperca phenax), and pelagic predators (Seriola sp., Sphyraena barracuda) showed significant differences in site density given exposure to transiting vehicles (e.g. before, during, after).  Species of the family Pomacentridae showed no significant difference in site density given exposure to a transiting vehicle.  Scamp showed highest local densities following the transit of the vehicle and generalized patterns observed on video show they were somewhat displaced by the approaching vehicle.  Jacks and barracuda showed highest densities during transit and tended to closely track vehicles from behind. Pomacentrid densities did not significantly change, there was a marked response of a quick descent down into the habitat during vehicle transit, but were observable in the MOUSS videos.  Ongoing analysis is being conducted that intends to match sampling volumes between MOUSS systems and the vehicles to potentially calculate catchability, and to measure swimming speeds and trajectories.