Drifting baited stereo-videography: a novel sampling tool for surveying pelagic wildlife in offshore marine reserves

We present a novel system of drifting pelagic baited stereo-video cameras that operate in deep-water, topographically complex environments typically considered inaccessible for sampling. The instruments are portable, semi-autonomous and inexpensive, allowing the recording of high-definition video footage in near-real time and over broad stretches of ocean space. We illustrate their benefits and potential as non-extractive monitoring tools for offshore marine reserves with a pilot study conducted within the newly established Perth Canyon Commonwealth Marine Reserve, southwestern Australia (32 degrees S, 115 degrees E). Using occupancy and maximum entropy models, we predict the distribution of midwater fishes and sharks and show that their most suitable habitat encompasses a wider fraction of the canyon head than is covered by park boundaries. Our proof-of-concept study demonstrates that drifting pelagic stereo-video cameras can serve as appropriate field platforms for the construction of species distribution models with implications for ocean zoning and conservation planning efforts.