Accounting for detection gaps when evaluating reef fish habitat use in an acoustic array Canadian Journal of Fisheries and Aquatic Sciences

Understanding the relationship between habitats and the distribution of fishes is critical to effective survey design and spatial management. Determining reef fish habitat utilization patterns from passive acoustic arrays is challenging for the following reasons: (i) habitat classifications must be meaningful to the species, (ii) the array must contain the species' home range, and (iii) the probability of detection may differ among habitats within the array. We conducted a multi-year tracking study in the marine protected areas (MPAs) of Dry Tortugas, Florida, using a calibrated passive acoustic array deployed over habitats classified by type (reef, rubble, sand), rugosity (high, medium, low relief), and patchiness (contiguous, spur-and-groove, isolated). Our design controlled for differences between individuals, diel and edge effects, and detection gaps resulting from the nonlinear relationship between acoustic tag detection probabilities as a function of distance from the receiver. We found red and black groupers preferred high-relief reef habitats, whereas mutton and yellowtail snappers preferred low-relief contiguous reef habitats. By identifying critical habitats for exploited species, our analysis may facilitate more efficient fishery-independent sampling and MPA designs. Grant no. NA17RJ1226 Grant no. NA08OAR4320892