A multidisciplinary approach to estimating red snapper, Lutjanus campechanus, behavioral response to mobile camera and sonar sampling gears

We examined the potential for Gulf of Mexico red snapper (RS) behavior to bias count estimates collected with a remotely operated vehicle (ROV), towed camera sled (TCS), subsurface towed acoustic sled (TAS), or SCUBA diver at artificial reef sites. Near- (≤ 5 m), mid- (≤ 15 m), and far-field (≤ 100 m) responses were examined using stationary stereo cameras, a horizontal acoustic profiler, and three-dimensional acoustic telemetry, respectively. Survey gears were deployed sequentially for 15 min with each gear immediately preceded by a 15-min control period. Near-field data (mean RS min−1) indicated counts were 7.3 times higher with the diver present and 1.9 times higher with the ROV. The TCS had a significant interaction effect with time on mean RS count in the near- and mid-field, as well as depth and acceleration. The TAS had no effect on RS behavior at any scale. Far-field data showed no significant effect of any gear on mean RS distance to reef. Overall, results indicate RS respond neutrally to survey gears at medium (≤ 15 m) to large (≤ 100 m) spatial scales, but small-scale (≤ 5 m) spatial attraction may bias RS counts with benthic survey gears, primarily by individuals near the periphery of the surveyed area approaching the gear.