Evaluation of an underwater solid state memory video system with application to fish abundance and diversity studies in southeast Australia
Lowry, M., Folpp, H. and Gregson, M., 2011. Evaluation of an underwater solid state memory video system with application to fish abundance and diversity studies in southeast Australia. Fisheries Research, 110: 10–17.
The use of remote underwater video as a tool for monitoring marine environments has increased rapidly over the last decade primarily due to the advantages offered by improvements in its utility, reliability, cost and accuracy. Sampling time frames for remote video remain relatively short (generally less than one hour), limiting its capability to account for variations in fish communities that are known to occur over longer time frames (i.e., tidal cycles) or for monitoring species that are either transient or rare.
This study evaluated a remote video system (CCD system) designed for extended deployments in the marine environment. We evaluated the utility of this system for carrying out long term (>12 hour) deployments and compared the performance of the test system against a ‘standard definition’ camera system. The objectives of this study were to (a) describe the CCD system, (b) quantify deployment times and assess the potential of varying a single video parameter (resolution) as a means of maximising deployment time and (c) compare the results of the CCD system to a conventional ‘standard definition’ video camera.
The CCD system performed reliably with a mean maximum continuous recording time of 13.3 (±0.3) hours. Results indicated no significant differences between the CCD system and the standard definition camera at the highest resolution setting, but a reduction in resolution resulted in significant differences in estimates of relative abundance, the number of species observed and the time at which each species was first detected. The direct implications of the results of this study are that there is limited potential (at least in south-east Australian estuarine systems) to extend deployment times of remote video observations through a reduction in video resolution without significantly compromising the ability to reliably estimate indices for diversity and abundance of fishes.