Conducting Visual Surveys with a Small ROV in Shallow Water

Abstract

Small remotely operated vehicles (ROVs), sometimes described as low-cost (<$150,000) ROVs, have become valuable tools in the study of marine organisms and their habitats. The versatility and relative simplicity of these vehicles is enabling scientists and fishery managers to develop a better understanding of the marine ecosystem that has not been possible using conventional survey methodologies. The ability to work at depths beyond the reach of scuba divers and in complex habitats inaccessible to trawl surveys is helping to “fill the information gap” between nearshore and deep offshore habitats, allowing for the development of more comprehensive management strategies of the ocean’s resources. Small ROVs are especially suited for use by natural resource agencies and academic institutions operating on limited budgets with minimal resources. In calm, nearshore conditions, a small ROV can be operated from vessels as small as 6 m with a minimum of equipment and crew. In contrast, conducting safe, quantitative surveys with a small ROV in more extreme marine environments increases the complexity of the operation and requires additional equipment and personnel to ensure success. This paper focuses on the technical aspects of designing and conducting shallow-water (<200 m) surveys with a small ROV, based on our experience using a Deep Ocean Engineering Phantom HD2+2 ROV in San Juan Channel, Washington. Topics addressed include equipment, navigation and tracking, deployment protocols, tether management, camera calibration, survey design, data collection, hazards and safety, transect length and width, and recent technological developments.