Development of New Tools and Innovative Application of Existing Instruments for Environmental Assessment and Permitting
Presently, there is a critical need for new cost effective survey tools for the assessment and monitoring required to site and monitor marine hydrokinetic energy generation technologies. One area where traditional approaches are particularly time-consuming and costly relates to bottom sediments and associated biotic communities and how these may be affected by the deployment of hydrokinetic energy generating technologies. Traditional surveys typically have limited spatial coverage due to the reliance on shipboard or diver based collection of sediments and biota. A potential new approach which addresses both cost and coverage issues relies on the use of Autonomous Underwater Vehicles (AUVs) instrumented with multi-beam sonar, side-scan sonar, and high definition geo-referenced video and still photography to monitor sediment characteristics, bottom morphology, submerged aquatic vegetation, benthic epifauna, and through surface expressions (worm tubes, castings, burrows), the abundance of benthic infauna.
Coastal Systems Program - Survey of the sub-bottom, bottom sediment and benthic biotic communities from an autonomous underwater vehicle
Site characterization and post-installation environmental monitoring of marine renewable energy projects represents one of the largest indirect costs associated with implementation. In addition to monitoring the environment at the point of power generation, transmission of that power to land based distribution nodes represents a significant environmental concern as many critical habitats such as eelgrass beds which exist only in shallow coastal waters. Present approaches using shipboard and diver surveys are typically limited in spatial coverage and expensive. This typically results in surveys of only areas determined a priori, and does support the development of alternative placements (primarily for cable) that can avoid key benthic habitats to ease environmental permitting.
The OceanServer IVER2 AUV developed at UMASS Dartmouth Advanced Technology Manufacturing Center (ATMC) is a unique tool and approach for characterizing and monitoring sediment environmental parameters in shallow coastal waters. The independent use of multi-beam sonar and side-scan sonar, and high definition geo-referenced video and still photography have been used extensively to obtain high resolution bathymetry, quantify sediment type, and identify the presence, type and distribution of submerged aquatic vegetation and benthic organisms. However, nearly all of these studies required extensive shipboard resources and were limited to water depths sufficient to allow for deep draft vessels and/or towed arrays. Only on a few occasions have all of these resources been deployed simultaneously on a single platform capable of operating in shallow coastal waters.
The Coastal Systems Program (CSP) with ATMC/OceanServer aims to field validate the utility of the OceanServer Technology Inc. IVER family of AUV vehicles to evaluate if it can be an effective approach for lowering the cost of collecting field data required for effective environmental monitoring of benthic habitats. Initial surveys will be conducted in areas of known benthic infaunal communities, sediment grain size, and areal extant of submerged aquatic vegetation. Field measurements and collection of samples along AUV track lines will be made to confirm previous findings.