Marine Mammal HiCUP: A High Current Underwater Platform for the Long-Term Monitoring of Fine-Scale Marine Mammal Behavior Around Tidal Turbines

Arrays of tidal turbines are being considered for tidally energetic coastal sites which can be important habitat many species marine mammal. Understanding risks to mammals from collisions with moving turbine blades must overcome before regulators issue licenses developments. To understand these risks, it is necessary how animals move around operational and document the rate at interactions occur. We report on design, performance, a seabed mounted sensor platform monitoring fine scale movements cetaceans pinnipeds turbines. The system comprises two high-frequency multibeam active sonars, accurately track in horizontal plane. By offsetting vertical angle relative intensity targets sonars also used resolve component animal location. For regularly vocalizing species, i.e., small cetaceans, tetrahedral array high frequency hydrophones close measure both angles cetacean echolocation clicks. This provides additional localization tracking information distinguish between detected sonar data, based presence or absence cabled shore power, data transfer, communications using infrastructure. allows continuous operation over months years, will required capture what may rare interactions. was tested during series multi-week field tests, designed test integrity, carry out calibrations, efficiency collection, analyses, archiving procedures. Overall, proved highly reliable, PAM providing bearing accuracies synthetic sounds 4.2 degrees clicks signal noise ratio above 15 dB. deployed an early 2022.