Assessment of echolocating cetacean (porpoise and dolphin) occurrence and behaviour in offshore development sites using a novel passive acoustic monitoring system

Project Description:

This PhD project aims to comprehensively assess the capacity of the NanoPAM system for monitoring occurrence and behaviour of porpoises and dolphins in relation to anthropogenic and environmental parameters.

Marine mammals use sound for navigation, prey detection and communication. Increased levels of anthropogenic generated noise from shipping, marine construction, seismic surveys and offshore renewable energy installations may impact marine mammal distribution, foraging and reproductive success, thus affecting their conservation status (Thompson et al. 2010). Passive Acoustic Monitoring (PAM) detects the presence of vocalising marine mammals and exploits the broadband click vocalisations produced by odontocetes (dolphins and porpoises) for navigation and foraging purposes (Nuuttila et al 2013; Temple et al. 2016). PAM is not significantly affected by time of day, weather, visibility, sea state or other factors which compromise visual surveys. PAM further facilitates fine-scale studies across large temporal scales and full diel cycles (Carstensen et al. 2006).  PAM also has the potential to significantly reduce dolphin and porpoise population surveys in large-scale offshore wind farm developments and as such lower upfront development and consenting costs, both in the UK and internationally.

Newcastle University has developed (NERC Innovation Grant NE/R014884/1) a proof of concept for a novel low-cost acoustically networked passive acoustic monitoring system that will revolutionise assessment of potential environmental impacts from offshore installations. NanoPAM is a complete system incorporating new hardware, software (including echolocating species identification algorithms) and analyses tools for recording and processing high (20kHz-160kHz) frequency sounds produced by animals and human activities. NanoPAMs transmit processed data back to shore, eliminating data loss and allowing assessment of echolocating cetaceans and noise in the deployment area with near real time spatial and temporal tracking of the sound producing sources through the network. Additional sensors may be incorporated into the system to allow further environmental monitoring.

Methodology

The project will conduct full-scale deployment of the NanoPAM system (Fig. 1) and test its performance against other commercially available PAM systems (SoundTrap300 HF, www.oceaninstruments.co.nz and C/F-POD, www.chelonia.co.uk) currently used by reserachers and industry. It will further conduct an assessment of porpoise and dolphin occurrence and behaviour in an offshore energy development site to assess potential impact from anthropogenic activities and environmental drivers.

Illustration of the acoustically networked passive acoustic monitoring system