HYDROPHONES

BC COAST HYDROPHONE NETWORK

The SIMRES Boundary Pass hydrophone array is now part of the BC Coast Hydrophone Network. This network collaborates to enable scientific quantification of how the ocean soundscape is changing. As we gain a greater understanding of the impacts of underwater anthropogenic noise on marine life, this hydrophone network will shape and serve society’s economic and ecological goals of protecting the ocean. In particular, this network will assist efforts focused on species at risk (SAR) including the Southern Resident Killer Whale (SRKW), Northern Resident Killer Whale (NRKW), Transient Bigg’s Killer Whale, Fin Whale, Humpback Whale, and Harbour Porpoise.

video: Mark Malleson

If you truly want to understand the world that whales live in, you need to listen. That is why hydrophone technology has become one of the most important tools we can use to research the communication and habitat use of whales worldwide.

THE EQUIPMENT AND INSTALLATION

A hydrophone is an extremely sensitive underwater microphone that connects us to the underwater world of whales. Hydrophone installations are not easy tasks, especially in the remote areas that are essential to most projects. The process requires a safe location for the hydrophone, which is connected to an 80-pound (36 kg) cement block. It must be close enough to shore to connect the hydrophone to a cable that passes through the intertidal zone and connects to a land-based transmitter that is powered by solar panels and a battery bank. The hydrophone and cables are secured by qualified divers 60 to 100 feet (20 to 30 metres) deep. We are now starting to use a remotely operated vehicle (ROV) for installation and maintenance of the hydrophone. The cables that tether and connect the hydrophone and data to shore, pass through the high surf intertidal zone, and must have armoured protection and very secure connection to the rocks. Each of these pieces needs to connect properly and be powered completely off-grid on rocky shores.

Recently, we have made significant improvements to our equipment. Prior to 2018, SIMRES hydrophones were collecting data at 64 MB/sec, today they are running at 128 MB/sec and the speed will double again soon. The amount of data collected is enormous; one of the greatest challenges is having a place to store it and a method to extract the data that is necessary for research.

THE COLLABORATION

With the help of generous donors, SIMRES has placed 3 hydrophones in Boundary Pass since 2015. In late 2019, SIMRES became a part of a project working together with other groups to better protect whale habitat along the coast of BC. This project is now called the BC Coast Hydrophone Network (BCCHN) and is a collaboration between North Coast Cetaceans Society, the Pacific Orca Society (OrcaLab)—together operating under the umbrella of BC Whales and SIMRES, each of which operates its own system of hydrophones and research labs on the north, central, and south coasts of British Columbia, Canada. 

HABITAT PROTECTION

Each organization carries the shared vision of habitat protection for whales at risk of losing their unique coastal habitats, as well as a shared focus on data collection to support recovery plans for each species. The purpose of the network is to enable our organizations to build, maintain, and contribute to a shared, coast-wide information system. Such a system allows us to collect acoustic and visual data on whale activity using consistent standards and protocols, via professionally maintained and consistently calibrated equipment. High quality, comparable ocean acoustic datasets gathered by all network members will be archived using one server to preserve its long-term integrity and will be made searchable and available to all researchers and students for scientific, stewardship, and educational purposes. This ocean acoustic database will enable the comparison of vessel traffic and its impact on whales in areas that differ environmentally and acoustically. The collaboration between network partners will enable scientists to quantify how the ocean soundscape is changing. To accomplish this, whale acoustic data from hydrophones and land-based visual surveys will be available on a central database.

As we gain a greater understanding of the impacts of underwater anthropogenic noise on marine life, this hydrophone network will shape and serve society’s economic and ecological goals of protecting the ocean environment. The network also exemplifies our ability to work together to accomplish critical environmental goals, demonstrating the importance of teamwork in the pursuit of long-lasting positive change.

IT TAKES A COMMUNITY

We would like to acknowledge all those who have helped along the way to establish and maintain the SIMRES hydrophones. Larry Peck was the visionary who brought the project to life and made it a reality. Susie Washington Smyth and the Flora Foundation, Joan Hoskinson, and Tom and Christine Gallagher all believed in the project and donated funds to purchase the hydrophones. David Osborne has generously provided a space to house the land-based equipment and we thank him for allowing research to take place on his property. A special thank you to Tom Dakin and his team for installing and troubleshooting our system. Without their time and expertise, this project would not have happened.

Thank you to the Capital Regional District (CRD), the Saturna Lions Club and the Saturna Community Club for start-up funding. Thank you to Ocean Networks Canada, who has been a major contributor. Many others have donated their time and expertise to operate the hydrophones and we are grateful to them all.