(Ships, Whales, Acoustics in Gitga'at Territory)
The SWAG hydrophone project is in collaboration with the Gitga'at First Nation and WWF-Canada. We recently installed a state-of-the-art long baseline hydrophone array in the coastal waters of Squally Channel, west of Gil Island. This array consists of four hydrophones, providing a wide bandwidth of 10 Hz up to 100 kHz. Each hydrophone is equipped with GPS clock providing microsecond time accuracy between each station. It acoustically monitors a terrain of about 200 km² in an area that needs to manage the balance between high cultural and commercial use, including proposed shipping routes for liquefied natural gas projects. This area has been identified as potential critical habitat for several at-risk marine mammals, including two distinct populations of orca as well as both humpback and fin whales.
The hydrophones in Squally Channel allow the 3D-localization and subsequent tracking of a vocalizing whale, as soon as a signal has been detected on all four hydrophones.
This hydrophone project is being developed by Ben Hendricks through a Mitacs ELEVATE Postdoctoral Fellow in partnership with the Gitga’at of Hartley Bay, WWF-Canada, and NCCS. Ben finished his PhD in 2015 with a focus on observational astrophysics with a strong skill set in statistical analyses of large data samples, data processing and image manipulation, programming, project planning and project management.
Ben’s part in this project is to develop the software that allows automated detection, classification, localization, and tracking of transient signals of marine mammals from long baseline array data, such as the Squally Channel Hydrophone Array. The software aims to provide the following information to the user in real-time: detect if a whale vocalized, determine when the vocalization happened, classify which whale species vocalized, and compute where it happened.
The primary goal is to use the acoustic data to analyze the presence, activity, and movement patterns of the different whale species in the area. Furthermore, acoustic recordings from the hydrophone array will be analyzed to monitor the ambient noise level in Squally Channel, as well as the additive noise though industrial noise such as ship traffic. This hydrophone project and the Fin Island Research Station will work hand in hand to provide both acoustic and visual data to study the impact of ambient noise on whales in the area. Thus, marine management will be improved, and research on habitat use of cetaceans and their interactions with marine vessels will be facilitated.