• Sunday, February 17, 2019

The tide is against underwater noise - Subscriber Access Only

By BCShippingNews 05 June 2017

The coastal waters of British Columbia are home to the iconic Killer Whale — a group considered at risk because of their small population size, low reproductive rate, and a variety of anthropogenic threats that have the potential to cause further declines or prevent recovery. B.C.’s coastal waters are also frequented by numerous deep-sea vessels, ferries, commercial tug and tow boats, and pleasure craft. Recently, the issue of underwater noise and its adverse impact on marine life, in particular Killer Whales, has been in the news.

Low frequency underwater noise has been doubling in intensity every decade for the past 60 years in some parts of the North Pacific Ocean. An increase in commercial vessel traffic is believed to be the main reason for increased underwater noise. At present, several voluntary initiatives are underway to address this issue; however, there are indications that regulatory requirements addressing vessel-generated underwater noise may be on the horizon.

Three distinct groups of Killer Whales — Transient (Bigg’s), Offshore, and Resident — inhabit Canadian Pacific waters. All groups are considered either threatened or endangered under Canada’s Species at Risk Act (SARA). These groups exhibit different dialects, prey preferences and social organization and, despite sharing the same waters, are believed to be socially and genetically isolated. The Resident Killer Whale Group is comprised of two distinct populations: the Northern Residents and Southern Residents. Although members of these two populations may overlap in range, they have not been observed interacting. In addition, these two populations rarely, if ever, interbreed.