The ocean is anything but silent.
At Roberts Bank Terminal, low frequency sounds generated from commercial ship propellers reverberate through the water. Travelling four and a half times faster than it would on land, the sound echoes around the terminal, reaching ships that are anchored offshore awaiting their turn to dock.
Eventually, the low rumblings of ships reach a group of orcas who are attempting to use their own peculiar calls to find prey in the Pacific waters.
These whales, if they were found not too far from Deltaport or southern Vancouver Island, could possibly be members of the Southern Resident Killer Whales clan, a distinct subspecies of orca listed as endangered by the Committee on the Status of Endangered Wildlife in Canada in 2003.
The southern resident whales are an extended family of only 76 individuals (as of December 2017) in three pods. They are identifiable by their unique calls and geographic range. They feed on Chinook salmon and, because of their close proximity to humans and marine traffic, are struggling to survive.
In 2011 and again in 2016, a federal recovery strategy for resident orcas identified three main threats to the recovery of the southern whales: the reduced availability of chinook salmon, environmental contaminants such as pesticides and coolants, and physical and audible disturbances.
Audible disturbances are simply noises that interfere with the lives of the whales. Because sounds travel exceptionally well in water — Southern Resident Killer Whale calls can travel for 16 kilometres or more — whales use it to hunt for food and communicate with other pod members. By the same token, human-based noises can easily disrupt the balance of underwater life.
The Port of Vancouver — which sees more than 3,000 ships visit its 27 terminals each year — started its ECHO program (short for Enhancing Cetacean Habitat and Observation) in 2014 with the aim of understanding how the port’s shipping activities affect at-risk whales along B.C.’s coast. The program’s most in-depth research focuses on sound.
“With the Port of Vancouver traffic transiting through critical habitat for the Southern Resident Killer Whales, it kind of was the impetus for the Port of Vancouver to start looking at this issue in more detail,” said Krista Trounce, project manager for ECHO.
It was meant to help the port authority “figure out a way for ships and the killer whales, and other at-risk whale species, to be able to cohabitate. The whales, their critical habitat is defined, and transit routes to the Port of Vancouver go through that critical habitat.”
ECHO has seen a number of research programs aimed at studying the relationship between shipping traffic and whales. Most recently, the Port of Vancouver (in association with other partners) launched a voluntary slowdown trial in the Haro Strait. Between Aug. 7 and Oct. 6, 2017, the port requested ship traffic in the area slow down to 11 knots to see if slower ships are quieter.
During the survey, Trounce said there was a 60 per cent reported participation rate, with most of those vessels slowing down to the requested 11 knots.
Preliminary results showed that slower vessels are significantly more quiet, and the port is considering a voluntary slow-down initiative for commercial traffic bound for its terminals. But how this slightly more quiet ocean would help the area’s orcas is still being studied.
“It’s a challenge to study the killer whale behaviour itself,” Trounce said. “It’s easier to model it, especially given this year there was a very low presence with killer whales in the Haro Strait, where we were doing the slow down trials.”
The potential changes in whale behaviour based on noise reduction are currently being modelled, with those results expected to be released in April or May.
In a voluntary slow down program, companies could choose to ignore the suggested restrictions. But Trounce is confident that wouldn’t be the case.
“There’s a lot of factors at play in an industry’s ability to participate,” she said.
Commercial mariners work in eight hour shifts, and slowing down vessels could result in some ship pilots working longer hours. It’s also possible a slower ship might miss certain tidal windows it needs to get through an area safely.
“But the industry in general, they’re all mariners,” she continued. “They want to help. They recognize the problem. They all love the sea life the same as we do. So they’re actually very interested in helping solve this issue.”
But, Trounce said, the goal isn’t just to inform people in the industry. It’s also to inform the public.
On Feb. 16, 17, 23 and 24, the Port of Vancouver’s Delta community office (5225A Ladner Trunk Rd.) will be hosting screenings of Sonic Sea, a 2015 documentary that looks at how man-made sound is changing the ocean landscape. The Feb. 23 showings, scheduled for 10:30 a.m. and 2 p.m., are geared towards Delta students Grade 7 and up, as it is a district Pro-D day.
On Feb. 21, Trounce will be hosting three talks at the Delta community office, inviting the public to come learn about the port’s ECHO program.
“The Southern Resident Killer Whales in particular, it’s an iconic species,” Trounce said. “Really, it’s good to raise awareness, not just within the commercial industry — who we’re working with on this — but to the public as well, to help them better understand the challenges that this species and other endangered whale species are facing.”
Like us on Facebook and follow us on Twitter