New vessels good news for orcas
B.C. Ferries plans to retire 18 aging vessels over the next 12 years and that is likely good news for the southern resident killer whales that share the waters with the ferry fleet.
The Crown corporation will spend $2 billion on 22 new vessels, with the next round of new vessels to begin service in 2020. New ferry construction will prioritize noise reduction through improved propellers, quiet military design features, wake management and engine noise dampening.
A typical ferry operating at service speed generates sound at about 185 decibels, which dissipates slowly over long distance, according to B.C. Ferries’ noise mitigation plan.
“Killer whale call intensity ranges up to 140 dB,” the plan states. “Ferry noise ... can interfere or mask (southern resident killer whale) communications and fish finding vocalizations.”
For now, “our deck crews are always on the lookout for whales and have standing permission to deviate away from whales,” reported B.C. Ferries CEO Mark Collins in the noise-mitigation plan. Vessels can also slow down, especially where space is tight.
The most recently delivered vessels — the Salish-class Orca, Eagle and Raven put in service last year — are already the quietest in the fleet.
When southern resident killer whales turn up in the Salish Sea each summer, it coincides with the peak of ferry service, adding to the total disruptive noise that vessels create, according to the noise-mitigation plan.
The ferry service is compelled to fast-track noise mitigation for the health of the orcas to meet its obligations under the Species at Risk Act, which lists the southern residents as endangered.
Only 74 southern resident killer whales remain after three died this past summer. Not a single calf born to the southern residents has survived in the past three years.
Cargo vessels create the greatest amount of underwater noise when they pass through orca feeding grounds in the Strait of Juan de Fuca and the Haro Strait. But the sheer number of vessels and time on water make the B.C. Ferries fleet a “significant contributor” to underwater noise.
B.C. Ferries vessel noise was measured for analysis by the Port of Vancouver’s Enhancing Cetacean Habitat and Observation (ECHO) program. While ECHO does not set specific goals for vessel noise, B.C. Ferries has set its own goal of a 50 per cent reduction.
Cargo ships and ferries from B.C. and Washington have voluntarily reduced their speed in an effort to reduce noise in critical orca feeding areas and large vessels have been asked to steer as far south as possible through the Juan de Fuca, in what is called lateral displacement.
Critics worry that slowdown programs might be counter productive.
“Lateral displacement could be temporarily beneficial, but the slowdown could just be subjecting whales to longer exposure periods,” said Misty MacDuffee, a biologist for Raincoast Conservation Foundation. “Yes it’s quieter, but it is still too loud for effective foraging and communication, and now it’s for longer time periods.”
Meanwhile, Washington State Ferries also announced last month that it would retire 13 ferries and build 16 new ferries with quiet electric-hybrid engines at a cost of $7 billion over about 22 years.
Washington Gov. Jay Inslee issued an executive order earlier this year creating a whole suite of new protections for the whales, including “strategies for quieting state ferries in the areas most important to southern residents.”