Southern resident killer whales are in serious trouble. Their population totals 78, positioning them on a countdown to extinction. In our previous blog, we talked about how the lack of salmon is a threat to orca recovery. Another major threat to their survival and growth is noise in the waters of the Salish Sea.
The sources of this noise are varied: oil tankers and freighters, ferries, cruise ships, commercial and private vessels, naval sonar, underwater construction, drilling, and resource exploration. The combination and growth of these sources mean that noise pollution in our waters is on the rise.
Here in BC, the number of oil tankers transiting through critical orca habitat would increase to 34 each month—up from five right now—with the expansion of the Kinder Morgan pipeline. That would dramatically increase noise resulting from propellers in the Salish Sea to the detriment of the fragile orca population. And that is just one of many projects being considered in the region which would result in more ships and more noise beneath the sea.
Hearing is essential for orcas. They use it to hunt for food, navigate their environment, and communicate with one another. Orcas produce sound by forcing air through the nasal passages in their head. They then focus and project these sounds through their melon, a fat-filled area in their forehead. When the sound waves hit an object, whether that be a fish, a rock or a boat, they bounce back and are received through a fat-filled cavity in the lower jawbone. From there, the sound then travels to the inner ear and into the brain where an image is formed. This is called echolocation.
Orcas rely on an echolocation sensory system that is the most advanced on Earth—it gives them the ability to ‘see’ what’s in front of them. The ability to ‘see’ using sound waves is not something we can comprehend. Scientists, however, believe the sounds that orcas use to communicate go beyond hunting and navigation. They think it helps tie families together and calms individual orcas who can hear and communicate with their family, making them feel safe and connected.
The impacts on orcas of the current and growing noise levels in their critical habitat needs to be better understood. Current noise levels along the West Coast, where orcas live, need to be measured and capped over the longer term, reducing them to levels that do not harm the orcas.
How you can help
To truly protect and recover the southern resident orca community, we need to address the major threats immediately. That requires hard work and commitment from all sectors and levels of government, and even you! Together, we can give orcas a voice and a path to protect their pods and rebuild their numbers.
Change needs to start now so we can successfully turn the tides for this unique and important family. Orcas can’t wait—the time to act is now!