Make sure to read Part 1 before you read this post. Regrettably, Part 2 is a bit of a downer but is necessary to address. The SRKWs population has been drastically decreasing. The most recent population estimate indicates a total of 73 individuals remaining. Scientists have identified three main threats to the SRKW population: starvation, noise pollution, and chemical pollution. All three threats play off each other, thus causing an endless detrimental cycle.
It’s too Noisy! I can’t see….
Constant commercial vessels and whale watching boats add to the ambient noise, the natural background noise of the ocean. Creating a more noisy environment makes it harder for the SRKW’s to communicate and echolocate during their hunts. Shipping noise resonates at the same frequency as their vocalization. Both are crucial for them in their murky world. The SRKW’s try to evade whale watching boats but these boats tend to follow them. This causes them to spend more energy on traveling but leaves less energy for hunting.
However, during this COVID-19 epidemic, the world’s oceans are quieter. Noise pollution has dropped by 75% in the Salish sea. Scientists up there are taking advantage of this unique opportunity to study the SRKW’s in a relatively silent ocean. Essentially, since the 1980s vessel traffic has been increasing, almost doubling every decade. Scientists hope to find out if the SRKW’s are more successful with their hunts, are repeating their calls less, and remain in their critical habitat longer during this quiet spell. All of these findings will help establish a better “baseline” to see if quieter environments can help their survival. You can read how Richard Dewey, the associated director of science at the Ocean Network Canada, describes this special research opportunity here.
Starving to Survive
The chinook salmon population (SRKW’s favorite food), is also on the decline. So adding that hurdle along with a loud environment yields for a difficult situation: starvation. Starvation results in the wales using their body fat to help them survive. This causes them to have a lower body mass, exposing them to detrimental effects.
Pollution impacts coastal regions because they are the closest areas to emission sites. Persistent organic pollutants (POPs) are man-made chemicals including industrial chemicals, pesticides, and flame retardants. They were mass-produced in the twentieth century. One of the major POPs detected in wildlife are polychlorinated biphenyls (PCBs). These industrial chemicals were utilized in a variety of items: heat transfer fluid, hydraulic fluids, lubricates, additives in paints, plastics, etc. They were banned decades ago but they do not degrade easily in the environment.
Though PCBs were banned in the late 1970s, they still accumulate in wildlife. They are soluble in oils and fats, meaning they like to accumulate in animal fat. Since they are difficult to break down, their concentrations get higher as they move up the food web. This phenomenon is called bioaccumulation.
PCB’s are toxins, which have been shown to impair a myriad of biological functions necessary for life. Studies have shown that PCBs hinder the immune and endocrine systems, increase the risk of cancer and impair reproduction. According to a study in 2018, some killer whale populations are at risk of disappearing due to their PCBs concentrations.
This constant chronic exposure to the presence of PCB’s not only in their food sources but also in their environment. This could explain the low birthing rates and population decline of killer whales in certain populations. There are only 30 reproductive mature individuals in the SRKW population. Unfortunately, two-thirds of the SRKW pregnancies fail. Their decline indicates a decline in their environment’s health, which inevitably will affect humans.
What researchers and local communities are trying to do
Task force, assemble!
On 14 March 2018, the governor of Washington Signed and Executive Order (18-02) that established a task force. They assessed and develop long-term actions for the SRKW recovery and future sustainability. This was an ENTIRE community effort. People participated from the Washington Legislature, the Canadian Government, representatives from tribal, federal, local, and other state governments, the private sector, and the non-profit sector. Not to mention, all the concerned citizens around the world writing in as well. November 8th, 2019 came out with its Year Two final comprehensive report. Year One’s final report addressed the major threats to the SRKWs and established 36 recommendations.
The purpose of Year Two was to see how Year One’s recommendations progressed, to see what else needed to addressed/changed, and to formulate new recommendations accordingly. They found that they were successful with Year One. However, they noted that a heavier legislative push and involvement was necessary to better their results. The Task Force came up with 13 new recommendations with most addressing contaminant threats. They also said that more efforts need to be put on mitigating climate change, ocean acidification, and the rapid human population growth and development in the area. You can read in more detail their recommendations and actions here.
Of course, countless scientists have been trying to do noninvasive studies on the SRKWs. An example of this is the University of Washington’s Center for Conservation Biology.
What we can do to help?
The EPA has five simple, but essential things we can do to help:
- Orcas are sensitive to noise and disturbance from boats. Instead of approaching them in your own vessel, spend a day watching them from a responsibly-managed whale watching vessel, or watch them from shore.
- Engage in citizen science by alerting researchers when you spot orcas so scientists can track their travel.
- Get involved in efforts to protect and restore salmon habitat in your community. Chinook salmon are especially important to killer whale populations in the Salish Sea.
- Choose to eat sustainably-harvested salmon and other seafood to help protect wild fish populations.
- Do your part to dispose of unused medicine and chemicals properly. Never dump them into household toilets and sinks or outside where they can get into ditches or storm drains. See if your community has a household hazardous waste collection facility that will take your old or unused chemicals.
- Dr. Sam Wasser and Tucker
- NOAA Fisheries: Recovery Planning and Implementation
- J35 the Mourning Orca
- The Roar Below
*Really cool article with heaps of audio examples about how noise is effecting the SRKWs
- First Task Force Meeting
Thanks for reading!! Remember to always always be “Whale Wise!“
Naomi Mathew is a PhD student at University of Louisiana at Lafayette. She works on bioacoustics in marine mammals from the Gulf of Mexico. She is the co-founder of Whale Scientists. You can read more about her here
2 thoughts on “Orca Awareness Month: Southern Residents (Part Two)”
Excellent read, I hope that gov agencies are receptive to the science. Reduce the noise and lower the Salmon ‘slaughter’ until a sustainable sharing of the sea is an option. Eat locally. Stop shiploads of exported salmon and seafood to Europe and China. The real cost is not what the market implies. The public needs to understand the real cost of the drag nets and dead oil well cleanup and climate impact which is never collected upfront! It’s a quick fix for short sighted investment money junkies with privileged lobbying rights. It will not feed the next generations. The seas are a barometer for life.
Sorry, this is just preaching to the choir. It’s just heart breaking sometimes and the bigger picture is framed by the smaller picture. As much as I really, really love salmon, I have not eaten it for over 8 years in order not to deprive a baby Orca.
Hello! Thankfully, the Washington Government has been really responsive and rallying up all they can do to better the SRKWs’ livelihoods. They are working quite closely with scientists to try and go the best possible route. No don’t be sorry! Preach away:) It’s good to have additional support and another voice out there. We all have to try and do the best we can to better our environment on all fronts! Thanks for your comment!