Kathleen Callaghy

Water connects us all on this blue planet, whether you’re a human, fish or whale. As toxic pollutants enter our waterways through storm drains, spills and dilapidated infrastructure, they pose long-term risks not only to endangered orcas and salmon, but to humans too. These risks disproportionately affect low-income and BIPOC communities, adding a justice and equity imperative to addressing them.  

In anticipation of this year’s Orca Month theme - Clean Water, Healthy Futures - Defenders is taking a closer look at three toxic contaminants. Each demonstrates just how closely intertwined our futures are with those of our killer whale and salmon neighbors, and why, ultimately, saving them means saving us.  

Why Contaminants?

Toxic pollution is one of three major threats to the survival of Southern Resident orcas, whose population is in dire risk of extinction. They are some of the most contaminated marine mammals in the world, mostly due to high levels of pollutants in the salmon they consume. Toxic chemicals that enter waterways are often absorbed by microscopic plankton that are then consumed by larger organisms, accumulating all the way up the food chain.  

Bioaccumulation of Toxics in Southern Resident Orcas Graphic_DOW

Typically, orcas’ healthy layer of blubber stores contaminants, largely preventing them from impacting the whales’ health. Unfortunately, Southern Resident orcas are extremely malnourished due to the scarcity of their primary prey, Chinook salmon. During food shortages, the whales metabolize their fat reserves and release the stored chemicals into their bodies, which causes harm.

Contaminants of Concern

PFAS, PCBs, POPs, CECs, 6PPD. A skilled lyricist could make a song from the alphabet soup of unfamiliar terms describing substances present in a staggering number of products we use, wear and consume every day. We’ll focus on three of the most prominent and problematic.  

PCBs (Polychlorinated biphenyls)  

PCBs are a “legacy” class of contaminants. Although they have been banned in the United States since 1979, they are still produced globally and linger in the environment decades later. A 2018 study alarmingly stated that their effects threaten the long-term viability of over 50% of the world’s killer whale populations.  

Polychlorinated biphenyls (PCB) Graphic_ DOW
Please note, the information in this graphic is not comprehensive.
PFAS (Per- and polyfluoroalkyl substances)

PFAS are a ubiquitous class of chemicals encompassing thousands of individual compounds that link carbon and fluorine atoms together. These chemicals have made the news in recent years as a drinking water contaminant in 43 U.S. states, affecting over 19 million people. Even more troubling, PFAS are known as a “forever chemicals” because they do not break down in the environment.  

Per- and polyfluoroalkyl substances (PFAS)_DOW
Please note, the information in this graphic is not comprehensive. You can learn more here about how to protect yourself and your family from PFAS.

If you drive a car, chances are your tires contain 6PPD. Tire manufacturers use it to slow down normal wear and tear. Unfortunately, when this compound reacts with ozone in the air it forms 6PPD-quinone, which has proven to be lethal for coho salmon and likely other species on which the Southern Resident orcas feed.

6PPD-quinone Graphic_DOW

Earlier this year, Washington state made strides in reducing the impacts of this chemical pollutant when the state government added it to its regulated chemical list. This list establishes protective limits on listed toxic chemicals and monitors their impact on water quality.

A Cleaner, Healthier Future

Knowing more about toxic chemicals and how to avoid them is the first step towards creating a cleaner future. Here are five more easy steps you can take to help orcas, salmon and your local community:

  • Use your power as a consumer to avoid purchasing products containing toxic chemicals.
  • Drive less to minimize contamination from your vehicle.
  • Build rain gardens to help filter pollutants already in use and that may be carried in runoff.
  • Ask your representatives to invest in clean and updated capture and filtration storm drainage systems.
  • Join us in celebrating Orca Month throughout June by sharing what you learn with others so more people can advocate for cleaner water in our communities.  

Defenders is grateful to our partners at Toxic Free Future and Wild Orca, who are helping us save these endangered animals one toxic pollutant at a time.


Kathleen Callaghy

Kathleen Callaghy

Northwest Representative
As a Representative for the Northwest field team, Kathleen leads Defenders’ policy engagement on endangered species in Washington State, working with local policymakers and coalition partners on the recovery of southern resident orcas, salmon, and grizzly bears.

Wildlife & Wild Places

Ocean Wave
Southern Resident Orca Breaching

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