Fin-tastic news about Passaic River fish

By Karen Zautyk

I have probably shared this story before, but bear with me. This time it has a purpose:

When I was a child growing up in Down Neck, Newark, my father and I would often spend summer evenings on the banks of the Passaic River. We’d walk the shoreline or just sit and watch the boat traffic (there was a lot of it back then: tugs, motorboats, freighters, etc.). But then I decided I wanted to learn to “fish.” 

I was too little for rod and reel, so my father got me one of those small nets that you use to take goldfish from a bowl. I used it to take killifish  from the Passaic.  

When I’d caught enough,  we carried them home in a big pickle jar full of cloudy river water and then I’d transfer them to a large fishbowl with fresh water.

In the morning, they were all dead.

We repeated this exercise the following week, and the same thing happened — at which point even my small brain realized that the killies probably could not survive in clean water. And there was no way my parents were going to let me keep a bowl of polluted Passaic water in the house.

Yes, even then, we knew the Passaic was polluted. We just didn’t know how badly, or with what. It could smell terrible, especially when the tide went out, but we just didn’t consider it dangerous. (However, no one I knew would ever swim in it.)

I bring up the killie story because of an astonishing new scientific study that was released recently and made headlines around the world: “Rapid evolution saved this fish from pollution” — N.Y. Times

“Fish have evolved to survive toxic waste . . .” — The Independent, U.K.

“Killifish survive on pollution” – UPI

Has there been some sort of genetic mutation resulting in killies becoming a kind of Superfish?

Since 2010, a team of scientists from the University of California-Davis have been studying killies taken from several severely polluted bodies of water, including Newark Bay. 

Quoted in the Bergen Record, biologist Andrew Whitehead, who led the study, said: “Killifish shouldn’t be there. They should be dead. These are some of the most polluted estuaries in the world, and yet this fish has survived.”

The conclusion (again quoting The Record): The local killifish have “developed an extraordinary resistance to the deadly dioxin, PCBs, heavy metals and other contaminants at the confluence of the Hackensack and Passaic rivers.” The Newark Bay (and other) killies “are 8,000 times more resistant thanother fish to this complex toxic stew.”

In essence, they have become “virtually immune” to pollutants. 

Way to go, killifish!

We learned of the study during a chat with Capt. Bill Sheehan, the Hackensack Riverkeeper, whose independent, non-governmental program has been at the forefront of efforts to rescue that waterway from pollution. Check his website ( for details on the work they do, and especially on the history of the Hackensack project.

(By the way, why is there no Passaic Riverkeeper? Of course, I am aware of the Passaic Valley Sewerage Commission, but the addition of a Riverkeeper couldn’t hurt.)

On a personal level, I can relate to the killies. Considering where I grew up — playing on the polluted Passaic shore, living  near a factory that was making Agent Orange, shuffling through the asbestos that kids had peeled from the laundry room pipes — and considering that I am still breathing, I do believe that I am 8,000 times more resistant than other humans to any complex toxic stew. 

(But I still wouldn’t swim in the Passaic.)

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