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[The Mystery of the Puget Sound Salmon Killer: A Scientific Investigation]-[The Mysterious Case of the Missing Salmon]

Wow in the World · B1 · 2021-04-26

Preschool Enlightenment
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📋 Summary

The Curious Incident of the Missing Salmon

In this episode of Wow in the World, hosts Mindy Thomas and Guy Raz adopt their personas as "Detectives at Large" to investigate a long-standing ecological mystery: the unexplained "mysterious die-offs" of coho salmon in the streams and creeks near Puget Sound, Washington. For nearly 20 years, these fish populations have faced sudden, catastrophic declines, with up to 90% of the salmon perishing shortly after rainfall events.

The Investigation Begins

The detectives initiate their inquiry by visiting a local shopkeeper, Mr. Stedikeman, who provides the first clue. He observes that the salmon often appear "jittery-like" and start "swimming in circles" before ultimately "belly up" in the water. Mindy and Guy Raz conclude that the fish are being poisoned, prompting them to collect water samples from the affected creeks to identify the source of the toxicity.

Scientific Analysis and Forensic Breakthrough

To solve the case, the detectives collaborate with Jennifer McIntyre, a toxicologist at Washington State University. The scientific investigation reveals that the salmon are suffocating. While fish typically extract oxygen from water using their gills, pollutants in the water interfere with this process. By utilizing a "high-resolution mass spectrometer," researchers at the university compared the creek water to the samples provided by the detectives.

The breakthrough came when the researchers identified that the water contained "tire particles." As vehicles drive, small bits of rubber wear off the tires. When it rains, this "road runoff" washes the debris, along with various chemicals, into the surrounding waterways.

Identifying the Culprit: 6PPD-Quinone

With the help of a forensic expert known as "G-Force," the team narrows down the thousands of chemicals found in tire residue to one specific, lethal culprit: 6PPD-quinone. This chemical is a byproduct found in tires that, when washed into streams, proves fatal to the coho salmon. The discovery confirms that the "mysterious cod killer" (playfully corrected to salmon) was an unintended consequence of modern infrastructure and road runoff.

Conclusion

The investigation highlights the intersection of human activity and environmental health. What initially seemed like an unsolvable "cold case" was ultimately resolved through rigorous scientific investigation and collaboration. By identifying 6PPD-quinone as the primary toxin, scientists are now better equipped to understand and potentially mitigate the impact of urban pollution on sensitive aquatic ecosystems. The episode serves as a reminder of the "wow" hidden in the natural world and the importance of scientific inquiry in protecting it.

🎯Key Sentences

1
It's the kind of case that comes across your desk once in a blue moon.
2
For 20 years, they've been trying to crack the case, but the trail went cold.
3
Well, now I've heard it all.
4
We heard that there was something fishy going on around here.
5
Ring any bells?
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📝Key Phrases

1
music to your ears
2
once in a blue moon
3
crack the case
4
the trail went cold
5
kicked the bucket
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📖 Transcript

Grownups, Wondery Plus subscribers can listen to Wow in the World early and ad-free right now.
Join Wondery Plus in the Wondery app or Wondery Kids Plus on Apple Podcasts.
Hey, Wowzer fans, Mindy here.
And before we start the show, I gotta let you know that this November, with a special new episode featuring our friends at Circle Round and Terrestrials on Radiolab for Kids,
And don't miss when Elmo from Sesame Street stops by Wow in the World to make us all belly laugh on November 24th.
Oh, but that's not all, Reg.

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