Dr. Know: Gender-Confused Fish

Are male bass in the Columbia gaining female traits?

Is it true that 80 percent of the male bass fish in Washington's major river are now exhibiting female traits as a result of contraceptive pills being flushed into the water? Say it ain't so! 

—Coho Before Coochie

Coho, you goober, that story was about Washington, D.C.'s, major river, i.e., the Potomac. In the Northwest, our stringent environmental standards and responsible stewardship of our waterways make such a thing impossible.

Nah, I'm just messin' with ya—our fish are switch-hitting with the best of them. In fact, a 2009 study by the U.S. Geological Survey found spots on the lower Columbia River where a staggering 67 percent of largemouth bass were well on their way to becoming largemouth tenors.

On a more serious note: Oh, shit. What have we done now? 

Probably because it contains the word "sex," the intersexuality angle has been grabbing headlines, but the problem isn't as simple as a bunch of male fish changing gender. It's more like the biology of fish reproduction is going haywire, with various proteins turning up in the wrong places on the wrong genders.

It's sort of like if you woke up one morning and discovered you were lactating. Through your penis. Would you say, "By Jove! I seem to be changing genders?" Or would it be something more along the lines of “AAAAGGGGHHHH?” 

Like a man lactating through his penis, fish biologists aren't sure what's going on, but they know it can't be good. The gender angle makes it easy to blame birth-control pills (or even natural lady pee), but lots of other contaminants—detergents, pesticides, even temperature variations—can screw up fish in this way. 

Really, it could be anything. For related reading, please see my paper, "Breast Growth in Males Through Exposure to Hostess Fruit Pies: A Self-Experiment.” 

WWeek 2015

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