Estrogen Kills Fish

For indispensable reporting on the coronavirus crisis, the election, and more, subscribe to the Mother Jones Daily newsletter.


Estrogen is bad for fish. In more ways than we thought.

We know that estrogen and estrogen-mimicking chemicals known as endocrine disruptors cause intersex fish—that is, males with immature female egg cells in their testes.

New research finds that fish exposed to estrogen produce less immune-related proteins, making them more susceptible to disease. This suggests why fish in the Shenandoah and Potomac Rivers are simultaneously afflicted by mass kills, lesions, and intersex fish.

US Geological Survey researchers suspected that estrogens were causing fish kills and fish lesions as well as intersex fish in the two river systems. So they exposed largemouth bass to estrogen and found the fish produced less hepcidin—an iron-regulating hormone of mammals, fish, and amphibians.

Exactly what hepcidin does to boost immune systems is unclear. But it may act as an antimicrobial peptide, the first line of defense against disease-causing bacteria, fungi, and viruses. Or it might affect the iron balance in infected vertebrates. Or both.

We do know we’re loosing megatons of synthetic chemicals into waterways every year. Most are plastics additives, surfactants, birth control agents, antimicrobials, pharmaceuticals, personal care products, or controls for insect, weed, and fungal populations.

But all too many wind their way from industry, livestock, irrigation, sewage, and storm run-off into lakes, ponds, oceans, marshes, streams, rivers, and groundwater—eventually into fish.

And from there into humans, perhaps accounting for the alarming rise of human male reproductive disorders in recent years, including birth defects of the penis, undescended testes, reduced sperm production, and testicular cancer.

You think that might slow down the chemical pipeline. Especially in rivers so close to Washington, DC. But apparently money is worth more than masculinity.
 

SIX TRUTHS

Reclaiming power from those who abuse it often starts with telling the truth. And in "This Is How Authoritarians Get Defeated," MoJo's Monika Bauerlein unpacks six truths to remember during the homestretch of an election where democracy, truth, and decency are on the line.

Truth #1: The chaos is the point.

Truth #2: Team Reality is bigger than it seems.

Truth #3: Facebook owns this.

Truth #4: When we go to work, we're in the fight.

Truth #5: It's about minority rule.

Truth #6: The only thing that can save us is…us.

Please take a moment to see how all these truths add up, because what happens in the weeks and months ahead will reverberate for at least a generation and we better be prepared.

And if you think journalism like Mother Jones'—that calls it like it is, that will never acquiesce to power, that looks where others don't—can help guide us through this historic, high-stakes moment, and you're able to right now, please help us reach our $350,000 goal by October 31 with a donation today. It's all hands on deck for democracy.

payment methods

SIX TRUTHS

Reclaiming power from those who abuse it often starts with telling the truth. And in "This Is How Authoritarians Get Defeated," MoJo's Monika Bauerlein unpacks six truths to remember during the homestretch of an election where democracy, truth, and decency are on the line.

Truth #1: The chaos is the point.

Truth #2: Team Reality is bigger than it seems.

Truth #3: Facebook owns this.

Truth #4: When we go to work, we're in the fight.

Truth #5: It's about minority rule.

Truth #6: The only thing that can save us is…us.

Please take a moment to see how all these truths add up, because what happens in the weeks and months ahead will reverberate for at least a generation and we better be prepared.

And if you think journalism like Mother Jones'—that calls it like it is, that will never acquiesce to power, that looks where others don't—can help guide us through this historic, high-stakes moment, and you're able to right now, please help us reach our $350,000 goal by October 31 with a donation today. It's all hands on deck for democracy.

payment methods

We Recommend

Latest

Sign up for our free newsletter

Subscribe to the Mother Jones Daily to have our top stories delivered directly to your inbox.

Get our award-winning magazine

Save big on a full year of investigations, ideas, and insights.

Subscribe

Support our journalism

Help Mother Jones' reporters dig deep with a tax-deductible donation.

Donate