Why Are These Male Fish Growing Eggs?

Fish in wildlife refuges are feminized, probably by hormone-skewing pollution. What does this portend for the health of all creatures—and people?

SWANTON, Vermont—Silver maples, lanky and bare, stand on the frozen flood plain at the Missisquoi National Wildlife Refuge. Two sets of tracks—fox and mouse—weave across the snowy surface of the river, which is home to bass, muskrats, and beavers. In the fall, more than 20,000 migrating ducks will converge here, and in the summer, one of the refuge’s rarest species, spiny softshell turtles, will bask and forage on its gravelly beaches and sandbars.

Sixty miles south of Montreal, near the U.S.-Canada border, Missisquoi National Wildlife Refuge is one of the most productive and pristine wetland ecosystems in the Northeast. Yet even here, scientists have found an abundance of fish with bizarre abnormalities that suggest exposure to hormone-disrupting water pollution.

Scientists from the

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