Farm runoff tough on fish

Evidence suggesting farm runoff may alter fish hormones is mounting, a report finds.

Using water taken from Indiana streams contaminated with natural and synthetic hormones from manure spread on fields, Purdue University researchers raised fathead minnow embryos, 60 percent of which turned out to be male, according to Environmental Health News.

The results don’t bode well for future generations; fish are typically born in equal gender ratios, and skewing the population toward males could threaten healthy reproduction. The researchers also found agricultural streams had 50 percent less fish diversity and 28 percent higher adult-minnow death rates than creeks with no farm runoff.