Male Fish Are Growing Female Eggs, Study
Strangely, "feminized fish" have been found in 37 species of male fish in the past 10 years, in lakes and rivers across North America, Europe and various parts of the world. This problem seems to be more prevalent today than thought earlier.
Researchers from the U.S. Geological Survey and the U.S. Fish and Wildlife Service examined fish in 19 national wildlife refuge locations in the Northeast. They found that about 60 to 100 percent of the male smallmouth bass showed female egg cells growing in their testes.
This is a phenomenon known as intersex, and is connected with manmade environmental chemicals that might reflect or block sex hormones. However, the real reasons for this are not clear.
"When fish are getting intersex, it's probably a good indication that something is wrong in the environment," said Vicki Blazer, a researcher at the U.S. Geological Survey.
These feminized fish may be caused by "chemicals stemming from agricultural runoff and hormone-based pharmaceuticals" that cannot be filtered by sewage treatment plants, says NorthJersey.
At present, it is also not clear how much damage the fish have on the health of "the species, environment and humans".
"There are no truly untouched areas," said Luke Iwanowicz, who led the current study. "I think the take away here is that everything we do, everything we use or put on the land, ends up in the water at some point."
A worrisome fallout is that the male behavior, which is vital for building and guarding spawning nests for offspring, might alter considerably, and disturb global marine ecology. It would throw the fish populations around the world into danger, according to Planet Experts.
The study was published in the February issue of Ecotoxicology and Environmental Safety.