Pollution Makes Spain’s Male Fish Produce Eggs

Mullet in Spanish rivers are producing eggs because of pollution

Pollution in Spanish rivers has reportedly been making male fish grow eggs in their testicles.

Spanish biologists have discovered that pollution in the rivers of the Basque region is having an unexpected effect on the local fish populations, and the male fish have actually been developing eggs.

According to The Local, chemical pollutants from farming and industrial activities have been functioning as oestrogens and feminizing the male fish populations. A new study says even everyday products like contraceptive pills and detergent are surviving the water cleaning systems and making it through to the rivers and estuaries. As a result, scientists have found eggs developing in the testicles of male mullet fish. Mullet roe is a delicacy, but this new development does not seem like a product anybody would be too eager to eat.

"Our discoveries are significant as they enable us to know how far these pollutants have spread in our rivers and estuaries and what effects they have," said researcher Miren Cajaraville.

Scientists at the Cell Biology in Environmental Toxicology group are pushing for the Spanish government to adopt regulations that would prohibit the production of pollutants that cannot be cleaned away through water treatment facilities.


“We will be able to adopt ways of keeping them from reaching out waters,” Cajaraville said.