Deep Ocean Fish Face Health Problems Due to Man-Made Pollution

Deep ocean fish are facing a host of health problems that may be due to man-made pollution, according to a new study.

Even as far down as 2,000 feet to one mile beneath the surface, marine fish are suffering from liver pathologies, tumors and other conditions as harmful pollutants are being dumped into our once pristine oceans. That's through activities such as pesticide use, the burning of fossil fuels, agriculture and industrial operations.

"In areas ranging from pristine, high mountain lakes of the United States to ocean waters off the coasts of France and Spain, we've now found evidence of possible human-caused pollution that's bad enough to have pathological impacts on fish," co-author Michael Kent, a professor of microbiology at Oregon State University (OSU), said in a statement.

"Deep in the ocean one might have thought that the level of contamination and its biological impact would be less," he added. "That may not be the case. The pathological changes we're seeing are clearly the type associated with exposure to toxins and carcinogens."

This includes a condition referred to as "intersex," in which fish species contain a blend of male and female sex organs. This study is the first to discover such a case in deep water fish.

It is known that as the sea deepens along continental slopes, heavy metal contaminants can build up there, including mercury, cadmium and lead, and organic contaminants such as PCBs and pesticides. In addition, the "intersex" fish researchers documented are supposedly the result of "endocrine disrupting chemicals" that can mimic estrogens, causing sex organs to mutate.

However, until now few studies have considered humanity's impact on fish living at deep ocean depths. Most focused only on their parasite fauna, not more internal biological problems such as liver damage.

This time around the OSU team looked at black scabbardfish, orange roughy, greater forkbeard and other less well-known species. They found a wide range of degenerative and inflammatory lesions that suggest human-made pollution is the cause.