Intersex Fish Found Off the Coast of California

Last year federal scientists were shocked when they discovered male fish in Maryland’s Potomac River that were able to lay eggs. So-called "intersex" animals are not a new finding among the scientific community. Researchers believe the abnormalities may be caused by pollutants from sewage plants, factories, and livestock farms being dumped into rivers and streams. Almost all instances of intersex animals have been discovered in freshwater fish.

Last week, however, scientists from the Southern California Coastal Water Research Project issued a report detailing their discovery of sexually altered fish off the Southern California coast. The report, presented at the Society of Environmental Toxicology and Chemistry in Baltimore, said that scientists caught 82 male hornyhead turbot and English sole off the coastline of Los Angeles and Orange counties. Doris Vidal, who led one of the studies, said that of those 82 male fish, 11 had ovarian tissue in their testes. Environmentalists say that this is study is one of the first to document the effects of pollution in a marine environment rather than freshwater.

Almost a billion gallons of treated sewage are dumped into the Pacific Ocean every single day, flooding through three underwater pipelines off Playa del Rey, Huntington Beach, and Palos Verdes Peninsula. The wastewater is filtered and treated, but it still contains contaminants that disperse into the water and settle onto the ocean floor. It is not known to what degree these contaminants are affecting the marine plant and animal life, and scientists do not yet know how significantly the sexual defects already discovered near these pipelines represent the overall fish population.

Two previous studies of intersex animals found that two-thirds of the male fish located near the Orange County pipeline had the capability to produce eggs. The scientist heading the water research project, Steve Weisberg, stated that the results of the recent discovery warrant further study to determine whether or not sexually altered "intersex" fish are becoming widespread throughout the waters of the ocean.