During a visit to a beach in Saint-Michel-en-Greve, Brittany, French Prime Minister Francois Fillon announced that the French government will pay to have the beaches of France cleaned from toxic seaweed.

“The state will assume all of its responsibilities and will take charge of the clean-up of the worst affected beaches, where there could be a public health risk,” he said.

Local communities in Brittany have long been urging the government to do something about the toxic green algae that has been flourishing on Brittany beaches for years.

Last month, a rider was rendered unconscious on the Saint-Michel-en-Greve beach and his horse died after slipping on the algae, apparently after inhaling the toxic gas hydrogen sulphide released by the rotting weed. Investigations carried out by France’s National Institute for Environmental Technology and Hazards (Ineris) showed a potentially lethal concentration of the gas on parts of the beach. Some stretches had a concentration of 1,000 hydrogen sulphide parts per million; a concentration which can be deadly in just a few minutes. Ineris recommends providing all cleaning workers with gas detectors and ban the public from the beach until its deemed safe.

The green seaweed thrives when the levels of nitrate is high, which means that excess field fertilizers and manure from local livestock flushed into the ocean by French farmers creates an ideal environment for the algae.

The algae problem is not peculiar to France; the same type of green algae is also turning up along the UK coast line, especially in Dorset, Hampshire, West Sussex, and on the Isle of Wight. According to the UK Environment Agency, the algae are a threat to wildlife along the coast and tighter controls on farming fertiliser and sewage plants will be required to starve the algae of nutrients.

A recent study on intersex abnormalities in fish living in the Potomac River watershed carried out by researchers from the U.S. Fish and Wildlife Service and the U.S. Geological Survey showed that at least 82 percent of male smallmouth bass and in 23 percent of the largemouth bass had immature female germ cells (oocytes) in their reproductive organs. This number is even larger than anticipated.

This type of intersex indicates that the fish has been exposed to estrogens or chemicals that mimic the activity of natural hormones. The condition is believed to be caused by hormone-like chemicals, so called endocrine disruptors, found in medicines and a variety of consumer products. Earlier, researchers suspected that the contaminants were entering the Potomac from the wastewater treatment plants that discharge into it, but further sampling showed that the problem existed in areas located upstream from sewage plants as well. Officials are now investigating if multiple chemicals, and not just those from sewage plants, may be responsible. A larger study that includes the entire Potomac River and other East Coast rivers will be launched to find out how widespread the problem actually is.

“At the moment we don’t know the ecological implications of this condition and it could potentially affect the reproductive capability of important sport fish species in the watershed,” said Leopoldo Miranda, Supervisor of the U.S. Fish and Wildlife Service’s Chesapeake Bay Field Office.

The Potomac River is the fourth largest river along the Atlantic coast of the USA (in terms of area), with a length of approximately 665 km (383 statute miles) and a drainage area of roughly 38,000 km² (14,700 square miles). It flows into the Chesapeake Bay along the mid-Atlantic coast of the U.S. The river is shared by West Virginia, Maryland, Virginia, and District of Columbia, and all of Washington, D.C., the nation’s capital city, lies within the Potomac watershed.

More information is available in the Intersex fact sheet released by the U.S. Fish and Wildlife Service’s Chesapeake Bay Field Office.