Toxic Seaweed Spread on French Coast

Mounds of algae are spreading across France's northwestern coast, releasing toxic gas that led to the recent death of a horse and the collapse of the rider.

The algae can post a serious health risk as they produce a toxic fume containing hydrogen sulphide when they rot. When trapped under a seaweed crust and released suddenly, the innocent-looking algae can be as deadly as cyanide.

The problem has been around in the area for more than 30 years. In previous years, the town spends around £150,000 annually to clean up the algae. This year, an unprecedented level of the algae have been washed ashore and 16,000 tonnes of the algae have been collected already. However, experts warn that simply removing truckloads of seaweed would not solve the root of the problem - "The only answer is to change farming practices in Brittany immediately to reduce the amount of nitrates used and promote sustainable agriculture."