Toxic Algae Blooms Threaten Lives With Deadly Gas

Decomposing algae releases hydrogen sulphide (H₂S), a toxic gas that carries the stench of rotten eggs. In high concentrations, this gas can swiftly overwhelm the nervous system, leading to respiratory failure, unconsciousness, and even death. French authorities have documented multiple incidents over the last thirty years where this dangerous gas caused fatalities among wild boar, horses, and beach-cleaning workers.

The gas becomes particularly treacherous as it numbs the sense of smell at concentrations as low as 50 parts per million. Environmental groups are critical of governmental responses, accusing them of downplaying the risks to protect tourism and farming. Despite several "seaweed plans" intended to reduce pollution, critics argue these have not addressed the core issue of intensive livestock farming. The situation serves as a critical warning for the UK, where rivers and coastal waters already face significant pressure from agricultural pollution and sewage spills, with concerns that toxic "green tides" may become more common during warmer summers.