Six beaches have been shut down in the French region of Brittany because of alarming algae blooms that have been tentatively linked to two deaths, according to CNN.
Initially, the two men who died, aged 18 and 70, were thought to have drowned while swimming, a tragic but common occurrence in the country. But teams are now looking into exactly how they died, and scientists are pointing to the harmful pollutants released by the algae blooms in the area as a potential culprit.
The six beaches are currently fenced off and feature signs that warn of toxic gas, according to CNN.
Algae blooms — excessive algae growth — thrive during the summer months when ordinary algae populations suddenly grow disproportionately, fueled by industrial or agricultural runoff or other environmental stressors, such as extremely high temperatures. The exponential growth of algae drains oxygen from its environment, causing mass die-offs of local wildlife, while also emitting gases and releasing poisons that are potentially lethal to humans.
Scientists warn that algae blooms pose an urgent and largely hidden public health crisis around the world that should be aggressively addressed through educational campaigns and environmental regulation.
Contact with algae blooms can cause nausea, skin problems, liver damage, cancer, and even death.
Algae blooms also threaten both local environments and economies. As algae blooms take over a body of water, they can destroy all the wildlife within, hollowing out vibrant ecosystems, and undermining tourism and fishing industries.
Sources of drinking water can also become heavily contaminated by algae blooms, leading to water shortages.
Read More: Climate Change May Make Most Drinking Water Toxic, Study Finds
In recent years, climate change has increased the likelihood of algae blooms, according to the US Environmental Protection Agency. As greenhouse gas emissions accumulate in the atmosphere, more heat is getting trapped in the world’s bodies of water. Algae flourish in warmer waters and are able to grow thicker and faster in warming lakes and oceans.
Additionally, intensifying storms and weather events cause more flooding incidents that carry fertilizer from farms and other industrial runoff into bodies of water, feeding algae blooms. Sea level rise from melting ice sheets, meanwhile, creates better conditions for algae to thrive, the EPA notes.
In #Qingdao, East China's Shandong province, the water near the seashore is covered in green algae. The bright green algae bloom is an annual phenomenon since the first outbreak in 2008. Researchers have attributed the phenomenon to warming sea temperatures. pic.twitter.com/sUkPcwmf6w— DW Global Ideas & Environment (@dw_environment) July 18, 2019
In short, worsening climate change, in combination with irresponsible industrial activity, has led to an explosion in algae blooms.
Beaches in Brittany, France are closed due to sea lettuce, or ulva lactuca (type of algae). Two swimmers' deaths investigated as part of this harmful algal bloom (no connection yet established). #HABshttps://t.co/bwG6AMQDYK— Kai O-S (@kolsaw) July 16, 2019
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In the US, the Environmental Working Group tracked 255 algae blooms in 2018, compared to just three in 2010.
Algae blooms are usually identifiable by the bluish-green film they create on a body of water, but they can often be hard to distinguish from normal water conditions. Without proper environmental monitoring, an algae bloom can occur in a popular beach area or lake; when people then swim in these water bodies they are exposed to potentially lethal levels of toxins.
That’s why it’s essential for local authorities to continuously monitor water conditions, according to the EPA. Environmental regulators must also better enforce rules against farms and companies that release runoff into bodies of water.
Otherwise, lakes and beaches will continue to become off-limits to people everywhere.