Why Chile’s marine wildlife is being killed by unprecedented red tide

The red tide, caused by the blooming of toxic algae, is killing thousands of sea animals off the coasts of Chile.

Sea is the cradle of life, but Chilean waters have turned into a grave. Unprecedented red tide is killing millions of marine creatures in the Pacific Ocean, off the coast of Chiloé Island, in Los Lagos region, southern Chile. It is the largest die-off of marine wildlife in the country’s history.


Distesa di calamari morti
The red tide caused a great variety of animal species to die from poisoning and asphyxiation

What caused the red tide

The red tide is an algal bloom that turns the seawater red. These algae produce poisonous toxins that – in large quantities – reduce oxygen in water, becoming lethal to marine wildlife.

Why El Nino is involved

Among the causes of the unusual algal proliferation is an increase in seawater temperatures combined with El Nino weather pattern. In fact, southern Pacific Ocean registered peaks in temperatures during last summer.


Leone marino morto
Dead sea lion. (AP Photo/Esteban Felix)

Environmental crisis

The red tide caused the death of an incredible variety of animal species, including sardines, jellyfish, shellfish, mussels, seals, sea birds and squid, and even altered whales’ migratory routes. In January, the catastrophe onset took place on the shores of the Chilean island of Santa María, with thousands of Humboldt squid (Dosidicus gigas) washed ashore. Ecosystems are perfect yet delicate mechanisms and changes risk threatening their survival. Animals that haven’t been affected directly, but ate other creatures’ carcasses, have been poisoned as well. Even creatures at the top of the food chain, namely humans, have symptoms of poisoning and have been hospitalised.

An economic catastrophe

Beyond ecological damages, the phenomenon is also affecting Chile’s economy. Algae caused the death of over 20 million salmons, casing huge losses to the country, which is the world’s second producer after Norway.


Allevamento di salmoni cileno
Intensive salmon farming, Chile

Some are blaming the salmon industry

Scientists say the phenomenon is caused by several concurrent factors, including the salmon industry. It would be responsible for the dumping of dead fish and nitrogenous substances that, by accumulating, favour the blooming of toxic algae. Fishermen took to the streets in Chiloé over the past few days to protest against salmon multinationals.

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