The Chilean government has declared an emergency zone along its southern coast as it deals with the spread of a new strand of toxic algae. The algal bloom, also known as a ‘red tide,’ effectively kills fish with a toxin that paralyzes the central nervous system, and would poison humans if they were to eat the affected fish.

In response to the contamination, Chilean authorities have banned fishing in the Los Lagos region, putting thousands of fishermen out of work.

Fishermen of Chiloé Island, home to about two-thirds of the country’s salmon processing plants, have barricaded the island in protest, demanding more compensation for losing their livelihood to the red tide. The local fishermen have been protesting since last Tuesday, arguing that 100,000 Chilean pesos (approximately 150 USD) offered to some 5,000 fishermen and their families by the regional mayor is not enough.

“We do not accept the proposal made by the Governor of the Region of Los Lagos, Leonardo de la Prida,” said Denisse Alvarado, the leader of Fishworkers Quellón, in an interview with Chilean online news outlet El Mostrador.

“Quellón [a port city on the island]has stopped receiving millions of pesos because of the red tide and the contingency. Nobody here lives on 100,000 [pesos], we estimate it should be 400,000, but we have to determine for how long.”

The barricade has blocked the flow of food and other basic supplies to tens of thousands of people on the island, and may be costing the salmon industry up to $9 million a day, as they are unable to deliver their product to ports, newspaper El Mercurio reported.

Most of the island’s residents seem to support the fishermen, though, who blame the salmon industry and the government for the contamination. The red tide, the protesters say, began just after 4,000 tons of dead salmon were dumped 181 miles from the island.

Most experts refute the fishermen’s claims, saying the algae is linked to warmer temperatures caused by El Niño. Chile has 2,500 miles of Pacific coastline, making it especially vulnerable to the fluctuating weather pattern, and this year’s El Niño is one of the strongest in recorded history.

“The Chilean ocean is shifting and changing,” said Sergio Palma, an oceanographer at Valparaiso Catholic University, in an interview with ABC News. “There has been a series of events that indicate an El Niño which is making its presence felt in many ways.”

In March, high ocean temperatures helped spread the bloom of a different strain of algae off the Chilean coast, killing upward of 23 million fish. The affected marine life included 40,000 tons of salmon – 12 percent of Chile’s annual production – in the Los Lagos region.

In the most recent algal bloom, some 8,000 tons of sardines were washed up at the mouth of the Queule River, and thousands of dead clams piled up on the coastline of Chiloé Island, according to the ABC News report.

Chile is among the world’s top suppliers of salmon, and the Chiloé community is just one of many along the country’s coast that relies on fishing for their livelihoods.