The Amazon rainforest in Brazil is in the grips of a severe drought that may affect around 500,000 people by the end of the year, limiting their access to food, drinking water and other supplies.

Water levels have already dropped, and dead fish now float atop some of the rainforest’s winding rivers.

Their rotting corpses have contaminated the water supply in some areas, officials told the news agency Reuters, with more than 110,000 people facing repercussions.

In Manacapuru — a town two hours’ drive from the major city of Manaus, considered a gateway to the Amazon — fish launched themselves out of the scorching, shallow waters in a desperate attempt to survive. The smell of rot, emanating from the brown water, filled the air.

“It is difficult because of the contamination of the water. We need a lot of it to bathe. And we also drink the water, but because it is contaminated, we’re not drinking it,” said 19-year-old shopkeeper Caroline Silva dos Santos in Manacapuru.

“We’re getting water by bringing it from the city.”

The Amazonas state, where Manacapuru is located, declared an environmental emergency two weeks ago in response to the prolonged drought and launched a response plan valued at $20m.

The drought is forecast to last longer and be more intense because of the El Nino climate phenomenon, which inhibits the formation of rain clouds, the civil defence authority said.

Climate change also exacerbates droughts by making them more frequent, longer and more severe. Warmer temperatures enhance evaporation, which reduces surface water and dries out soils and vegetation.