The surge of fires before the peak of the dry season has raised alarm for the Pantanal, which extends into Bolivia and Paraguay and is home to a rich array of wildlife, including the world's highest density of jaguars.
The six-month state of emergency was declared by the state of Mato Grosso do Sul, home to much of the wetlands in Brazil.
Experts say the blazes are a result of a harsh drought and deliberate fires set to expand agricultural land into the forest that burn out of control.
According to environmental satellite data from the Federal University of Rio de Janeiro, 627,000 hectares of the Pantanal have already gone up in flames since the start of the year.
The Pantanal, a region slightly bigger than England, experienced its worst year for fires in 2020, when 30 percent of the wetlands were affected.
So far this year, there are 33 percent more fires than seen over the same period in 2020.
"Does this mean that the Pantanal will burn more than in 2020? Not necessarily, but it will depend directly on authorities who will have to mobilize maximum resources to prevent a tragedy like we saw in 2020," Gustavo Figueiroa, director of the SOS Pantanal NGO, said in a video on Instagram.
