Fishing in Ilha Grande National Park

Ilha Grande National Park sits in the far west of Paraná state, near the border with Paraguay, where the Paraná River — one of South America's great waterways — spreads across a broad floodplain of islands, channels, sandbars, and wetlands.

The park covers roughly 573 square kilometers of this riverine landscape, and the water is the park. Flat terrain, seasonal flooding, riparian forest, and aquatic vegetation define the character of the place far more than any single landmark.

The Rio Paraná is the axis around which everything else turns.

Its channels shift with the seasons, and the floodplain dynamics that shaped this ecosystem for millennia were altered significantly when the Itaipu reservoir was formed upstream — an event that artisanal fishermen in the region describe as a turning point, bringing changes to the riverbed, the banks, silting, and the presence of certain fish species.

That history is part of fishing here. The Rio Paracaí and the Ribeirão Itabuna are among the interior waters within the park, though the Paraná's main channels and the islands it creates remain the dominant fishing ground.

The park protects habitat for giant otters and neotropical otters alongside the fish — a reminder that the food web here is intact in ways that are increasingly rare along the upper Paraná. Marsh deer and capybaras work the margins.

The presence of these animals is a reasonable indicator of water quality and ecosystem health. Before you go, check current rules directly with the park. Contact the park administration for what applies now.

The Paraná at this latitude is not a casual day-trip fishery. It rewards anglers who take the time to understand how the river moves across the floodplain and what the seasonal flood pulse does to fish distribution.

Come with that patience, and the park gives you something worth the effort.