Home of the Largest Golden Dorado – the Parana River

Home of the Largest Golden Dorado

the Parana River

Beginning its life in southern Brazil, the mighty Parana River flows south through Paraguay and Argentina for over 3000 miles. It is the second largest river system in South America (yielding only to the Amazon in reach), fourth longest in the world, and the number one biomass producing river on earth. Most of that biomass comes from the central and lower portions of the river that envelope huge flood plains for a good part of the year.

The central floodplains provide the ideal ecosystem for untold numbers of plants, fish, and amphibious creatures to multiply, as it transforms during the flood cycles into a protected nursery for predator and prey fish species alike. One species in particular, the Sabalo, which is the only one capable of filtering nutrients from the silt and mud river bottom, is the keystone for the survival of other predatory fish.

A school of Sabalos under the jungle trees.

As the Parana flows through Brazil, its waters are interceded repeatedly by a series of dams that negatively affect the natural balance of the ecosystems over the first 900 miles of river. These successive dams have a dramatic impact on the Golden Dorado population, as well as other migratory species, during the times of year when they move north along the river to reproduce.

Once the river reaches Argentina, it faces only one more obstacle, the Yacyretá Dam. This reservoir is relatively new, having been completed in 1994, and reached its maximum level in 2009. Beyond this dam the river runs freely for another 750 miles before connecting with the La Plata River, and the volume of water that eventually flows into the Atlantic Ocean is roughly equivalent to that of the Mississippi River delta.

This last long stretch of river is usually thought of as three distinct sections: the Upper, Middle, and Lower Parana (also known as the Delta near Buenos Aires.)

What is known as the Upper Parana River, starts below the Yacyretá Dam and flows in an east to west direction until it connects with the Paraguay River. This is a highly distinctive section of the river that runs in a narrow strip through and around densely covered jungle and islands inhabited by monkeys, toucans, and wildlife typical of jungle ecosystems.

The bottom in the Upper river is fine yellow sand, interspersed with ancient basalt rock formations lining the banks and many jutting up through the center of the river. These rock formations, as well as an abundance of large fallen trees along the shoreline, are used by the Golden Dorado in heavy current to ambush prey. So too, are the uniquely formed sandbars in the shallows that are a favored location for the Dorado to hunt Sabalo.
Drone view of the Parana River.

There are numerous effects the dams have on the river, including on the water clarity in the river below, which turns out to be very beneficial for fly fishermen chasing the largest of the Golden Dorado that this section of the Upper Parana holds. The clear, stable water conditions are precisely the reason why we chose this region as the home for our Itati Lodge.

This section of the river offers the possibility of taking trophy sized Dorado of over 40 pounds in areas where they gather during the spawning season. And another major attraction, is the ability to target a host of other unique omnivorous species like, Pacu, Pirapita, and Boga, in the same sections of river using flies that mimic fallen fruits, nuts, flowers, and insects.

To date, we have only covered the waters that drain into the Parana system from southeast Brazil, but another large part of the basin is fed from south central Brazil, starting its journey at the largest wetland in the world, El Pantanal. Draining into the Paraguay River, this watershed runs 2150 miles to the Atlantic Ocean and is the longest free running water in the world, with no interruptions from dams.

Before joining with the Parana River, the Bermejo River comes in from the northwest and joins the Paraguay, carrying thousands of metric tons of fine sediment from as far away as the Andes Mountains, and the jungles of Bolivia and Argentina. This massive contribution of sediment is the reason why the middle and upper sections of the Parana River have the capacity to generate so much life and biodiversity. Unfortunately, this sediment is also what makes the river system from the Paraguay junction down, typically un-fishable with fly fishing techniques during the rainy season in the Andean Yungas of Bolivia.
Smaller streams, most of them tributaries of the Bermejo in the Andean Yungas of Salta and Jujuy Provinces, are remarkable fisheries. They are typically beautiful medium-sized clear water mountain streams, running along valleys covered by dense subtropical jungle. They are fabulous rivers to sight fish for Dorado, but very seasonal, as one summer rain storm can muddy the waters to the point of being impossible to fish for over a week.
The Bermejo river (yellow-ish color) joining the Paraguay (brown-ish), and the Parana (green-ish) joining the Paraguay.
The middle section of the Parana begins below its intersection with the Paraguay River, and changes direction to due south. And even though it holds similar numbers of Dorado in average sizes, there are fewer chances of landing a really trophy-sized fish. The predictable summer rains that arrive between November through May, bring higher levels of sediment that spoil the clarity of the water, as well as raising the water levels far above the rocks and structure. The river deepens, widens, and slows to a point that is unproductive to fish.

In addition to the Parana River Basin holding the largest wetland in the world, it also contains the second largest, the Iberá Wetlands. The Iberá occupies over 4630 square miles, fully one-third of the Corrientes Province, and drains into the Parana through the Corrientes River. The wetlands were created over 10,000 years ago when the Parana River made a sudden change in direction from southwest to straight west (where the Yacreta Dam now stands) and the abandoned river bottom grew into wetland habitat.

It is an enormous ecosystem formed by streams, channels, lagoons, and filled with diverse reeds and aquatic vegetation. There are gigantic floating islands that, depending on the water levels, will rise and move to periodically open new channels and close others. The waters in the wetland are nearly crystal clear with a hint of tea color, and are an amazing place to fish for Golden Dorado in one of the most pristine and conservation-minded environments in Argentina.
The Iberá Wetlands are protected by two national parks, provincial reserves, and private organizations like the Re-Wilding Argentina project of the Douglas Tompkins Foundation. We are blessed to be the only fly fishing operation taking anglers into the most distant parts of the Iberá Wetlands, with remote camps in the farthest reach of the system, where few humans are ever seen.
For an extraordinary fly fishing adventure in search of the largest Golden Dorado, join us for a combination trip between our La Alondra’i Lodge in the wetlands, and Itati Lodge on the shores of the Parana River.

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