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Rio Grande

The Rio Grande in Tierra del Fuego is one of the great trout rivers of Argentina. In this large and windswept river you can catch some of the largest sea run brown trout in the world.

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The prize
Rio Grande prize
Federico Prato

The Rio Grande flows East from the Chilean Andes through the Island of Tierra del Fuego to the Atlantic Ocean into the estuary next to the City of Rio Grande in Argentina. It meanders slowly (1% gradient) for about 120 kilometers through the Patagonian steppes; the average flow is about 40 cubic meters per second. The bed of the rivers is shale, cobbles and pebbles and easy to wade.

As in all Patagonia

, trout of several species were introduced by settlers in the early 20th century.

Though numerous attempts

have been heard of, as far back as the late 19th century when trout were sown in the Chilean mountain streams of Tierra del Fuego, possibly including the head waters of the Rio Grande, the earliest recorded seedings were undertaken by sheep ranch manager John Goodall in the mid1930's. With eggs brought from Chile he hatched and reared Browns (Salmo trutta), Rainbows (onchoryincus mykiss) and Atlantic Salmon (Salmo salar). Today Brown Trout, both resident and anadromous, dominate the fish population of the Rio Grande. Though not documented it is said that the Chilean Brown Trout were originally brought from Germany.

Colored
Scarred female
3.5 kilos or 7 lbs sea trout
Pelle
Sea trout
Pedro Alfredo Miles

These fish thrived

in the river and its tributaries and it is presumed that the healthy growth of the population affected the availability of food and brought about their migration to the sea, where the large and shallow estuary offers the food they could not find in the river, principally the abundant Fuegian Sprat or Sardine (Spattus fuegensis) and the salt water Silverside (Odontesthes regia). These sea trout do not travel far into the ocean but remain close to the coast where the notably productive southern Patagonian shelf provides ample nourishment.

Recovering
Away it goes!
One more
Catch and release
Pedro Alfredo Miles - Federico Prato

In the late spring

(November) they start moving into the river in schools to start their annual migration to their spawning waters. This migration continues throughout summer. I am told that in large numbers they hold in fresh water pools close to the sea to work out the salt in their systems, process which involves something like calisthenics and a rumbling sound.

The first reports

of sea run browns in the Rio Grande date from the mid 1950's, 20 years after their introduction.

The author
The author
Federico Prato

The Rio Grande

and tributaries (Menendez, MacLennan, Rasmussen, etc.) flow through privately owned sheep farms, of great extensions due to their low productivity. Good management on behalf of the owners and operators of the Lodges on the river with a strict catch and release policy with little mortality and a low human population density have ensured the continued success of the Rio Grande as one of the best places in the world for fishing sea run Brown trout with about 6,000 fish caught and released annually as registered by the lodges on the river.

Additionally

human impact, such as dams, roads, bridges and pollution, is virtually nonexistent. Today it is estimated that more than 50,000 browns migrate up river each year to spawn making it the largest sea run Brown Trout population in the world.
They migrate to the sea at about two years of age and have a high rate of return to spawn. Trout of up to 13 years of age that have spawned 6 times have been caught on the river.
These Browns are generally longer than their anadromous European cousins as they can measure up to 1.20 meters as against about .90 meters in Europe.

Though they do not

feed during their stay in the river, they take a fly vigorously and are not leader shy. A wide variety of flies are used on the Rio Grande, from small nymphs, Jumbo John, Bitch Creek, Scuds to Wooly Buggers, streamers and Leeches. At times dry flies can be used, the green machine and it's variations, attractors, etc. Guides will have proven flies on hand. During a study undertaken by U.S. scientists, non fatal Stomach lavage of resident trout produced scud (Hyalella patagonica), snails as well as caddis, stone, mayflies, chironomids, other insect nymphs and terrestrials, and fish remains. Lavage of sea run brown stomachs showed mostly empty digestive tracts, a few had some scuds.

Guanacos
This rio is grande
Fighting the wind
The landscape
Pedro Alfredo Miles

The river and weather

conditions are ideal for two handed rods as in most spots long casts are required with weighted flies and it can be very windy.

I have fished

the Rio Grande both up and downstream of where the Menendez River joins the Grande, and found that the Lodges are experienced, well run with knowledgeable guides, some of which guide in the northern hemisphere during our winter. The sections of the river they operate are long, about 10 to 15 kilometers with numerous productive pools and runs. Anglers are driven to the assigned area in the morning (two anglers per guide and vehicle with a hamper with soft drinks, warm coffee and snacks) which is fished until lunchtime. After lunch at the lodge, a rest and then drive to a different spot to fish until dusk. Assigned areas are changed twice daily to ensure that all anglers have the opportunity to fish those places that during the week have proven most productive.

Small fish
Bitch Creek
Slightly colored
Fish and fly
Pedro Alfredo Miles

I use

a Spey 14' #9 rod with a 650 grain Skagit head with interchangeable floating and fast sinking lines. The guides will recommend the length of the leader according to gear and conditions. A spool of tippet material (12/13 lb test) is necessary. The Lodge will usually have a supply of proven flies for sale. As with nymphs and streamers, non slip loop knots are what are most used to join tippet and fly.

In view of its latitude

(54º S) summer days on the Rio Grande are long. The water is cold (9 to 12º Celsius) so suitable clothing is a must, long-johns under waders and a waterproof parka and hood. Gloves and dark glasses are also necessary. On occasion have fished in shirtsleeves, but this is not usual.

The best take

I had on the Rio Grande was at dusk. At the time was using a single handed # 8 rod with a shooting taper and a black bunny strip streamer. I managed to see the fish as it leaped out of the water and in no time was into my backing. My guide guesstimated that it was over 20 pounds, it felt as much and more, the rod felt puny as a toothpick. By the time I managed to stumble out of the water it was already dark, and trying to recover line chasing along the bank I fell and lost control of the rod. The line cut and I was left without the catch of a lifetime.
I caught several fish daily, the attached photographs show some of the more notable of them, including fresh arrivals from the sea and fish that had been in the river for some time and had started to acquire their characteristic coloring.

There are daily flights

from Buenos Aires to Rio Grande and the lodges are up to a one hour drive from the airport. Generally arrival is early on a Saturday in time to start fishing in the mid morning, Fish until Friday and on Saturday morning back to the airport for the flight home.

Cityscape
Windswept trees
Surroundings
Pedro Alfredo Miles

Links

www.nervouswaters.com
www.maribety.com.ar
www.despedidalodge.wix.com

References

Sarah L. O'Neal and Jack. A. Stanford, Flat Lake Biological Station, University of Montana, USA. "Partial migration in a robust Brown Trout population of a Patagonian river".

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