Fresh water sharks haunt Nicaraguan lake


SOLENTINAME ARCHIPELAGO, Nicaragua -- From the depths of Lake Nicaragua comes a fish story to rival 'The Old Man and the Sea' and the legend of Moby Dick.

Lake residents -- everyone from wizened old fishermen to housewives who wash clothes on the shore -- insist that deep down in these murky brown waters are man-eating sharks.


'You used to see a dozen an hour,' said Mariano Roblero, who operates a tour boat from the lake port city of Granada. 'You could see their fins. Sometimes they would even upset the boats.'

Unlike most fishing lore, such accounts actually check out. For years, scientists have maintained that Lake Nicaragua is the only fresh water lake in the world with sharks.

The evidence dates back to 1526 when the Spanish explorer Gonzalo Fernandez de Oviedo wrote of Nicaragua's freshwater sharks. They also impressed E.G. Squire, the first U.S envoy to Nicaragua.

'Sharks abound in the lake. They are called 'Tigrones' for their rapacity...Instances are known of their having attacked and killed bathers within a stone's throw of the beach at Granada,' Squier wrote in 1852.

At first, experts explained the phenomenon by saying Lake Nicaragua used to form part of the Pacific Ocean and became land locked through a series of volcanic eruptions. Sharks and other marine life, they said, adapted as the water lost its salt content.


But after a decade of research,including an extensive tagging program, American zoologist Thomas B. Thorson determined that bull sharks in search of food make their way into the lake through the San Juan river, which connects Lake Nicaragua with the Atlantic Ocean.

While no fully freshwater sharks are known, the bull shark is a ferocious and versatile predator capable of functioning either in fresh or salt water, Thorson wrote in a 1966 study titled 'The Status of the Freshwater Shark in Lake Nicaragua.'

Bull sharks can reach 10 feet in length and and weigh up to 400 pounds. Other sea creatures in the lake include snook, tarpin and sawfish, which reach weights of 1,000 pounds.

Several hotels and restaurants on the lake display moldy sets of shark jaws and three-foot-long sawfish bills spiked with 32 teeth.

Documented shark attack on humans are rare but stories abound. Years ago, lake residents used to blame sharks whenever bathers were reported missing. That prompted authorities in Granada to place a bounty on sharks.

Bosco Centeno, who lives on the Solentiname Archipelago, an island chain at the south end of the lake, claims one swimmer lost his foot in a shark attack and later died of gangrene.


In the 1950s and 1960s, commercial fishermen netted thousands of sharks and sawfish at the mouth of the San Juan River.

Enrique Sandino, who managed a fish processing plant in Granada in the 1970s, remembers selling shark steaks for nine cents a pound. More profitable was the export of the dorsal and tail fins to Japan, where they are prized as an aphrodisiac.

But heavy fishing appears to have decimated the shark and sawfish population. Few have been hooked or netted over the past decade though a large sawfish was caught last year during a fishing contest off the Solentiname islands.

Motoring his 25-foot wood 'panga' near the islands, veteran fisherman Cesar Garcia recently set out to land a freshwater shark to convince his skeptical passengers.

He began by digging up clams and catching a few small bait fish. He bloodied one of the fish with machete cuts and skewered it with a six- inch barbed hook that was attached to 30 feet of cable.

As waves rocked the boat, Garcia trolled and talked of past fishing glories and the lake's history.

During the California gold rush in the 1850s, Americans en route to the west coast were ferried up the San Juan river and across Lake Nicaragua to the Pacific Ocean by Cornelius Vanderbilt's Accessory Transit Company.


The route was later considered for a trans-isthmus canal but, due to the many volcanoes in the region, U.S. legislators chose Panama.

Now, the lake's main attraction is an artist's colony on the Solentiname islands, which was founded by Ernesto Cardenal, a poet, priest and culture minister under the former Sandinista government.

The sharks, in turn, draw scientists such as Thorson and French oceanographer Jacques Cousteau, who studied the fish for his popular TV series.

Some say the bull shark could eventually disappear from the lake altogether, but Thorson writes that the river connection to the Atlantic assures their survival.

Meanwhile, although Garcia pulled in his line without so much as a nibble he and many other fishermen remain convinced the sharks are still down there.

'Nature is infinite,' said Manuel Perez, a bearded man who fishes near Granada. 'There are some things that you can't see and can't know but that you just go after.'

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