Sy Montgomery - Amazon Adventure: How Tiny Fish Are Saving the World’s Largest Rainforest

A pair of blue and gold macaws.

But wait: Capturing and exporting wild animals from their natural habitat sounds like a terrible ideadoesnt it?

Our host, Scott Dowd, agrees. Thats exactly what I thought when I first came here, he explains from aboard the deck of our boat, the MV Dorinha. A big man with a silvery beard and twinkling blue eyes, Scott knows better now. Today he eagerly admits, I couldnt have been more wrong!

Scott vividly recalls his first trip up the Ro Negro. It was 1991. He was twenty-four years old, and he had teamed up with a prominent professor from the Federal University of Amazonas in Brazil, Dr. Ning Labbish Chao, to charter a boat with ten other fish enthusiasts. Thrilled to be in the green heart of the rainforest, Scott loved watching red and yellow macaws streak across the sky; he loved sleeping in a hammock on the boat at night and waking to the growling roars of howler monkeys in the morning. But mainly he came for the fish.

Today he is senior aquarist with the New England Aquarium in Boston, in charge of twelve thousand fish, frogs, snakes, and turtles in its Freshwater Gallery. Hes always been, as he puts it, a fish nerd. He started keeping fish tanks before he was ten. And, like just about any kid who keeps a freshwater fish tank, many of his first pet fish were species native to the tea-colored waters of the Ro Negro.

Scott Dowd, at home in the dark waters of the Rio Negro.

An adult dwarf pike cichlid.

The river water here is stained dark from tanninsnatural chemicals that come from plants whose leaves fall into these pure waters. The tannins make the water acidic. The waters are pristinebut its a hard place to make a living if youre a fish, Scott says. Adaptation to the difficult conditions here has sculpted beautiful and bizarre fish such as cardinal tetras, who glow in the dark with neon stripes of electric red and hyacinth blue; marbled hatchetfish, who can fly out of the water to escape predators; and splash tetras, who spawn on the wet undersides of overhanging tree leaves to keep their eggs safe (the male lurks below in the water for days and uses his fins to throw water up at the eggs to keep them moist). Scott could not wait to visit Barcelos, the town from which so many of the fish he had kept as a child and tended at the New England Aquarium had been shipped.

The rivers glassy surface reflects the trees and the sky.

But when his group finally arrived at the town, Scott was horrified. The riverfront was jammed with men in dugout and plank canoes. They had come from an area of rainforest the size of Pennsylvania, bringing hand-woven plastic-lined baskets full of living fish that would fill hundreds of eight-gallon tubs, each containing eight hundred fish. There were so many tubs that they covered the entire bottom floor of the eighty-foot ferry that was docked at the pier, readying to return to Manaus.

My knee-jerk reaction was, This is out of control! Scott remembers. I thought, we shouldnt be taking wildlife from the rainforest; we should be farming them!

But back then, he says, he didnt realize what would happen if the fishermen simply left these fish alone.

In the Amazon rainforest there are only two seasons: wet and dry. During the wet season, which corresponds to North Americas winter and spring, it rains every day and the forest floods. Trees stand up to their crowns in water. People build houses on stilts, or on pontoons so they can float. Kids dont take a bus to schoolthey take a boat. Then, in the dry season, during our summer and fall, the water level dropssometimes more than thirty feet. Nearly ninety percent of the small fish here are stranded, doomed in drying puddles.