It begins as a tiny trickle of melting glacial ice high in the Andes; making its way down the 18,363 foot tall Nevado Mismi deep inside Peru near the town of Arequipa. Some 75 miles downstream, at an elevation of 12,000 feet, it is joined by one of over 500 tributaries, the Apurimac River flowing milky turquoise due to pollutants, principally mercury, dumped into it by gold and silver mining operations. The expanding river continues is northerly flow toward Iquitos, Peru, where it is joined by the Rio Marañón, the Ene´, the Tambo, and the Rio Ucayali.
At Iquitos, the rapidly growing river turns to the East, where it is joined by the Rio Napo from Ecuador, and crosses into the state of Amazonas in Brazil. Now known as the Solimões River, it travels on for another 1,200 miles before reaching Manaus, Brazil, where it is joined by the Rio Negro, the ‘Black River’. Although actually more the color of strong tea due to the concentration of acid from decaying plant life entering the river as the Negro flows out of the mountains of Columbia, the confluence of the Solimões and the Negro is distinct. The muddy reddish waters of the Solimões and the black waters of the Negro do not mix immediately, instead, the expanding river, which becomes the great Amazon River at Manaus, flow side by side; the two colors visible from the air as well as from land and boat.
Before reaching the Atlantic Ocean, the Amazon is joined by approximately 500 additional rivers with headwaters in Bolivia, Columbia, Guyana, Peru, Suriname, Venezuela, northern-most Brazil, and Ecuador. Among these 500 tributaries the Tapajos River, which joins the Amazon at Santarem half-way between Manaus and the Atlantic, is, as many of the other tributaries, highly contaminated with mercury as well as other dangerous and potentially deadly pollutants.
About one million miners work along the banks of the Rio Tapajos, using mercury to remove the gold. During testing, scientists found high mercury levels in every fish pulled from the river, in all the river sediment, and in the tissues and hair of everyone living along the Tapajos. According to Dr. Donna Megler from the Institute of Science and Environment at the University of Quebec in Montreal, studies she conducted seem to indicate the contamination did not come solely from mining.
The Amazon River Basin covers more than 44% of the total land mass in South America and within the Basin lies the Amazon Rainforest which covers about one billion acres. A hectare (2.471 acres) of undisturbed rainforest contains an average of 750 species of trees, over 1,500 species of plants, and untold birds, reptiles, insects, and mammals. One in ten of the world’s known species of plants, animals, birds, and insects live in the Amazon Rainforest and cannot be found anywhere else on earth.
The Amazon Rainforest produces 20% of the world’s oxygen. The Amazon River carries approximately 20% of the world’s freshwater. Over 120 prescription drugs used worldwide are derived from plants found in tropical rainforests. The U.S. National Cancer Institute has found 3,000 rainforest plants with some cancer fighting properties. And yet, only about 1% of the plants found in the Amazon have been tested for medicinal properties even though the indigenous peoples of the Amazon are known to successfully use over 2,000 forest plants for various infections and diseases.
The Amazon River, running through the heart of the Amazon Rainforest is the longest river in the world with a total length of over 4,000 miles. In addition to being the longest, it is also the widest and the deepest; ranging from seven to 28 miles wide during the rainy season with an average depth of 131 feet.
When the Amazon River reaches the Atlantic Ocean it spews forth between 200,000 and 300,000 cubic meters of freshwater per second—per second!, making the Amazon’s outflow more than the combined total of the next nine largest rivers in the world. The force behind that outflow carries the freshwater many miles out to sea, by some estimates almost 200 miles out. It has been said that the force behind this fresh water discharge and the speed at which it flows forth will allow one to dip a cup of fresh water from the Atlantic over 100 miles to sea.
Why anyone would consider drinking the Amazon’s water, or bathing, or swimming in it is beyond imagination. Mercury contamination in the Rio Tapajos is not thought to come from mining activities so much as it comes from deforestation. Logging, slash and burn agriculture, and scouring the land bare for mining has released mercury filtered out of the air by trees and long held within the ground. Without cover and roots to anchor the land, it is washed away and eventually ends up in the Amazon River.
To date, 20% of the Amazon Rainforest has been lost to deforestation. The Amazon River Basin I flew over in 1966, just as the sun rose at the mouth of that mighty river, no longer exists. From August, 2007, to August, 2008, over 3,200 square miles of forest was cleared…2,048,000 acres; 828,815 hectares; approximately 621,610,683 trees (using the average of 750 species of trees per hectare); approximately 1,243,222,500 plants; and countless birds, mammals, insects, and invertebrates.
What does the loss of the Amazon Rainforest and the pollution and sedimentation in the Amazon River have to do with Central America, the Caribbean Islands, the Florida Keys, and the Eastern Atlantic? In addition to the loss of millions of carbon monoxide-cleaning, oxygen-producing plants, the pollution sent forth by the Amazon River does not stay in Brazilian waters.
The Caribbean Current picks up along the horn of Brazil, south of the Amazon’s mouth and that current flows past Central America, through the Caribbean, and into the Straits of Florida past which it flows toward the Gulf Stream.
How much sediment with beginnings in the Peruvian Andes, how much mercury from deforestation and mining in the Amazon, what quantities of what other dangerous chemicals are traveling on ocean currents to places far and wide—killing reefs, contaminating seafood, and tainting water?
After 30 years as a wild and domestic animal rescuer, rehabber, and educator in the states, Becky Bauer became a scuba instructor and award-winning journalist covering the marine environment in the Caribbean. She is a contributing photographer to NOAA.