Millions of Dead Fish Poison Bolivian Drinking Water
Image credit: psyberartist/Flickr
In the northern hemisphere, the winter of 2010 was notable for its unpredictability and extreme conditions. From East Coast blizzards to a devastating cold snap in Florida, cities struggled to to keep pace and entire ecosystems hovered on the brink of collapse.
Now, as winter wears on in the Southern Hemisphere, Bolivia is reeling from uncharacteristically cold weather that is clearing entire watersheds of life.Bolivian rivers that normally run around 59 degrees Fahrenheit this time of year have dropped below 39 degrees Fahrenheit. This 20 degree drop has been enough to kill an astonishing number of fish and other wildlife.
Already, an estimated six million fish have died. Michel Jégu, a researcher from the Institute for Developmental Research in Marseilles, France, commented that:
There's just a huge number of dead fish...in the rivers near Santa Cruz there's about 1,000 dead fish for every 100 metres of river.
The exceptional quantity of dead and decomposing fish in the rivers has tainted the water supplies of several Bolivian towns and completely destroyed the livelihoods of fisherman living in the area. With bans now in place to protect the small populations of fish that remain, the economic recovery will be slow even after temperatures begin to warm.
Cause of the Cold
The cold snap has, at least in part, been attributed to a mass of Antarctic cold air that has settled over the southern tip of the continent. The same cold air has also been linked to the deaths of more than 500 penguins off the coast of Brazil.
Fish, in particular, are very susceptible to cold shock—sudden influxes of dramatically cooler water—but large-scale die offs are rarely caused by a single stressor. In Bolivia, fish have been found with unusual white spots that may be indicators of a disease.
Michel Jégu believes that the burning of forests upriver may have released pollutants into the water that is contributing to the deaths.
Regardless of the contributing factors, officials in Bolivia are now scrambling to save the fragile populations before the ecosystems collapse completely.
Read more about cold snaps:
Florida Cold Snap Killing Hundreds of Manatees
Florida Cold Snap Devastating Coral and Marine Life
2,000 Endangered Sea Turtles Killed or Injured by Frigid Waters in Florida (Photos)