We may not miss the phantom shiner, the thicktail chub, the stumptooth minnow or the harelip sucker, but these freshwater fishes are among 39 species (3.2 percent of North America's freshwater fish population) and 18 subspecies that have vanished from the continent's waters over the past century. By 2050 the tally could reach as high as 86, an extinction rate that is about 877 times higher than normal and that has accelerated in the past 20 years, according to a study in the September issue of BioScience. When so many fish disappear in a short period, “you know something's up,” says study author Noel M. Burkhead of the U.S. Geological Survey.

Many of the extinct freshwater fishes lived in the Great Lakes region and most likely died off because settlements and cities built on the lakes contributed to pollution, overfishing and the introduction of nonnative species that outcompeted them. As compared with saltwater and terrestrial animals, freshwater species are particularly vulnerable because many depend on small, local water bodies. “The numbers should be a wake-up call that we urgently need to apply freshwater conservation efforts,” says Marguerite A. Xenopoulos of Trent University in Ontario, who authored a 2005 study on freshwater fish extinctions but was not involved in the current research.

Scientists are still working to understand what impact these extinctions might have on other populations. Although they understand the dynamics of large ecosystems, ecologists cannot yet “predict what the loss of a certain organism would mean,” Burkhead says. These fish are “doing something beneficial. We just don't know what all those benefits are yet.”

COMMENT AT ScientificAmerican.com/nov2012

This article was originally published with the title Dead in the Water.

4 Comments

1. 1. CM doran 11:15 AM 11/9/12

   Is there any link to the decrease in populations and outbreaks of infection? I recently read this piece by a Univeristy of Michigan student--http://www.mindthesciencegap.org/2012/11/08/botulism-in-the-great-lakes-not-just-for-canned-foods-anymore/#comment-9807

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2. 2. NC10T 06:03 PM 11/9/12

   If we don't get off this AGW-for-funding nonsense and start working, full time, on how to clean up the 7,000,000,000 Bq/hr pouring out of 3 melted-down GE reactors at Fukushima-Daiichi 1, right under the Jet Stream and into the Pacific since 3/11/11, there aren't going to be any fish, crabs, or anything else in the radioactive Pacific Ocean no matter what perceived depth the sinking volcanic islanders are bitching about.
   
   The world's ecoscientists, in there little funded AGW cubes, sit and do nothing....just like the nuclear industry who are trying their best to get us to forget this horrible DISASTER that will NEVER go away!
   

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3. 3. geojellyroll 07:18 PM 11/9/12

   Yes, we should protect all species.
   
   However, the fish mentioned are marginal to 99.9% of Canada's freshwater lakes.
   
   According to the GSC there are 2.1 million lakes in Canada. 1.93 million don't even have names let alone any human popiulation bordering them, access, etc.
   
   Canadian waters are in good condition. So let's concentrate on protecting these species without making an issue 'in general' about the state of freshwater systems.

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4. 4. nburkhead 10:35 AM 11/13/12

   Regarding botulism and increased modern extinction rates in North American freshwater fishes, no fish extinctions have been attributed to botulism. Ninety-one percent of freshwater fish extinctions are due to habitat loss and effects of non-native fish introductions and another 7% are due to over-use (primarily over-fishing). The Great Lakes has lost eight native fishes, more than any other ecoregion in North America and the principal causes are habitat degradation (from pollution), overfishing, and non-native fishes. Fishes may be a vector of type E neurotoxin from the bacteria Clostridium botulinum, which is linked to bird mortality in Lake Erie. At this time no fish kills have been attributed to botulism. For more information on fish extinctions, see: http://fl.biology.usgs.gov/extinct_fishes/index.html. Noel Burkhead, U.S. Geological Survey, Gainesville, FL.

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