Did you know?

Did you know that freshwater occupies less than 1% of the earth's surface? And did you also know that such a limited freshwater surface area is home to almost half of the world's 30,000 known species of fish? And most importantly, did you know that 39% of North American freshwater fish are in danger? That's nearly twice as many as 20 years ago!

Wow.. so what do we do?!

Well those are the facts, and some people are trying to do something about it. Freshwater streams and rivers are threatened by human activities including....

• industrial pollution
• agricultural runoff
• alien species introductions
• alterations of stream flows

The article Silent Streams from the April 2010 issue of National Geographic outlines the efforts of a group of biologists to preserve threatened species of marine life using a technique called captive propagation. Conservation Fisheries Inc. (CFI) identifies threatened species of freshwater marine life with the help of other interested organizations. Once the species are identified, CFI collects and then preserves as many fish as possible in large glass aquariums housed in Knoxville, Tennessee. Once a stream or creek is deemed clean enough, preserved fish are reintroduced in the hopes that they will now be able to thrive in a more hospitable habitat.

On our way to solving the problem..

While the ideal solution would be to clean up polluted water ways before species are threatened, frequently time does not allow this to happen. With the proper use of captive propagation and translocation, some species have been saved who likely would now be extinct!

One example of successful use of this technique is found in Abrams Creek in Tennessee. In an article published in Southeastern Naturalist, J.R. Shute and colleagues report the successful reintroduction of four threatened fishes to Abrams Creek (pictured above). In a project which began in 1986, by the year 2000 there was evidence of reproduction of all four species! By 2003, three of the four showed increasing populations, and two had numbers comparable to native populations in nearby unpolluted creeks.

While the Abrams Creek project is a success story, a number of similar programs have been met with failure. As the science has evolved and experience has been gained, guidelines have now been established for propagation of threatened species of fish. In an article published in 2009 in Fisheries, Anna George and her colleagues have published a set of guidelines for propagation, translocation, reintroduction, and augmentation (PTRA) of at risk marine life. She writes that when such guidelines are followed, PTRA is an important management tool for recovery of imperiled fish.

So what...?

Some of the threatened fishes in the Southeastern United States are displayed on my blog. Though most of their names have never been heard of before now, it is clear to me that protecting species and maintaining biodiversity is an important issue for my generation. While the ultimate solution is reducing pollution and cleaning up damaged waters, PTRA is a proven and successful stop-gap measure to save species while the long term solution is being implemented.

Works Cited

Main National Geographic Article

Chadwick, Doug. "Silent Streams." National Geographic. April 2010: 117-127. Print.

Supporting Articles

George, Anna L. "Guidelines for Propagation and Translocation for Freshwater Fish Conservation." Fisheries. 34. (2009): 529-545. Print.

Shute, J.R. "Reintroduction of Four Imperiled Fishes in Abrams Creek Tennessee." Southeastern Naturalist. 4.1 (2005): 93-110. Print.

Pictures courtesy of:

http://ngm.nationalgeographic.com/2010/04/freshwater-species/chadwick-text

conservationfisheries.org