There's absolutely nothing cooler than big fish. Of course, being of the ichthyological persuasion, I might be biased. But I think a lot of people would agree with me. And there's something particularly magical about big FRESHWATER fish. Sure, bluefin tuna, blue marlin, and great white sharks can be huge. But they're way out THERE. A 12 foot fish in your local river is something else entirely.

That's one reason the news reported yesterday at ScientificAmerican.com is especially sad. Two of the world's largest freshwater fish are in danger of extinction. Shocker, right? The Kootenai River population of white sturgeon (Acipenser transmontanus), reported to reach lengths of 18 feet and weigh a half ton, has dwindled from an estimated population of 10,000 in the 1970s to some 500 today. You probably wouldn't be that surprised by the cause of this decline either. Freshwater river living in rivers, declining in numbers in the last century? You can generally bet "dam", and you won't be wrong very often. Libby Dam, built in 1975, impounds the Kootenai and creates Lake Koocanusa, which extends some 90 miles up the river basin behind the dam. The impoundment prevents the periodic flooding, which served as a spawning signal for the river's sturgeon. As a result, the Kootenai white sturgeon have not spawned in the wild for 35 years.
Wildlife biologists are not giving up, and are spearheading a drive to save the sturgeon by opening the floodgates to increase river flow at key times. The Fish and Wildlife Service reports that, thus far, these efforts have been unsuccessful.

The Neotropics have (had?) their own, equally impressive giant, the Amazonian arapaima (Arapaima gigas). The arapaima, also known locally as the piraracu, is the world's largest scaled fish, reaching lengths of over 8 feet (it should be noted that a single, unverified report indicates a maximum size of over 12 feet). Recent museum studies suggest that the arapaima is not a single species, but actually four unique types of fish. This has led to the fear that one or more species may already be gone. The problem for the arapaima is not river impoundment, but overfishing. It is a prized food fish in South America, and its air-breathing habits make it particularly vulnerable to a variety of fishing techniques.
Wanna see the arapaima in action? Sure you do...