This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American
A funny thing happened on the way to the endangered species list.
Five years ago the Center for Biological Diversity (CBD) petitioned to protect an Appalachian crayfish species under the U.S. Endangered Species Act. This week the U.S. Fish and Wildlife Service (FWS) concurred and agreed that the Big Sandy crayfish of Kentucky, Virginia and West Virginia probably deserves that protection.
But the CBD actually got more than they asked for. Shortly after they submitted their petition new evidence emerged that the Big Sandy crayfish is actually two different species.
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Oh yeah, and they’re both endangered. And the FWS is proposing to protect them both.
Here’s what happened. What is now called the Big Sandy crayfish was first described 101 years ago from a specimen collected in West Virginia’s Upper Guyandotte Basin. Scientists renamed and re-described the crayfish a few times over the years but by 1969 they finally settled on the taxonomic name of Cambarus veteranus.
Flash forward to 1989. That’s when C. veteranus was also located in the tributaries of the Big Sandy Basin, which includes all three states. It was only then that the name Big Sandy crayfish was attached to the taxonomic name.
But wait, there’s more. In 2011 researchers conducted genetic tests on the crayfishes in the Upper Guyandotte and Big Sandy basins. The crayfish in Big Sandy not only had different DNA, they also had at least four major morphological differences from the crays in Guyandotte.
And so we ended up with two species. The crayfish in Big Sandy got a new taxonomic designation (C. callainus) while keeping the common name. The newly discovered species was dubbed the Guyandotte River crayfish, and retained the old C. veteranus designation in deference to the original 1914 samples.
Okay, so now that we have two species instead of one, something else has emerged. The Big Sandy crayfish is probably endangered but the Guyandotte River crayfish is likely critically endangered—it only exists at a single site in West Virginia.
What’s killing these little guys off? Well, the CBD places the blame pretty heavily on pollution from mountaintop-removal coal mining. In a prepared statement CBD senior scientist Tierra Curry called the proposal to protect the two crayfishes “historic,” noting that “these are the first species to be proposed for protection under the Endangered Species Act because of harm caused by mountaintop-removal coal mining.”
FWS considers the threats to be a bit broader. They agree that coal mining is a major threat—the shell of the crayfish in the photo accompanying this article is embedded with manganese and iron from coal-mining runoff—but they also cite ongoing erosion and sedimentation in the crayfish streams. They link these problems to the timber industry in the first half of the last century and ongoing development today.
It’s not just crayfishes that have suffered in the process. FWS cites numerous state agency reports that found the waterways in which the crayfishes swim violate all kinds of water safety and health standards—they contain feces, bacteria, selenium, Escherichia coli and chemical contaminants. At least one stream contains fishes that aren’t safe for human consumption, and you probably wouldn’t want to swim in all that many others. The reports link all of this to coal mining, urban runoff and related factors.
Water quality in particular seems to be correlated with the crash in Guyandotte River crayfish populations over the past few years. In addition to pollution the river had also been highly channelized, making it easier for boats to pass through by removing the boulders and other large rocks under which crayfish like to hide.
In a prepared statement, FWS Southeast Regional Director Cindy Dohner said “we are concerned about the future of both species. We base our decisions on the best available science, so we are asking people who may have information about the condition of these crayfishes to contact us to help us make the right decision about their status.”
FWS will now collect data and comments from the public through June 8, after which they will make a final decision on the fate of these two crayfishes. Hopefully the final results won’t contain any additional surprises.
Photo: Zachary Loughman, West Liberty University, courtesy of the U.S. Fish and Wildlife Service