ENVIRONMENTAL NEWS NETWORK (USA) 30 May 03 The hellbender's swaggering name belies its delicate nature (Ken Burton)
The Hellbender salamander — the largest in North America — is declining in Arkansas and Missouri, and a team of biologists is determined to unravel the mystery before the 2.5-foot-long amphibian requires listing as a threatened species.
By definition, a hellbender is both reckless and extreme, but a subspecies of the largest salamander in North America, called hellbender, is neither. But it's faced with a somewhat reckless, extreme — and sudden — decline in its population, and that has biologists concerned.
This subspecies of hellbender — one of two that inhabits the United States — is native to the Ozarks of Arkansas and Missouri. Unlike common salamanders, these grow to 2.5 feet in length and spend their entire lives in the heavily oxygenated water that is normally found in cool, higher-elevation mountain streams.
Hellbenders breathe through their skin, which is highly permeable. Unfortunately for them, that also means they will absorb any pollutants. Pollution and sedimentation are suspected factors in the species' decline, since both also substantially reduce the oxygen level in the water. But precisely pinpointing what is to blame is a tedious process.
Susan Rogers, who works in the U.S. Fish and Wildlife Service ecological services field office in Conway, Ark., said the three river systems that harbor the hellbender salamander — the Spring, White, and Eleven Point rivers — also are home to a lot of freshwater mussels, and those species seem to be having their own population problems. Freshwater mussels are nature's water filters, but if they are filtering toxins at too high a level, the mussels can die.
"The big question for our working group at the moment is what's causing the population crash — for certain — of the hellbender," said Rogers. "These are animals that are highly sensitive to environmental stress."
The working group is an impressive one: Besides five staffers from the Fish and Wildlife Service, it includes representatives from the Missouri Department of Conservation, Arkansas State University, the University of Missouri, the St. Louis Zoo, the Arkansas Game and Fish Commission, Ozark Scenic Riverways, Southwest Missouri State University, and the Mammoth Spring National Fish Hatchery in Mammoth Spring, Ark.
Large committees can frequently be their own worst enemy, imploding because of sheer size. But the working group assembled to unravel the hellbender puzzle, which has 20 members, has demonstrated that old adages are not always true.
"This group of partners has really taken off," said Rogers. "I think we're all really pleased with how well the work has gone. This is a smooth operation. It's a model for what we can accomplish when we invite our friends over."
Irwin Kelly, a herpetologist with the Arkansas Game and Fish Commission in Benton, Ark., is optimistic about "getting ahead of the game." Kelly, a member of the working group, said the plan is to try to pre-empt the necessity of listing the hellbender as a threatened or endangered species. "We're just starting to scratch the surface," said Kelly.
That's the kind of collaboration that draws warm praise from U.S. Fish and Wildlife Service Director Steve Williams. "When I see our people putting together partnerships like this one, I know we can't lose," Williams said. "These kinds of relationships are so important and so fundamental to our work. It means giving a voice to the states and to local people who frequently have special insights into their area ecosystems. Their help is invaluable."
The fish hatchery at Mammoth Spring has become an important link in the work, providing a place for the salamander to breed in captivity, a process that so far has been successful, holding great promise for eventual reintroduction. But there are only two hellbenders in residence, and biologists want to learn more about what changes might be taking place in their systems that could be disrupting reproduction. The big salamanders have been known to live up to 55 years in captivity.
Hellbenders thrive in clean, cool streams with rocky bottoms and fast-flowing rapids, the kind of high-oxygen river systems that have always been a hallmark of the Ozark Mountains of southern Missouri and northern Arkansas. For the most part, the waterways are still like that, but the fact that the hellbenders are having difficulties means something has changed.
Female hellbenders lay several hundred ping-pong-ball-sized eggs that are guarded by the male until they hatch. All hellbenders have flat bodies and heads; large, flat tails; and tiny eyes. Nature has given them perfect camouflage: dull brown or gray to bright orange or red. They are extremely slimy, making them difficult to handle, although the slime is not toxic.
"We're going to make headway on this," said Rogers. "Our working group is one of the best. You keep running tests, looking at blood samples, watching their reproductive habits, and peeling away another layer of the onion, one mystery at a time. Eventually, we're going to know what's at the bottom of the hellbenders' problem. It's just a matter of time."
Hellbender's swaggering name belies its delicate nature