Park curator Adriean Mayor with the new biohazard cabinet at Twin Creeks Science Center.
New biohazard cabinet protects scientists from disease
This spring, researchers at the Twin Creeks Science Center added a new science tool to their supplies: a biohazard cabinet. The cabinet is a 600 pound, glass-sided case that can attach to a hood (a vent that carries away, purifies the air, and releases it outside). Researchers will use it when they find animals in the Park that they need to dissect or inspect; the cabinet is specially designed to protect them from any zoonotic (animal-spread) diseases. Wildlife here can pass rabies, pseudorabies, hantavirus, Rocky Mountain Spotted Fever (via ticks) and other diseases on to people and their pets.
Freezes, fire, & worms: research on new possibilities for managing invasive earthworms
Jimmy Blackmon and Paul Hendrix of the University of Georgia have completed research in two studies in the Park on the biology of invasive earthworms. The Chinese Jumping Worm (Amynthas agrestis) is a common bait worm sold at sporting goods stores, and raised in large commercial worm farms throughout the southeast. It comes into the Park’s forests when anglers release their unused bait (which is prohibited within the Park’s boundaries). These worms devour leaf litter at a very fast rate, and in much larger quantities, than native worms, millipedes, and other decomposers do, stripping the forest floor of essential duff (decaying plant and leaf matter) layers. Since the introduction of the invasive Jumping Worm, native worms and millipedes have died off at alarming rates. Park managers need to find a way to control the worm, and to figure out how it spreads in a climate that is much colder than the one in which they evolved.
To answer these questions, researchers measured the effect that cold temperatures had on worm hatching rates, and the effect that fire had on worm survival. They expected that worm hatching rates would be much lower with colder temperatures (below 10 degrees C, or about 50 degrees), since the worms came from subtropical parts of the globe. However, this cool temperature proved to be the optimal hatching climate, indicating that the spread of worms through the Smokies could happen more quickly than scientists initially thought and also that this worm may not actually be from the subtropics, but rather from cooler parts of Asia.
Another project used soil scorching—similar to what forests would experience during lightning or controlled burns—to measure the impact of fire on these invasive earthworms. While there was no decrease in worms at first (the worms dug deeper down to protect themselves), over time many did die, probably from starvation. This tells managers that fire is an effective way to control invasive worms, because it limits their food supply. What effect it has on native animals that depend on that same food supply needs further investigation. It may be that millipedes and native worms have evolved to deal with regular, low intensity fires, because these were a regular part of Smoky Mountain ecology before humans began suppressing fires.
Return to Resource Roundup: April-May, 2009.