Thu November 7, 2013
Earth Notes: Grand Canyon's Tiny Snail
Biologists have been putting in a big effort to protect a rare, tiny snail that lives beside the Colorado River in Grand Canyon.
The Kanab Ambersnail is named for one of the few places where it's found, near Kanab, Utah. The only other place where it lives in the wild is at Vasey's Paradise, a lush spring beside the Colorado.
Ambersnails love wet places like Vasey's, among watercress, monkey flower, sedge and cattails. They're holdovers from the last ice age. The snails adapted to the river's naturally varying seasonal flows by staying in the deep, moist vegetation above the historic high water line.
But, after Glen Canyon Dam was built in 1963, river levels were greatly reduced, and became more stable. The snails moved down into the newly exposed habitat and did fine. But when a new, experimental high flow was released from the dam, many of the snails were washed away.
Besides being very rare, the snails - about the size of a dime - are really hard to find. So, rather than physically removing every one before a planned "flood", Jeff Sorenson, with the Arizona Game and Fish Department, along with his "snail crew", took a different approach. They actually picked up whole mats of vegetation, snails and all, and moved them to higher ground.
Once the temporary "floods" went by, they put the snail habitat back in place - and in about 6 months, it had fully recovered.
Sorenson will continue monitoring ambersnail populations, and keep an eye on rising water.