Sunday, March 22, 2009

Shell Shocked

This column was originally written in September 2008.

Our mission: upon locating North America’s largest species of turtle, pry it out from under the submerged logs and limestone caves on the bottom of frigid Spring Creek, taking great care to avoid its prominent jaws as we brought it to the surface. Easier said than done.

The alligator snapping turtle is found primarily in the southeastern United States in rivers and creeks that drain into the Gulf of Mexico. They can reach over 200 lbs, although they’re seldom that big. A beast of a turtle, they prowl creek bottoms searching for dead fish to eat. A turtle this size has few natural predators, patrolling its riverine hideaways with impunity. And yet, we almost lost it forever.

Close your eyes and picture a can of turtle soup. This is the closest that many people have ever gotten to an alligator snapping turtle. After decades of unregulated harvesting, populations of this species declined precipitously. Protections were recently put in place and these turtles have slowly started to rebound, but it’s a precarious recovery and populations are still vulnerable.

This species is a secretive and rarely studied animal; but John Jensen of the Georgia Department of Natural Resources is researching a population in southwest Georgia. By trapping for turtles over many years, he can estimate the size of the population based on how many individuals he recaptures. These efforts also provide baseline data necessary to monitor the population and determine if it’s stable.

Once a year, John supplements his normal trapping routine by inviting biology graduate students and his colleagues for a snorkeling trip in an attempt to root up some turtles that have eluded capture. We met early at the public boat ramp before the crowds arrived to cool off in the water. It was a large group this year, about 20 people. Some had brought their SCUBA gear; they knew what they were in for. I looked forlornly at my snorkel and wondered how long I could hold my breath while wrestling with a giant turtle.

After a brief introduction to our mission (the only reason we were able to handle these protected animals is because we were helping a state biologist), our fleet of kayaks and canoes slipped into the water and headed downstream to the study site. I was content to float along but others quickly donned their gear and submerged. I saw snorkels crisscrossing the creek and bubbles burst through the water’s surface as divers explored the depths.


It wasn’t long before I started seeing hands full of turtles thrust skywards as Barbour’s map turtles, yellow-bellied sliders, and river cooters were found. Although these weren’t the species that we were targeting, they still provided valuable information. One student even collected leeches for a parasite study.

As the morning waned, our flotilla dispersed widely. But suddenly I heard some news that had spread quickly among the trail of boats. One of the SCUBA divers had found a snapping turtle.

I muscled my kayak around and doubled back, paddling against the current until I reached a crowd of boats floating around a mass of giant logs and trees lying flush against the steep banks of Spring Creek. Apparently there was not one, but two giant alligator snapping turtles wedged in a submerged cave. A strategy had to be crafted, the turtles were too far back and in too tight to simply be dragged out. The divers submerged repeatedly with no success. Finally, from the depths came a massive turtle, firmly within the grasp of one of the intrepid biologists.

The beast’s massive jaws gaped menacingly, daring us to let a careless hand stray too closely. Water poured off its serrated shell, sufficient protection from any predator besides us. The turtle was carefully maneuvered to shore, where it was measured and marked for future identification. After a few photos, we allowed the 40 lb animal to slip back into the creek. In the excitement, the other turtle had given us the slip as well, and we didn’t catch another turtle on this trip.

When we reached the designated end of our survey, we were free to enjoy the scenery. At our start point, Spring Creek is small and almost completely shaded by overhanging trees. But as we flow south the water flow becomes increasingly influenced by Lake Seminole. The creek opens up widely and marshy areas are more common. Good habitat for alligators, not so great for snorkeling.

Despite our day-long effort, the miles we covered, and all the seasoned turtle biologists on the trip, we caught sight of only two alligator snappers. We have no way of knowing how many we missed, surely there are more prowling the depths. But our efforts indicate how the loss of only a few individuals may resonate within a creek.

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