The Night Watchman
Phil Allman explains why Ghana's turtles are so endangered
Editor's Note: This story complements a spring 2007 Ohio Today magazine story. Allman, who earned his doctorate at Ohio University last year, spent a year in Ghana studying and tracking turtles thanks to a Fulbright grant.
By David ForsterWherever they go, sea turtles today face multiple threats that have decimated their populations. The U.S. government lists six of the seven species as endangered and the other as threatened.
One of the biggest threats to sea turtles is fishing. Big commercial fishing vessels often use drag nets or gill nets that may stretch for miles or long-lines from which hundreds or thousands of baited hooks dangle. These operators are after other catch, but the turtles get tangled in the nets or snagged on the hooks. It's not just big ventures that are a problem: Family fishing operations that use the same tools, just on a smaller scale and closer to shore, far outnumber the commercial vessels and pose just as much danger to the turtles.
Deliberate hunting of sea turtles is another major threat. It's a reasonable assumption that humans always have hunted turtles for their meat or shells, or raided their nests for eggs, but until the last century, this was done largely to satisfy local needs. There now is global demand for turtle meat, shells and other body parts. Hunting sea turtles is illegal in Ghana, but there is little enforcement, Allman says.
The two wildlife officers stationed in Ada Foah have a lot of ground to cover, and protecting sea turtles means working through the night on top of their daytime duties. Poachers around Ada Foah target the olive ridleys because they're easier to handle than the massive leatherbacks.
Sadly, Allman finds more tracks made by turtles that are flipped on their backs and dragged away than by turtles that made a successful nesting run. Sea turtles also face a host of environmental perils, particularly loss of nesting habitat. The growth of beachfront developments around the world is one issue. Such properties often include privacy or retaining walls that enclose part of the beach, keeping the female turtles from reaching dry sand. If they deposit their clutches below the high-tide line, the scouring of waves can unearth the eggs and wash them out to sea or expose them to predators.
"The amount of beach acceptable to sea turtles for nesting dramatically decreased over the last 30 years," Allman says. When baby sea turtles hatch, instinct tells them to head for the brightest horizon, which until recently has been the natural light of the moon and stars reflecting off the waves. On developed beaches, the brightest light may instead be coming from a condominium, tennis court or parking lot. Hatchlings headed the wrong direction face may get run over by a car or eaten by an animal, or they may simply dry out and die in the heat of day before they find the ocean.
Once researchers plot the where and when of turtle migration, they can develop tailored conservation plans narrow enough that businesses will accept the cost or inconvenience of compliance. "If we know where they are and when they're going to be there, we can focus our energy at that location at that point in time," Allman says.
For example, fishing operations can be asked to steer clear of an area when a sea turtle population is expected to pass through, or beachfront properties can dim or screen their lights during the nesting season.
David Forster is a freelance writer for Ohio Today.
Phil Allman's blog:
More information on Phil Allman's work: Posted 05-09-07