Posted by Bryan Wallace | 09.14.2011
Originally posted on Conservation International’s blog
Throughout September, CI is bringing you stories about sea turtles and their conservation. Check out the Sea Turtle September website, see our blog post about a surprising new home for hawksbill turtles, and be sure to follow the #SeaTurtleSeptember hashtag on Twitter for breaking sea turtle news!
Imagine that you are a sea turtle. By your nature, you live life in the slow lane. You aren’t a very fast swimmer. When you are on land, you awkwardly heave and drag your body over sand beaches for hours while laying your eggs. You grow slowly, taking decades to grow from a hatchling to an adult. Years pass between your chances to breed.
I’m sure you can see that being a sea turtle in a fast-paced human world — full of fishing gear and plastic debris in the water, hotels and vehicles on beaches — can be tough.
It turns out that one of the toughest places to be a sea turtle is the Gulf of Mexico. CI, along with our partners at Duke University, just published a study of sea turtle bycatch in all U.S. fisheries during the past two decades. This study showed that up to 98% of all turtle bycatch — and 80% of all turtle deaths due to bycatch — occurred in shrimp trawls, mostly in the Gulf.
(In case you’re unaware, trawling, or the dragging of nets behind fishing boats, is a common way to catch fish. But it also kills many species that aren’t the target of fishermen, particularly when they’re trawling for shrimp. Some estimates are as high as 1 pound of shrimp for every 5-20 pounds of bycatch!)
A Solution to the Bycatch Problem
Fortunately, there is a solution. Turtle Excluder Devices, or TEDs, are trapdoors installed in trawl nets that let big animals like turtles escape. Little animals, like shrimp, go to the back of the net. When installed and used properly, these devices are nearly 100% effective in purging turtles from trawls.
In fact, the implementation of TEDs in the late 1980s is widely credited for the recovery of the smallest sea turtle species, the Kemp’s ridley (Lepidochelys kempii), whose entire range is essentially confined to the Gulf of Mexico. This species nearly went extinct due to bycatch in shrimp trawls as well as human consumption of their eggs and meat.
However, fishermen sometimes tie TEDs shut or don’t install them at all, citing decreased shrimp catch and other burdens on their ability to do their jobs. Although TED use is mandatory in U.S. shrimp trawls, the high degree of non-compliance, especially in the Gulf of Mexico, means that turtles continue to be trapped in trawls with no way out. Thousands of sea turtles are estimated to die in shrimp trawls annually.
And this was all before there was an oil spill in the Gulf.
The Oil Spill: Tough on Turtles, Tough on Fishermen
When the Deepwater Horizon well dumped nearly 5 million barrels of crude oil into the Gulf of Mexico, the vitality of the entire Gulf region — turtles, fish, ocean, coasts, and humans alike — was jeopardized. The near-term and long-term impacts of the oil spill on sea turtles, in particular, are still poorly understood, but they are believed to be widespread and significant. Sea turtle biologists throughout the Gulf region are keeping a watchful eye out for any signs that turtle populations take a turn for the worst.
And turtles weren’t the only ones that suffered from the eruption of murky plumes of crude. People throughout the Gulf region, including local businesspeople and those in the tourism industry, suffered greatly. One group that was hit really hard was fishermen — and shrimpers in particular. They were prohibited from fishing in areas that had been fished for generations while U.S. government agencies scrambled to piece together what had happened and what the impacts might be to marine ecosystems — especially those that produce seafood.
And while the fishermen idled at shore, unable to fish even in good weather and calm seas (a fisherman’s definition of hell on Earth), their already hard-knock lifestyle got harder. Rising fuel costs, long, hard hours at sea, and competition from shrimp imported to the U.S. from countries with far more relaxed environmental regulations on shrimping have all made being a shrimp fisherman in the U.S. very difficult.
For the turtles, this reduction in shrimp trawling activity caused by the oil spill was a reprieve. But for the shrimpers themselves, this was a loss of income, job security, and another direct threat to their way of life.
Ultimately, TED implementation needs to be enforced, because loss of sea turtle life has been proven to be significant, while loss of catch has not. Sea turtle populations cannot withstand high bycatch rates, and multiple populations that occur in U.S. waters have declined as a result of accidental capture in fisheries. Impacts of the oil spill only compound these bycatch problems, making sea turtle populations more vulnerable to decline. TEDs are a tool that works, a rare thing in conservation these days, a thing not to be overlooked.
But the slow-going sea turtles aren’t the only ones who have it rough in the Gulf, and finding a healthy balance between shrimpers and turtles will be the key to both living long and happy futures together. One place to start would be to prevent a common enemy — another catastrophic oil spill — from again marauding the Gulf of Mexico, that long-time home to generations of turtles and fishermen.
Bryan Wallace is director of science and strategy for CI’s Marine Flagship Species Program.