The sea turtle to the left has fibropapillomatosis, a tumor-forming disease linked to a herpes virus. While these tumors can appear grotesque, not all are malignant. Fibropapillomatosis has been around since the 1980s, but the cause has been unknown. A new paper in PLoS ONE by Van Houtan, Hargrove, and Balazs analyzed clusters of the virus in locations with high nutrient runoff. And here’s where the story gets interesting…
The authors discovered a relationship between eutrophication (excess nitrogen), an invasive species of algae, sea turtles, and the disease. It goes like this:
So it turns out that the root cause of the whole chain of events–leading to the large tumors we’re observing in sea turtles–is not the result of one of the usual suspects (i.e. carcinogens such as PCBs or 3-Nitrobenzanthrone).
When I spoke to lead author Kyle Van Houtan, he explained, “To me what is really fascinating about the whole argument is how it all begins with simple nitrogen [inputs from runoff] and how that travels through the physical watershed, the ecosystem, and ends up promoting tumors.”
The paper identifies the amino acid arginine as being involved in this process and, coincidentally, clinical trials for cancer drugs for human liver cancers are specifically targeting and destroying arginine. So as Van Houten points out, “There is perhaps more to this than simply sea turtle tumors. After all, 15-20% of human cancers are viral in origin.” In other words, understanding the cause of tumors in sea turtles may help researchers understand why they form in our species too.
The first sea turtle eggs rescued from the Gulf have hatched! From the Associated Press:
About 700 sea turtle nests — each containing about 100 eggs — are being trucked from oiled shores along the Gulf to Cape Canaveral, where they’re kept at a climate-controlled facility. The turtles are being released into the Atlantic as they hatch.
Scientists feared that a generation of the imperiled species would die if they hatched and swam into the oil.
One small step toward restoration. One giant leap for the oil spill’s tiniest refugees. They face a tough road ahead.
Godspeed and good luck little dudes!
(Photo: The Ocean Conservancy)
This is a guest post from Wallace J. Nichols, a marine scientist and oceans conservationist who in 1998 founded the Grupo Tortuguero, an international grassroots movement dedicated to restoring Pacific sea turtles and to sustainable management of ocean fisheries. He currently works with several universities and organizations to protect the oceans, including Ocean Revolution and the California Academy of Sciences.
My brave friend Leilani Munter called from the field to report that the National Wildlife Federation and CNN had documented the first sea turtle caught in a slick at sea, gasping for air through an iridescent sheen. Tragically, just as nesting season for a number of the Gulf of Mexico’s sea turtle species is set to begin, these highly endangered animals become the poster species of the BP Gulf of Mexico oil spill.
Soon, if not already, adult male and female turtles will gather in shallow coastal waters, mate and prepare to nest, precisely where oil is accumulating. The pregnant females will scuttle across beaches at night to lay eggs, just as they’ve done for millions of years, but these beaches will be different—they will be blacked with oil. In a few short weeks, a new generation of hatchlings will emerge from the sand and make their way across oily beaches to an oily sea where tar balls and slicks will make their already-long odds of survival even longer. As they mature, they will have to rise through oil slicks to breathe and survive by eating oil-coated animals, algae and seagrass. While sea turtle will be among the most recognizable victims, they won’t be alone. Many species of birds, fish, invertebrates and plants will fare just as badly.
Even before the spill, sea turtles had it tough. Read More