For nearly four decades, scientists have suspected that persistent organic pollutants (POPs) contributed to a green turtle's susceptibility to the virus that causes fibropapilomatosis (FP), a disease that forms large benign tumors that can inhibit the animal's sight, mobility and feeding ability.
In a new study,* researchers from the Hollings Marine Laboratory (HML), a government-university partner facility in Charleston, S.C., and from university and federal collaborators in Hawaii demonstrated POPs are not, in fact, a co-factor linked to the increasing number of green sea turtles afflicted with FP.
POPs are a large group of man-made chemicals that, as their name indicates, persist in the environment. They also spread great distances through air and water, accumulate in human and animal tissues, increase in concentration up food chains, and may have carcinogenic and neurodevelopmental effects.
POPs include banned substances such as DDT and toxaphenes, once used as pesticides; polychlorinated biphenyls (PCBs), once used as insulating fluids; and polybrominated diphenyl ethers (PDBEs), still used as flame retardants. Two previous studies attempting to link POPs and FP were unable to rule out the impact of the pollutants on the disease.
"We wanted to do a thorough study looking at a large, statistically valid population of turtles and using methods that could detect even tiny levels of POPs in their tissues," says National Institute of Standards and Technology (NIST) research biologist Jennifer Keller, lead author on the paper appearing in the journal Environmental Science and Technology.
Keller and her colleagues collected turtle blood samples at four locations across Hawaii, each one having a different prevalence of FP—none, low, moderate and high—in the marine turtle population residing there. "We analyzed the plasma for 164 different organic compounds to see if POP concentrations increased with increasing prevalence of FP," Keller says. "We also looked at the levels of halogenated phenols, chemicals which can come from either man-made [POP] sources or naturally from the green turtle's main food source, marine algae."
The researchers discovered that increasing POP concentrations did not correspond with a like rise in the numbers of FP tumors observed. "Our findings show that POPs are not the trigger for FP, so we can eliminate these pollutants from future studies trying to explain why the disease is more common in certain areas or why its prevalence is changing with time," Keller says.
As for halogenated phenols, the team found that the sampled turtles did have detectable concentrations of the compounds. "While it's a novel discovery for sea turtles, we believe that these phenols are likely from the turtle's diet of algae rather than man-made POPs," Keller explains.
Collaborating with Keller were researchers from Hawaiian branches of two federal agencies, the National Marine Fisheries Service and the U.S. Geological Survey, as well as from Hawaii Pacific University and the Hawaii Preparatory Academy.
The HML is a unique partnership of governmental and academic organizations including NIST, NOAA's National Ocean Service, the South Carolina Department of Natural Resources, the College of Charleston and the Medical University of South Carolina.
*J.M. Keller, G.H. Balazs, F. Nilsen, M. Rice, T.M. Work and B.A. Jensen. Investigating the potential role of persistent organic pollutants in Hawaiian green sea turtle fibropapillomatosis. Environmental Science and Technology. Accepted for publication June 25, 2014, DOI: 10.1021/es5014054
Michael E. Newman | Eurek Alert!
Strong Evidence – New Insight in Muscle Function
27.04.2015 | Austrian Science Fund FWF
Cell fusion ‘eats up’ the ‘attractive cell’ in flowering plants
27.04.2015 | Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University
KAIST researchers published an article on the development of a novel technique to precisely track the 3-D positions of optically-trapped particles having complicated geometry in high speed in the April 2015 issue of Optica.
Daejeon, Republic of Korea, April 23, 2015--Optical tweezers have been used as an invaluable tool for exerting micro-scale force on microscopic particles and...
A very small and rare species of shark is swimming its way through scientific literature. But don't worry, the chances of this inches-long vertebrate biting...
Ever since computers have been small enough to be fixtures on desks and laps, their central processing has functioned something like an atomic Etch A Sketch, with electromagnetic fields pushing data bits into place to encode data.
Unfortunately, the same drawbacks and perils of the mechanical sketch board have been just as pervasive in computing: making a change often requires starting...
How is lightning initiated in thunderclouds? This is difficult to answer - how do you measure electric fields inside large, dangerously charged clouds? It was discovered, more or less by coincidence, that cosmic rays provide suitable probes to measure electric fields within thunderclouds. This surprising finding is published in Physical Review Letters on April 24th. The measurements were performed with the LOFAR radio telescope located in the Netherlands.
How is lightning initiated in thunderclouds? This is difficult to answer - how do you measure electric fields inside large, dangerously charged clouds? It was...
Max Planck researcher Buhalqem Mamtimin determines how much nitrogen oxide is released into the atmosphere from agriculturally used oases.
In order to make statements about current and future air pollution, scientists use models which simulate the Earth’s atmosphere. A lot of information such as...
23.04.2015 | Event News
23.04.2015 | Event News
13.04.2015 | Event News
27.04.2015 | Life Sciences
27.04.2015 | Power and Electrical Engineering
27.04.2015 | Life Sciences