Fibropapillomatosis in Green Turtles ( Chelonia mydas ) in Juvenile Foraging Areas: Epidemiologic and Population Genetic Perspectives on Conservation Planning

Reece, J., Hirama, T. and L.M. Ehrhart

Disease is an important threat to many endangered species. Historically, conservation plans have rarely considered the impacts of disease, but in long-lived species, disease can lead to persistent decreases population levels and abruptly change demography. The roles that gene flow, migratory patterns, and population structure play in the impact of disease are often difficult to determine when aggregations arise from mixed stocks. These confounding factors converge to make conservation efforts difficult in species such as the green turtle ( Chelonia mydas ), a long-lived widely ranging sea turtle subject to a poorly understood and debilitating disease. The green turtle represents an extreme along a continuum of the ecological mechanisims that allow disease to migrate and persist in the world. In many respects, it also serves as a model organism on which multiple ecological, epidemiological and population genetic methods may unite. This synergism of methods provides predictive estimates of the effects of disease on conservation planning.

The Loggerhead Turtles of Oman and Florida : Connectivity Between Ocean Basins

J. S. Reece, A. Al Kiyumi, A. Al Ansari, A. Al Kindi, I. Mahmoud, C. L. Parkinson

The conservation of wide ranging marine species is dramatically influenced by the discovery of migratory pathways and incidence of long-distance gene flow. Marine turtles as a group are capable of massive migratory events and yet species such as the loggerhead maintain genetic structure over distances fewer than 100 kilometers.

Currently, the loggerhead is managed without consideration of across-ocean basin migratory events. In this study, we identify evidence for recent genetic exchange between the Indian and Atlantic Oceans . We identify historical patterns of colonization and secondary contact between the two largest loggerhead rookeries in the world, those of the Southeastern United States and Masirah Island , Oman . Our findings support an initial invasion into the Indian Ocean during the Middle Pleistocene. Following major population fluctuations in the Atlantic during late Pleistocene glaciation, our data support a repatriation of regions of the Atlantic from more equatorial refugia. Our findings suggest that during these range expansions from equatorial refugia, Atlantic nesting beaches were augmented with genetic stocks originating from the Indian Ocean , arriving in the Atlantic during the Eemian Interglacial Period.

Cellular diagnostics and health of juvenile green turtles (Chelonia mydas): Identifying environmental co-factors of fibropapillomatosis

Fauth, J.E., Reece, J. , Downs , C., and L.M. Ehrhart

Fibropapillomatosis (FP), a tumor-causing disease caused by a herpes virus, is increasingly common in marine turtles worldwide. In Florida, FP is common in juvenile green turtles ( Chelonia mydas ) foraging in heavily-polluted Indian River Lagoon (IRL) and increasing in frequency on a near-shore sabellarid worm rock reef (SWRR), but very rare in a man-made Trident submarine basin (TSB). In 2004-2005, blood samples were collected from juvenile C. mydas and turtle health was evaluated in these three sites. Comparative cellular-diagnostic analysis indicated that IRL turtles had elevated levels of enzymes implicating exposure to environmental pollutants. Elevated levels of heat shock protein 70 were significantly correlated with increased probability of FP tumors. Mononuclear cells incubated in vitro with malathion or endosulfan confirmed that cellular-diagnostic profiles of IRL were consistent with pesticide stress. These results identify likely environmental cofactors to disease and link anthropogenic pollutants and declining health in a federally-endangered sea turtle.

Effects of a shore protection project on loggerhead and green turtle nesting activity and reproduction.

Brock, K.A., Reece, J. , and L.M. Ehrhart

Marine turtle reproductive success is strongly correlated with the stability and quality of the nesting environment. Because females show fidelity to key nesting beaches, management practices and physical characteristics of these beaches directly affect the recovery of threatened and endangered marine turtles.

We compared and contrasted the impacts of beach restoration (nourishment) on the loggerhead ( Caretta caretta ) and green turtle ( Chelonia mydas ) between nourished and non-nourished areas. We observed negative effects on nesting success for both loggerheads and green turtles. Physical attributes of the fill sand did not physically impede turtles in their attempts to nest. We argue that the decrease in nesting success resulted from an absence of abiotic and/or biotic factors that cue nesting behavior. During the second season post-nourishment and following the equilibration of the beach profile and putative recolonization of biota, loggerhead nesting success rates returned to normal levels.