Sea Turtle Diseases Active
Sea turtles are one of the oldest groups of reptiles and are found worldwide. There are seven species of sea turtles in the world, and Hawaii has two of them, the hawksbill and the far more numerous green turtle. Threats to turtles include by-catch from fisheries activity, over harvesting of eggs on nesting beaches, and disease. Of the latter, the most significant disease of sea turtles is called fibropapillomatosis (FP).
Research on Fibropapillomatosis (FP)
Since 1995, the Honolulu Field Station and National Marine Fisheries Marine Turtle Biology and Assessment Program have had an ongoing collaboration to elucidate the cause and epizootiology of fibropapillomatosis (FP). FP causes unsightly external and internal tumors in sea turtles. It affects mainly green and loggerheads and is found in almost all the tropical marine ecosystems where these species reside. FP has also been documented in other species of sea turtles, but much more infrequently. FP was first described in green turtles from Florida in the early 1920s. In Hawaii, the first record of the disease occurred somewhere about the early to mid-1950s. FP affects mainly immature turtles, and in Hawaii, the percentage of individuals affected can range from 20 to 40% depending on the location. In addition to causing tumors on the skin, eyes, and mouth, about 20-30% of sea turtles with the disease also have tumors in internal organs such as the lungs, kidneys, and heart.
What causes FP?
FP was deemed not much more than a curiosity until the 1980s and 90s when serious research began on the disease. Microscopic examination of tumors by researchers as the University of Florida, Gainesville, revealed particles suggestive of a herpes virus. Since herpes viruses are known to cause tumors in animals and humans, this agent as a potential cause of FP was certainly plausible. However, many other things can cause tumors in animals. Investigators in Florida then reproduced the disease in captive green turtles by injecting tumor homogenates that had been filtered to eliminate all but the smallest particles (viruses). In doing so, they were able to reproduce tumors similar to those seen in the wild. This was very compelling evidence that whatever caused the disease, it was either something very small (maybe a virus or protein) but almost certainly not something like a bacterium or parasite that would have been eliminated in the filtration process. Subsequent molecular biology studies have consistently shown the presence of a herpesvirus in tumors.
Effects of FP on turtles
Although FP is a major threat of stranding of sea turtles in Hawaii, the disease is waning in Hawaii for unknown reasons. In contrast, its presence is increasing in Florida, and it has recently appeared in Texas. About 30% of turtles recover from the disease, so it has detrimental effects on affected animals. Turtles with severe FP become immunosuppressed and get secondary bacterial infections. Furthermore, many stranded turtles have concomitant infections with worms that live in blood vessels and cause inflammation of internal organs. Hawaii is also unique in that turtles here get tumors in the glottis (opening to the trachea). This prevents closure of the glottis allowing seawater and food to get into the lungs. Not surprisingly, many turtles that strand with glottal tumors also have infections and inflammation in the lungs. A system to score the severity of FP in Hawaiian green turtles shows that animals with moderate to severe disease have a lower likelihood of being observed again in the wild. All this implies that FP is more than a mere cosmetic disease and warrants further investigation.
Where to go from here?
In order to have any hope of managing this disease, several critical pieces of information are needed. How is the virus transmitted? Why does FP show up more often in what appear to be "degraded" habitats? Does the herpes virus cause the tumors? The presence of a highly visible disease in a large animal like the turtle suggests something is awry with the ecosystem. Understanding why this is so may add a piece to the puzzle of sustainable management of marine ecosystems.
Resources
Sea Turtle Necropsy Manual
- English language edition
- Spanish language edition
- Italian language edition
- Japanese language edition
- Chinese (simplified) edition
- Chinese (traditional) edition
- French language edition
- Portuguese language edition
- Arabic language edition
- Korean language edition
- Persian language edition available by request to asknwhc@usgs.gov
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The genome of Chelonid herpesvirus 5 harbors atypical genes
Coastal habitat degradation and green sea turtle diets in Southeastern Brazil
Comparative health assessment of western Pacific leatherback turtles (Dermochelys coriacea) foraging off the coast of California, 2005-2007
Leatherback turtles (Dermochelys coriacea) are critically endangered, primarily threatened by the overharvesting of eggs, fisheries entanglement, and coastal development. The Pacific leatherback population has experienced a catastrophic decline over the past two decades. Leatherbacks foraging off the coast of California are part of a distinct Western Pacific breeding stock that nests on beaches in
Pathology and distribution of sea turtles landed as bycatch in the Hawaii-based North Pacific pelagic longline fishery
Identification of CD3+ T lymphocytes in the green turtle Chelonia mydas
In vitro biology of fibropapilloma-associated turtle herpesvirus and host cells in Hawaiian green turtles (Chelonia mydas)
Postmortem diagnostic investigation of disease in free-ranging marine turtle populations: A review of common pathologic findings and protocols
Rise and fall over 26 years of a marine epizootic in Hawaiian green sea turtles
Cause-specific temporal and spatial trends in green sea turtle strandings in the Hawaiian Archipelago (1982-2003)
Genomic variation of the fibropapilloma-associated marine turtle herpes virus across seven geographic areas and three host species
Geographic variation in marine turtle fibropapillomatosis
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- Overview
Sea turtles are one of the oldest groups of reptiles and are found worldwide. There are seven species of sea turtles in the world, and Hawaii has two of them, the hawksbill and the far more numerous green turtle. Threats to turtles include by-catch from fisheries activity, over harvesting of eggs on nesting beaches, and disease. Of the latter, the most significant disease of sea turtles is called fibropapillomatosis (FP).
Research on Fibropapillomatosis (FP)
Since 1995, the Honolulu Field Station and National Marine Fisheries Marine Turtle Biology and Assessment Program have had an ongoing collaboration to elucidate the cause and epizootiology of fibropapillomatosis (FP). FP causes unsightly external and internal tumors in sea turtles. It affects mainly green and loggerheads and is found in almost all the tropical marine ecosystems where these species reside. FP has also been documented in other species of sea turtles, but much more infrequently. FP was first described in green turtles from Florida in the early 1920s. In Hawaii, the first record of the disease occurred somewhere about the early to mid-1950s. FP affects mainly immature turtles, and in Hawaii, the percentage of individuals affected can range from 20 to 40% depending on the location. In addition to causing tumors on the skin, eyes, and mouth, about 20-30% of sea turtles with the disease also have tumors in internal organs such as the lungs, kidneys, and heart.
What causes FP?
FP was deemed not much more than a curiosity until the 1980s and 90s when serious research began on the disease. Microscopic examination of tumors by researchers as the University of Florida, Gainesville, revealed particles suggestive of a herpes virus. Since herpes viruses are known to cause tumors in animals and humans, this agent as a potential cause of FP was certainly plausible. However, many other things can cause tumors in animals. Investigators in Florida then reproduced the disease in captive green turtles by injecting tumor homogenates that had been filtered to eliminate all but the smallest particles (viruses). In doing so, they were able to reproduce tumors similar to those seen in the wild. This was very compelling evidence that whatever caused the disease, it was either something very small (maybe a virus or protein) but almost certainly not something like a bacterium or parasite that would have been eliminated in the filtration process. Subsequent molecular biology studies have consistently shown the presence of a herpesvirus in tumors.
Effects of FP on turtles
Although FP is a major threat of stranding of sea turtles in Hawaii, the disease is waning in Hawaii for unknown reasons. In contrast, its presence is increasing in Florida, and it has recently appeared in Texas. About 30% of turtles recover from the disease, so it has detrimental effects on affected animals. Turtles with severe FP become immunosuppressed and get secondary bacterial infections. Furthermore, many stranded turtles have concomitant infections with worms that live in blood vessels and cause inflammation of internal organs. Hawaii is also unique in that turtles here get tumors in the glottis (opening to the trachea). This prevents closure of the glottis allowing seawater and food to get into the lungs. Not surprisingly, many turtles that strand with glottal tumors also have infections and inflammation in the lungs. A system to score the severity of FP in Hawaiian green turtles shows that animals with moderate to severe disease have a lower likelihood of being observed again in the wild. All this implies that FP is more than a mere cosmetic disease and warrants further investigation.
Where to go from here?
In order to have any hope of managing this disease, several critical pieces of information are needed. How is the virus transmitted? Why does FP show up more often in what appear to be "degraded" habitats? Does the herpes virus cause the tumors? The presence of a highly visible disease in a large animal like the turtle suggests something is awry with the ecosystem. Understanding why this is so may add a piece to the puzzle of sustainable management of marine ecosystems.
Resources
Sea Turtle Necropsy Manual
- English language edition
- Spanish language edition
- Italian language edition
- Japanese language edition
- Chinese (simplified) edition
- Chinese (traditional) edition
- French language edition
- Portuguese language edition
- Arabic language edition
- Korean language edition
- Persian language edition available by request to asknwhc@usgs.gov
- Multimedia
Below are multimedia items associated with this topic.
- Publications
Below are publications associated with this topic.
Filter Total Items: 53The genome of Chelonid herpesvirus 5 harbors atypical genes
The Chelonid fibropapilloma-associated herpesvirus (CFPHV; ChHV5) is believed to be the causative agent of fibropapillomatosis (FP), a neoplastic disease of marine turtles. While clinical signs and pathology of FP are well known, research on ChHV5 has been impeded because no cell culture system for its propagation exists. We have cloned a BAC containing ChHV5 in pTARBAC2.1 and determined its nucleAuthorsMathias Ackermann, Maxim Koriabine, Fabienne Hartmann-Fritsch, Pieter J. de Jong, Teresa D. Lewis, Nelli Schetle, Thierry M. Work, Julie Dagenais, George H. Balazs, Jo-Ann C. LeongCoastal habitat degradation and green sea turtle diets in Southeastern Brazil
To show the influence of coastal habitat degradation on the availability of food for green turtles (Chelonia mydas), we assessed the dietary preferences and macroalgae community at a feeding area in a highly urbanized region. The area showed low species richness and was classified as degraded. We examined stomach contents of 15 dead stranded turtles (CCL = 44.0 cm (SD 6.7 cm)). The diet was composAuthorsRobson G. Santos, Agnaldo Silva Martins, Julyana da Nobrega Farias, Antunes Paulo Horta, Hudson Tercio Pinheiro, Cecilia Baptistotte, Jeffrey A. Seminoff, George H. Balazs, Thierry M. WorkComparative health assessment of western Pacific leatherback turtles (Dermochelys coriacea) foraging off the coast of California, 2005-2007
Leatherback turtles (Dermochelys coriacea) are critically endangered, primarily threatened by the overharvesting of eggs, fisheries entanglement, and coastal development. The Pacific leatherback population has experienced a catastrophic decline over the past two decades. Leatherbacks foraging off the coast of California are part of a distinct Western Pacific breeding stock that nests on beaches in
AuthorsHeather S. Harris, Scott R. Benson, Kirsten V. Gilardi, Robert H. Poppenga, Thierry M. Work, Peter H. Dutton, Jonna A.K. MazetPathology and distribution of sea turtles landed as bycatch in the Hawaii-based North Pacific pelagic longline fishery
We examined the gross and microscopic pathology and distribution of sea turtles that were landed as bycatch from the Hawaii, USA–based pelagic longline fishery and known to be forced submerged. Olive ridley turtles (Lepidochelys olivacea) composed the majority of animals examined, and hook-induced perforation of the esophagus was the most common gross lesion followed by perforation of oral structuAuthorsThierry M. Work, George H. BalazsIdentification of CD3+ T lymphocytes in the green turtle Chelonia mydas
To understand the role of the immune system with respect to disease in reptiles, there is the need to develop tools to assess the host's immune response. An important tool is the development of molecular markers to identify immune cells, and these are limited for reptiles. We developed a technique for the cryopreservation of peripheral blood mononuclear cells and showed that a commercially availabAuthorsF.A. Munoz, S. Estrada-Parra, A. Romero-Rojas, Thierry M. Work, E. Gonzalez-Ballesteros, I. Estrada-GarciaIn vitro biology of fibropapilloma-associated turtle herpesvirus and host cells in Hawaiian green turtles (Chelonia mydas)
Fibropapillomatosis (FP) of green turtles has a global distribution and causes debilitating tumours of the skin and internal organs in several species of marine turtles. FP is associated with a presently non-cultivable alphaherpesvirus Chelonid fibropapilloma-associated herpesvirus (CFPHV). Our aims were to employ quantitative PCR targeted to pol DNA of CFPHV to determine (i) if DNA sequesters byAuthorsThierry M. Work, Julie Dagenais, George H. Balazs, Joanne Schumacher, Teresa D. Lewis, Jo-Ann C. Leong, Rufina N. Casey, James W. CaseyPostmortem diagnostic investigation of disease in free-ranging marine turtle populations: A review of common pathologic findings and protocols
Over the past few decades, there have been increasing numbers of reports of diseases in marine turtles. Furthermore, in recent years, there have been documented instances of apparently new diseases emerging in these species of which the etiology and/or pathogenesis remain unknown. These instances i) raise concern for the survival of marine turtles, and ii) question the health and stability of theAuthorsMark Flint, Janet C. Patterson-Kane, C.J. Limpus, Thierry M. Work, David Blair, Paul C. MillsRise and fall over 26 years of a marine epizootic in Hawaiian green sea turtles
Estimates of chronic disease prevalence are needed to improve our understanding of marine disease epizootiology, which is poorly known for marine megafauna such as marine turtles. An emerging worldwide threat to green sea turtles (Chelonia mydas) is fibropapillomatosis (FP), which is a pandemic tumor-forming disease associated with herpesviruses. We report on a 26-yr FP epidemic in the Hawaiian ArAuthorsMilani Chaloupka, George H. Balazs, Thierry M. WorkCause-specific temporal and spatial trends in green sea turtle strandings in the Hawaiian Archipelago (1982-2003)
We investigated cause-specific temporal and spatial trends in sea turtle strandings in the Hawaiian Archipelago. Five species of sea turtle were recorded in 3,861 strandings over a 22-year period (1982–2003). Green turtles comprised 97% of these strandings with size and gender composition reflecting the demographic structure of the resident green turtle population and relative green turtle abundanAuthorsMilani Chaloupka, Thierry M. Work, George H. Balazs, Shawn K. K. Murakawa, Robert MorrisGenomic variation of the fibropapilloma-associated marine turtle herpes virus across seven geographic areas and three host species
Fibropapillomatosis (FP) of marine turtles is an emerging neoplastic disease associated with infection by a novel turtle herpesvirus, fibropapilloma-associated turtle herpesvirus (FPTHV). This report presents 23 kb of the genome of an FPTHV infecting a Hawaiian green turtle (Chelonia mydas). By sequence homology, the open reading frames in this contig correspond to herpes simplex virus genes UL23AuthorsR.J. Greenblatt, S.L. Quackenbush, R.N. Casey, J. Rovnak, G.H. Balazs, Thierry M. Work, J.W. Casey, C.A. SuttonGeographic variation in marine turtle fibropapillomatosis
We document three examples of fibropapillomatosis by histology, quantitative polymerase chain reaction (qPCR), and sequence analysis from three different geographic areas. Tumors compatible in morphology with fibropapillomatosis were seen in green turtles from Puerto Rico and San Diego (California) and in a hybrid loggerhead/ hawksbill turtle from Florida Bay (Florida). Tumors were confirmed as fiAuthorsR.J. Greenblatt, Thierry M. Work, P. Dutton, C.A. Sutton, T.R. Spraker, R.N. Casey, C.E. Diez, Dana C. Parker, J. St. Ledger, G.H. Balazs, J.W. Casey - News
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