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PubMed2004

Good news for sea turtles.

Following the overexploitation of sea turtle populations, conservation measures are now in place in many areas. However, the overall impact of these measures is often unknown because there are few long time-series showing trends in population sizes. In a recent paper, George Balazs and Milani Chaloupka chart the number of green turtles Chelonia mydas nesting in Hawaii over the past 30 years and reveal a remarkably quick increase in the size of this population following the instigation of conservation measures during the 1970s. Importantly, this work shows how even a small population of sea turtles can recover rapidly, suggesting that Allee effects do not impede conservation efforts in operation worldwide.

Journal Article↗
PubMed2005

Underwater, low-frequency noise in a coastal sea turtle habitat.

Underwater sound was recorded in one of the major coastal foraging areas for juvenile sea turtles in the Peconic Bay Estuary system in Long Island, New York. The recording season of the underwater environment coincided with the sea turtle activity season in an inshore area where there is considerable boating and recreational activity, especially during the summer between Independence Day and Labor Day. Within the range of sea turtle hearing, average noise pressure reached 110 dB during periods of high human activity and diminished proportionally, down to 80 dB, with decreasing human presence. Therefore, during much of the season when sea turtles are actively foraging in New York waters, their coastal habitats are flooded with underwater noise. During the period of highest human activity, average noise pressures within the range of frequencies heard by sea turtles were greater by over two orders of magnitude (26 dB) than during the lowest period of human activity. Sea turtles undoubtedly are exposed to high levels of noise, most of which is anthropogenic. Results suggest that continued exposure to existing high levels of pervasive anthropogenic noise in vital sea turtle habitats and any increase in noise could affect sea turtle behavior and ecology.

Acoustics↗
PubMed1982

Spirorchidiasis in loggerhead sea turtles (Caretta caretta): pathology.

Loggerhead sea turtles (Caretta caretta) from the Atlantic seaboard (Florida to Massachusetts) were examined at the Marine Pathology Laboratory, University of Rhode Island, from March through December, 1980. Three genera of blood flukes (spirorchids) were found in 14 (33%) of the 43 turtles. Gross signs in heavily infected animals included cachexia, anemia and enteritis. Histopathological lesions were similar to those present in homeotherms with schistosomiasis. Granulomatous gastritis, enteritis, hepatitis, pneumonitis, and nephritis were present. Acute and chronic vasculitis accompanied metastasis of eggs. Infected animals had severe hepatic hemosiderosis, indicative of the anemia observed grossly. Evidence is presented that spirorchidiasis is prevelent in sub-adult loggerhead sea turtles, is responsible for extensive lesions and may be responsible for significant debilitation and mortality.

Animals↗
PubMed1986

Conjunctivitis, tracheitis, and pneumonia associated with herpesvirus infection in green sea turtles.

Fourteen juvenile (15- to 20-month-old) green sea turtles (Chelonia mydas), representative of a group of sea turtles with clinical signs of respiratory tract disease, were euthanatized and submitted for necropsy. Macroscopically, lesions included periglottal necrosis, tracheitis with intraluminal caseous and laminated necrotic debris, and severe pneumonia. Several turtles had caseous conjunctival exudate covering the eyes. Microscopically, the turtles had fibrinonecrotic inflammation around the glottal opening, tracheitis, and severe bronchopneumonia and interstitial pneumonia. In multifocal areas, periglottal and tracheal epithelial cells adjacent to areas of necrosis had hypertrophic nuclei with amphophilic intranuclear inclusions. A mixed population of primarily gram-negative microorganisms was isolated from the tracheal and glottal lesions. Attempts at viral isolation in cultures of green sea turtle kidney cells resulted in the development of cytopathic effects characterized by giant cell formation and development of intranuclear inclusions. Using electron microscopy, intranuclear viral particles (88 to 99 nm in diameter) were seen in inclusion-containing tracheal and glottal epithelial cells and infected green sea turtle kidney cells; particles were consistently seen enveloping from nuclear membranes, and mature particles (132 to 147 nm) were found in the cytoplasm. On the basis of size, conformation, location, and presence of an envelope, the particles most closely resembled those of herpes-viruses.

Animals↗
PubMed1991

Characteristics of the anion transport system in sea turtle erythrocytes.

Erythrocytes of Kemp's ridley sea turtle (Lepidochelys kempi) contain a 100- to 105-kDa protein that is reactive with a monoclonal antibody to the membrane domain of human erythrocyte band 3. Based on inhibition of membrane HCO(3-)-Cl- exchange with 4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid (SITS), sea turtle erythrocytes were found to contain 4 x 10(6) copies of band 3 per cell. Unidirectional HCO3- transfer, specifically HCO3- out----in-Cl-in----out exchange, where subscript in----out represents transfer from inside to outside and subscript out----in represents transfer from outside to inside, was characterized by a maximal exchange rate of 1.0-1.1 nmol.cm-2.s-1, substrate affinity coefficients of 0.1-0.2 mM for HCO3- and 1.6 mM for Cl-, and an apparent inhibition constant for SITS of 0.6-1.0 microM (10 degrees C, pH 7.6). Under physiological conditions (30 degrees C, pH 7.4), the rate of net HCO3- transfer (i.e., the difference between HCO3- in----out-Cl-out----in and HCO3- out----in-Cl-in----out) was 1.13 nmol. cm-2.s-1 for cells subjected to a 5-mM decrement in CO2 content. This yields a rate coefficient for the "physiological" anion shift in sea turtle blood of 1.7 s-1, indicating that the anion shift may require 2.6 s to reach 99% completion in vivo. The erythrocyte anion shift appears to be a potential rate-limiting step for capillary CO2 exchange in these turtles.

4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfo↗
PubMed2003

Venous blood gases and lactates of wild loggerhead sea turtles (Caretta caretta) following two capture techniques.

During summer of 2001, venous blood gases were determined in loggerhead sea turtles (Caretta caretta) captured by trawl (n = 16) in coastal waters of South Carolina and Georgia (USA) as part of a sea turtle census program and captured in pound nets (n = 6) in coastal North Carolina (USA) during a study of sea turtle population biology. Trawls were towed for 30 min, so turtles captured were forcibly submerged for < or = 30 min. Pound nets are passive gear in which fish and sea turtles are funneled into a concentrated area and removed periodically. Sea turtles in pound nets are free to surface and to feed at will. Blood was obtained from the dorsal cervical sinus as quickly as possible after landing on the boat (range 2-10 min trawl, 1-2 min pound net) and at 30 min after landing just prior to release. Blood gases including pH, partial pressures of O2 and CO2 (pO2, pCO2), and lactate were measured within 10 min. Instrument measurements for pH, pO2, and pCO2 made at 37 C were corrected to cloacal temperature and HCO3- was calculated from temperature-corrected pH and pCO2. Venous blood pH and bicarbonate were higher, and pO2 and lactate were lower from pound net-captured turtles compared to trawl captured turtles at the initial sampling time. In pound net turtles, pH and bicarbonate declined and lactate increased during 30 min on deck. In trawled sea turtles, venous blood pH increased and pCO2 and pO2 decreased during the 30 min on deck. Both capture systems caused perturbations in blood gas, acid-base, and lactate status, though alterations were greater in trawl captured turtles.

Acid-Base Imbalance↗
PubMed2001

Marine debris and human impacts on sea turtles in southern Brazil.

Dead stranded sea turtles were recovered and examined to determine the impact of anthropogenic debris and fishery activities on sea turtles on the coast of Rio Grande do Sul State, Brazil. Esophagus/stomach contents of 38 juvenile green Chelonia mydas, 10 adults and sub-adults loggerhead Caretta caretta, and two leatherback Dermochelys coriacea turtles (adult or sub-adult) included plastic bags as the main debris ingested, predominated by white and colorless pieces. The ingestion of anthropogenic debris accounted for the death of 13.2% of the green turtles examined. Signs of damage over the body and carapace indicated that fishing activities caused the death of 13.6% (3/22) of loggerheads and 1.5% (1/56) of green turtles. Therefore, it appears that direct and indirect effects of fishing activities may pose a threat to these species in Brazilian waters. Other sources of plastic debris should be investigated as well as the direct impact of fisheries, especially bottom trawl and gill nets, in order to establish effective conservation action.

Animals↗
PubMed2005

Do open-cycle hatcheries relying on tourism conserve sea turtles? Sri Lankan developments and economic-ecological considerations.

By combining economic analysis of markets with ecological parameters, this article considers the role that tourism-based sea turtle hatcheries (of an open-cycle type) can play in conserving populations of sea turtles. Background is provided on the nature and development of such hatcheries in Sri Lanka. The modeling facilitates the assessment of the impacts of turtle hatcheries on the conservation of sea turtles and enables the economic and ecological consequences of tourism, based on such hatcheries, to be better appreciated. The results demonstrate that sea turtle hatcheries serving tourists can make a positive contribution to sea turtle conservation, but that their conservation effectiveness depends on the way they are managed. Possible negative effects are also identified. Economic market models are combined with turtle population survival relationships to predict the conservation impact of turtle hatcheries and their consequence for the total economic value obtained from sea turtle populations.

Animals↗
PubMed2006

Morphologic and cytochemical characteristics of blood cells of juvenile loggerhead sea turtles (Caretta caretta).

A morphologic classification based on the cytochemical characteristics of blood cells of 35 juvenile loggerhead sea turtles (Caretta caretta) is described. Cytochemical stains included benzidine peroxidase, chloroacetate esterase, alpha-naphthyl butyrate esterase (with and without sodium fluoride), acid phosphatase (with and without tartaric acid), Sudan black B, periodic acid-Schiff, and toluidine blue. The morphologic characteristics of erythrocytes were similar to those reported in green turtles. Six types of white blood cells were identified: heterophils, eosinophils, basophils, lymphocytes, monocytes and thrombocytes. Except for the basophils, the rest of the white blood cells from loggerhead turtles had different cytochemical characteristics compared to blood cells from other sea turtle species. The leukocyte differential count was different from that reported for other sea turtle species. Heterophils were the most numerous leukocytes from these loggerhead turtles, followed by lymphocytes, eosinophils, monocytes and basophils. This paper provides a morphologic classification of blood cells of loggerhead sea turtles that is useful for veterinary surgeons involved in sea turtle conservation.

Animals↗
PubMed1995

Perception of ocean wave direction by sea turtles

At the beginning of their offshore migration, hatchling sea turtles enter the ocean at night and establish a course away from land by swimming directly into oceanic waves. How turtles can detect wave direction while swimming under water in darkness, however, has not been explained. Objects in a water column beneath the surface of the ocean describe a circular movement as waves pass above. In principle, swimming turtles might, therefore, detect wave direction by monitoring the sequence of accelerations they experience under water. To determine whether loggerhead (Caretta caretta L.) and green turtle (Chelonia mydas L.) hatchlings can detect wave direction in this way, we constructed a wave motion simulator to reproduce in air the circular movements that occur beneath small ocean waves. Hatchlings suspended in air and subjected to movements that simulated waves approaching from their right sides attempted to turn right, whereas movements that simulated waves from the left elicited left-turning behavior. Movements simulating waves from directly in front of the turtles elicited little turning in either direction. The results demonstrate that hatchling sea turtles can determine the propagation direction of ocean waves by monitoring the circular movements that occur as waves pass above. Although sea turtles are the first animals shown to be capable of detecting wave direction in this way, such an orientation mechanism may be widespread among other transoceanic migrants such as fish and cetaceans.

Journal Article↗
PubMed2004

Organochlorine contaminants in loggerhead sea turtle blood: extraction techniques and distribution among plasma and red blood cells.

Few studies have described the organochlorine (OC) contaminant concentrations found in sea turtle tissues. These studies have relied on the opportunistic sampling of either eggs or tissues from stranded carcasses. In this study, the use of whole blood samples as well as both blood components (plasma and red blood cells) were examined as a non-destructive alternative for monitoring OCs in free-ranging loggerhead sea turtles (Caretta caretta). Blood samples were collected from juvenile loggerhead sea turtles (n = 12) captured in Core Sound, North Carolina, USA and analyzed for 55 polychlorinated biphenyl (PCB) congeners and 24 OC pesticides by gas chromatography with electron capture detection and mass spectrometry. Using pooled loggerhead sea turtle whole blood, three different liquid:liquid extraction techniques were compared. Results were similar in terms of recovery of internal standards, lipids, and OC concentrations. An extraction technique, employing formic acid and 1:1 methyl-tert-butyl-ether: hexane, was found to be satisfactory. This method was applied to the extraction of OCs from whole blood, plasma, and red blood cell (RBC) samples from five loggerhead sea turtles. Plasma contained the highest OC concentrations on a wet mass basis, followed by whole blood and RBCs. The majority of each OC compound was found in the plasma rather than the RBCs, suggesting that OC compounds preferentially partition into the plasma. On average (SD), 89.4% (3.1 %) of total PCBs, 83.4% (11.9%) of total chlordanes, 74.3% (15.1%) of mirex, 72.6% (4.8%) of total DDTs, and 80.1% (16.6%) of dieldrin were found in the plasma. The concentrations of total PCBs, mirex, total chlordanes, and total DDTs measured in both components of the blood significantly correlated to those in whole blood. These are the first reported OC concentrations in sea turtle blood. They were found to be similar to previously reported levels in blood components of humans and of reptiles from relatively clean sites, but lower than those measured in blood of fish-eating birds and marine mammals. The results indicate that blood, preferably plasma, can be used to detect and monitor OC contaminants in loggerhead sea turtles.

Animals↗
PubMed2003

Use of a supraplastron approach to the coelomic cavity for repair of an esophageal tear in a loggerhead sea turtle.

A juvenile loggerhead sea turtle (Caretta caretta) was referred for removal of a fishhook lodged in the coelomic portion of the esophagus. Attempts at manual and endoscopic extraction were unsuccessful and resulted in a 6-cm tear in the coelomic portion of the esophagus. A supraplastron approach was made to the coelomic cavity, allowing access to and repair of the esophageal tear. The turtle recovered well and was able to be released to the wild. The surgical approach was associated with less trauma and shorter healing and rehabilitation times, compared with traditional plastron osteotomy.

Animals↗
PubMed1993

Structural studies on the loggerhead sea turtle (Caretta caretta) myoglobin.

The primary structure of myoglobin from the loggerhead sea turtle (Caretta caretta) has been determined; the protein consists of 153 amino acid residues. The ferric loggerhead sea turtle myoglobin has been crystallized in a form suitable for X-ray structural investigations. The crystals were grown at pH 8.0, in 0.05 M tris/HCl buffer, using 3.2 M ammonium sulfate as precipitating agent, at 4 degrees C, and belong to the orthorhombic space group P2(1)2(1)2(1), with unit cell constants a = 37.2 A, b = 61.1 A, c = 75.2 A (one molecule, 17,000 M(r), in the asymmetric unit). A molecular replacement solution was found for the loggerhead sea turtle myoglobin crystals using sperm whale myoglobin structure as search model. The R-factor value, after molecular replacement, is 0.387, for the data in the 15-3.3 A resolution range. The results here reported are the basis for the first X-ray crystallographic investigation on a reptile myoglobin, and indicate a strong overall structural similarity between the loggerhead sea turtle and mammalian (i.e. sperm whale) myoglobins.

Amino Acid Sequence↗
PubMed2005

Comparison of sea turtle thrombocyte aggregation to human platelet aggregation in whole blood.

The endangered sea turtles are living "fossils" that afford us an opportunity to study the hemostatic process as it likely existed millions of years ago. There are essentially no data about turtle thrombocyte aggregation prior to our studies. Thrombocytes are nucleated cells that serve the same hemostatic functions as the anucleated mammalian platelet. Sea turtle thrombocytes aggregate in response to collagen and beta-thrombin. Ristocetin induces an agglutination/aggregation response indicating the presence of a von Willebrand-like receptor, GPIb, found in all mammalian platelets. Samples treated with alpha-thrombin plus gamma-thrombin followed by ristocetin results in a rapid, stronger response than ristocetin alone. These responses are inhibited by the RGDS peptide that blocks fibrinogen cross-linking of mammalian platelets via the fibrinogen receptor, GPIIb/IIIa. Three platelet-like proteins, GPIb, GPIIb/IIIa and P-selection are detected in sea turtle thrombocytes by fluorescence activated cell sorting. Turtle thrombocytes do not respond to ADP, epinephrine, serotonin, thromboxane A2 mimetic, U46619, trypsin, or alpha-thrombin and gamma-thrombin added alone. Comparison of hemostasis in sea turtles to other vertebrates could provide a framework for understanding the structure/function and evolution of these pathways and their individual components.

Animals↗
PubMed2006

Heavy metal accumulation in four species of sea turtles from the Baja California peninsula, Mexico.

Heavy metals were assessed in four species of sea turtles from the Baja California Peninsula, Mexico, representing the first report of heavy metal concentrations in tissues of post-yearling sea turtles from the Eastern Pacific. Concentrations of Cd measured in C. mydas kidney (653 microg/g dry wt) were the highest ever reported for any sea turtle species. Cd accumulated preferentially in kidney and the ratios of kidney to liver Cd in Baja California turtles were among the highest reported for sea turtles globally. Zn, Ni, and Mn concentrations were also significantly higher in kidney than other tissues, while Cu and Fe were greatest in liver, and all metals were lowest in muscle. With the exception of one value (69.9 microg/g in kidney of C. caretta), Pb was low in all tissues from Baja California. In comparisons across species, kidney of C. mydas had greater Zn and Ni concentrations as compared to other species, although there was no difference in liver metal levels among the species. Positive correlations were detected in the concentrations of Cd, Cu and Ni with the straight carapace length of C. caretta.

Animals↗
PubMed2004

Organochlorine contaminants in sea turtles: correlations between whole blood and fat.

Monitoring toxic organochlorine (OC) compounds is an important aspect in wildlife studies, especially in protected species such as sea turtles. The goal of this study was to determine whether blood OC concentrations can predict those in adipose tissue of sea turtles. Blood offers many benefits for monitoring OCs. It can be collected nondestructively from live turtles and can be sampled repeatedly for continuous monitoring. Organochlorine concentrations in blood may better represent the exposure levels of target tissues, but blood concentrations may fluctuate more than those in fatty tissues following recent dietary exposure or lipid mobilization. Paired fat and blood samples were collected from 44 live, juvenile loggerhead sea turtles and 10 juvenile Kemp's ridley sea turtle carcasses. Organochlorines were analyzed using gas chromatography with electron capture detection and mass spectrometry. Lipid-normalized OC concentrations measured in the blood significantly correlated to levels found in the fat samples of both species. This result suggests that sea turtle blood is a suitable alternative to fatty tissues for measuring OCs because blood concentrations reasonably represent those observed in the paired fat samples. However, blood OC concentrations calculated on a wet-mass basis were significantly and inversely correlated to lipid content in the fat samples. Therefore, caution should be used when monitoring spatial or temporal trends, as OC levels may increase in the blood following mobilization of fat stores, such as during long migrations, breeding, or disease events.

Adipose Tissue↗
PubMed2000

Organochlorine, PCB, PAH, and metal concentrations in eggs of loggerhead sea turtles (Caretta caretta) from northwest Florida, USA.

Composite samples of unhatched and physically unaltered loggerhead sea turtle, Caretta caretta, eggs collected from 20 nests along northwest Florida were analyzed for organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and metals. Chemical analyses revealed that turtle eggs contained detectable amounts of metals, PAHs, and PCBs. Only one OCP, p,p'-DDD, was detected, and its presence was restricted to eggs from two nesting sites. None of the PCB concentrations exceeded the Food and Drug Administration's (FDA) action limit. Concentrations of dioxin-like PCB congeners, 105, 118, and 126, and total PCBs were also detected and are contributors to the toxic burden of loggerhead sea turtle eggs. Concentrations of PAHs, 1,2,5,6-dibenzanthracene, 1-methyl naphthalene, C1-naphthalene and naphthalene were variable at nesting sites. Comparison of mean metal burdens in eggs from different beaches suggested that no uniform geographic gradients exist. Presence of OCPs, PCBs, PAHs and metals and their additive or synergistic toxicity is a concern to loggerhead sea turtle eggs; however, additive or synergistic impacts for loggerhead sea turtles are largely undocumented.

Animals↗
PubMed2004

Pulmonary hyalohyphomycosis caused by Fusarium spp in a Kemp's ridley sea turtle (Lepidochelys kempi): an immunohistochemical study.

AIM: To describe the microscopic and immunohistochemical findings in a case of pulmonary hyalohyphomycosis in a Kemp's ridley sea turtle (Lepidochelys kempi). METHODS: Samples of lung, liver and kidney from a stranded, dead Kemp's ridley sea turtle were routinely processed for histopathological studies. Two monoclonal antibodies that reacted specifically with antigens of Aspergillus spp and the Mucorales (Zygomycetes) group, and a panel of polyclonal antibodies raised against Aspergillus fumigatus, Candida albicans, Geotrichum candidum, Fusarium solani, and Scedosporium apiospermum were used for immunohistochemical or immunofluorescence staining. RESULTS: Histologically, a severe multifocal granulomatous pneumonia associated with fungal infection was diagnosed. All hyphae were identified as Fusarium spp because a strong and uniform reactivity was obtained only with a heterologously-absorbed polyclonal antibody raised against somatic antigens of Fusarium solani. CONCLUSIONS: Fusarium spp should be included in the differential diagnosis of mycotic pneumonia in Kemp's ridley sea turtles. CLINICAL RELEVANCE: This is the first report of a pulmonary mycotic infection in a sea turtle diagnosed using immunohistochemistry. Wildlife rehabilitators and pathologists should be aware of the availability of immunohistochemical techniques for identifying fungi in sea turtles.

Journal Article↗