Cold-stunned Kemp's Ridley Research Articles

Modelling drift of cold-stunned Kemp's ridley turtles stranding on the Dutch coast

Background Every few years, juvenile Kemp’s ridley turtles (Lepidochelys kempii) are stranded on the Dutch coasts. The main population distribution of this critically endangered species primarily inhabits the Gulf of Mexico and the east coast of the United States. This study focuses on five reports from the Netherlands between 2007 and 2022, where juvenile turtles were reported to strand alive during the winter, albeit in a hypothermic state. At ambient ocean temperatures between 10°C and 13°C, Kemp’s ridley turtles begin to show an inability to actively swim and remain afloat on the ocean’s surface, a condition termed ‘cold stunning’. Understanding their transport in cold-stunned state can help improve the rehabilitation process of stranded turtles. Methods Cold-stunned turtles are back-tracked as passive, virtual particles from their stranding location using Lagrangian flow modelling. This study investigates when and where these juvenile turtles cross the threshold temperatures between 10° C and 14° C before stranding by tracking the temperature along the trajectories. Results As expected, the simulations show the transport of the cold-stunned turtles via the English Channel. More surprisingly, the analysis suggests they likely experience cold-stunning in the southern North Sea region and encounter temperatures below 10°C for only a few days to up to three weeks, and below 12°C for up to a month before stranding. Conclusions The estimate of cold-stunned drift duration of the turtles provides additional knowledge about their health status at the time of stranding. Adherence to rehabilitation protocols for Kemp’s ridley and post-release monitoring are recommended to improve their long-term survival.

Modelling drift of cold-stunned Kemp's ridley turtles stranding on the Dutch coast.

Every few years, juvenile Kemp's ridley turtles ( Lepidochelys kempii) are stranded on the Dutch coasts. The main population distribution of this critically endangered species primarily inhabits the Gulf of Mexico and the east coast of the United States. This study focuses on five reports from the Netherlands between 2007 and 2022, where juvenile turtles were reported to strand alive during the winter, albeit in a hypothermic state. At ambient ocean temperatures between 10°C and 13°C, Kemp's ridley turtles begin to show an inability to actively swim and remain afloat on the ocean's surface, a condition termed 'cold stunning'. Understanding their transport in cold-stunned state can help improve the rehabilitation process of stranded turtles. Cold-stunned turtles are back-tracked as passive, virtual particles from their stranding location using Lagrangian flow modelling. This study investigates when and where these juvenile turtles cross the threshold temperatures between 10° C and 14° C before stranding by tracking the temperature along the trajectories. As expected, the simulations show the transport of the cold-stunned turtles via the English Channel. More surprisingly, the analysis suggests they likely experience cold-stunning in the southern North Sea region and encounter temperatures below 10°C for only a few days to up to three weeks, and below 12°C for up to a month before stranding. The estimate of cold-stunned drift duration of the turtles provides additional knowledge about their health status at the time of stranding. Adherence to rehabilitation protocols for Kemp's ridley and post-release monitoring are recommended to improve their long-term survival.

Modelling drift of cold-stunned Kemp's ridley turtles stranding on the Dutch coast

Background Every few years juvenile Kemp’s ridley turtles (Lepidochelys kempii) are found stranded on the Dutch coasts. The main population distribution of this critically endangered species primarily inhabits the Gulf of Mexico and east coast of the United States. This study focuses on five reports from the Netherlands over the past 15 years, where juvenile turtles were reported to strand alive during the winter, albeit in a hypothermic state. Between ambient ocean temperatures of 10°C and 13°C, Kemp’s ridley turtles are unable to actively swim and remain afloat on the ocean’s surface, a condition termed ‘cold stunning’. Understanding their transport in cold-stunned state can help improve the rehabilitation process of stranded turtles. Methods Cold-stunned turtles are back-tracked as passive, virtual particles from their stranding location using Lagrangian flow modelling. This study investigates when and where juveniles of the Kemp's ridley turtles cross the threshold temperatures between 10–14° C before stranding by tracking the temperature along the trajectories. Results As expected, the simulations show transport of the turtles to the Dutch coast via the English Channel. More surprisingly, the analysis suggests that they likely experience cold-stunning in the southern North Sea region and encounter temperatures below 10°C for only a few days to up to three weeks, and below 12°C for up to a month before stranding. Conclusions Adherence to rehabilitation protocols for Kemp’s ridley and monitoring individuals post-release are recommended to improve their long-term survival.

Osteomyelitis in cold-stunned Kemp's ridley sea turtles (Lepidochelys kempii) hospitalized for rehabilitation: 25 cases (2008-2018).

To characterize osteolytic lesions in cold-stunned Kemp's ridley sea turtles (Lepidochelys kempii) hospitalized for rehabilitation and describe methods used for the management of such lesions. 25 stranded, cold-stunned Kemp's ridley sea turtles hospitalized between 2008 and 2018. Medical records of sea turtles with a diagnosis of osteolytic lesions were reviewed retrospectively to obtain the date of diagnosis, clinical signs, radiographic findings, microbial culture results, hematologic and plasma biochemical data, cytologic and histologic findings, antimicrobial history, time to first negative culture result, treatment duration, and outcome. Lesions were identified radiographically a median of 50 days after admission and were located within epiphyses or metaphyses of various appendicular joints. Lesions were associated with periarticular swelling (n = 24), lameness (16), lethargy (2), and hyporexia (2). Bacterial culture yielded growth of single organisms (n = 16), multiple organisms (2), or no growth (6). Significant differences in hematologic and biochemical data were detected between the times of diagnosis and convalescence. Cytologic and histologic findings characterized the lesions as osteomyelitis leading to septic arthritis. Sixteen sea turtles were managed medically, and 8 were managed medically and surgically. Surgery resulted in rapid improvement in joint mobility and overall clinical status. Most (22/25 [88%]) sea turtles survived and were released after long-term management. During rehabilitation, cold-stunned Kemp's ridley sea turtles may be affected by osteomyelitis. Medical management based on antimicrobial susceptibility testing was effective for most turtles. Long term management efforts in turtles are justified by high survival rate.

Characterization of oral and cloacal microbial communities in cold-stunned Kemp's ridley sea turtles (Lepidochelys kempii) during the time course of rehabilitation.

Microbial communities of animals play a role in health and disease, including immunocompromised conditions. In the northeastern United States, cold-stunning events often cause endangered Kemp’s ridley turtles (Lepidochelys kempii) to become stranded on beaches in autumn. These sea turtles are admitted to rehabilitation facilities when rescued alive and are presumed immunocompromised secondary to hypothermia. To better understand the role that microbes play in the health of cold-stunned sea turtles, we characterized the oral and cloacal microbiome from Kemp’s ridley turtles at multiple timepoints during rehabilitation, from admission to pre-release, by using Illumina sequencing to analyze the 16S rRNA gene. Microbial communities were distinct between body sites and among turtles that survived and those that died. We found that clinical parameters such as presence of pneumonia or values for various blood analytes did not correlate with oral or cloacal microbial community composition. We also investigated the effect of antibiotics on the microbiome during rehabilitation and prior to release and found that the type of antibiotic altered the microbial community composition, yet overall taxonomic diversity remained the same. The microbiome of cold-stunned Kemp’s ridley turtles gradually changed through the course of rehabilitation with environment, antibiotics, and disease status all playing a role in those changes and ultimately the release status of the turtles.

The Effect of Delayed Hospitalization in Cold-Stunned Kemp's Ridley Turtles (Lepidochelys kempii)

Abstract Kemp's ridley turtles (Lepidochelys kempii) are a critically endangered marine species found along the eastern coast of the United States and Mexico. During autumn and early winter, turtles in the northern end of this range may become cold-stunned and stranded if they fail to migrate to warmer waters. Depending on the time of day that stranded turtles are discovered, turtles may be kept overnight by stranding officials before being hospitalized. Turtles for which hospitalization was delayed overnight had higher respiratory rates, packed cell volumes, plasma total solids, and blood potassium concentrations in comparison to turtles that were hospitalized on the day of stranding. There was no significant difference in outcome for turtles presented immediately versus those affected by delayed presentation. These findings suggest that cold-stunned turtles affected by an overnight hospitalization delay may benefit from basic medical treatments, such as fluid therapy, until they can be transferred to a ...

Diagnosis and management of Enterococcus spp infections during rehabilitation of cold-stunned Kemp's ridley turtles (Lepidochelys kempii): 50 cases (2006-2012).

To evaluate clinical data for cold-stunned Kemp's ridley turtles (Lepidochelys kempii) with Enterococcus spp infections during rehabilitation. Retrospective case series. 50 stranded cold-stunned Kemp's ridley turtles hospitalized between 2006 and 2012. Medical records for turtles from which Enterococcus spp were isolated were reviewed retrospectively, and clinical data, including morphometric data, body temperature at admission, physical examination findings, antimicrobial medication history, history of medications administered IV, environmental data, day of diagnosis, clinical signs at diagnosis, microbiological testing results, sources of positive culture results, hematologic and plasma biochemical data, cytologic and histopathologic results, radiographic findings, antimicrobial treatments, time to first negative culture result, treatment duration, results of subsequent cultures, and case outcome, were collated and analyzed. Enterococcus spp were isolated from bacteriologic cultures of blood, bone, joint, and respiratory tract samples and a skin lesion, with supporting evidence of infection provided by histopathologic, cytologic, and radiographic data. Positive culture results were associated with clinical problems such as lethargy, anorexia, and lameness. Most (34/43 [79%]) turtles for which an antemortem diagnosis was made survived with treatment and were released into the wild. Cold-stunned Kemp's ridley turtles may be affected by serious Enterococcus spp infections during rehabilitation. Recognition and treatment of these infections are important for successful rehabilitation.

Development and evaluation of three mortality prediction indices for cold-stunned Kemp's ridley sea turtles (Lepidochelys kempii).

Kemp's ridley sea turtle is an endangered species found in the Gulf of Mexico and along the east coast of the USA. Cold-stunned Kemp's ridley turtles are often found stranded on beaches of Massachusetts and New York in November and December each year. When found alive, turtles are transported to rehabilitation centres for evaluation and treatment. Blood gas and chemistry analytes of major clinical relevance in sea turtles were selected to develop mortality prediction indices (MPI)s. Testing the diagnostic performance of various combinations of blood gas and chemistry analytes by receiver operating characteristics (ROC) analysis resulted in the development of three mortality prediction indices. The sensitivity and specificity of the best performing MPI (based on three blood analytes: pH, pO2, and potassium) was 88 and 80%, respectively. Using ROC analysis, the area under the curve = 0.896 (95% confidence interval = 0.83-0.94). The use of validated MPIs based on four blood analytes (pH, pCO2, pO2, and potassium) could be useful for better diagnosis, treatment, and prognosis of cold-stunned sea turtles when admitted to rehabilitation facilities.

Prevalence, distribution, and progression of radiographic abnormalities in the lungs of cold-stunned Kemp's ridley sea turtles (Lepidochelys kempii): 89 cases (2002–2005)

To evaluate the prevalence, distribution, and progression of radiographic abnormalities in the lungs of cold-stunned Kemp's ridley sea turtles (Lepidochelys kempii) and associations between these abnormalities and body weight, carapace length, and hematologic and plasma biochemical variables. Retrospective case series. 89 cold-stunned juvenile Kemp's ridley sea turtles. Medical records were reviewed. Dorsoventral and horizontal beam craniocaudal radiographs were evaluated for the presence, distribution, and progression of lung abnormalities. Turtles were categorized as having radiographically normal or abnormal lungs; those with abnormalities detected were further categorized according to the distribution of abnormalities (left lung, right lung, or both affected). Body weight, carapace length, and hematologic and plasma biochemical data were compared among categories. 48 of 89 (54%) turtles had radiographic abnormalities of the lungs. Unilateral abnormalities of the right or left lung were detected in 14 (16%) and 2 (2%), respectively; both lungs were affected in 32 (36%). Prevalence of unilateral abnormalities was significantly greater for the right lung than for the left lung. Evaluation of follow-up radiographs indicated clinical improvement over time for most (18/31 [58%]) turtles. Prevalence of bilateral radiographic abnormalities was positively correlated with body weight and carapace length. There was no significant association between radiographic category and hematologic or plasma biochemical variables. Radiographic abnormalities of the lungs were commonly detected in cold-stunned Kemp's ridley turtles. Results of this study may aid clinicians in developing effective diagnostic and treatment plans for these patients.

SURGICAL REMOVAL OF AN ABSCESS ASSOCIATED WITHFUSARIUM SOLANIFROM A KEMP'S RIDLEY SEA TURTLE (LEPIDOCHELYS KEMPII)

A cold-stunned Kemp's ridley sea turtle, Lepidochelys kempii, developed an abscess associated with Fusarium solani, Vibrio alginolyticus, and a Shewenalla species after receiving a bite wound to the front flipper during rehabilitation. The lesion failed to respond to medical therapy and was treated successfully with surgery. Histopathology of the excised tissue demonstrated septic heterophilic inflammation with necrosis and granulation tissue, fungal elements, and bacteria, despite appropriate antimicrobial therapy. Variably thick bands of dense collagenous tissue partially surrounded affected areas which might have limited drug penetration into the tissue. Postoperative healing and eventual releases were uneventful. This is the first report of surgical treatment of cutaneous Fusarium infection in a sea turtle and supports surgery as an effective treatment for a fungal abscess in a reptile.

Metabolic and respiratory derangements associated with death in cold-stunned Kemp's ridley turtles (Lepidochelys kempii): 32 cases (2005–2009)

To assess selected clinicopathologic variables at hospital admission (day 1) for cold-stunned Kemp's ridley turtles (Lepidochelys kempii) that died during the first 3 days after admission (nonsurvivors) and turtles that survived (survivors) and to determine the percentage change of each variable from day 1 to day of death (nonsurvivors) or to day 2 or 3 of hospitalization (survivors). Retrospective case-control study. Animals-64 stranded, cold-stunned Kemp's ridley turtles hospitalized from October 2005 through December 2009. Blood gas, pH, Hct, and selected biochemical values in blood samples determined on day 1 and day of death (nonsurvivors; n = 32) or day 2 or 3 of hospitalization (survivors; 32) were obtained from medical records. For each variable, initial values and percentage changes (from initial values to values at the day of death or day 2 or 3 of hospitalization) were compared between survivors and nonsurvivors. Compared with blood analysis findings for survivors, nonsurvivors initially had significantly higher potassium concentration and Pco(2) and significantly lower Po(2), pH, and bicarbonate concentration than did survivors. For the first 2 or 3 days of hospitalization, percentage changes in potassium, lactate, and ionized calcium concentrations were significantly higher and percentage changes in pH and plasma glucose and bicarbonate concentrations were significantly lower in nonsurvivors. At hospital admission, cold-stunned Kemp's ridley turtles were affected by metabolic and respiratory derangements; severe derangements were associated with death. Evaluation of blood gas, pH, Hct, and selected clinicopathologic variables provided useful clinical and prognostic information during rehabilitation of cold-stunned Kemp's ridley turtles.

Single‐dose pharmacokinetics of ceftazidime and fluconazole during concurrent clinical use in cold‐stunned Kemp’s ridley turtles (Lepidochelys kempii)

Single-dose pharmacokinetics of intramuscularly administered ceftazidime (22 mg/kg) and subcutaneously administered fluconazole (21 mg/kg) were investigated during concurrent clinical use in naturally cold-stunned Kemp's ridley turtles (Lepidochelys kempii). Maximum mean concentration for ceftazidime was 61.31 μg/mL, and time of maximum concentration was 1.56 h postinjection. Maximum mean concentration for fluconazole was 26.16 μg/mL, and time of maximum concentration was 0.79 h postinjection. Results indicate that the ceftazidime dose and dosing interval used in this study are likely to be effective in treating susceptible strains of bacteria in Kemp's ridley turtles. However, the fluconazole dose and dosing interval are not likely to be effective against filamentous fungal pathogens that are often involved in marine turtle fungal infections.

Hematologic and plasma biochemical findings in cold-stunned Kemp's ridley turtles: 176 cases (2001–2005)

To document hematologic and plasma biochemical values for a large number of cold-stunned Kemp's ridley turtles at the beginning of rehabilitation, to investigate differences in hematologic and plasma biochemical values of turtles that ultimately survived versus those that died, and to compare values of survivors during convalescence with initial values obtained at the time of admission. Retrospective case series. 176 stranded, cold-stunned Kemp's ridley turtles hospitalized between 2001 and 2005. Hematologic and plasma biochemical values obtained at the time of admission were compared retrospectively for turtles that died versus turtles that survived. Initial results for survivors were compared with convalescent results obtained later in rehabilitation. Turtles that died had significantly greater plasma concentrations of sodium, chloride, potassium, calcium, phosphorus, and uric acid than did turtles that survived. For survivors, values obtained during convalescence for BUN concentration and plasma calcium concentration were significantly greater than initial values obtained at the time of admission, whereas values obtained during convalescence for glucose, sodium, and uric acid concentrations were significantly lower than initial values. Cold-stunned Kemp's ridley turtles may be affected by electrolyte derangements, dehydration, and decreased renal function. Hematologic and plasma biochemical evaluation of such turtles provided useful clinical and prognostic information during the rehabilitation process.

Trace Metal and Organochlorine Pesticide Concentrations in Cold-Stunned Juvenile Kemp's Ridley Turtles (Lepidochelys kempii) from Cape Cod, Massachusetts

Whole blood and keratin mercury concentrations, complete blood cell counts, and plasma biochemical health profiles were evaluated in 31 juvenile cold-stunned Kemp's ridley turtles (Lepidochelys kempii) from Cape Cod, Massachusetts. In addition, plasma copper, zinc, selenium, and cadmium concentrations were measured for 16 of these turtles. Liver mercury concentrations were measured for 6 turtles that were dead upon acquisition or died during rehabilitation. Concentrations of 18 organochlorine pesticides were measured in plasma of 18 live turtles, and liver, kidney, fat, and brain of 3 deceased turtles. Metal levels were generally similar to those previously published for sea turtles, with mean values (wet weight) of 24 ng/g for blood mercury, 67 ng/g for liver mercury, 389 ng/g for keratin mercury, 690 ng/g for plasma copper, 2290 ng/g for plasma zinc, and 490 ng/g for plasma selenium. Cadmium was not detected in any sample. Organochlorine levels were generally low in comparison to values published for cold-stunned juvenile Kemp's ridley turtles in the 1980s. Several significant correlations between metal levels, hematology, and plasma biochemical health parameters were detected; however, the cause of these correlations could not be determined. This study demonstrates that Kemp's ridley turtles may be exposed to contaminants at a young age. Further investigation of the sources and effects of contaminants in juvenile sea turtles is warranted.

SCINTIGRAPHIC AND RADIOGRAPHIC EVALUATION OF APPENDICULAR SKELETAL LESIONS IN COLD‐STUNNED KEMP'S RIDLEY SEA TURTLES

Osteolytic appendicular skeletal lesions in eight-stranded, cold-stunned Kemp's ridley sea turtles (Lepidochelys kempii) were evaluated using radiography and skeletal scintigraphy. Radiographic studies were performed monthly in most animals. Follow-up scintigraphy was performed 45-120 days after the initial exams in six turtles. Radiographically, lesions slowly progressed from an early osteolytic process contained to either the proximal or distal end of long bones, to a later stage characterized by thickening of the affected bone, sclerosis, and remodeling of the lesion borders. In seven turtles, the initial scintigrams were characterized by at least one focus of abnormal radiopharmaceutical uptake that correlated with a lytic site noted in radiographs. In five turtles, scintigraphic lesions were characterized by asymmetric radiopharmaceutical uptake rather than by increased intensity of uptake. Scintigraphic studies obtained more than 4 months after the appearance of clinical and radiographic signs had minimal, if any, abnormal radiopharmaceutical uptake, despite the persistence of abnormal radiographic findings. Skeletal scintigraphy is an effective method for more precisely determining if and when these animals can be returned to the wild. Animals were released if normal radiopharmaceutical uptake was seen during initial examination, or if decreased uptake was noted between serial examinations. In four of the turtles, resolution of abnormal scintigraphic findings permitted an objective decision to discontinue antibiotic and antifungal therapy. Seven of the eight turtles were released after correlation of the clinical signs with the imaging findings. Radiographs, however, are still needed to facilitate the correct identification of lesions with scintigraphy.

Metabolic and respiratory status of cold-stunned Kemp’s ridley sea turtles (Lepidochelys kempii)

"Cold-stunning" of sea turtles has been reported as a naturally occurring stressor for many years; however, the physiologic status of cold-stunned turtles has only been partially described. This study investigated initial and convalescent venous blood gas, acid-base, and critical plasma biochemical data for 26 naturally cold-stunned Kemp's ridley sea turtles (Lepidochelys kempii) from Cape Cod, MA, USA. Samples were analyzed for pH, pCO(2), pO(2), bicarbonate, plasma osmolality, sodium, potassium, chloride, ionized calcium, ionized magnesium, glucose, lactate, and blood urea nitrogen using a clinical point-of-care analyzer. Data were corrected for the patient's body temperature using both species-specific and more general correction methods. In general, venous blood gas, acid-base, and plasma biochemical data obtained for surviving cold-stunned Kemp's ridley sea turtles were consistent with previously documented data for sea turtles exposed to a wide range of temperatures and physiologic stressors. Data indicated that turtles were initially affected by metabolic and respiratory acidosis. Initial pH-corrected ionized calcium concentrations were lower than convalescent concentrations, and initial pH-corrected ionized magnesium concentrations were higher than convalescent concentrations.