Lepidochelys Kempii Research Articles

Report of Enodiotrema megachondrus (Looss, 1899) Looss, 1901 (Digenea: Plagiorchiidae) in a green turtle Chelonia mydas Linnaeus, 1758 (Testudines, Cheloniidae) from Brazil

Summary This paper describes the occurrence of Enodiotrema megachondrus (Looss, 1899) Looss, 1901 in a juvenile green sea turtle (Chelonia mydas Linnaeus, 1758) found on the coast of Brazil. This parasite has been described in Caretta caretta from Egypt, France, the Mediterranean Sea, the Madeira Archipelago, the Adriatic Sea and the USA, in C. mydas from Egypt and the USA, in Eretmochelys imbricata from Cuba, in Lepidochelys olivacea from Mexico and Costa Rica and in Lepidochelys kempii from USA. This note represents the first report of E. megachondus in a green sea turtle in the South-West Atlantic Ocean.

Ophthalmic variables in rehabilitated juvenile Kemp's ridley sea turtles (Lepidochelys kempii).

To determine central corneal thickness (total corneal thickness [TCT], epithelial thickness [ET], and stromal thickness [ST]), anterior chamber depth (ACD), and intraocular pressure (IOP) in Kemp's ridley sea turtles (Lepidochelys kempii). Prospective cross-sectional study. 25 healthy rehabilitated juvenile Kemp's ridley sea turtles. PROCEDURES; Body weight and straight-line standard carapace length (SCL) were recorded. All turtles underwent a complete anterior segment ophthalmic examination. Central TCT, ET, ST, and ACD were determined by use of a spectral-domain optical coherence tomography device. Intraocular pressure was determined with a rebound tonometer; the horse setting was used to measure IOP in all 25 turtles, and the undefined setting was also used to measure IOP in 20 turtles. For each variable, 3 measurements were obtained bilaterally. The mean was calculated for each eye and used for analysis purposes. The mean ± SD body weight and SCL were 3.85 ± 1.05 kg (8.47 ± 2.31 lb) and 29 ± 3 cm, respectively. The mean ± SD TCT, ET, ST, and ACD were 288 ± 23 μm, 100 ± 6 μm, 190 ± 19 μm, and 581 ± 128 μm, respectively. Mean ± SD IOP was 6.5 ± 1.0 mm Hg when measured with the horse setting and 3.8 ± 1.1 mm Hg when measured with the undefined setting. Results provided preliminary reference ranges for objective assessment of ophthalmic variables in healthy juvenile Kemp's ridley sea turtles.

Sea Turtle Bycatch in the Large-Mesh Gillnet Flounder Fishery in Carteret County, North Carolina, USA, June-November 2009

Abstract Sea turtle bycatch has been documented in the large-mesh gillnet fishery that targets flounder in estuarine waters of North Carolina (NC). However, only portions of the fishery operated under Endangered Species Act Incidental Take Permits and had regular observer coverage to determine the occurrence and extent of sea turtle bycatch. From June through November 2009, an Alternative Platform Observer Program (APOP) was initiated in southeastern Carteret County, NC, to document turtle entanglements. Observers covered 1.6% of the total number of large-mesh gillnet trips reported (1.1% of landings) and documented turtle bycatch (n = 22) on 36% of the observed trips (12 of 33). Most turtles were recovered alive (n = 15), and all interactions occurred in June, July, and August. Bycaught sea turtle species included 12 greens (Chelonia mydas), 5 Kemp’s ridleys (Lepidochelys kempii), and 5 loggerheads (Caretta caretta). Hauls with bycaught turtles in June had a significantly greater mean string length than those without bycatch (P = 0.02), but despite the institution of regulations limiting string length, no difference was found in mean string length overall before (June) and after (July-November) regulations went into effect. Documented turtle bycatch in this area supports the need for observer coverage across the entire spatio-temporal scope of the fishery at levels necessary for robust bycatch estimates. Representative observer data across longer time series can inform managers where and when bycatch risks are greatest and help in developing mitigation measures that decrease bycatch risk while reducing negative economic impacts on the fishers.

Estimating the historic size and current status of the Kemp's ridley sea turtle (Lepidochelys kempii) population

AbstractThis study is a quantitative evaluation of historic nesting levels of the Kemp's ridley sea turtle (Lepidochelys kempii) in 1947 based on (1) the Herrera film of a 1947 arribada, (2) Hildebrand's 1947 report regarding the 1947 arribada shown in the Herrera film, (3) historic documentation regarding the Herrera film, and (4) current nesting characteristics related to arribada size relative to total nests for a season. Using this information in a quantitative approach, we estimate a total of approximately 26 916 nests during the 1947 arribada recorded by Herrera. Based on current nesting trends, we also predict that this would equate to approximately 121 517 total nests for the 1947 season (range of 82 514–209 953), which would represent approximately 48 607 nesting females (range of 33 006–83 981). This suggests that during and prior to the 1947 nesting season a relatively robust population of Kemp's ridleys existed, which could support arribadas consisting of at least 26 916 females. The results of the current study indicate that from 1947 through 1985 (the lowest point in the decline of Kemp's ridley nesting) the Kemp's ridley population underwent a 99.4% decline (range of 99.2–99.7%) from an estimated 121 517 nests per season in 1947 to 702 nests per season in 1985. Although the Kemp's ridley population has been recovering since the 1985 season, it has deviated from its exponential recovery rate and has declined in recent years. The current levels of nesting (12 053 nests in 2014) are still relatively low at 9.9% (range of 5.7–14.6%) of the total estimated nests that occurred in 1947. It is currently not clear whether this population will recover to historic levels considering recent nesting trends and due to a variety of threats that may hinder its recovery.

Assessment of ground transportation stress in juvenile Kemp's ridley sea turtles (Lepidochelys kempii).

Sea turtle rehabilitation centres frequently transport sea turtles for long distances to move animals between centres or to release them at beaches, yet there is little information on the possible effects of transportation-related stress ('transport stress') on sea turtles. To assess whether transport stress is a clinically relevant concern for endangered Kemp's ridley sea turtles (Lepidochelys kempii), we obtained pre-transport and post-transport plasma samples from 26 juvenile Kemp's ridley sea turtles that were transported for 13 h (n = 15 turtles) or 26 h (n = 11 turtles) by truck for release at beaches. To control for effects of handling, food restriction and time of day, the same turtles were also studied on 'control days' 2 weeks prior to transport, i.e. with two samples taken to mimic pre-transport and post-transport timing, but without transportation. Blood samples were analysed for nine clinical health measures (pH, pCO2, pO2, HCO3, sodium, potassium, ionized calcium, lactate and haematocrit) and four 'stress-associated' parameters (corticosterone, glucose, white blood cell count and heterophil-to-lymphocyte ratio). Vital signs (heart rate, respiratory rate and cloacal temperature) were also monitored. Corticosterone and glucose showed pronounced elevations due specifically to transportation; for corticosterone, this elevation was significant only for the longer transport duration, whereas glucose increased significantly after both transport durations. However, clinical health measures and vital signs showed minimal or no changes in response to any sampling event (with or without transport), and all turtles appeared to be in good clinical health after both transport durations. Thus, transportation elicits a mild, but detectable, adrenal stress response that is more pronounced during longer durations of transport; nonetheless, Kemp's ridley sea turtles can tolerate ground transportation of up to 26 h in good health. These results are likely to depend on specific transportation and handling protocols.

Head-Started Kemp's Ridley Turtle (Lepidochelys kempii) Nest Recorded in Florida: Possible Implications

Abstract A head-started Kemp's ridley sea turtle (Lepidochelys kempii) was documented nesting on South Walton Beach, Florida on 25 May 2015. This record supports the possibility that exposure to Florida waters after being held in captivity through 1–3 yrs of age during the head-starting process may have influenced future nest site selection of this and perhaps other Kemp's ridley turtles. Such findings could have important ramifications for marine water experimentation and release site selection for turtles that have been reared in captivity.

Long-Term Movements of an Adult Male Kemp's Ridley Sea Turtle (Lepidochelys kempii) in the Northwestern Gulf of Mexico

Long-Term Movements of an Adult Male Kemp's Ridley Sea Turtle (Lepidochelys kempii) in the Northwestern Gulf of Mexico

Trends in Kemp's Ridley Sea Turtle (Lepidochelys kempii) Relative Abundance, Distribution, and Size Composition in Nearshore Waters of the Northwestern Gulf of Mexico

Trends in Kemp's Ridley Sea Turtle (Lepidochelys kempii) Relative Abundance, Distribution, and Size Composition in Nearshore Waters of the Northwestern Gulf of Mexico

Introduction to the Special Issue on the Kemp's Ridley Sea Turtle (Lepidochelys kempii)

Introduction to the Special Issue on the Kemp's Ridley Sea Turtle (Lepidochelys kempii)

Thousands of Single Nucleotide Polymorphisms in the Critically Endangered Kemp's Ridley Sea Turtle (Lepidochelys kempii) Revealed by Double-Digest Restriction-Associated DNA Sequencing: Opportunities for Previously Elusive Conservation Genetics Research

Thousands of Single Nucleotide Polymorphisms in the Critically Endangered Kemp's Ridley Sea Turtle (Lepidochelys kempii) Revealed by Double-Digest Restriction-Associated DNA Sequencing: Opportunities for Previously Elusive Conservation Genetics Research

Migratory corridors of adult female Kemp's ridley turtles in the Gulf of Mexico

For many marine species, locations of migratory pathways are not well defined. We used satellite telemetry and switching state-space modeling (SSM) to define the migratory corridor used by Kemp's ridley turtles (Lepidochelys kempii) in the Gulf of Mexico. The turtles were tagged after nesting at Padre Island National Seashore, Texas, USA from 1997 to 2014 (PAIS; n=80); Rancho Nuevo, Tamaulipas, Mexico from 2010 to 2011 (RN; n=14); Tecolutla, Veracruz, Mexico from 2012 to 2013 (VC; n=13); and Gulf Shores, Alabama, USA during 2012 (GS; n=1). The migratory corridor lies in nearshore Gulf of Mexico waters in the USA and Mexico with mean water depth of 26m and a mean distance of 20km from the nearest mainland coast. Migration from the nesting beach is a short phenomenon that occurs from late-May through August, with a peak in June. There was spatial similarity of post-nesting migratory pathways for different turtles over a 16year period. Thus, our results indicate that these nearshore Gulf waters represent a critical migratory habitat for this species. However, there is a gap in our understanding of the migratory pathways used by this and other species to return from foraging grounds to nesting beaches. Therefore, our results highlight the need for tracking reproductive individuals from foraging grounds to nesting beaches. Continued tracking of adult females from PAIS, RN, and VC nesting beaches will allow further study of environmental and bathymetric components of migratory habitat and threats occurring within our defined corridor. Furthermore, the existence of this migratory corridor in nearshore waters of both the USA and Mexico demonstrates that international cooperation is necessary to protect essential migratory habitat for this imperiled species.

Baseline Corneal Sensitivity and Duration of Action of Proparacaine in Rehabilitated Juvenile Kemp's Ridley Sea Turtles (Lepidochelys kempii)

Abstract Corneal sensitivity and the duration of action of a topical anesthetic drop, proparacaine, were evaluated prospectively. Baseline corneal touch threshold (CTT) was determined using a Cochet-Bonnet esthesiometer in 25 healthy, rehabilitated Kemp's ridley sea turtles (Lepidochelys kempii). Corneal touch threshold was defined as the filament length required to elicit a blink in at least three out of five applications. The onset and duration of action of proparacaine was determined in nine of the Kemp's ridley sea turtles. One drop of proparacaine was applied to each eye and the CTT was subsequently measured at 1, 5, 15, 30, and 45 min. Results demonstrated that the mean CTT for the Kemp's ridley sea turtles was 5.7 cm, with a median of 6 cm. Additionally, proparacaine had an onset of action within 1 min after application (17/18 eyes). The duration of action of proparacaine exceeded the 45 min time limit in all eyes. This study shows that Kemp's ridley sea turtles have an exceptionally sensitive corn...

Diet Analysis of Subadult Kemp’s Ridley (Lepidochelys kempii) Turtles from West-Central Florida

Abstract The present study is the first to characterize Kemp’s ridley turtle (Lepidochelys kempii) diets between the west-central Florida estuaries of Tampa Bay to Charlotte Harbor. We analyzed the stomach contents of 20 stranded subadult L. kempii and found that their diets were primarily carnivorous, consisting mostly of calico crab (Hepatus epheliticus), stone crab (Menippe mercenaria), and blue crab (Callinectes sapidus). In addition, we found uncommon prey items including fish and horseshoe crab (Limulus polyphemus), suggesting these L. kempii are opportunistic feeders. When separated into 2 size classes (25–45 [n = 9] and > 45 [n = 11] cm straight carapace length), there was a significant difference in the turtles’ diet composition. These new insights into the ecology and life history of a critically endangered sea turtle reveal essential prey resources used by a poorly studied yet crucial subadult life stage.

Deepwater Horizon oil spill impacts on sea turtles could span the Atlantic.

We investigated the extent that the 2010 Deepwater Horizon oil spill potentially affected oceanic-stage sea turtles from populations across the Atlantic. Within an ocean-circulation model, particles were backtracked from the Gulf of Mexico spill site to determine the probability of young turtles arriving in this area from major nesting beaches. The abundance of turtles in the vicinity of the oil spill was derived by forward-tracking particles from focal beaches and integrating population size, oceanic-stage duration and stage-specific survival rates. Simulations indicated that 321 401 (66 199–397 864) green (Chelonia mydas), loggerhead (Caretta caretta) and Kemp's ridley (Lepidochelys kempii) turtles were likely within the spill site. These predictions compared favourably with estimates from in-water observations recently made available to the public (though our initial predictions for Kemp's ridley were substantially lower than in-water estimates, better agreement was obtained with modifications to mimic behaviour of young Kemp's ridley turtles in the northern Gulf). Simulations predicted 75.2% (71.9–76.3%) of turtles came from Mexico, 14.8% (11–18%) from Costa Rica, 5.9% (4.8–7.9%) from countries in northern South America, 3.4% (2.4–3.5%) from the United States and 1.6% (0.6–2.0%) from West African countries. Thus, the spill's impacts may extend far beyond the current focus on the northern Gulf of Mexico.

Sea Turtle Rehabilitation Success Increases with Body Size and Differs Among Species

Wildlife rehabilitation can contribute to species conservation by releasing healthy individuals back into the wild and educating the public about threatening processes. Rehabilitation has substantial financial costs, however, and thus it is important to understand the success rates of these potential conservation management actions. We quantified the success rates for 1700 sea turtles admitted to rehabilitation facilities in Florida (USA) between 1986 and 2004. Rehabilitation success was low: 61.5% of turtles died in rehabilitation and only 36.8% were released back into the wild. A further 1.6% of turtles were maintained in captivity permanently due to the severe nature of their injuries. Most mortality occurred early during the rehabilitation process (within a few weeks), and successful rehabilitation often took several months to more than 3 yr. Loggerhead turtles (Caretta caretta) were most likely to survive rehabilitation, followed by Kemp’s ridleys (Lepidochelys kempii) and green turtles (Chelonia mydas); for all three species, larger individuals had an increased chance of successful rehabilitation. At face value, the low rates of rehabilitated turtles successfully released back into the wild may contribute only modestly to conservation in terms of contributing to population viability. However, many rehabilitation facilities provide important educational experiences that increase public awareness of the threats facing animals and highlight potential conservation solutions. Media coverage highlighting the release of rehabilitated animals further extends the conservation value of these efforts. Wildlife rehabilitation provides important direct benefits that, combined with social benefits, together may justify the expense and difficulty of rehabilitating individual animals.

TISSUE ENZYME ACTIVITIES IN KEMP'S RIDLEY TURTLES (LEPIDOCHELYS KEMPII).

This study determined the tissue distribution and activities of eight enzymes in 13 juvenile Kemp's ridley turtles (Lepidochelys kempii) that died after stranding. Samples from the liver, kidney, skeletal muscle, cardiac muscle, pancreas, lung, small intestine, and spleen were evaluated for activities of alanine aminotransferase (ALT), alkaline phosphatase (ALP), amylase, aspartate aminotransferase (AST), creatine kinase (CK), γ-glutamyl transferase (GGT), lactate dehydrogenase (LDH), and lipase. AST, CK, and LDH activities were highest in cardiac and skeletal muscle but were also found in all other tissues. Amylase and lipase activities were highest in the pancreas and low in all other tissues. ALP activity was highest in the lung. ALT activity was highest in liver, kidney, and cardiac muscle, and GGT activity was highest in the kidney, but activities of these enzymes were low in all tissues. These data may assist clinicians in interpretation of plasma enzyme activities of Kemp's ridley turtles.

The ontogeny of morphological defenses in Kemp's ridley (Lepidochelys kempii) and loggerhead (Caretta caretta) sea turtles.

Marine turtles are large reptiles that compensate for high juvenile mortality by producing hundreds of hatchlings during a long reproductive lifespan. Most hatchlings are taken by predators during their migration to, and while resident in, the open ocean. Their survival depends upon crypticity, minimizing movement to avoid detection, and foraging efficiently to grow to a size too difficult for predators to either handle or swallow. While these behavioral antipredator tactics are known, changes in morphology accompanying growth may also improve survival prospects. These have been only superficially described in the literature. Here, we compare the similarities and differences in presumed morphological defenses of growing loggerhead (Caretta caretta) and Kemp's ridley (Lepidochelys kempii) posthatchlings, related species that differ in growth rate, timing of habitat shift (the return from oceanic to neritic locations), and size at maturity. In both species, vertebral spination and carapace widening increase disproportionally as small turtles grow, but later in ontogeny, the spines regress, sooner in ridley than in loggerhead turtles. Carapace widening occurs in both species but loggerheads are always longer than they are wide whereas in Kemp's ridley turtles, the carapace becomes as wide as long. Our analysis indicates that these changes are unrelated to when each species shifts habitat but are related to turtle size. We hypothesize that the spines function in small turtles as an early defense against gape-limited predators, but changes in body shape function throughout ontogeny-initially to make small turtles too wide to swallow and later by presenting an almost flat and hardened surface that large predators (such as a sharks) are unable to grasp. The extremely wide carapace of the Kemp's ridley may compensate for its smaller adult size (and presumed greater vulnerability) than the loggerhead.

Direct evidence of swimming demonstrates active dispersal in the sea turtle ‘lost years’

Although oceanic dispersal in larval and juvenile marine animals is widely studied, the relative contributions of swimming behavior and ocean currents to movements and distribution are poorly understood [1-4]. The sea turtle "lost years" [5] (often referred to as the surface-pelagic [6] or oceanic [7] stage) are a classic example. Upon hatching, young turtles migrate offshore and are rarely observed until they return to coastal waters as larger juveniles [5]. Sightings of small turtles downcurrent of nesting beaches and in association with drifting organisms (e.g., Sargassum algae) led to this stage being described as a "passive migration" during which turtles' movements are dictated by ocean currents [5-10]. However, laboratory and modeling studies suggest that dispersal trajectories might also be shaped by oriented swimming [11-15]. Here, we use an experimental approach designed to directly test the passive-migration hypothesis by deploying pairs of surface drifters alongside small green (Chelonia mydas) and Kemp's ridley (Lepidochelys kempii) wild-caught turtles, tracking their movements via satellite telemetry. We conclusively demonstrate that these turtles do not behave as passive drifters. In nearly all cases, drifter trajectories were uncharacteristic of turtle trajectories. Species-specific and location-dependent oriented swimming behavior, inferred by subtracting track velocity from modeled ocean velocity, contributed substantially to individual movement and distribution. These findings highlight the importance of in situ observations for depicting the dispersal of weakly swimming animals. Such observations, paired with information on the mechanisms of orientation, will likely allow for more accurate predictions of the ecological and evolutionary processes shaped by animal movement.

Effects of hook and bait in a tropical northeast Atlantic pelagic longline fishery: Part I—Incidental sea turtle bycatch

The interaction between tuna fisheries and sea turtles is commonly recognized as one of the major threats and causes for the decline of sea turtle populations. Within the tuna and swordfish fisheries, the incidental sea turtle bycatch is usually more frequent from longline fisheries targeting swordfish. Therefore it is important to test possible mitigation measures, particularly in areas where fishing activities and high abundance of these species overlaps, as is the case of the Tropical Northeast Atlantic Ocean. Between August 2008 and December 2011, a total of 202 experimental pelagic longline sets were carried out in that region (latitude: 11–22°N, longitude: 20–38°W). The aim was to test the effects of changing the traditional J-style hooks (10° offset) baited with squid used by the fishing industry, against two circle hooks (one non-offset and one with 10° offset) and mackerel bait. Four sea turtle species were captured, with the leatherback Dermochelys coriacea comprising most of the bycatches (BPUE, bycatch per unit of effort using the traditional configuration of 0.990 turtles/1000 hooks), followed by three hardshell species: the loggerhead Caretta caretta and the olive ridley Lepidochelys olivacea (BPUE=0.165 turtles/1000 hooks), and the Kemp ridley Lepidochelys kempii (BPUE=0.024 turtles/1000 hooks). In general, the sea turtle interactions in the fishery can be reduced by changing from the traditional gear to one of the experimental combinations. However, those reductions were species-specific, with the leatherback bycatches reduced only when changing from J-style to the non-offset circle hook, while for the hardshell turtles both the hook style (using a circle hook, with or without offset) and the bait (using mackerel) significantly reduced the incidental bycatches. Hooking location was also species-specific, with most hardshell specimens hooked by the mouth and esophagus, while leatherbacks were mostly hooked externally by the flippers. Most of the sea turtles were captured and released alive with the mortality rates independent of the hook style and bait type used. A reduction of 55% in leatherback incidental bycatches can be expected in this fishery by changing from J-style to circle hooks, whereas for the hardshell species a 50–59% reduction can be obtained by changing to circle hooks (respectively with and without offset), and a 55% reduction by using mackerel bait.

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.