Running against time: conservation of the remaining hawksbill turtle (Eretmochelys imbricata) nesting population in the Dominican Republic

2012 ◽  
Vol 93 (4) ◽  
pp. 1133-1140 ◽  
Author(s):  
Ohiana Revuelta ◽  
Yolanda M. León ◽  
Francisco J. Aznar ◽  
Juan A. Raga ◽  
Jesús Tomás
Keyword(s):  
Sex Ratio ◽  
Dominican Republic ◽  
Preliminary Survey ◽  
Eretmochelys Imbricata ◽  
Emergence Success ◽  
Human Predation ◽  
Incubation Temperatures ◽  
Artificial Incubation

Saona Island hosts the last hawksbill turtle (Eretmochelys imbricata) nesting population in the Dominican Republic, which has experienced a severe decline in the last decades, mostly due to illegal egg take. Here we present the results of an artificial incubation programme started in 2007 to protect the clutches from human predation. A preliminary survey in 2006 showed that about 60% of clutches laid were taken by humans. Over the study period (2007–2010) we recorded 400 clutches, of which 38.2% were predated by humans, 40.7% were artificially incubated and 21% were incubated in situ. Overall, the artificial incubation programme allowed the release of 12,340 hatchlings. No differences were found in hatching and emergence success between clutches incubated in situ and clutches artificially incubated. However, incubation temperatures and incubation durations recorded suggest a male-biased hatchling sex-ratio in artificially incubated clutches. Although artificial incubation may mitigate the effect of egg take, our results indicate that other measures, such as clutch relocation to protected sections of the beach should be taken. Beach patrolling and education are currently implemented so that artificial incubation will be eventually phased out in favour of in situ incubation.

scholarly journals Assessing the efficacy of direct conservation interventions: clutch protection of the leatherback marine turtle in the Dominican Republic

Oryx ◽  
2014 ◽  
Vol 49 (4) ◽  
pp. 677-686 ◽  
Author(s):  
Ohiana Revuelta ◽  
Yolanda M. León ◽  
Annette C. Broderick ◽  
Pablo Feliz ◽  
Brendan J. Godley ◽  
...  
Keyword(s):  
Dominican Republic ◽  
Hatching Success ◽  
Marine Turtle ◽  
Dermochelys Coriacea ◽  
Protection Measures ◽  
Nesting Site ◽  
Incubation Duration ◽  
Artificial Incubation

AbstractThe beaches of Jaragua National Park in the Dominican Republic are the country's last known major nesting site for the leatherback marine turtle Dermochelys coriacea. This nesting aggregation is threatened by widespread illegal egg take, and clutch relocation and artificial incubation have been carried out as protection measures since 1974. We assess the efficacy of such efforts and investigate how artificial incubation may be influencing the success and sex ratios of clutches. We compare hatching success, incubation duration and embryo mortality in in-situ clutches (n = 43) with those incubated artificially at sites in the east and west of the Park (n = 35 and n = 31, respectively). Our results show that in the west, artificial incubation significantly decreases hatching success in clutches. In the east the duration of incubation is increased, which we predict would result in an increase in the number of males from these clutches. Clutch relocation is currently the only viable conservation option for clutches on eastern beaches because of illegal egg take but action is needed to ensure that the natural sex ratio is not distorted. However, on the western beaches in situ clutch incubation seems possible through beach protection. Further community engagement and enforcement are required to improve conservation measures at eastern beaches if long-term, less sustainable intervention is to be avoided.

scholarly journals A matrix population model for the hawksbill sea turtle (Eretmochelys imbricata) in the Gulf of Paria, Venezuela

2020 ◽  
Vol 48 (5) ◽  
pp. 739-748
Author(s):  
Clemente Balladares ◽  
María Fernanda Gonzalez ◽  
Diego Rodriguez
Keyword(s):  
Growth Rate ◽  
Population Growth ◽  
Population Growth Rate ◽  
Sea Turtle ◽  
Local Conservation ◽  
Eretmochelys Imbricata ◽  
Emergence Success ◽  
Stage 4 ◽  
Stage 1

Following classical literature in herpetology, we built two five-stage life tables for the endangered hawksbill sea turtle Eretmochelys imbricata in the Gulf of Paria, eastern Venezuela, using data from incidental captures by industrial trawl fisheries from 1991 until 2000, artisanal fisheries effect and regional stranding from 1999 to 2017, and a local conservation project with the nesting females from 2003 to 2018. We estimated the survivorship for the managed, translocated nests, and a portion of the natural in situ nests (≈31%). We used the resultant life graph and matrices to estimate the hawksbills population status in the region and determine differences in population growth rate and elasticity between translocated and in situ nests. Eggs/hatchlings (stage 1) and small juveniles of less than three years old (stage 2), had high mortalities. We controlled stage 1 mortality by translocating nests into a hatchery. The in situ nests suffered almost 88% predation or poaching. Conversely, these non-translocated nests' emergence success was greater than that of managed nests, but overall survivorship was the lower. We propose that fecundity could begin with sub-adults (stage 4) after the 7th year with 60 cm of curved carapace length. Finite rates of increase of both populations, managed and natural, were significantly higher than 1, and that of the managed population is significantly higher than that of the natural one, meaning that both populations would grow and that the managed one would grow faster than the natural one. Then protection of stage 1 is essential to the population of hawksbills in the region, although uncertainties of survivorship of stage 2 and fecundity of stage 4 were not properly confirmed locally. Notwithstanding, elasticity analysis indicated that the population growth rate was more affected by proportional changes in sub-adults and adults' fecundity than any other life-history element.

NEsting by the hawsbill turtle (Eretmochelys imbricata) on Milman Island, Great Barrier Reef, Australia

1995 ◽  
Vol 22 (2) ◽  
pp. 241 ◽  
Author(s):  
KA Loop ◽  
JD Miller ◽  
CJ Limpus
Keyword(s):  
Clutch Size ◽  
Carapace Length ◽  
Average Diameter ◽  
Average Weight ◽  
Nesting Biology ◽  
Eretmochelys Imbricata ◽  
Nest Sites ◽  
Emergence Success ◽  
Incubation Temperatures ◽  
Hawksbill Turtles

Nesting biology of hawksbill sea turtles (Eretmochelys imbricata) is described with morphometric and meristic measurements collected from 365 turtles over 76 nights of beach patrols on Milman I. The nesting season was already in progress when the study began in January and continued after the research team left in March 1991. Average renesting interval was 14.2 days, and the hawksbill turtles laid an average of 2.6 clutches during the study period. Nest sites were located most commonly under trees (67.2%). Average curved carapace length was 81.7 cm, width was 70.6 cm, and weight after laying was 50.3 kg. Mean clutch size was 124 eggs. Eggs had an average diameter of 3.48 cm and an average weight of 25.7 g. Emergence success rate was 79.9% for hawksbill hatchlings, which had an average straight carapace length of 3.96 cm and weight of 13.3 g. Incubation temperatures were monitored and sex ratios determined in four clutches, two in shaded and two in unshaded sand. The sexes of 25 hatchlings from each clutch were identified. Two unshaded clutches produced 92% and 100% female hatchlings while two shaded clutches produced 64% and 44% female hatchlings. Statistical differences were not found between the presented hawksbill turtle curved carapace length, weight after laying and clutch size and those collected elsewhere in Queensland by earlier studies.

scholarly journals Air Pollution and Human Sperm Sex Ratio

2018 ◽  
Vol 12 (4) ◽  
pp. 907-912 ◽  
Author(s):  
Michał Radwan ◽  
Emila Dziewirska ◽  
Paweł Radwan ◽  
Lucjusz Jakubowski ◽  
Wojciech Hanke ◽  
...  
Keyword(s):  
Air Pollution ◽  
Particulate Matter ◽  
Sex Ratio ◽  
Human Sperm ◽  
Quality Data ◽  
Aerodynamic Diameter ◽  
Limited Data ◽  
Study Population ◽  
Air Quality Data

The present study was designed to address the hypothesis that exposure to specific air pollutants may impact human sperm Y:X chromosome ratio. The study population consisted of 195 men who were attending an infertility clinic for diagnostic purposes and who had normal semen concentration of 15–300 mln/ml (WHO, 2010). Participants represented a subset of men in a multicenter parent study conducted in Poland to evaluate environmental factors and male fertility. Participants were interviewed and provided a semen sample. The Y:X ratio was assessed by fluorescent in situ hybridization (FISH). Air quality data were obtained from the AirBase database. In multivariate analysis the significant reduction was observed in the proportion of Y/X chromosome bearing sperm and exposure to particulate matter >10 μm in aerodynamic diameter PM10 ( p = .009) and particulate matter <10 μm in aerodynamic diameter PM2.5 ( p = .023). The observed effects of a lower Y:X sperm chromosome ratio among men exposed to air pollution support the evidence that the trend of declining sex ratio in several societies over past decades has been due to exposure to air pollution; however due to limited data on this issue, the obtained results should be confirmed in longitudinal studies.

scholarly journals Heat, health and hatchlings: associations of in situ nest temperatures with morphological and physiological characteristics of loggerhead sea turtle hatchlings from Florida

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Kelsey A Fleming ◽  
Justin R Perrault ◽  
Nicole I Stacy ◽  
Christina M Coppenrath ◽  
Alison M Gainsbury
Keyword(s):  
Life Stage ◽  
Sea Turtle ◽  
Additional Stress ◽  
Loggerhead Sea Turtle ◽  
Righting Response ◽  
In Situ Incubation ◽  
Risk Of Predation ◽  
Increased Risk ◽  
Incubation Temperatures

Abstract Incubation temperatures, in addition to an embryo’s genetic makeup, are critical in many aspects of adequate sea turtle embryonic development. The effects of high and low incubation temperatures on hatchling quality have been previously examined; however, many of these studies were conducted on relocated or laboratory-reared nests, which do not accurately reflect natural nest temperature fluctuations. To observe the impacts of varying in situ incubation temperatures on loggerhead sea turtle (Caretta caretta) hatchling morphology, various health variables and locomotor performance, temperature data loggers were deployed in 15 loggerhead nests on Juno Beach, Florida, between May and July 2018. Over the course of the study period, 10 morphological traits were measured, blood analytes and heart rate were assessed for the establishment of reference intervals and the self-righting response in seawater was evaluated. Warmer months were associated with smaller body size and higher body condition index, larger umbilical scar size, slower righting time, lower heart rates and higher packed cell volume, hemoglobin, total solids, total white blood cell count, absolute heterophils and absolute basophils. These findings provide evidence that higher in situ incubation temperatures have the potential to adversely affect hatchlings from warmer nests due to increased risk of predation from smaller body sizes, decreased physical responses and overall fitness, altered hemodynamic balance (e.g. dehydration) and potential inflammation and/or stress. With rising temperatures, we predict sea turtle hatchlings may have increasing risks of developing suboptimal physiological features affecting overall fitness and ultimately survival. These results demonstrate that rising environmental temperatures can negatively impact sea turtle hatchlings, thus representing additional stress on sea turtle populations and contributing to our understanding of potential pathophysiological effects of climate change on the delicate life-stage class of the sea turtle hatchling. This information will be useful for formulating effective future sea turtle management plans.

scholarly journals New cave-dwelling amphipods (Lysianassidae, Hadziidae) from the Dominican Republic (Hispaniola)

1998 ◽  
Vol 68 (1) ◽  
pp. 37-66 ◽  
Author(s):  
Damià Jaume ◽  
H.P. Wagner
Keyword(s):  
Dominican Republic ◽  
Regression Model ◽  
West Indian ◽  
Swimming Behaviour ◽  
Marine Origin ◽  
Fresh Waters ◽  
Anchialine Caves ◽  
The Way

Two new stygobiont amphipods are described from anchialine caves located in the Jaragua region (Pedernales Prov., Dominican Republic, Hispaniola). Ottenwalderia kymbalion gen. et sp. nov. is the first lysianassoid known to have penetrated into completely fresh waters, and the fourth colonizing hypogean habitats. Bahadzia jaraguensis sp. nov. is the second representative of this West Indian thalasso-stygobiont genus to be reported from fresh waters; it exhibits the most troglomorphic aspect (i.e. elongation of first antennae and sixth pereiopods) recorded for the genus. Its diagnosis is complemented with a key to the species of the genus Bahadzia. The in situ swimming behaviour of both taxa is briefly described. It is postulated that both amphipods share a rather recent, Plio-Pleistocene marine origin, having invaded passively the continental waters in the way described by the so-called Regression model.

Emergence Success and Sex Ratio of Natural and Relocated Nests of Olive Ridley Turtles from Alas Purwo National Park, East Java, Indonesia

Copeia ◽  
2012 ◽  
Vol 2012 (4) ◽  
pp. 738-747 ◽  
Author(s):  
Risma I. Maulany ◽  
David T. Booth ◽  
Greg S. Baxter
Keyword(s):  
Sex Ratio ◽  
National Park ◽  
Olive Ridley ◽  
Emergence Success

scholarly journals A comparative study of histological conditions suitable for both immunofluorescence and in situ hybridization in the detection of Herpesvirus and its antigens in chicken tissues.

1996 ◽  
Vol 44 (3) ◽  
pp. 259-265 ◽  
Author(s):  
M S Holland ◽  
C D Mackenzie ◽  
R W Bull ◽  
R F Silva
Keyword(s):  
In Situ Hybridization ◽  
Incubation Temperature ◽  
Picric Acid ◽  
Calf Serum ◽  
Blue Dye ◽  
Chicken Tissues ◽  
Tissue Sections ◽  
Incubation Temperatures ◽  
Technical Basis

Our objective was to identify an optimal single set of conditions for use in both indirect immunofluorescence assays (IFA) and in situ hybridization (ISH) to detect viral proteins and nucleic acids in avian lymphoid and neural tissues. Various fixatives were evaluated for use with IFA to detect turkey Herpesvirus (HVT) glycoprotein B (gB) and ISH to identify HVT mRNA in chicken tissues. A precipitating fixative (acetone) was compared to crosslinking fixatives [buffered glutaraldehyde-picric acid (BGPA), 10% formalin, and 4% paraformaldehyde] for both IFA and ISH using spleen, thymus, bursa, sciatic plexus, and brachial plexus of 28-day-old chickens. Four percent paraformaldehyde was found to be the optimal fixative for preservation of all chicken tissues examined with both IFA and ISH. Glass slide preparation, incubation temperatures, and tissue processing were each individually evaluated for ISH and IFA. Silylated slides provided the best retention of tissue sections for both procedures. For IFA, 37 degrees C was the ideal incubation temperature tested, whereas the optimal incubation temperature tested for ISH was 47 degrees C. Of the blocking agents compared, Evans blue dye prevented background fluorescence to a greater extent than either calf serum or bovine serum albumin. These findings provide a technical basis for investigations into various aspects of the molecular pathology of avian diseases.

scholarly journals A preliminary survey of the non-biting midges (Diptera: Chironomidae) of the Dominican Republic

2015 ◽  
pp. 12 ◽  
Author(s):  
Fabio Laurindo da Silva ◽  
Sofia Wiedenbrug ◽  
Brian Dorsey Farrell
Keyword(s):  
Dominican Republic ◽  
Aquatic Insects ◽  
Preliminary Survey ◽  
Biting Midges ◽  
Chironomid Fauna ◽  
Made In

<p>Chironomidae (Diptera) are among the most diverse and widespread aquatic insects, with roughly 5,500 described species. However, prior to the present work, no species of Chironomidae had been documented from the island of Hispaniola. Collections of non-biting midges, with emphasis on the lotic fauna, were made in the Dominican Republic during July of 2015. In total, 578 specimens belonging to 27 genera and at least 44 species within the subfamilies Chironominae (20 taxa), Orthocladiinae (16 taxa) and Tanypodinae (8 taxa) were found. The subfamilies Chironominae and Orthocladiinae predominated. Polypedilum was the most widespread and diverse genus of Chironominae. Metriocnemus were collected in bromeliad tanks. The chironomid fauna in Dominican Republic includes multiple genera with worldwide distributions, including Holarctic and Neotropical components.</p>

scholarly journals Temperature-Dependent Sex Determination and Artificial Incubation of Tuatara, Sphenodon Punctatus

2021 ◽  
Author(s):  
◽  
Nicola J Nelson
Keyword(s):  
Sex Ratio ◽  
Sex Determination ◽  
Hatching Success ◽  
Conservation Management ◽  
Incubation Temperature ◽  
Management Tool ◽  
Relative Fitness ◽  
Temperature Dependent ◽  
Sphenodon Punctatus ◽  
Artificial Incubation

<p>Juveniles resulting from artificially induced and incubated eggs are often used to found or augment populations of rare reptiles, but both procedures may compromise the health of hatchlings or their fitness in natural environments. I aimed to test whether these procedures affected size or performance of juvenile tuatara, Sphenodon punctatus, New Zealand reptiles with temperature-dependent sex determination (TSD). Size and performance are phenotypic traits likely to influence fitness and eventual lifetime reproductive success, and are thus important measures of the suitability of artificial induction and incubation techniques for conservation management. I incubated 320 tuatara eggs artificially at 18, 21 and 22ºC; 52% of these were obtained by induction, the remainder were collected from natural nests. An additional 25 natural nests were left intact for investigation of TSD and effects of incubation temperature in nature. Juveniles from all incubation regimes were kept for ten months post-hatching in similar rearing conditions and sexed by laparoscopy. Induced eggs were significantly smaller than naturally laid eggs, and resulted in significantly smaller hatchlings, even when variation among clutches was accounted for. Incubation temperature did not greatly influence size at hatching, but was an important determinant of size by ten months of age; initial egg mass was the most important factor affecting size of hatchlings. Data indicate that TSD occurs in nature. The sex of hatchlings from 21 nests was investigated: 10 nests produced 100% male hatchlings, 4 nests produced 100% female hatchlings, and only 7 nests produced mixed sex ratios which ranged from 11% to 88% males. Sex of juveniles was related to temperature with a larger proportion of males produced in warmer nests. The overall percentage of male hatchlings in natural nests was 64%. Hatching success was 65% from natural nests during the 1998/99 season. Incubation temperatures throughout the year ranged from 2.9 to 34.4ºC. Global warming is likely to skew the hatchling sex ratio towards males if female tuatara are unable to select nest sites according to environmental cues. Evidence from size patterns of tuatara incubated in natural nests supports differential fitness models for the adaptive significance of TSD. The evaluation of artificial incubation as a conservation management tool demonstrated that it is a procedure that benefits conservation as it can be used reliably to produce founders; hatching success was 94% during this study. The sex ratio of artificially incubated juveniles can be easily manipulated; the pivotal temperature lies between 21 and 22ºC. Constant artificial incubation conditions resulted in larger juveniles by ten months of age than those from natural incubation. Naturally incubated juvenile tuatara, however, were faster for their size, their reaction norm to predator stimuli was to run, and they were possibly more aggressive, suggesting naturally incubated juveniles could survive better in nature. No firm conclusions can be reached on the quality of artificially incubated juvenile tuatara because further research will be required to establish the relevance of performance test results in nature and consequences of incubation regimes in the longer term with respect to relative fitness of individuals.</p>

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