The Effect of Invertebrate Infestation on Green Turtle (Chelonia mydas) Nests on Kazanlı Beach, Mersın, Turkey

2020 ◽  
Vol 27 (5) ◽  
pp. 245-256
Author(s):  
Cemil Aymak ◽  
Aşkın Hasan Uçar ◽  
Yusuf Katılmış ◽  
Eyup Başkale ◽  
Serap Ergene
Keyword(s):  
Green Turtle ◽  
Hatching Success ◽  
Negative Relationship ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Faunal Composition ◽  
Independent Variables ◽  
Invertebrate Species ◽  
First Time ◽  
Nesting Season

In this study invertebrate infestation in green turtle (Chelonia mydas) nests were recorded for the first time for Kazanlı beach, Mersin, Turkey. For this aim, in 2006 nesting season, 294 natural intact green turtle nests were sampled to examine their contents and invertebrate infestation was found in 76 (25.85% of the total sampling green turtle nests). These infested nests were examined in terms of the invertebrate faunal composition. The specimens found in the green sea turtle nests were identified to order, family or genus levels and they were represented in 5 orders. These invertebrate groups are Elater sp. larvae (Elateridae; Coleoptera), Pimelia sp. larvae (Tenebrionidae; Coleoptera), Enchytraeidae (Oligochaeta), Cyrptostigmata (Acari), Oniscidae (Isopoda), Formicidae (Hymenoptera). Elater sp. was the most common invertebrate group in the green turtle nests. According to student t test, we found statistically significant differences between 7 independent variables and invertebrate species presence. Furthermore, logistic regression analysis explained that there is a negative relationship between hatching success rate and invertebrate species presence.

Low male production at the world’s largest green turtle rookery

2020 ◽  
Vol 653 ◽  
pp. 181-190
Author(s):  
DT Booth ◽  
A Dunstan ◽  
I Bell ◽  
R Reina ◽  
J Tedeschi
Keyword(s):  
Green Turtle ◽  
Hatching Success ◽  
Incubation Temperature ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Green Turtles ◽  
Nesting Site ◽  
Almost All ◽  
Monthly Variations ◽  
Nesting Season

Because the sex of all sea turtle hatchlings is determined by incubation temperature, with low temperatures producing mainly males and high temperatures producing mainly females, sea turtle populations worldwide are threatened by feminization of hatchlings due to increases in global temperature. Data obtained by laparoscopic sexing of immature individuals captured from a major feeding ground indicates that over several decades there has been little recruitment of males into the northern Great Barrier Reef (nGBR) green turtle Chelonia mydas population, one of the largest sea turtle populations in the world. Over 2 nesting seasons, we measured nest temperatures at Raine Island, the most important nesting site for this nGBR population, and predicted that almost all nests would have produced all female hatchlings. The few nests that produced some male hatchlings were constructed at the very end of the nesting season, and these nests had the lowest hatching success. Taking into account monthly variations in nest construction, hatching success, and hatchling sex ratio, we estimate that over an entire nesting season only 0.7% of hatchlings produced are male. Hence, we conclude that the nGBR population of green turtles has likely recruited very few males in recent years.

scholarly journals ASPEK MORFOLOGI, REPRODUKSI, DAN PERILAKU PENYU HIJAU (Chelonia mydas) Di PANTAI PANGUMBAHAN, KABUPATEN SUKABUMI, JAWA BARAT

2017 ◽  
Vol 3 (2) ◽  
pp. 93
Author(s):  
Adriani Sri Nastiti Krismono ◽  
Achmad Fitriyanto ◽  
Ngurah Nyoman Wiadnyana
Keyword(s):  
Green Turtle ◽  
Carapace Width ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Stratified Sampling ◽  
Hatching Rate ◽  
Brood Stock ◽  
Green Turtles ◽  
And Behavior ◽  
Nesting Season

Penyu hijau (Chelonia mydas) termasuk dalam phylum Chordata dan famili Cheloniideae. Jumlah penyu hijau yang singgah ke Pantai Pangumbahan untuk bertelur semakin menurun karena tidak terkendalinya masyarakat melakukan penangkapan induk penyu dan pengambilan telurnya. Penelitian tentang morfologi, reproduksi, dan perilaku penyu hijau sebagai salah satu dasar pengelolaan telah dilakukan di Pantai Pangumbahan pada bulan Agustus 2008. Metode penelitian yang digunakan pengambilan contoh berstrata. Penelitian ini dilaksanakan pada bulan Agustus 2008 (pada saat puncak peneluran). Parameter yang diamati antara lain ukuran penyu dari 89 ekor jumlah penyu bersarang, jumlah telur dan tingkat penetasan, serta perilaku pada saat penyu bertelur. Hasil penelitian menunjukan yang diamati diperoleh panjang karapas berkisar antara 97-15 cm dan lebar karapas 83,5-108 cm, jumlah penyu naik ke pantai 89 ekor dan penyu yang bertelur 39 ekor. Jumlah telur penyu hijau berhasil dihitung 80-105 butir per induk penyu. Bulan Agustus 2008 merupakan puncak musim peneluran. Kegiatan peneluran penyu hijau dibagi menjadi enam tahap. Upaya konservasi yang sudah dilakukan adalah penetasan telur penyu semi alami, restocking tukik, dan menjaga keamanan sarang telur penyu. Green turtles (Chelonia mydas), including the phylum Chordata and families Cheloniideae. The number of green turtles come to lay eggs Pangumbahan beach to decline because of increasingly unmanageable public do making arrests turtles brood stock and their eggs. Research on the morphology, reproduction, and behavior of green turtles as one of the basic management has been conducted on the Pangumbahan Beach in August 2008. The method used stratified sampling. The experiment was conducted in August 2008 (at the peak of nesting). Other parameters were observed between the size of the 89 tail number of turtles nesting turtles, the number of eggs and hatching rate and behavior during turtle nesting. Results obtained showed that the observed length ranges from 97- 15 cm carapace and carapace width from 83.5-108 cm, the number went up to the beach 89 sea turtle and sea turtle nesting tail as much as 39 tails. The number of green turtle eggs had counted as many as 80-105 eggs per turtles brood stock. Month August 2008 is the peak nesting season of green turtle nesting activities are divided into six stages. Conservation efforts that have been done is semi natural turtle hatchery, restocking hatchlings, and nest of turtle eggs to maintain security.

scholarly journals Incubation temperatures, hatching success and congenital anomalies in green turtle nests from Guanahacabibes Peninsula, Cuba

2021 ◽  
Vol 4 (4) ◽  
pp. 321-330
Author(s):  
Randy Calderón Peña ◽  
Julia Azanza Ricardo
Keyword(s):  
Congenital Anomalies ◽  
Green Turtle ◽  
Thermal Tolerance ◽  
Elevated Temperatures ◽  
Hatching Success ◽  
Incubation Temperature ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Green Turtles ◽  
Incubation Temperatures

Elevated incubation temperatures of sea turtle nests decrease hatching success and alter the resulting hatchlings' morphology. There is an absence of studies assessing the relationships between temperature and hatching success in Cuba, even when they could improve understanding the limits of thermal tolerance in these species. This study evaluated the influence of incubation temperature on hatching success and phenotypic malformations in green turtle hatchlings (Chelonia mydas); and analyzed the temporal variation in hatching success on the studied beaches. In 48 green turtles nests distributed along two beaches, incubation temperature and hatching success were recorded between 2014 and 2019. Increasing incubation temperature caused a decrease in the hatching success and an increase in the frequency of supernumerary scutes. Despite the elevated temperatures (average > 30°C), hatching was higher than 80%. Significant differences in hatching success were only observed among seasons for nests in Antonio Beach (lower values in 2016 and 2019 compared to 2014).

scholarly journals Nest inundation from sea-level rise threatens sea turtle population viability

2015 ◽  
Vol 2 (7) ◽  
pp. 150127 ◽  
Author(s):  
David A. Pike ◽  
Elizabeth A. Roznik ◽  
Ian Bell
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Green Turtle ◽  
Hatching Success ◽  
Developmental Stages ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Life Cycles ◽  
Coastal Habitats ◽  
Indirect Impacts

Contemporary sea-level rise will inundate coastal habitats with seawater more frequently, disrupting the life cycles of terrestrial fauna well before permanent habitat loss occurs. Sea turtles are reliant on low-lying coastal habitats worldwide for nesting, where eggs buried in the sand remain vulnerable to inundation until hatching. We show that saltwater inundation directly lowers the viability of green turtle eggs ( Chelonia mydas ) collected from the world's largest green turtle nesting rookery at Raine Island, Australia, which is undergoing enigmatic decline. Inundation for 1 or 3 h reduced egg viability by less than 10%, whereas inundation for 6 h reduced viability by approximately 30%. All embryonic developmental stages were vulnerable to mortality from saltwater inundation. Although the hatchlings that emerged from inundated eggs displayed normal physical and behavioural traits, hypoxia during incubation could influence other aspects of the physiology or behaviour of developing embryos, such as learning or spatial orientation. Saltwater inundation can directly lower hatching success, but it does not completely explain the consistently low rates of hatchling production observed on Raine Island. More frequent nest inundation associated with sea-level rise will increase variability in sea turtle hatching success spatially and temporally, due to direct and indirect impacts of saltwater inundation on developing embryos.

Structural description of sea turtle fibropapilloma

2020 ◽  
Vol 13 (3) ◽  
pp. 585-591
Author(s):  
Luana Melo ◽  
Isabel Velasco ◽  
Julia Aquino ◽  
Rosangela Rodrigues ◽  
Edris Lopes ◽  
...  
Keyword(s):  
Green Turtle ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Tumor Formation ◽  
Neoplastic Disease ◽  
Structural Description ◽  
Chemical Carcinogens ◽  
Epidermal Proliferation ◽  
Turtle Population ◽  
Bulky Mass

Fibropapillomatosis is a neoplastic disease that affects sea turtles. It is characterized by multiple papillomas, fibropapillomas and cutaneous and/or visceral fibromas. Although its etiology has not been fully elucidated, it is known that there is a strong involvement of an alpha - herpesvirus, but the influence of other factors such as parasites, genetics, chemical carcinogens, contaminants, immunosuppression and ultraviolet radiation may be important in the disease, being pointed out as one of the main causes of a reduction in the green turtle population. Thus, the objective of this article was to describe the morphology of cutaneous fibropapillomas found in specimens of the green turtle (Chelonia mydas), using light and scanning electron microscopy in order to contribute to the mechanism of tumor formation. Microscopically, it presented hyperplastic stromal proliferation and epidermal proliferation with hyperkeratosis. The bulky mass was coated with keratin, with some keratinocyte invaginations, that allowed the keratin to infiltrate from the epidermis into the dermis, forming large keratinized circular spirals. Another fact that we observed was the influence of the inflammation of the tumors caused by ectoparasites.

A Revision of the Subfamily Microscaphidiinae (Platyhelminthes, Digenea, Microscaphidiidae) Parasitic in Marine Turtles (Reptilia, Chelonia)

1986 ◽  
Vol 34 (2) ◽  
pp. 241 ◽  
Author(s):  
D Blair
Keyword(s):  
Green Turtle ◽  
Chelonia Mydas ◽  
Nomen Nudum ◽  
Taxonomic Significance ◽  
Marine Turtles ◽  
As Species ◽  
First Time ◽  
Species Inquirendae

A revision of the subfamily Microscaphidiinae Looss, 1900 is presented and characters of taxonomic significance discussed. The genus Microscaphidium Looss, 1900, contains M. reticulare (van Beneden, 1859) Looss, 1901 (synonyms M. japonicum Oguro, 1941; M. caballeroi Groschaft, 1977); M. aberrans Looss, 1902 (synonym M. reticulare in part); and M, warui, sp. nov. Confusion in the literature over the identities of M. reticulare and M. aberrans is discussed. A neotype is selected for the former species and a lectotype for the latter. Polyangium linguatula (Looss, 1899) Looss, 1902 (synonyms P. miyajimai Kobayashi, 1921; P. colymbi Poche, 1925; P. longiseminale Chattopadhyaya, 1972) is the sole species in Polyangium Looss, 1902. The genus Angiodictyum Looss, 1902 contains A. parallelum (Looss, 1901) Looss, 1902; A. posterovitellatum Chattopadhyaya, 1972; A. longum, sp, nov.; A. glossoides, sp. nov. Polygorgyra, gen. nov., is proposed for P. cholados, sp. nov. Microscaphidium chelonei Chattopadhyaya, 1972 nec Mehrotra, 1973 and Angiodictyum anteroporum Chattopadhyaya, 1972 are regarded as species inquirendae. Microscaphidium chelonei Mehrotra, 1973 nec Chattopadhyaya, 1972 is a nomen nudum. The following species are recorded for the first time from the green turtle, Chelonia mydas (L.) in Australian waters: Microscaphidium reticulare; M. aberrans; M. warui; Angiodictyum posterovitellatum; A. longum; Polygorgyra cholados.

scholarly journals The Effects of Nest Location and Beach Environment on Hatching Success for Leatherback (Dermochelys Coriacea) and Green (Chelonia Mydas) Sea Turtles on Bioko Island, Equatorial Guinea

2021 ◽  
Author(s):  
Callie A. Veelenturf ◽  
Elizabeth M. Sinclair ◽  
Peter Leopold ◽  
Frank V. Paladino ◽  
Shaya Honarvar
Keyword(s):  
Green Turtle ◽  
Hatching Success ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Dermochelys Coriacea ◽  
Equatorial Guinea ◽  
Leatherback Turtles ◽  
Nest Location ◽  
Bioko Island ◽  
Elevation Range

Abstract Hatching success in sea turtles is hindered by a variety of biotic and abiotic factors. This study of the nesting ecology of leatherback (Dermochelys coriacea) and green (Chelonia mydas) sea turtles, investigated how several environmental factors and beach characteristics on Bioko Island, Equatorial Guinea influence sea turtle reproductive success. Average clutch hatching success was 40.4% for green turtles and 41.73% for leatherback turtles. For leatherback turtles, clutch elevation relative to the high tide line (HTL) was found to be the most influential factor in determining hatching success, highlighting the sensitivity of this species to sea level rise (SLR). Multiple linear regression analysis demonstrated that nest distance to vegetation and sand conductivity also played significant roles in leatherback clutch hatching success. For leatherback clutches, 33% percent of experimental nests were affected by inundation and 17% by predation. An optimum clutch elevation range for leatherback turtles was identified, where a distinct increase in hatching success was observed between -0.286 m to -0.0528 m above the HTL. For green sea turtles, 64% of experimental nests were affected by predation, confounding conclusions about the roles of environmental characteristics in green turtle hatching success. We propose further investigation into influential characteristics in green turtle nests and confirmation of the observed optimum elevation range on Bioko Island and other nesting grounds. Identified sensitivities of each species to SLR and beach characteristics will be used to encourage the government of Equatorial Guinea to consider the vulnerability of their resident turtle populations when planning for future coastal development.

Estimating past and present sex ratios of sea turtles in Suriname

1996 ◽  
Vol 74 (2) ◽  
pp. 267-277 ◽  
Author(s):  
Matthew H. Godfrey ◽  
N. Mrosovsky ◽  
R. Barreto
Keyword(s):  
Sea Turtles ◽  
Sex Ratios ◽  
Negative Relationship ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Dermochelys Coriacea ◽  
Green Turtles ◽  
Sand Temperature ◽  
Turtle Conservation ◽  
Sea Turtle Conservation

Leatherback (Dermochelys coriacea) and green (Chelonia mydas) sea turtles in Suriname lay eggs over several months of the year. During this nesting season, changes in rainfall produce changes in sand temperature, which in turn influence the sexual differentiation of incubating sea turtle embryos. The overall sex ratio of leatherback and green sea turtle hatchlings produced at Matapica beach in Suriname was investigated. Estimates of the sex ratios of these turtles in 1993 (green turtles 63.8% female, leatherbacks 69.4% female) were roughly 10% more female-biased than those from an earlier study in 1982. For both species, a significant negative relationship was found between monthly rainfall and monthly sex ratios. Using this relationship and data on rainfall in the past, it was possible to estimate overall sex ratios for an additional 12 years. These estimates varied considerably among different years, ranging from 20 to 90% female in the case of green turtles. Nevertheless, males tended to be produced primarily in April and May, while some females were produced in all months. Such seasonal patterns of production of turtles of different sexes have implications for sea turtle conservation programs that involve manipulating or harvesting eggs.

scholarly journals The value of long-term, community-based monitoring of marine turtle nesting: a study in the Lamu archipelago, Kenya

Oryx ◽  
2017 ◽  
Vol 53 (1) ◽  
pp. 71-80 ◽  
Author(s):  
Mike I. Olendo ◽  
Gladys M. Okemwa ◽  
Cosmas N. Munga ◽  
Lilian K. Mulupi ◽  
Lily D. Mwasi ◽  
...  
Keyword(s):  
Green Turtle ◽  
Low Cost ◽  
Western Indian Ocean ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Marine Turtle ◽  
Olive Ridley ◽  
Community Based ◽  
Green Turtles ◽  
Incubation Duration

AbstractMonitoring of nesting beaches is often the only feasible and low-cost approach for assessing sea turtle populations. We investigated spatio-temporal patterns of sea turtle nesting activity monitored over 17 successive years in the Lamu archipelago, Kenya. Community-based patrols were conducted on 26 stretches of beach clustered in five major locations. A total of 2,021 nests were recorded: 1,971 (97.5%) green turtleChelonia mydasnests, 31 (1.5%) hawksbillEretmochelys imbricatanests, 8 (0.4%) olive ridleyLepidochelys olivaceanests and 11 (0.5%) unidentified nests. Nesting occurred year-round, increasing during March–July, when 74% of nests were recorded. A stable trend in mean annual nesting densities was observed in all locations. Mean clutch sizes were 117.7 ± SE 1 eggs (range 20–189) for green turtles, 103±SE 6 eggs (range 37–150) for hawksbill turtles, and 103±SE 6 eggs (range 80–133) for olive ridley turtles. Curved carapace length for green turtles was 65–125 cm, and mean annual incubation duration was 55.5±SE 0.05 days. The mean incubation duration for green turtle nests differed significantly between months and seasons but not locations. The hatching success (pooled data) was 81.3% (n = 1,841) and was higher for in situ nests (81.0±SE 1.5%) compared to relocated nests (77.8±SE 1.4%). The results highlight the important contribution of community-based monitoring in Kenya to sustaining the sea turtle populations of the Western Indian Ocean region.

The effect of on-shore light pollution on sea-turtle hatchlings commencing their off-shore swim

2017 ◽  
Vol 44 (2) ◽  
pp. 127 ◽  
Author(s):  
Zoe Truscott ◽  
David T. Booth ◽  
Colin J. Limpus
Keyword(s):  
Environmental Conditions ◽  
Green Turtle ◽  
Sea Turtle ◽  
Swimming Behaviour ◽  
Light Pollution ◽  
The World ◽  
Near Shore ◽  
Turtle Population ◽  
Nesting Beaches ◽  
Nesting Season

Context Off-shore recruitment impairment of sea-turtle hatchlings because of light pollution is a growing concern to conservation of sea-turtle population throughout the world. Studies have focussed on sea-turtle hatchling sea-finding behaviour, and ignored the possible effect that on-shore lighting might have on hatchlings after they have entered the sea. Aims We experimentally evaluated the effect that on-shore light pollution has on the swimming behaviour of green turtle hatchlings once they have entered the sea and begun swimming off-shore. We also estimated the decrease in off-shore recruitment of hatchlings as a result of light pollution disruption of the off-shore swim. Methods Hatchling misorientation rates were quantified by releasing marked hatchlings to the sea from different land-based locations adjacent to light-polluted beach areas under a variety of environmental conditions. The beach in light-polluted regions was then searched for marked hatchlings returning to shore from the sea. Key results Misorientation rates were highest in trials conducted during moonless nights (66.7% of trials had some hatchlings return to shore) and lowest during trials conducted during moonlit nights (no trials had hatchlings return to shore). Green turtle hatchling off-shore recruitment for the entire 2014–15 nesting season at Heron Island was estimated to decrease 1.0 –2.4% as a result of on-shore lights disrupting hatchling off-shore swimming behaviour. Conclusions On moonless nights, sea-turtle hatchlings after having successfully completed their journey from nest to sea and entered the sea can be lured back to shore again by shore-based light pollution and, this will decrease their off-shore recruitment success. Implications To ensure maximum off-shore recruitment of sea-turtle hatchlings, on-shore light pollution adjacent to nesting beaches needs to be minimised so as to minimise misorientation and disorientation of hatchlings while on the beach and in near-shore waters.

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