scholarly journals Assessing the evidence of ‘infertile’ sea turtle eggs

2020 ◽  
Vol 41 ◽  
pp. 329-338
Author(s):  
AD Phillott ◽  
MH Godfrey
Keyword(s):  
Climate Change ◽  
Incubation Period ◽  
Sea Turtle ◽  
Successful Mating ◽  
Physical Evidence ◽  
Breeding Populations ◽  
Sperm Penetration ◽  
Anthropogenic Drivers ◽  
Perivitelline Membrane ◽  
Nesting Season

There is increasing concern about feminization of sea turtle populations resulting from female-biased production of hatchlings due to climate change and selective loss of males from other anthropogenic drivers. Extreme female-biased breeding populations would reduce the likelihood of successful mating and potentially result in high rates of infertile eggs. Infertile eggs are those in which none of the events between sperm penetration of the ovum and syngamy have occurred. Distinguishing between fertile and infertile eggs is challenging, especially in field conditions, and researchers often have relied on physical evidence gathered from unhatched eggs at the end of the incubation period, which likely have experienced tissue decomposition. We argue that infertility in sea turtle eggs can be demonstrated only by the absence of holes caused by sperm penetration of the inner perivitelline membrane; sperm bound between the inner and outer perivitelline membranes; nuclei in the blastodisc; embryonic tissue or membranes in egg contents; and/or the characteristic white spot on the egg exterior. Unhatched eggs can be examined at the end of the incubation period, but we recommend that studies specifically investigating infertility examine at least 20 oviposited eggs each from clutches laid by at least 20 different turtles at the peak of the nesting season.

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.

Vegetation ecology with anthropic drivers and consequences

2021 ◽  
pp. 030913332199937
Author(s):  
George P Malanson ◽  
Michelle L Talal ◽  
Elizabeth R Pansing ◽  
Scott B Franklin
Keyword(s):  
Climate Change ◽  
Invasive Species ◽  
Plant Communities ◽  
Fire Ecology ◽  
Progress Report ◽  
Processes Of Change ◽  
Community Classification ◽  
The Status ◽  
Plant Community Classification ◽  
Anthropogenic Drivers

Current research on vegetation makes a difference in people’s lives. Plant community classification is a backbone of land management, plant communities are changing in response to anthropogenic drivers, and the processes of change have impacts on ecosystem services. In the following progress report, we summarize the status of classification and recent research on vegetation responses to pollution, especially nitrogen deposition, invasive species, climate change, and land use and direct exploitation. Two areas with human feedbacks are underscored: fire ecology and urban ecology. Prominent questions at the current research frontier are highlighted with attention to new perspectives.

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 period of Hemileia vastatrix in coffee plants in Brazil simulated under climate change

2011 ◽  
Vol 37 (2) ◽  
pp. 85-93 ◽  
Author(s):  
Raquel Ghini ◽  
Emília Hamada ◽  
Mário José Pedro Júnior ◽  
Renata Ribeiro do Valle Gonçalves
Keyword(s):  
Climate Change ◽  
Incubation Period ◽  
General Circulation ◽  
Management Strategies ◽  
General Circulation Models ◽  
Plant Diseases ◽  
Future Scenarios ◽  
Hemileia Vastatrix ◽  
Distribution Maps ◽  
Coffee Plants

Risk analysis of climate change on plant diseases has great importance for agriculture since it allows the evaluation of management strategies to minimize future damages. This work aimed to simulate future scenarios of coffee rust (Hemileia vastatrix) epidemics by elaborating geographic distribution maps using a model that estimates the pathogen incubation period and the output from three General Circulation Models (CSIRO-Mk3.0, INM-CM3.0, and MIROC3.2.medres). The climatological normal from 1961-1990 was compared with that of the decades 2020s, 2050s and 2080s using scenarios A2 and B1 from the IPCC. Maps were prepared with a spatial resolution of 0.5 × 0.5 degrees of latitude and longitude for ten producing states in Brazil. The climate variables used were maximum and minimum monthly temperatures. The maps obtained in scenario A2 showed a tendency towards a reduction in the incubation period when future scenarios are compared with the climatological normal from 1961-1990. A reduction in the period was also observed in scenario B1, although smaller than that in scenario A2.

scholarly journals Shading and Watering as a Tool to Mitigate the Impacts of Climate Change in Sea Turtle Nests

PLoS ONE ◽  
2015 ◽  
Vol 10 (6) ◽  
pp. e0129528 ◽  
Author(s):  
Jacob E. Hill ◽  
Frank V. Paladino ◽  
James R. Spotila ◽  
Pilar Santidrián Tomillo
Keyword(s):  
Climate Change ◽  
Sea Turtle ◽  
Impacts Of Climate Change

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.

Sedimentological characteristics of key sea turtle rookeries: potential implications under projected climate change

2010 ◽  
Vol 61 (4) ◽  
pp. 464 ◽  
Author(s):  
M. M. P. B. Fuentes ◽  
J. L. Dawson ◽  
S. G. Smithers ◽  
M. Hamann ◽  
C. J. Limpus
Keyword(s):  
Climate Change ◽  
Sea Turtles ◽  
Sea Turtle ◽  
Ecological Impacts ◽  
Coarse Grained ◽  
Sediment Characteristics ◽  
Emergence Success ◽  
Ecological Implications ◽  
Turtle Population ◽  
Reef Islands

Sea turtles rely on reef islands for key parts of their reproductive cycle and require specific sediment characteristics to incubate their eggs and dig their nests. However, little is known about the sedimentological characteristics of sea turtle rookeries, how these sediment characteristics affect the vulnerability of rookeries to climate change, and the ecological implications of different sediment or altered sediment characteristics to sea turtles. Therefore, we described the sediment and identified the reef-building organisms of the seven most important rookeries used by the northern Great Barrier Reef (nGBR) green turtle population. We then reviewed the literature on the vulnerability of each identified reef-building organism to climate change and how various sediment characteristics ecologically affect sea turtles. Sediments from the studied rookeries are predominantly composed of well-sorted medium-grained to coarse-grained sands and are either dominated by Foraminifera, molluscs or both. Dissimilarities in the contemporary sedimentology of the rookeries suggest that each may respond differently to projected climate change. Potential ecological impacts from climate change include: (1) changes in nesting and hatchling emergence success and (2) reduction of optimal nesting habitat. Each of these factors will decrease the annual reproductive output of sea turtles and thus have significant conservation ramifications.

scholarly journals Non-invasive monitoring of the fertilization rate in sea turtle nests: comparison between two techniques

2017 ◽  
Author(s):  
Elena Abella ◽  
Rosa García-Cerdá ◽  
Adolfo Marco
Keyword(s):  
Hatching Success ◽  
Sea Turtle ◽  
Fertilization Rate ◽  
Egg Laying ◽  
White Spot ◽  
Invasive Technique ◽  
Invasive Monitoring ◽  
Non Invasive ◽  
History Of ◽  
Nesting Season

Egg fertilization rate is a defining event in the life history of reproducing oviparous species. However, for many terrestrial oviparous species, this parameter is only estimated after hatching, studying evidences of embryonic development in unhatched eggs. We compared the accuracy of this method with a second non-invasive technique based in the careful nest excavation within the first 96 hours after egg-laying and counting the proportion of eggs with a white spot in the shell. The study was conducted in a nesting population of loggerhead turtles (Caretta caretta) from Boavista Island (Republic of Cabo Verde). We found significant differences on the estimation of fertilization rate between both techniques. After hatching experimented researchers significantly overestimated the number of unfertilised eggs and this parameter was not correlated with the estimation after laying. The earlier estimation had no effect on hatching success and hatchling phenotype. There was no correlation between the number of alive embryos at laying and the hatching success. Unfertile eggs have no effect on survival of developing embryos withing a nest. Fertilization rate in loggerheads did not show spatial or temporal variation during nesting season. We proposed the implementation in sea turtle nesting monitoring programs of an annual, accurate and non-invasive estimation of egg fertilization rate based in the excavation of a sample of representative nests immediately after the formation of the white spot in the shell of developing embryos.

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