Nesting activities of Green turtles (Chelonia mydas) on the beaches of Zabargad Island, southern Egyptian Red Sea

Major aggregations of nesting green turtles (Chelonia mydas) occur in the northern Red Sea, although little is known about the reproductive ecology of this endangered species in the region. To address this issue, we satellite-tracked 30 female green turtles to document their movements and to identify factors driving habitat use at two major rookeries in the Red Sea, Jazirat Mashabah (Mashabah Island) and Ras Al Baridi in Saudi Arabia. Between successive nesting events, turtles displayed high fidelity to nesting beaches and adjacent in-water habitats (inter-nesting habitats). Using generalized linear mixed models, we estimated the mean probability of nesting per beach emergence (nesting success rate) to be 0.628, and the mean duration between a successful nesting event and the successive emergence onto the beach (re-nesting interval) to be 10.8 days at each site. The nesting success rate was relatively high (>0.8) when the preceding daytime land surface temperature (LST) was lower than 37°C but decreased with elevated daytime LST (<0.4 when >47°C). Re-nesting interval was longer at lower water temperatures and towards the end of the nesting season of individuals. Our study improves the robustness of abundance estimates from census data (e.g., track counts) and shows that the protection of nesting and inter-nesting habitats during a breeding season would be an effective conservation strategy for the species. We discuss how global warming could increase energy expenditure due to lowered nesting success, ultimately compromising the reproductive fitness of these populations.

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Satellite Tracking of Post-nesting Green Sea Turtles (Chelonia mydas) From Ras Baridi, Red Sea

Frontiers in Marine Science ◽

10.3389/fmars.2021.758592 ◽

2021 ◽

Vol 8 ◽

Author(s):

Ahmed M. Al-Mansi ◽

Anas Z. Sambas ◽

Baleegh A. Abukaboos ◽

Ahmed H. Al Zahrani ◽

Ahmed S. Abdulaziz ◽

...

Keyword(s):

Saudi Arabia ◽

Red Sea ◽

Chelonia Mydas ◽

Marine Turtles ◽

Green Turtles ◽

The North ◽

Nesting Site ◽

Nesting Sites ◽

Coastal Margin ◽

Anthropogenic Threats

Identifying migratory pathways and linking nesting sites to foraging areas is essential for effective conservation management of migratory species, such as marine turtles. Post-nesting marine turtles disperse from their nesting sites to multiple foraging areas located from a few to hundreds of kilometers away. Over a six-year period 16 female green turtles (Chelonia mydas) were equipped with satellite transmitters between October and December of five nesting seasons to determine their migratory routes from their nesting area at five contiguous beaches at Ras Baridi, Saudi Arabia, to their foraging areas. All foraging areas for these turtles were located in shallow coastal areas or in shallow areas around offshore islands within the Red Sea basin. The majority (n = 12) migrated through the shallow (<200 m) water along the coastal margin to reach foraging areas located to the North (n = 4) and South (n = 12) of the nesting site. Four turtles crossed the deep trough of the Red Sea during their journeys. Ten of the 16 turtles migrated to foraging areas within the territorial waters of Saudi Arabia. The other six turtles migrated to foraging areas in Egypt (n = 4) and Eritrea (n = 2). These 16 turtles traveled between 130 and 1749 km from their nesting site to foraging areas located in the northern, middle and southern parts of the Red Sea. Because these turtles utilized foraging areas in at least three countries (Saudi Arabia, Egypt, and Eritrea) and one passed through the territorial waters of Sudan, conservation and management of green turtles in the Red Sea requires multinational cooperation to address anthropogenic threats in the region.

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Post-nesting migrations patterns of Green Turtles (Chelonia mydas) from the Egyptian Red Sea

Zoology in the Middle East ◽

10.1080/09397140.2014.962833 ◽

2014 ◽

Vol 60 (4) ◽

pp. 299-305 ◽

Cited By ~ 4

Author(s):

Omar Attum ◽

Andrew Kramer ◽

Tamer Mahmoud ◽

Moustafa Fouda

Keyword(s):

Red Sea ◽

Chelonia Mydas ◽

Green Turtles

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Stock composition of green turtles Chelonia mydas foraging in the Ryukyu Archipelago differs with size class

Marine Ecology Progress Series ◽

10.3354/meps12657 ◽

2018 ◽

Vol 600 ◽

pp. 151-163 ◽

Cited By ~ 6

Author(s):

T Hamabata ◽

H Nishizawa ◽

I Kawazu ◽

K Kameda ◽

N Kamezaki ◽

...

Keyword(s):

Chelonia Mydas ◽

Size Class ◽

Ryukyu Archipelago ◽

Green Turtles

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Effects of El Niño Southern Oscillation and local ocean temperature on the reproductive output of green turtles (Chelonia mydas) nesting at Tortuguero, Costa Rica

Marine Biology ◽

10.1007/s00227-020-03749-z ◽

2020 ◽

Vol 167 (9) ◽

Author(s):

Renato Saragoça Bruno ◽

Jaime Alberto Restrepo ◽

Roldán Arturo Valverde

Keyword(s):

Costa Rica ◽

El Niño ◽

Reproductive Output ◽

El Nino ◽

Southern Oscillation ◽

Chelonia Mydas ◽

El Niño Southern Oscillation ◽

El Nino Southern Oscillation ◽

Ocean Temperature ◽

Green Turtles

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Plasma proteomics of green turtles (Chelonia mydas) reveals pathway shifts and potential biomarker candidates associated with health and disease

Conservation Physiology ◽

10.1093/conphys/coab018 ◽

2021 ◽

Vol 9 (1) ◽

Author(s):

David P Marancik ◽

Justin R Perrault ◽

Lisa M Komoroske ◽

Jamie A Stoll ◽

Kristina N Kelley ◽

...

Keyword(s):

Chelonia Mydas ◽

Sea Turtle ◽

Protein Abundance ◽

Plasma Samples ◽

Important Species ◽

Green Turtles ◽

Rehabilitation Programs ◽

Potential Biomarker ◽

Health And Disease

Abstract Evaluating sea turtle health can be challenging due to an incomplete understanding of pathophysiologic responses in these species. Proteome characterization of clinical plasma samples can provide insights into disease progression and prospective biomarker targets. A TMT-10-plex-LC–MS/MS platform was used to characterize the plasma proteome of five, juvenile, green turtles (Chelonia mydas) and compare qualitative and quantitative protein changes during moribund and recovered states. The 10 plasma samples yielded a total of 670 unique proteins. Using ≥1.2-fold change in protein abundance as a benchmark for physiologic upregulation or downregulation, 233 (34.8%) were differentially regulated in at least one turtle between moribund and recovered states. Forty-six proteins (6.9%) were differentially regulated in all five turtles with two proteins (0.3%) demonstrating a statistically significant change. A principle component analysis showed protein abundance loosely clustered between moribund samples or recovered samples and for turtles that presented with trauma (n = 3) or as intestinal floaters (n = 2). Gene Ontology terms demonstrated that moribund samples were represented by a higher number of proteins associated with blood coagulation, adaptive immune responses and acute phase response, while recovered turtle samples included a relatively higher number of proteins associated with metabolic processes and response to nutrients. Abundance levels of 48 proteins (7.2%) in moribund samples significantly correlated with total protein, albumin and/or globulin levels quantified by biochemical analysis. Differentially regulated proteins identified with immunologic and physiologic functions are discussed for their possible role in the green turtle pathophysiologic response and for their potential use as diagnostic biomarkers. These findings enhance our ability to interpret sea turtle health and further progress conservation, research and rehabilitation programs for these ecologically important species.

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Dietary analysis of two sympatric marine turtle species in the eastern Mediterranean

Marine Biology ◽

10.1007/s00227-021-03895-y ◽

2021 ◽

Vol 168 (6) ◽

Author(s):

Josie L. Palmer ◽

Damla Beton ◽

Burak A. Çiçek ◽

Sophie Davey ◽

Emily M. Duncan ◽

...

Keyword(s):

Green Turtle ◽

Eastern Mediterranean ◽

Chelonia Mydas ◽

Marine Turtle ◽

Dietary Analysis ◽

Low Frequencies ◽

Turtle Species ◽

Dietary Shift ◽

Green Turtles ◽

Loggerhead Turtles

AbstractDietary studies provide key insights into threats and changes within ecosystems and subsequent impacts on focal species. Diet is particularly challenging to study within marine environments and therefore is often poorly understood. Here, we examined the diet of stranded and bycaught loggerhead (Caretta caretta) and green turtles (Chelonia mydas) in North Cyprus (35.33° N, 33.47° E) between 2011 and 2019. A total of 129 taxa were recorded in the diet of loggerhead turtles (n = 45), which were predominantly carnivorous (on average 72.1% of dietary biomass), foraging on a large variety of invertebrates, macroalgae, seagrasses and bony fish in low frequencies. Despite this opportunistic foraging strategy, one species was particularly dominant, the sponge Chondrosia reniformis (21.5%). Consumption of this sponge decreased with increasing turtle size. A greater degree of herbivory was found in green turtles (n = 40) which predominantly consumed seagrasses and macroalgae (88.8%) with a total of 101 taxa recorded. The most dominant species was a Lessepsian invasive seagrass, Halophila stipulacea (31.1%). This is the highest percentage recorded for this species in green turtle diet in the Mediterranean thus far. With increasing turtle size, the percentage of seagrass consumed increased with a concomitant decrease in macroalgae. Seagrass was consumed year-round. Omnivory occurred in all green turtle size classes but reduced in larger turtles (> 75 cm CCL) suggesting a slow ontogenetic dietary shift. Macroplastic ingestion was more common in green (31.6% of individuals) than loggerhead turtles (5.7%). This study provides the most complete dietary list for marine turtles in the eastern Mediterranean.

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The impact of fibropapillomatosis on clinical characteristics, blood gas, plasma biochemistry, and hematological profiles in juvenile green turtles ( Chelonia mydas)

Bulletin of Marine Science ◽

10.5343/bms.2019.0120 ◽

2020 ◽

Vol 96 (4) ◽

pp. 723-734

Author(s):

Tsung-Hsien Li ◽

Chao-Chin Chang

Keyword(s):

White Blood Cells ◽

Extracellular Fluid ◽

Chelonia Mydas ◽

Sea Turtle ◽

Total Carbon ◽

Blood Gas ◽

Green Turtles ◽

Cell Counts ◽

Significant Difference ◽

The Impact

Fibropapillomatosis (FP) is a tumor- forming disease that afflicts all marine turtles and is the most common in green turtles (Chelonia mydas). In this study, the morphometric characteristics, blood gas, biochemistry, and hematological profiles of 28 (6 FP-positive and 22 FP-negative) green turtles from the coast of Taiwan were investigated. The results indicated that body weight ( P < 0.001) and curved carapace length (CCL; P < 0.001) in green turtles with FP were significantly higher than in turtles without FP. Furthermore, green turtles with FP had a significantly lower value of hemoglobin (HB; P = 0.010) and packed cell volume (PCV; P = 0.005) than turtles without FP. Blood cell counts of white blood cells (WBC; P = 0.008) and lymphocytes ( P = 0.022) were observed with significant difference; green turtles with FP had lower counts than turtles without FP. In addition, turtles with FP had significantly higher pH ( P = 0.036), base excess in extracellular fluid (BEecf; P = 0.012), bicarbonate (HCO3– ; P = 0.008), and total carbon dioxide (TCO2 ; P = 0.025) values than turtles without FP. The findings of this study provide valuable clinical parameters for the medical care of the species in sea turtle rehabilitation centers and help us to understand the physiological response of green turtles to different tumor-forming conditions.

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