scholarly journals The nesting success of green turtles on beaches at Kazanli, Turkey

Oryx ◽  
1992 ◽  
Vol 26 (3) ◽  
pp. 165-171 ◽  
Author(s):  
Stephanie J. Coley ◽  
Andrew C. Smart
Keyword(s):  
Nest Site ◽  
Chelonia Mydas ◽  
Nesting Success ◽  
Beach Erosion ◽  
Marine Turtle ◽  
Chemical Pollution ◽  
Turtle Species ◽  
Green Turtles ◽  
Nesting Beaches ◽  
Turkish Society

The green turtle Chelonia mydas is one of two marine turtle species to nest in Turkey. Its three main nesting beaches are in eastern Turkey, with possibly the densest congregation of nesting turtles in the Mediterranean being found at Kazanli. However, beach erosion, hatchling predation, agricultural encroachment and chemical pollution mean that the future of the Kazanli nest site is uncertain. The Turkish Society for the Protection of Nature (Dogal Hayati Koruma Dernegi) is making valiant efforts to protect all the turtle nesting beaches in Turkey but lacks detailed information on the numbers of nesting turtles on many beaches. This paper describes a short study of nesting turtles at Kazanli during 1990 and makes recommendations for the conservation of the nesting beach.

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

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.

scholarly journals Heavy metals contaminants in the eggs and temperatures of nesting beaches of sea turtles in Kaimana, West Papua, Indonesia

2020 ◽  
Vol 21 (10) ◽  
Author(s):  
Ricardo F Tapilatu ◽  
Hengki Wona ◽  
Rima Siburian ◽  
SEFRIANTO T. SALEDA
Keyword(s):  
Heavy Metals ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Marine Turtle ◽  
Turtle Species ◽  
Turtle Conservation ◽  
West Papua ◽  
Nesting Beaches ◽  
Nesting Season

Abstract. Tapilatu RF, Wona H, Siburian RHS, Saleda ST. 2020. Heavy metals contaminants in the eggs and temperatures of nesting beaches of sea turtles in Kaimana, West Papua, Indonesia. Biodiversitas 21: 4582-4590. Etna Bay and Venu Island in Kaimana, West Papua, Indonesia are two of many areas that sea turtles use during the nesting season. Here, we report data on heavy metals contaminants from a sample of eggs of green (Chelonia mydas) and hawksbill (Eretmochelys imbricata) turtles collected from a subset of two nests during the 2016 nesting season at Venu Island, Kaimana, West Papua, Indonesia. Three heavy metals contaminants (i.e. mercury, cadmium, arsenic) found in eggs exceeded the established safety limits for human consumption. Other contaminants such as lead, zinc, manganese, iron, and copper were found below the established safety standards. There is an implication of the containment of heavy metals in sea turtle eggs to human health in Kaimana when it is consumed. It is highly recommended that the harvesting of turtle eggs and adults of all of sea turtles at Kaimana be totally prohibited. In addition, overall, beach temperatures in Lakahia fluctuated at a larger range between 26.5o and 33.8oC than at Venu island that fluctuated between 25.9o and 30.2oC. Mean daily temperatures of in-situ nests during the middle third of the incubation period were above the pivotal temperature of 29.0oC for temperature-dependent sex determination suggesting a female bias may already exist. The chemical contamination found in the eggs of C. mydas and E. imbricata at Venu Island is thought to assist sea turtle conservation initiatives in the area. The conservation program at the prime nesting habitat for green and hawksbill turtles on the small islands west of Kaimana such as Venu Island should be intensified to reverse the decline and increase population size of nesting sea turtle species. It is recommended that education and outreach be implemented in surrounding communities in Kaimana to raise awareness about marine turtle conservation.

scholarly journals Status of Marine Turtles in British Columbia Waters: A Reassessment

2004 ◽  
Vol 118 (1) ◽  
pp. 72 ◽  
Author(s):  
Donald F. McAlpine ◽  
Stan A. Orchard ◽  
Kelly A. Sendall ◽  
Rod Palm
Keyword(s):  
British Columbia ◽  
Marine Environment ◽  
Chelonia Mydas ◽  
Marine Turtle ◽  
Dermochelys Coriacea ◽  
Concerted Effort ◽  
Leatherback Turtles ◽  
Marine Turtles ◽  
Green Turtles

Marine turtles in British Columbia have previously been considered off course stragglers. Here we document 20 new reports for Green Turtles, Chelonia mydas, and Leatherback Turtles, Dermochelys coriacea, for the province. Until recently there had been no concerted effort to acquire data on marine turtle abundance or frequency off British Columbia. Observations presented here allow a reassessment of marine turtle status in British Columbia waters. We suggest Green Turtles and Leatherbacks should be considered rare vagrants and uncommon seasonal residents, respectively, off British Columbia and that they are a natural part of the British Columbia marine environment.

scholarly journals Does behaviour affect the dispersal of flatback post-hatchlings in the Great Barrier Reef?

2017 ◽  
Vol 4 (5) ◽  
pp. 170164 ◽  
Author(s):  
Natalie Wildermann ◽  
Kay Critchell ◽  
Mariana M. P. B. Fuentes ◽  
Colin J. Limpus ◽  
Eric Wolanski ◽  
...  
Keyword(s):  
Great Barrier Reef ◽  
Early Life ◽  
Marine Turtle ◽  
Life Stages ◽  
Barrier Reef ◽  
Early Life Stages ◽  
Turtle Species ◽  
Local Water ◽  
Natator Depressus ◽  
Nesting Beaches

The ability of individuals to actively control their movements, especially during the early life stages, can significantly influence the distribution of their population. Most marine turtle species develop oceanic foraging habitats during different life stages. However, flatback turtles ( Natator depressus ) are endemic to Australia and are the only marine turtle species with an exclusive neritic development. To explain the lack of oceanic dispersal of this species, we predicted the dispersal of post-hatchlings in the Great Barrier Reef (GBR), Australia, using oceanographic advection-dispersal models. We included directional swimming in our models and calibrated them against the observed distribution of post-hatchling and adult turtles. We simulated the dispersal of green and loggerhead turtles since they also breed in the same region. Our study suggests that the neritic distribution of flatback post-hatchlings is favoured by the inshore distribution of nesting beaches, the local water circulation and directional swimming during their early dispersal. This combination of factors is important because, under the conditions tested, if flatback post-hatchlings were entirely passively transported, they would be advected into oceanic habitats after 40 days. Our results reinforce the importance of oceanography and directional swimming in the early life stages and their influence on the distribution of a marine turtle species.

scholarly journals Some of them came home: the Cayman Turtle Farm headstarting project for the green turtle Chelonia mydas

Oryx ◽  
2005 ◽  
Vol 39 (2) ◽  
pp. 137-148 ◽  
Author(s):  
Catherine D.L. Bell ◽  
Joe Parsons ◽  
Timothy J. Austin ◽  
Annette C. Broderick ◽  
Gina Ebanks-Petrie ◽  
...  
Keyword(s):  
Chelonia Mydas ◽  
Breeding Population ◽  
Marine Turtle ◽  
Management Technique ◽  
Cayman Islands ◽  
Age At Maturity ◽  
Green Turtles ◽  
Local Breeding ◽  
The Caribbean ◽  
Cayman Turtle Farm

Headstarting is a management technique employed to enhance recruitment of turtles into diminished or extirpated marine turtle populations. Although there have been numerous projects worldwide, there has been a paucity of detailed investigations into its efficacy. Between 1980 and 2001, 16,422 captive-raised hatchlings and 14,347 yearling green marine turtles Chelonia mydas were released from the Cayman Turtle Farm. Approximately 80% of all turtles released were subject to some form of tagging, including living tags. A total of 392 tagged animals have been recaptured at intervals of up to 19 years. Of this total, 160 individuals were captured in the Cayman Islands and 232 were recorded from other locations within the wider Caribbean and southeastern USA. There was significant variation in the release-recapture intervals at the three countries with most returns (Cayman, Cuba and Nicaragua). A positive relationship exists between time at large and size at recapture and data suggest growth rates comparable to those of wild green turtles in the region. There have been at least six living tag returns, four involving turtles released as yearlings and two involving turtles released as hatchlings. This demonstrates an age at maturity that may be as short as 15–19 years, depending on stage of release. Results show that some headstarted turtles are moving around the Caribbean, surviving for long periods of time, contributing to the local breeding population, and are possibly displaying shifts in habitat utilization with age similar to those recorded by wild individuals.

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.

Sea Turtle Navigation and the Detection of Geomagnetic Field Features

1998 ◽  
Vol 51 (1) ◽  
pp. 10-22 ◽  
Author(s):  
Kenneth J. Lohmann ◽  
Catherine M. F. Lohmann
Keyword(s):  
Chelonia Mydas ◽  
Sea Turtle ◽  
Ocean Basin ◽  
Open Ocean ◽  
Continuous Series ◽  
Turtle Species ◽  
Green Turtles ◽  
Open Sea ◽  
Circular Current ◽  
Distant Target

The lives of sea turtles consist of a continuous series of migrations. As hatchlings, the turtles swim from their natal beaches into the open sea, often taking refuge in circular current systems (gyres) that serve as moving, open-ocean nursery grounds. The juveniles of many populations subsequently take up residence in coastal feeding areas that are located hundreds or thousands of kilometres from the beaches on which the turtles hatched; some juveniles also migrate between summer and winter habitats. As adults, turtles periodically leave their feeding grounds and migrate to breeding and nesting regions, after which many return to their own specific feeding sites. The itinerant lifestyle characteristic of most sea turtle species is thus inextricably linked to an ability to orient and navigate accurately across large expanses of seemingly featureless ocean.In some sea turtle populations, migratory performance reaches extremes. The total distances certain green turtles (Chelonia mydas) and loggerheads (Caretta caretta) traverse over the span of their lifetimes exceed tens of thousands of kilometres, several times the diameter of the turtle's home ocean basin. Adult migrations between feeding and nesting habitats can require continuous swimming for periods of several weeks. In addition, the paths of migrating turtles often lead almost straight across the open ocean and directly to the destination, leaving little doubt that turtles can navigate to distant target sites with remarkable efficiency.

Long-distance migrations by the hawksbill turtle, Eretmochelys imbricata, from north-eastern Australia

1998 ◽  
Vol 25 (1) ◽  
pp. 89 ◽  
Author(s):  
Jeffrey D. Miller ◽  
Kirstin A. Dobbs ◽  
Colin J. Limpus ◽  
Neil Mattocks ◽  
André M. Landry Jr
Keyword(s):  
Adult Female ◽  
Solomon Islands ◽  
Satellite Telemetry ◽  
Marine Turtle ◽  
Long Distance ◽  
Eretmochelys Imbricata ◽  
Turtle Species ◽  
Eastern Australia ◽  
Nesting Beaches ◽  
Hawksbill Turtles

Tag recoveries from four adult female hawksbill turtles, Eretmochelys imbricata, tagged on the Great Barrier Reef, Australia, are reported. Hawksbill turtles on breeding migrations move between Australia and neighbouring countries including Vanuatu, Solomon Islands, Papua New Guinea and Indonesia. Migratory distances between foraging areas and nesting beaches ranged from 368 to 2425 km. A review of data from tag recoveries, genetic analysis and satellite telemetry indicates that adult female hawksbill turtles often exhibit migratory behaviour parallelling that of other marine turtle species. This study refutes the myth that hawksbill turtles remain resident at reefs associated with their nesting beaches.

scholarly journals ANALYSIS 16S RDNA OF THE TURTLES IN FORECLOSURE CAGES AT PADEI LAUT, CENTRAL SULAWESI, INDONESIA

2017 ◽  
Vol 23 (1) ◽  
pp. 39
Author(s):  
Adriani Sri Nastiti ◽  
Masayu Rahmia Anwar Putri ◽  
Joni Haryadi ◽  
Arif Wibowo ◽  
Ngurah N Wiadnyana
Keyword(s):  
Carapace Length ◽  
Genetic Relationships ◽  
Chelonia Mydas ◽  
Iucn Red List ◽  
Red List ◽  
Marine Turtle ◽  
Green Turtles ◽  
Illegal Fishing ◽  
Central Sulawesi

Marine turtle is one of the protected aquatic animals as listed in CITES Appendix and IUCN red list. However, illegal fishing of marine turtle is still occurred Padei Laut Village, in Morowali Regency, Central Sulawesi Province, Indonesia. The research aims to study the population of marine turtle based on the carapace length and the genetic relationships. Data of carapace length was measured in-situ and genetic analysis was used mitochondrial DNA. The results showed that the carapace (ten samples which was green turtles/Chelonia mydas) was ranges between 42-102 cm; 91% of samples was immature and 9% was mature. Moreover, it also revealed that those turtles resembled by 99.98% of genetic similarity.

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