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 Managing fisheries in a world with more sea turtles

2020 ◽  
Vol 287 (1930) ◽  
pp. 20200220
Author(s):  
Nathan F. Putman ◽  
Jesse Hawkins ◽  
Benny J. Gallaway
Keyword(s):  
Stock Assessment ◽  
Sea Turtles ◽  
Sea Turtle ◽  
Fishing Effort ◽  
Eastern United States ◽  
Green Turtles ◽  
Management Actions ◽  
Nesting Sites ◽  
Near Shore ◽  
Turtle Population

For decades, fisheries have been managed to limit the accidental capture of vulnerable species and many of these populations are now rebounding. While encouraging from a conservation perspective, as populations of protected species increase so will bycatch, triggering management actions that limit fishing. Here, we show that despite extensive regulations to limit sea turtle bycatch in a coastal gillnet fishery on the eastern United States, the catch per trip of Kemp's ridley has increased by more than 300% and green turtles by more than 650% (2001–2016). These bycatch rates closely track regional indices of turtle abundance, which are a function of increased reproductive output at distant nesting sites and the oceanic dispersal of juveniles to near shore habitats. The regulations imposed to help protect turtles have decreased fishing effort and harvest by more than 50%. Given uncertainty in the population status of sea turtles, however, simply removing protections is unwarranted. Stock-assessment models for sea turtles must be developed to determine what level of mortality can be sustained while balancing continued turtle population growth and fishing opportunity. Implementation of management targets should involve federal and state managers partnering with specific fisheries to develop bycatch reduction plans that are proportional to their impact on turtles.

scholarly journals Population dynamic between vulnerable coastal jaguars (Panthera onca) and endangered green sea turtles (Chelonia mydas) in Tortuguero National Park, Costa Rica.

2018 ◽  
Author(s):  
Stephanie Butera ◽  
Jaime Restrepo
Keyword(s):  
National Park ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Predator Prey ◽  
Green Sea Turtles ◽  
Turtle Population ◽  
Nest Depredation ◽  
The Impact ◽  
Nest Predators

New-born sea turtles face a number of predators between the time the mothers lay eggs on the beach to when the hatchlings grow into larger juveniles. Nest depredation impacts reproductive success of nesting sea turtles, reducing the number of new turtles that make it to the sea. On Tortuguero beach nest predators include; dogs, coati, and raccoons. Nest depredation within Tortuguero National Park (TNP) has decreased dramatically since 1979. This decrease in nest depredation is linked to the increased jaguar population within TNP as the aforementioned species are considered the jaguars natural prey. Although jaguars prey on nesting turtles, they also control the populations of nest predators. Even more, jaguars have been demonstrated to change their behaviour to suit their preference in prey species therefore the nest predator distribution in TNP was examined to investigate whether changes in jaguar prey preference had an effect. Nest predation and the number of adult turtles lost to jaguar depredation were examined to determine the significance of the threat jaguars pose to the sea turtle population. This study investigates the predator prey relationship between jaguars, nest predators, and nesting female sea turtles; aiming to assessing the impact that jaguars have on the turtle's population.

scholarly journals Climate change and green sea turtle sex ratio – Preventing possible extinction

2020 ◽  
Author(s):  
Jana Blechschmidt ◽  
Meike J. Wittmann ◽  
Chantal Blüml
Keyword(s):  
Climate Change ◽  
Sex Ratio ◽  
Nest Site ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Change Scenario ◽  
Green Sea Turtles ◽  
The Face ◽  
Nest Depth

AbstractClimate change poses a threat to species with temperature-dependent sex determination. A recent study on green sea turtles (Chelonia mydas) at the northern Great Barrier Reef (GBR) showed a highly female-skewed sex ratio with almost all juvenile turtles being female. This shortage of males might eventually cause population extinction, unless rapid evolutionary rescue, migration or conservation efforts ensure a sufficient number of males. We built a stochastic individual-based model inspired by C. mydas, but potentially transferrable to other species with TSD. Nest depth, level of shade, and pivotal temperature were evolvable traits. Additionally, we considered the effect of crossbreeding between the northern and southern GBR, nest-site philopatry, and conservation efforts. Among the evolvable traits, nest depth was the most likely to rescue the population in the face of climate change, but even here the more extreme climate-change scenario led to extinction. Surprisingly, nest-site philopatry elevated extinction rates. Conservation efforts to artificially increase nest depth promoted population survival and did not preclude trait evolution. Although extra information is needed to make reliable predictions for the fate of green sea turtles, our results illustrate how evolution can shape the fate of long lived, vulnerable species in the face of climate change.Graphical Abstract

scholarly journals Effectiveness of Sea Turtle Conservation Management at the Turtle Conservation and Education Center of Serangan, Denpasar Bali

2021 ◽  
Vol 10 (1) ◽  
pp. 18
Author(s):  
Taurus Zeno Adi Eti Harnino ◽  
I Nyoman Yoga Parawangsa ◽  
Luthfiana Aprilianita Sari ◽  
Sulastri Arsad
Keyword(s):  
Sea Turtles ◽  
Marine Ecosystem ◽  
Sea Turtle ◽  
Sand Temperature ◽  
Observation Methods ◽  
Turtle Conservation ◽  
Sea Turtle Conservation ◽  
Nest Depth ◽  
Turtle Population ◽  
The Government

Turtles are one of the reptile animals that can migrate long distances along the Indian Ocean, Pacific Ocean and Southeast Asia. The purpose of turtle migration is to mate, find spawning locations and to find food. Sea turtles have an important role in maintaining the balance of the marine ecosystem. However, the high utilization of sea turtles by humans causes the turtle population to decline. One of the conservation sites that help the government program is in Serangan, Denpasar Bali, namely the TCEC (Turtle Conservation and Education Center), where there are several types of turtles such as the lekang turtle, hawksbill and green turtle. Data collection techniques in this study used observation methods including beach monitoring, relocation of turtle eggs to semi-natural hatchery hatching, hatchling and turtle nesting as well as measurement of turtle length and width carapase curve (CCL/CCW), sand temperature, nest depth, nest diameter, nest distance and nest calculation of the number of eggs to see the success of hatching. The results are turtle conservation activities, ranging from turtle maintenance, hatching of turtle eggs, relocation of eggs, and maintenance of hatchlings to release turtles. The effectiveness given by TCEC to manage and preserve the existence of sea turtles in Indonesia, especially in the Bali region is to provide awareness to the community by not consuming eggs and turtle meat.

scholarly journals Balanced primary sex ratios and resilience to climate change in a major sea turtle population

2017 ◽  
Vol 577 ◽  
pp. 189-203 ◽  
Author(s):  
AR Patrício ◽  
A Marques ◽  
C Barbosa ◽  
AC Broderick ◽  
BJ Godley ◽  
...  
Keyword(s):  
Climate Change ◽  
Sex Ratios ◽  
Sea Turtle ◽  
Turtle Population

Assessing the relative importance of conservation measures applied on sea turtles: comparison of measures focusing on nesting success and hatching recruitment success

2009 ◽  
Vol 30 (2) ◽  
pp. 221-231 ◽  
Author(s):  
Giannis Matsinos ◽  
Antonios Mazaris ◽  
Karin Johst ◽  
Joseph Tzanopoulos ◽  
John Pantis ◽  
...  
Keyword(s):  
Positive Impact ◽  
Eastern Mediterranean ◽  
Sea Turtles ◽  
Sea Turtle ◽  
Nesting Success ◽  
Relative Importance ◽  
Recruitment Success ◽  
Conservation Measures ◽  
Emergence Success ◽  
Nesting Sites

AbstractConservation measures applied to sea turtle nesting sites have a beneficial effect on population trends and dynamics. Such measures aim to protect nesting females, increase nesting success (proportion of female emergences resulting in nests) and/or to improve hatching and hatchling emergence success. However, taking into account financial and time constrains it is important to identify those measures that have the most positive impact on the sea turtle population. The aim of this paper is to assess and compare the relative importance of the different factors that may influence the efficiency of conservation actions and to investigate which factors, those associated with decreased nesting success, or others leading to higher embryonic and hatchling mortality have a higher impact on overall hatchling recruitment. We developed a model that simulates the nesting activity of sea turtles. For model parameterization, we used data collected from nesting sites of the loggerhead sea turtles (Caretta caretta) in the Eastern Mediterranean. We conducted a series of simulations by simultaneously changing model input parameters. The results of the model illustrate that an increase in hatchling recruitment success (i.e., hatching and hatchling emergence success) would have a more positive effect on overall hatchling production than a similar in nesting success. Our analysis further suggests that changes in hatchling recruitment success even at a single site, could have an important impact on overall hatchling production of the rookery.

Smaller longer, larger shorter: energy budget calculations explain intrapopulation variation in remigration intervals for loggerhead sea turtles (Caretta caretta)

2008 ◽  
Vol 86 (7) ◽  
pp. 595-600 ◽  
Author(s):  
Hideo Hatase ◽  
Katsumi Tsukamoto
Keyword(s):  
Feeding Habits ◽  
Sea Turtles ◽  
Caretta Caretta ◽  
Sea Turtle ◽  
Energy Budgets ◽  
Loggerhead Sea Turtles ◽  
Intrapopulation Variation ◽  
Turtle Population ◽  
The Difference ◽  
And Migration

Adult female loggerhead sea turtles ( Caretta caretta (L., 1758)) show a size-related behavioural and trophic dichotomy within several populations: oceanic planktivory by small females and neritic benthivory by large females. Within a Japanese population, smaller females have longer remigration intervals (the intervals between successive nesting years) than larger females. We hypothesized that this is attributed to the size-related foraging dichotomy, and calculated energy budgets and food requirements for the small and large females. Total reproductive energy costs for the small and large females were 1003 and 434 MJ, equivalent to 4043 kg of planktonic items and 275 kg of benthic items, respectively. The minimum durations necessary for accumulating the total reproductive energy for the small and large females were 430 and 26 days, equivalent to remigration intervals of 2 years and 1 year taking into account the nesting and migration durations and seasonal reproduction. Therefore, it was theoretically demonstrated that the intrapopulation variation in remigration intervals for Japanese loggerheads could be caused by the difference in their feeding habits, implying that remigration dynamics in a sea turtle population that shows a foraging dichotomy is regulated by feeding conditions not in a single habitat but in multiple habitats.

scholarly journals A veterinary perspective on the conservation physiology and rehabilitation of sea turtles

2020 ◽  
pp. 241-254
Author(s):  
Charles Innis ◽  
Kara Dodge
Keyword(s):  
Climate Change ◽  
Habitat Loss ◽  
Sea Turtles ◽  
Sea Turtle ◽  
Severe Weather ◽  
Conservation Physiology ◽  
Wildlife Rehabilitation ◽  
Life Threatening ◽  
Physiological Evaluation ◽  
Fisheries Interactions

Sea turtle populations are threatened globally due to anthropogenic and natural factors, including fisheries interactions, watercraft strike, hunting, habitat loss, pollution, climate change, and severe weather. Injured and ill sea turtles are often evaluated by wildlife rehabilitation centres, and many sea turtles can be returned to the wild after rehabilitation. Physiological evaluation of injured and ill sea turtles has revealed life-threatening physiological dysfunction such as acidosis, hypoxia, hypercarbia, dehydration, and hyperkalaemia. Recognition and management of such conditions has improved the outcome for these patients. In addition to clinical advancement, veterinary evaluation has improved our understanding of general sea turtle biology, and increased the safety of procedures such as anaesthesia and laparoscopy. These modalities, combined with emerging biotelemetry technologies, will continue to improve our understanding of sea turtle ecology and conservation physiology.

scholarly journals JUMLAH TEMPAT PENELURAN PENYU HIJAU (Chelonia mydas) BERDASARKAN VEGETASI PANTAI DI TAMAN WISATA ALAM (TWA) TANJUNG BELIMBING KECAMATAN PALOH KABUPATEN SAMBAS

2020 ◽  
Vol 8 (3) ◽  
Author(s):  
Wawan Kurniawan ◽  
Erianto Erianto ◽  
Iswan Dewantara
Keyword(s):  
Sea Turtles ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Coastal Vegetation ◽  
Survey Method ◽  
Green Sea Turtle ◽  
Nature Tourism ◽  
Green Sea Turtles ◽  
Nesting Sites ◽  
Turtle Population

The decline in the population of green sea turtles (Chelonia mydas) occurs continuously due to the destruction of the nesting beach habitat, therefore efforts are needed to increase the green sea turtle population by rearranging nesting sites. One thing that is considered important from the green sea turtle nesting habitat is the coastal vegetation. This research was conducted in Tanjung Belimbing Nature Tourism Park, Sambas Regency, West Kalimantan Province. This study aims to obtain information on vegetation conditions that are preferred by green sea turtles to lay eggs through the number of nesting sites approach. The method used is a survey method. Data collection was carried out by direct observation in the field. In this study, 12 nesting sites were found spread over four observation sites, with the highest number of nesting site found at observation location 1 as many as 8 nesting sites. At observation location 1, besides cemara laut (Casuarina equisetifolia) and pandan laut (Pandanus tectorius) also found waru (Hibiscus tiliaceus) and api-api (Avicennia sp) as well as shrub plants such as kamboja laut (Scaevola taccada), serunai laut (Melanthera biflora) ) and herbal plants such as tapak kuda (Ipomoea pes-caprae), alaban tanah (Vitex rotundifolia), rumput tembaga (Ischaemum muticum), bayam berduri (Amaranthus sp) and bakung laut (Crynum asiaticum L).Keywords: Nesting Sites, Vegetation, Green sea turtle, Tanjung Belimbing Nature Tourism Park

scholarly journals Insights Into Sea Turtle Population Composition Obtained With Stereo-Video Cameras in situ Across Nearshore Habitats in the Northeastern Gulf of Mexico

2021 ◽  
Vol 8 ◽  
Author(s):  
Tabitha Siegfried ◽  
Christopher Noren ◽  
Jackson Reimer ◽  
Matthew Ware ◽  
Mariana M. P. B. Fuentes ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Sea Turtles ◽  
Sea Turtle ◽  
Life Stages ◽  
Turtle Species ◽  
Stereo Video ◽  
Population Size Estimates ◽  
Turtle Population ◽  
Northeastern Gulf Of Mexico

Population size estimates are key parameters used in assessments to evaluate and determine a species’ conservation status. Typically, sea turtle population estimates are made from nesting beach surveys which capture only hatchling and adult female life stages and can display trends opposite of the full population. As such, in-water studies are critical to improve our understanding of sea turtle population dynamics as they can target a broader range of life stages – though they are more logistically and financially challenging to execute compared to beach-based surveys. Stereo-video camera systems (SVCS) hold promise for improving in-water assessments by removing the need to physically capture individuals and instead extract 3D measurements from video footage, thereby simplifying monitoring logistics and improving safety for the animals and surveyors. To demonstrate this potential, snorkel surveys were conducted at artificial habitats in the northeastern Gulf of Mexico (neGOM) to collect size and photo-identification data on sea turtles in situ using a SVCS. Over 29.86 survey hours, 35 sea turtles were observed across three species (Caretta caretta, Chelonia mydas, and Lepidochelys kempii) and all neritic life stages (juvenile, sub-adult, and adult) utilizing different habitats, including artificial reefs, jetties, and fishing piers. Greens straight carapace length ranged from 28.55 to 66.96 cm (n = 23, mean 43.07 cm ± 11.26 cm standard deviation; SD) and loggerheads ranged from 59.71 to 91.77 cm (n = 10, mean 74.50 cm ± 11.35 cm SD), and Kemp’s ridleys ranged from 42.23 cm to 44.98 cm (mean 43.61 cm ± 1.94 cm SD). Using a linear mixed model, we found that species and habitat type were the most important predictors of sea turtle body length distribution. Overall, this case study demonstrates the potential of SVCS surveys to enhance our understanding of the population structure of sea turtle species within the neGOM and elsewhere.

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