Artificial lighting and disrupted sea-finding behaviour in hatchling loggerhead turtles (Caretta caretta) on the Woongarra coast, south-east Queensland, Australia

2013 ◽  
Vol 61 (2) ◽  
pp. 137 ◽  
Author(s):  
Megan Berry ◽  
David T. Booth ◽  
Colin J. Limpus
Keyword(s):  
Population Decline ◽  
Sea Turtle ◽  
Management Plan ◽  
Coastal Development ◽  
Marine Turtle ◽  
Artificial Lighting ◽  
Light Management ◽  
Turtle Population ◽  
Conservation Park ◽  
Nesting Beaches

Coastal development adjacent to sea turtle nesting beaches can result in an increase in exposure to artificial lighting at night. That lighting can repel nesting females and interfere with the orientation of hatchlings from the nest to the sea. Disrupted hatchling orientation is a serious source of turtle mortality, sufficient to reduce recruitment and contribute to a long-term marine turtle population decline. The purpose of this study was to assess whether artificial lighting disrupts hatchling sea-finding behaviour at the largest loggerhead rookery in the South Pacific, the Woongarra coast, south-east Queensland. The crawling tracks of hatchlings that emerged from nests, as well as staged emergences, were used to assess the effect of lighting conditions at several local beaches on hatchling sea-finding behaviour. Disrupted orientation was observed at only a few locations, excluding the majority of the main nesting beach at Mon Repos Conservation Park. At the sites where orientation was disrupted, normal orientation was restored when a full moon was visible, presumably because lunar illumination reduced the perceived brightness of the artificial lights. The controlled use of lights used for guided turtle-viewing tour groups within Mon Repos conservation Park did not interfere with the sea-finding behaviour of hatchling turtles. Further coastal development, especially at the nearby town of Bargara, requires that a light management plan be formulated to ensure that development does not adversely affect the marine turtles that utilise the local nesting beaches.

scholarly journals A Global Analysis of Anthropogenic Development of Marine Turtle Nesting Beaches

2020 ◽  
Vol 12 (9) ◽  
pp. 1492
Author(s):  
Sarah J. Biddiscombe ◽  
Elliott A. Smith ◽  
Lucy A. Hawkes
Keyword(s):  
Global Analysis ◽  
Earth Satellite ◽  
Google Earth ◽  
Coastal Development ◽  
Marine Turtle ◽  
Intergovernmental Panel ◽  
Sea Levels ◽  
Marine Turtles ◽  
Coastal Squeeze ◽  
Nesting Beaches

The Intergovernmental Panel on Climate Change predicts that sea levels will rise by up to 0.82 m in the next 100 years. In natural systems, coastlines would migrate landwards, but because most of the world’s human population occupies the coast, anthropogenic structures (such as sea walls or buildings) have been constructed to defend the shore and prevent loss of property. This can result in a net reduction in beach area, a phenomenon known as “coastal squeeze”, which will reduce beach availability for species such as marine turtles. As of yet, no global assessment of potential future coastal squeeze risk at marine turtle nesting beaches has been conducted. We used Google Earth satellite imagery to enumerate the proportion of beaches over the global nesting range of marine turtles that are backed by hard anthropogenic coastal development (HACD). Mediterranean and North American nesting beaches had the most HACD, while the Australian and African beaches had the least. Loggerhead and Kemp’s ridley turtle nesting beaches had the most HACD, and flatback and green turtles the least. Future management approaches should prioritise the conservation of beaches with low HACD to mitigate future coastal squeeze.

Ocean-finding in marine turtles: the importance of low horizon elevation as an orientation cue

Behaviour ◽  
2013 ◽  
Vol 150 (8) ◽  
pp. 863-893 ◽  
Author(s):  
Col Limpus ◽  
Ruth L. Kamrowski
Keyword(s):  
Effective Means ◽  
Sea Turtle ◽  
Current Theory ◽  
Light Reduction ◽  
Artificial Lighting ◽  
Marine Turtles ◽  
Nest Sites ◽  
Reduction Strategies ◽  
Horizon Line ◽  
Nesting Beaches

Sea finding behaviour in hatchling sea turtles is widely believed to be guided by orientation towards the brightest horizon and away from high silhouettes. We propose that the horizon profile at the lowest angle of elevation is a more important cue for ocean finding than light intensity. Examples of hatchling orientation occurring at natural nest sites, at preselected beach release sites, and within a walled wooden arena under various conditions in the field, are presented. We conclude that hatchlings orient as follows: (1) Hatchlings move towards the horizon line at the lowest angle of elevation; (2) Hatchlings move away from high silhouettes, in a direction that remains close to the horizon line at the lowest angle of elevation; (3) Should a conflict exist regarding the direction of lowest horizon elevation, hatchlings move towards the brightest lowest horizon. This refinement to current theory explains numerous instances of natural non-ocean-finding behaviour in marine turtles, which occur both by day and by night, and in the absence of artificial lighting. We propose that the disruption caused to hatchling orientation by artificial lighting close to nesting beaches occurs because bright lights mask the horizon line as a cue by making it impossible to discern, causing the hatchlings to move towards the only visible “horizon” — the artificial lights. Consequently, we recommend that managers of sea turtle rookeries where turtles have an ocean-finding problem should manipulate the beach profile to ensure the direction of the ocean matches the lowest angle of elevation, in combination with light reduction strategies — as the most effective means of preventing disrupted orientation.

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.

scholarly journals Exploring scenarios of light pollution from coastal development reaching sea turtle nesting beaches near Cabo Pulmo, Mexico

2014 ◽  
Vol 2 ◽  
pp. 170-180 ◽  
Author(s):  
Gregory M. Verutes ◽  
Charles Huang ◽  
Ricardo Rodríguez Estrella ◽  
Kara Loyd
Keyword(s):  
Sea Turtle ◽  
Coastal Development ◽  
Light Pollution ◽  
Nesting Beaches

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.

Population model analysis for the loggerhead sea turtle, Caretta caretta, in Queensland

1996 ◽  
Vol 23 (2) ◽  
pp. 143 ◽  
Author(s):  
SS Heppel ◽  
CJ Limpus ◽  
DT Crouse ◽  
NB Frazer ◽  
LB Crowder
Keyword(s):  
Population Decline ◽  
Survival Rates ◽  
Loggerhead Turtle ◽  
Caretta Caretta ◽  
Sea Turtle ◽  
Marine Turtle ◽  
Emergence Success ◽  
Eastern Australia ◽  
Loggerhead Turtles ◽  
The Usa

Worldwide declines of marine turtle populations have forced a need for sound conservation policies to prevent their extinction. Loggerhead turtles, Caretta caretta, are declining rapidly at eastern Australian nesting beaches, which are visited by females from all feeding areas for the stock. In some feeding areas of eastern Australia, loggerheads have been protected from deleterious anthropogenic effects. Using long-term mark-recapture data from one such protected group of turtles feeding on Heron Island Reef, Queensland, we created a matrix model to analyse loggerhead demography. We also produced a model for the females nesting at Mon Repos, Queensland, a major rookery where the annual nesting population has declined at rates approaching 8% per year. As indicated by a similar model for loggerheads in the USA, our models predicted that small declines in annual survival rates of adult and subadult loggerheads can have a profound impact on population dynamics. A loss of only a few hundred subadult and adult females each year could lead to extinction of the eastern Australian loggerheads in less than a century. Survival in the first year of life is relatively less important in these long-lived and slow-maturing animals. At Mon Repos, nesting female survival is apparently so low that even beach protection efforts resulting in 90% hatchling emergence success would not prevent population decline. Our research suggests that continued mortality pressure on subadult and adult turtles in their dispersed feeding areas of eastern and northern Australia is a major threat to the eastern Australian loggerhead turtle population. Measures that protect adult and subadult loggerhead turtles should be supported, including the use of turtle excluder devices (TEDs) on prawn trawls.

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.

PERÍODO DE DESOVA E SUCESSO REPRODUTIVO DO TRACAJÁ Podocnemis unifilis TROSCHEL 1848 (TESTUDINES: PODOCNEMIDIDAE) NA VÁRZEA DA RDSM – MÉDIO SOLIMÕES, BRASIL

2008 ◽  
Vol 2 (1) ◽  
pp. 63-75
Author(s):  
Augusto Fachín Terán ◽  
Eduardo Matheus Von Mülhen
Keyword(s):  
Hatching Success ◽  
Management Program ◽  
Nesting Biology ◽  
Sand Beach ◽  
Podocnemis Unifilis ◽  
Turtle Population ◽  
Nesting Beaches ◽  
Conservation And Management ◽  
Tegu Lizard ◽  
Solimões River

In this study the nesting biology of Podocnem is unifilis was investigated from July to November 1998 at the Mamirauá Sustainable Development Reserve, located in the Solimões river, near Tefé, Amazonas, Brazil. Podocnemis unifilis nested in August and September, with the hatching event occurring in October and November. Nests were excavated in clay soils (67.5%), sand (25%), and leaf litter (7.5%). Hatching success was highest in the sand beach nests and lowest in the clay banks nests. Humans and the tegu lizard (Tupinambis) were the main egg predators. This turtle population can recover only by the protection of nesting beaches, educational programs for the in habitants of the Reserve, participation of the community in the conservation and management program , and permanent guarding of the nesting beaches by Instituto Brasileiro do Meio Ambiente e Dos Recursos Naturais Renováveis-IBAMA authorities.

scholarly journals Long-term decline of the western Pacific leatherback,Dermochelys coriacea: a globally important sea turtle population

Ecosphere ◽  
2013 ◽  
Vol 4 (2) ◽  
pp. art25 ◽  
Author(s):  
Ricardo F. Tapilatu ◽  
Peter H. Dutton ◽  
Manjula Tiwari ◽  
Thane Wibbels ◽  
Hadi V. Ferdinandus ◽  
...  
Keyword(s):  
Sea Turtle ◽  
Western Pacific ◽  
Dermochelys Coriacea ◽  
Turtle Population ◽  
The Western Pacific

scholarly journals The Olive Ridley Project (ORP): A successful example of how to engage researchers, conservation practitioners and civil society

2021 ◽  
Vol 5 (2) ◽  
Author(s):  
Martin Stelfox ◽  
Mercedes Martin-Cereceda ◽  
Karim Vahed ◽  
Jillian Hudgins ◽  
Stephanie Köhnk ◽  
...  
Keyword(s):  
Spatial Ecology ◽  
Community Education ◽  
Knowledge Exchange ◽  
Sustainable Use ◽  
Sea Turtle ◽  
Marine Turtle ◽  
Olive Ridley ◽  
Turtle Species ◽  
Research Engagement ◽  
The Uk

The Olive Ridley Project (ORP) was set up to protect sea turtles and their habitats. The project was formed in 2013, and it became a registered charity in the UK in 2016. From its inception, ORP took a multidisciplinary approach to achieve its goals. Part of its objectives, and the reason why the charity came to fruition, are related to the issue of olive ridley sea turtle (Lepidochelys olivacea) entanglement in abandoned, lost or discarded fishing gear (also known as ‘ghost gear’ or ‘ghost nets’), and the search for ghost gear and turtle entanglement ‘hot spots’ throughout the Indian Ocean. The initial ORP research questions were soon challenged by societal interests to develop inclusive educational programmes in local communities and tourist resorts that could raise awareness about the need for conservation of all sea turtle species. In February 2017, ORP opened the first veterinarian-run, fully equipped Marine Turtle Rescue Centre in the Maldives, bringing together the work of researchers, citizen scientists, volunteers, environmentalists, marine biologists and veterinarians. The present work of ORP sits on a strong and scientifically robust collaborative plan. Current ORP research projects range from sea turtle population analyses, spatial ecology, rehabilitation of injured and sick individuals, epibiont parasite analyses, precise turtle identification through photo-ID research, linking ghost gear to responsible fisheries, and analyses of ghost gear drift patterns. The programme enhances community education and outreach by engaging schoolchildren, organizing workshops, promoting sustainable use of ghost gear waste, and training citizen scientists and local fishing communities. The ORP programme encompasses many principles of research engagement, effectively combining scientific knowledge, education and action. This article explores all stages of the process (from research planning and design, to knowledge exchange and inter- and trans-disciplinary impact assessments), describing the active engagement originated by the ORP initiative. A reflective insight into the learning, enrichment and challenges of engaging researchers and community actors is also included, considering the current social and scientific framework.

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