scholarly journals Assessing coastal artificial light and potential exposure of wildlife at a national scale: the case of marine turtles in Brazil

2020 ◽  
Vol 29 (4) ◽  
pp. 1135-1152 ◽  
Author(s):  
Liliana P. Colman ◽  
Paulo H. Lara ◽  
Jonathan Bennie ◽  
Annette C. Broderick ◽  
Juliana R. de Freitas ◽  
...  
Keyword(s):  
Nest Site Selection ◽  
Marine Turtle ◽  
Conservation Strategies ◽  
Brazilian Coast ◽  
Light Pollution ◽  
Artificial Light ◽  
Turtle Species ◽  
Marine Turtles ◽  
Light Levels ◽  
Nesting Beaches

AbstractCoastal areas provide critical nesting habitat for marine turtles. Understanding how artificial light might impact populations is key to guide management strategies. Here we assess the extent to which nesting populations of four marine turtle species—leatherback (Dermochelys coriacea), olive ridley (Lepidochelys olivacea), hawksbill (Eretmochelys imbricata) and two subpopulations of loggerhead (Caretta caretta) turtles—are exposed to light pollution across 604 km of the Brazilian coast. We used yearly night-time satellite images from two 5-year periods (1992–1996 and 2008–2012) from the US Air Force Defense Meteorological Satellite Programme (DMSP) to determine the proportion of nesting areas that are exposed to detectable levels of artificial light and identify how this has changed over time. Over the monitored time-frame, 63.7% of the nesting beaches experienced an increase in night light levels. Based on nest densities, we identified 54 reproductive hotspots: 62.9% were located in areas potentially exposed to light pollution. Light levels appeared to have a significant effect on nest densities of hawksbills and the northern loggerhead turtle stock, however high nest densities were also seen in lit areas. The status of all species/subpopulations has improved across the time period despite increased light levels. These findings suggest that (1) nest site selection is likely primarily determined by variables other than light and (2) conservation strategies in Brazil appear to have been successful in contributing to reducing impacts on nesting beaches. There is, however, the possibility that light also affects hatchlings in coastal waters, and impacts on population recruitment may take longer to fully manifest in nesting numbers. Recommendations are made to further this work to provide deeper insights into the impacts of anthropogenic light on marine turtles.

Influence of industrial light pollution on the sea-finding behaviour of flatback turtle hatchlings

2014 ◽  
Vol 41 (5) ◽  
pp. 421 ◽  
Author(s):  
Ruth L. Kamrowski ◽  
Col Limpus ◽  
Kellie Pendoley ◽  
Mark Hamann
Keyword(s):  
Cloud Cover ◽  
Industrial Development ◽  
Large Scale ◽  
Marine Turtle ◽  
Artificial Light ◽  
Moon Phase ◽  
Light Levels ◽  
Combination Of Methods ◽  
Industrial Lighting ◽  
Nesting Beaches

Context Numerous studies show that artificial light disrupts the sea-finding ability of marine turtle hatchlings. Yet very little has been published regarding sea-finding for flatback turtles. Given the current industrialisation of Australia’s coastline, and the large potential for disruption posed by industrial light, this study is a timely investigation into sea-finding behaviour of flatback turtle hatchlings. Aims We investigate sea-finding by flatback turtle hatchlings in relation to ambient light present in areas of planned or ongoing industrial development, and evaluate the fan and arena-based methods that are frequently used for quantifying hatchling dispersion. Methods Using a combination of methods, we assessed the angular range and directional preference of sea-finding hatchlings at two key flatback turtle rookeries, Peak and Curtis Islands, during January–February 2012 and 2013, and at Curtis Island in January 2014. Relative light levels at each site were measured using an Optec SSP-3 stellar photometer, and moon phase, moon stage and cloud cover were also recorded. Key results We found no evidence of impaired hatchling orientation, and observed very low levels of light at Peak Island. However, at Curtis Island, hatchlings displayed reduced sea-finding ability, with light horizons from the direction of nearby industry significantly brighter than from other directions. The sea-finding disruption observed at Curtis Island was less pronounced in the presence of moonlight. Conclusions The reduced sea-finding ability of Curtis Island hatchlings was likely due to both altered light horizons from nearby industry, as well as beach topography. Both methods of assessing hatchling orientation have benefits and limitations. We suggest that fan-based methods, combined with strategically placed arenas, would provide the best data for accurately assessing hatchling sea-finding. Implications Sky glow produced by large-scale industrial development appears detrimental to sea-finding by flatback turtle hatchlings. As development continues around Australia’s coastline, we strongly recommend continued monitoring of lighting impacts at adjacent turtle nesting beaches. We also advise rigorous management of industrial lighting, which considers cumulative light levels in regions of multiple light producers, as well as moon phase, moon-stage, cloud cover and time of hatchling emergence. All these factors affect the likelihood of disrupted hatchling sea-finding behaviour at nesting beaches exposed to artificial light-glow, industrial or otherwise.

scholarly journals Plastic ingestion by freshwater turtles: a review and call to action

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Adam G. Clause ◽  
Aaron J. Celestian ◽  
Gregory B. Pauly
Keyword(s):  
Marine Species ◽  
Marine Turtle ◽  
Freshwater Turtle ◽  
Freshwater Turtles ◽  
Plastic Pollution ◽  
Potential Threat ◽  
Implementation Quality ◽  
Turtle Species ◽  
Marine Turtles ◽  
Conservation Concern

AbstractPlastic pollution, and especially plastic ingestion by animals, is a serious global issue. This problem is well documented in marine systems, but it is relatively understudied in freshwater systems. For turtles, it is unknown how plastic ingestion compares between marine and non-marine species. We review the relevant turtle dietary literature, and find that plastic ingestion is reported for all 7 marine turtle species, but only 5 of 352 non-marine turtle species. In the last 10 years, despite marine turtles representing just 2% of all turtle species, almost 50% of relevant turtle dietary studies involved only marine turtles. These results suggest that the potential threat of plastic ingestion is poorly studied in non-marine turtles. We also examine plastic ingestion frequency in a freshwater turtle population, finding that 7.7% of 65 turtles had ingested plastic. However, plastic-resembling organic material would have inflated our frequency results up to 40% higher were it not for verification using Raman spectroscopy. Additionally, we showcase how non-native turtles can be used as a proxy for understanding the potential for plastic ingestion by co-occurring native turtles of conservation concern. We conclude with recommendations for how scientists studying non-marine turtles can improve the implementation, quality, and discoverability of plastic ingestion research.

scholarly journals Natal foraging philopatry in eastern Pacific hawksbill turtles

2017 ◽  
Vol 4 (8) ◽  
pp. 170153 ◽  
Author(s):  
Alexander R. Gaos ◽  
Rebecca L. Lewison ◽  
Michael P. Jensen ◽  
Michael J. Liles ◽  
Ana Henriquez ◽  
...  
Keyword(s):  
Genetic Research ◽  
Eastern Pacific ◽  
Marine Turtle ◽  
Natal Philopatry ◽  
Eretmochelys Imbricata ◽  
Turtle Species ◽  
Marine Turtles ◽  
Complex Processes ◽  
Natal Homing ◽  
Hawksbill Turtles

The complex processes involved with animal migration have long been a subject of biological interest, and broad-scale movement patterns of many marine turtle populations still remain unresolved. While it is widely accepted that once marine turtles reach sexual maturity they home to natal areas for nesting or reproduction, the role of philopatry to natal areas during other life stages has received less scrutiny, despite widespread evidence across the taxa. Here we report on genetic research that indicates that juvenile hawksbill turtles ( Eretmochelys imbricata ) in the eastern Pacific Ocean use foraging grounds in the region of their natal beaches, a pattern we term natal foraging philopatry. Our findings confirm that traditional views of natal homing solely for reproduction are incomplete and that many marine turtle species exhibit philopatry to natal areas to forage. Our results have important implications for life-history research and conservation of marine turtles and may extend to other wide-ranging marine vertebrates that demonstrate natal philopatry.

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 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.

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.

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 Apparent Effects of Light Pollution on Singing Behavior of American Robins

The Condor ◽  
2006 ◽  
Vol 108 (1) ◽  
pp. 130-139 ◽  
Author(s):  
Mark W. Miller
Keyword(s):  
Bird Species ◽  
Population Level ◽  
Light Pollution ◽  
Artificial Light ◽  
Turdus Migratorius ◽  
Singing Behavior ◽  
Light Levels ◽  
American Robins ◽  
A Site ◽  
Avian Song

Abstract Astronomers consider light pollution to be a growing problem, however few studies have addressed potential effects of light pollution on wildlife. Sunlight is believed to initiate song in many bird species. If light initiates song, then light pollution may be influencing avian song behavior at a population level. This hypothesis predicts that birds breeding in areas with large amounts of artificial light will begin singing earlier in the day than birds in areas with little artificial light. Birds in highly illuminated areas might begin singing earlier than did birds in those same areas in previous years when artificial light levels were known to be, or were presumably, lower. Also, birds should begin singing earlier within a site on brightly lit nights. In 2002 and 2003 I documented initiation of morning song by breeding American Robins (Turdus migratorius) in areas with differing intensity of artificial nocturnal light. I compared my observations among sites and against historical studies. Robin populations in areas with large amounts of artificial light frequently began their morning chorus during true night. Chorus initiation time, relative to civil twilight, was positively correlated with amount of artificial light present during true night. Robin choruses in areas with little, or presumably little, artificial light have almost never begun during true night, instead appearing to track the onset of civil twilight. Proliferation of artificial nocturnal light may be strongly affecting singing behavior of American Robins at a population level.

scholarly journals The evolution of the flippers and the paleoecology of Panchelonioidea (Testudines, Cryptodira)

2015 ◽  
Author(s):  
Isadora Gerheim ◽  
Pedro S. R. Romano
Keyword(s):  
Sister Group ◽  
Marine Turtle ◽  
Benthic Habitat ◽  
Remarkable Feature ◽  
Fossil Species ◽  
Turtle Species ◽  
Marine Turtles ◽  
The Family ◽  
Family Level ◽  
Pelagic Habitat

Background. The recent data on Panchelonioidea’s phylogeny suggested the family level relationships as (Toxochelyidae, (Cheloniidae, (Protostegidae, Dermochelyidae))). Despite the similarity between their limbs, it is known that the flippers morphology on marine turtles evolved independently in these clades. A remarkable feature is the presence of phalangeal condyles in Toxochelyidae and basal Protostegidae, a plesiomorphic state that allows the movement of the hand. On the other hand, the apomorphic state of having a rigid paddle is found in modern turtles (Cheloniidae and Dermochelyidae). Also, living Chelonioidea (Cheloniidae and Dermochelyidae) has the longest length of the hand and the shortest length of the humerus compared to other Testudines, as analyzed by Joyce and Gauthier (2004, Proc. R. Soc. Lond. B, 271). Methods. We took measurements of the forelimb (the length of humerus, ulna and digit III) from five Panchelonioidea fossil species (Protostega gigas, Toxochelys latiremys, Allopleuron hoffmanni, Eochelone brabantica and Archelon ischyros) using ImageJ 1.48v. The percentages of the length of the hand and the humerus with respect to the whole limb were then calculated. The percentages of the five species were added to the two-dimension ternary diagram made by Joyce and Gauthier (2004) in order to evaluate the plot of these species and compare them to other turtles. Results. Archelon ischyros was plotted near Toxochelys latiremys. The Toxochelidae are the sister group of Chelonioidea and they are known to have a poor development of the limbs into flippers and a preference for shallow and benthic habitat. Both were located near non-marine turtle species, showing that they had the relatively shortest hand within Panchelonioidea, whereas Protostega gigas, Allopleuron hoffmanni and Eochelone brabantica was plotted close to the recent Cheloniidae. Discussion. The results suggest a less pelagic habitat for Protostega gigas and Archelon ischyros, resembling a hypothesis formulated by Hay (1905, Bull. Am. Mus. Nat. Hist., 21) that Archelon was not as pelagic as Dermochelys and by Wieland (1909, Am. Jour. Sci., 27) that this species did not have a powerful type of muscular insertion, maybe indicating a less strong swimming power. These results together with the fact that basal species of Protostegidae retain the phalangeal condyles, suggests that after the split between these families, the flippers retained the primitive length of limbs. It also brings back a Zangerl’s hypothesis (1980, Amer. Zool., 20) of a Chelydra-like ancestor for Panchelonioidea, with unspecialized limbs. As conclusion, we suggest that Panchelonioidea ancestor flipper condition would last in stem Toxochelyidae and stem Chelonioidea and then get independently specialized in Cheloniidae and Dermochelyidae.

scholarly journals The evolution of the flippers and the paleoecology of Panchelonioidea (Testudines, Cryptodira)

2015 ◽  
Author(s):  
Isadora Gerheim ◽  
Pedro S. R. Romano
Keyword(s):  
Sister Group ◽  
Marine Turtle ◽  
Benthic Habitat ◽  
Remarkable Feature ◽  
Fossil Species ◽  
Turtle Species ◽  
Marine Turtles ◽  
The Family ◽  
Family Level ◽  
Pelagic Habitat

Background. The recent data on Panchelonioidea’s phylogeny suggested the family level relationships as (Toxochelyidae, (Cheloniidae, (Protostegidae, Dermochelyidae))). Despite the similarity between their limbs, it is known that the flippers morphology on marine turtles evolved independently in these clades. A remarkable feature is the presence of phalangeal condyles in Toxochelyidae and basal Protostegidae, a plesiomorphic state that allows the movement of the hand. On the other hand, the apomorphic state of having a rigid paddle is found in modern turtles (Cheloniidae and Dermochelyidae). Also, living Chelonioidea (Cheloniidae and Dermochelyidae) has the longest length of the hand and the shortest length of the humerus compared to other Testudines, as analyzed by Joyce and Gauthier (2004, Proc. R. Soc. Lond. B, 271). Methods. We took measurements of the forelimb (the length of humerus, ulna and digit III) from five Panchelonioidea fossil species (Protostega gigas, Toxochelys latiremys, Allopleuron hoffmanni, Eochelone brabantica and Archelon ischyros) using ImageJ 1.48v. The percentages of the length of the hand and the humerus with respect to the whole limb were then calculated. The percentages of the five species were added to the two-dimension ternary diagram made by Joyce and Gauthier (2004) in order to evaluate the plot of these species and compare them to other turtles. Results. Archelon ischyros was plotted near Toxochelys latiremys. The Toxochelidae are the sister group of Chelonioidea and they are known to have a poor development of the limbs into flippers and a preference for shallow and benthic habitat. Both were located near non-marine turtle species, showing that they had the relatively shortest hand within Panchelonioidea, whereas Protostega gigas, Allopleuron hoffmanni and Eochelone brabantica was plotted close to the recent Cheloniidae. Discussion. The results suggest a less pelagic habitat for Protostega gigas and Archelon ischyros, resembling a hypothesis formulated by Hay (1905, Bull. Am. Mus. Nat. Hist., 21) that Archelon was not as pelagic as Dermochelys and by Wieland (1909, Am. Jour. Sci., 27) that this species did not have a powerful type of muscular insertion, maybe indicating a less strong swimming power. These results together with the fact that basal species of Protostegidae retain the phalangeal condyles, suggests that after the split between these families, the flippers retained the primitive length of limbs. It also brings back a Zangerl’s hypothesis (1980, Amer. Zool., 20) of a Chelydra-like ancestor for Panchelonioidea, with unspecialized limbs. As conclusion, we suggest that Panchelonioidea ancestor flipper condition would last in stem Toxochelyidae and stem Chelonioidea and then get independently specialized in Cheloniidae and Dermochelyidae.

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