An assessment of ‘turtle-friendly' lights on the sea-finding behaviour of loggerhead turtle hatchlings (Caretta caretta)

2016 ◽  
Vol 43 (1) ◽  
pp. 27 ◽  
Author(s):  
Katharine Robertson ◽  
David T. Booth ◽  
Colin J. Limpus
Keyword(s):  
Red Light ◽  
Loggerhead Turtle ◽  
Sea Turtle ◽  
Eastern Coast ◽  
Loggerhead Sea Turtles ◽  
Cumulative Impact ◽  
Artificial Lighting ◽  
Light Peak ◽  
Peak Intensity ◽  
Red Led

Context It is well established that artificial light can disrupt the sea-finding ability of sea turtle hatchlings, and some manufactures are now marketing ‘turtle-friendly’ lights that are supposed to be minimally disruptive to this sea-finding behaviour. However, there have been no studies that have tested whether ‘turtle-friendly’ lights are benign to hatchling sea turtle sea-finding ability. Aims We tested two different types of ‘turtle-friendly’ lights (LED amber-light peak intensity 620 nm and LED red-light peak intensity 640 nm) to see whether they are disruptive to the sea-finding ability of eastern-coast Australian loggerhead turtle hatchlings. Methods Using standard circular-arena experiments, we assessed the directional preference of newly emerged loggerhead turtle hatchlings from the Woongarra Coast of Queensland, Australia, during different moon phases without artificial lighting and in the presence of ‘turtle-friendly’ lights. Key results Contrary to expectations, sea-finding ability of hatchlings was disrupted by the amber lights, particularly in the absence of a moon. The less intense red lights were less disruptive to hatchlings; however, misorientation and disorientation events still occurred when lights were within 4 m of hatchlings. The disruptive impact on sea-finding ability increased with the cumulative impact of multiple lights increasing light intensity. Conclusions The ‘turtle-friendly’ lights we used disrupted the sea-finding ability of eastern-coast Australian loggerhead turtle hatchlings, with the most pronounced disruption occurring under moonless conditions. Implications The use of amber and red LED lights adjacent to the nesting beaches of loggerhead sea turtles should be managed because this lighting has the potential to disrupt the sea-finding ability of sea turtle hatchlings.

Going back to the roots: finding a strategy for the management of nesting loggerhead sea turtles in New Caledonia

2018 ◽  
Vol 66 (6) ◽  
pp. 394
Author(s):  
Tyffen C. Read ◽  
Marion Petit ◽  
Marion Magnan ◽  
David Booth
Keyword(s):  
Hatching Success ◽  
Incubation Temperature ◽  
New Caledonia ◽  
Loggerhead Turtle ◽  
Sea Turtle ◽  
Vital Role ◽  
Morning Glory ◽  
Root Penetration ◽  
Loggerhead Sea Turtles ◽  
Emergence Success

Incubation temperature plays a vital role in sea turtle life history because it influences embryonic growth, sex determination and hatchling attributes such as body size, residual yolk size, self-righting ability, crawling speed and swimming speed. For these reasons there is concern that predicted increases in air temperature, as a result of global warming, will increase nest temperatures and result in decreased hatching success, decrease or cease male hatchling production, and decreased hatchling quality. In a previous study examining incubation temperature at a loggerhead turtle (Caretta caretta) rookery located at La Roche Percée, New Caledonia, high nest temperatures and root invasion by beach morning glory (Ipomoea pes-caprae) were found to adversely affect hatching success and locomotor performance. In the current study, we relocated loggerhead turtle nests into shaded hatcheries. Shading nests decreased sand and nest temperatures and was predicted to increase male hatchling production slightly, but nest emergence success was decreased due to invasion of cottonwood (Hibiscus tiliaceus) roots into some nests. Using shaded structures is a viable and affordable management option to counteract the high sand temperatures found on some sea turtle nesting beaches, but these shade structures need to be located some distance from trees and other plants to ensure that root penetration into nests does not adversely affect nest emergence success.

scholarly journals Globally important refuge for the loggerhead sea turtle: Maio Island, Cabo Verde

Oryx ◽  
2021 ◽  
pp. 1-9
Author(s):  
Juan Patino-Martinez ◽  
Leno Dos Passos ◽  
Inês O. Afonso ◽  
Arnau Teixidor ◽  
Manjula Tiwari ◽  
...  
Keyword(s):  
Management Strategy ◽  
Hatching Success ◽  
Management Strategies ◽  
Loggerhead Turtle ◽  
Sea Turtle ◽  
Sandy Beaches ◽  
Loggerhead Sea Turtle ◽  
Artificial Lighting ◽  
Cabo Verde ◽  
Comprehensive Study

Abstract One of the largest nesting colonies of the Vulnerable loggerhead sea turtle Caretta caretta is in Cabo Verde. Here we present the first comprehensive study of loggerhead turtle nesting on the island of Maio in Cabo Verde. During 2016–2019 we monitored 38 km of undeveloped sandy beaches that have minimal artificial lighting and where all nesting on Maio takes place. We counted 4,063 nests in 2016, 5,429 in 2017, 14,364 in 2018 and 7,937 in 2019. The estimated total number of females was 1,016, 1,357, 3,591 and 1,984 in each of these years, respectively. Our findings suggest there are more loggerhead turtles nesting in Cabo Verde than previously estimated, and that this could be the species’ largest nesting subpopulation (followed by Florida, USA and Oman). The inter-annual hatching success (the proportion of eggs producing hatchlings) was 29–38% for the whole island but varied between sites. Our study of 250 clutches showed that flooding affected 38–61% and predation by crabs 40–42%, with hatching success on different beaches in the range of 1–59%. Poaching of eggs was rare (< 2% of clutches), but dogs predated 68.4% of all clutches on the beach nearest the largest human settlement. We evaluated different nest management strategies at multiple sites and estimated productivity of hatchlings (the number of hatchlings that would reach the sea for each management strategy), finding that hatcheries are not always the best option for nest management. As the beaches on Maio are relatively undisturbed, and there is a high abundance and density of turtle nests, the island should be protected as a globally important site for the conservation of the loggerhead turtle, and of coastal biodiversity more broadly.

scholarly journals Critical Photoperiod and Optimal Quality of Night Interruption Light for Runner Induction in June-Bearing Strawberries

Agronomy ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1996
Author(s):  
Yali Li ◽  
Jie Xiao ◽  
Jiangtao Hu ◽  
Byoung Ryong Jeong
Keyword(s):  
Red Light ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Light Emitting ◽  
Red Led ◽  
Critical Photoperiod ◽  
Closed Walk ◽  
White Light Emitting Diodes ◽  
Optimal Quality

The optimal photoperiod and light quality for runner induction in strawberries ‘Sulhyang’ and ‘Maehyang’ were investigated. Two experiments were carried out in a semi-closed walk-in growth chamber with 25/15 °C day/night temperatures and a light intensity of 250 μmol·m–2·s–1photosynthetic photon flux density (PPFD) provided from white light-emitting diodes (LEDs). In the first experiment, plants were treated with a photoperiod of either 12, 14, 16, 18, 20, or 22 h In the second experiment, a total of 4 h of night interruption (NI) light at an intensity of 70 μmol·m–2·s–1PPFD provided from either red, blue, green, white, or far-red LED in addition to 11 h short day (SD). The results showed that both ‘Sulhyang’ and ‘Maehyang’ produced runners when a photoperiod was longer than 16 h, and the number of runners induced positively correlated with the length of photoperiod. However, the plant growth, contents of chlorophyll, sugar and starch, and Fv/Fo decreased in a 22 h photoperiod. All qualities of the NI light, especially red light, significantly increased the number of runners and daughter plants induced per plant as compared with those in the SD treatment in both cultivars. In a conclusion, a photoperiod between 16 and 20 h and NI light, especially red NI light, can be used for quality runner induction in both ‘Sulhyang’ and ‘Maehyang’.

scholarly journals Red LED Light Acts on the Mitochondrial Electron Chain of Donkey Sperm and Its Effects Depend on the Time of Exposure to Light

2020 ◽  
Vol 8 ◽  
Author(s):  
Jaime Catalán ◽  
Marion Papas ◽  
Lina Trujillo-Rojas ◽  
Olga Blanco-Prieto ◽  
Sebastián Bonilla-Correal ◽  
...  
Keyword(s):  
Red Light ◽  
Specific Inhibitor ◽  
Motile Sperm ◽  
Light Stimulation ◽  
Led Light ◽  
Mitochondrial Atp Synthase ◽  
Red Led ◽  
Oligomycin A ◽  
Rate Of Oxygen Consumption ◽  
Stimulation Of

This work aimed to investigate how stimulation of donkey sperm with red LED light affects mitochondrial function. For this purpose, freshly diluted donkey semen was stimulated with red light for 1, 5, and 10 min, in the presence or absence of oligomycin A (Omy A), a specific inhibitor of mitochondrial ATP synthase, or FCCP, a specific disruptor of mitochondrial electron chain. The results obtained in the present study indicated that the effects of red LED light on fresh donkey sperm function are related to changes in mitochondria function. In effect, irradiation of donkey sperm resulted in an increase in mitochondrial membrane potential (MMP), the activity of cytochrome C oxidase and the rate of oxygen consumption. In addition, in the absence of oligomycin A and FCCP, light-stimulation augmented the average path velocity (VAP) and modified the structure of motile sperm subpopulations, increasing the fastest and most linear subpopulation. In contrast, the presence of either Omy A or FCCP abolished the aforementioned effects. Interestingly, our results also showed that the effects of red light depend on the exposure time applied, as indicated by the observed differences between irradiation protocols. In conclusion, our results suggest that exposing fresh donkey sperm to red light modulates the function of their mitochondria through affecting the activity of the electron chain. However, the extent of this effect depends on the irradiation pattern and does not exclude the existence of other mechanisms, such as those related to thermotaxis.

Fundamentals and Applications of Red Light-Emitting Diodes (LEDs) In Vitro Plant Growth on Tomato Lycopersicon esculentum Mill

2019 ◽  
Vol 805 ◽  
pp. 141-145
Author(s):  
Nguyen Phuc Thien
Keyword(s):  
Lycopersicon Esculentum ◽  
Plant Growth ◽  
Significant Influence ◽  
Growth And Development ◽  
Red Light ◽  
Light Emitting ◽  
Red Led ◽  
In Vitro Plant ◽  
Normal Light

The aim of these studies was mainly to investigate the effects of monochromatic LEDs applied singly on the in vitro plant growth and morphogenesis. Various morphological and physiological parameters are considered that influence the growth and development of plants in vitro under red LED light as compared to those under normal light. Upon exposure to LED, in vitro-raised plants have shown significant improvements in growth and morphogenesis. In particular, red and blue lights, either alone or in combination, have a significant influence on plant growth. The present study gives an overview of the fundamentals of LEDs and describes their effects on in vitro plant growth and morphogenesis and their future potentials. The main objective of this study was to carry out line and combing ability of plant growth on tomato.

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.

scholarly journals Sea Turtle Population Genomic Discovery: Global and Locus-Specific Signatures of Polymorphism, Selection, and Adaptive Potential

2019 ◽  
Vol 11 (10) ◽  
pp. 2797-2806 ◽  
Author(s):  
Julie C Chow ◽  
Paul E Anderson ◽  
Andrew M Shedlock
Keyword(s):  
Linkage Disequilibrium ◽  
Large Body ◽  
Population Monitoring ◽  
The United States ◽  
Sea Turtle ◽  
Nucleotide Polymorphisms ◽  
Loggerhead Sea Turtles ◽  
Snp Calling ◽  
Ecological Importance ◽  
New Biomarkers

Abstract In the era of genomics, single-nucleotide polymorphisms (SNPs) have become a preferred molecular marker to study signatures of selection and population structure and to enable improved population monitoring and conservation of vulnerable populations. We apply a SNP calling pipeline to assess population differentiation, visualize linkage disequilibrium, and identify loci with sex-specific genotypes of 45 loggerhead sea turtles (Caretta caretta) sampled from the southeastern coast of the United States, including 42 individuals experimentally confirmed for gonadal sex. By performing reference-based SNP calling in independent runs of Stacks, 3,901–6,998 SNPs and up to 30 potentially sex-specific genotypes were identified. Up to 68 pairs of loci were found to be in complete linkage disequilibrium, potentially indicating regions of natural selection and adaptive evolution. This study provides a valuable SNP diagnostic workflow and a large body of new biomarkers for guiding targeted studies of sea turtle genome evolution and for managing legally protected nonmodel iconic species that have high economic and ecological importance but limited genomic resources.

Syntheses, crystal structures and photoluminescence properties of Ca9Y(PO4)5(SiO4)F1.5O0.25:Ln3+ (Ln3+ = Eu3+/Tb3+/Dy3+/Sm3+) phosphors for near-UV white LEDs

RSC Advances ◽  
2016 ◽  
Vol 6 (95) ◽  
pp. 92371-92377 ◽  
Author(s):  
Man Liu ◽  
Wei Lü ◽  
Jiansheng Huo ◽  
Baiqi Shao ◽  
Yang Feng ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Red Light ◽  
Photoluminescence Properties ◽  
Light Emitting ◽  
White Leds ◽  
Red Led

We report red light-emitting Ca9Y(PO4)5(SiO4)F1.5O0.25:Eu3+/Sm3+ phosphors for the fabrication of red LED devices.

Tursiocola neliana sp. nov (Bacillariophyceae) epizoic on South African leatherback sea turtles (Dermochelys coriacea) and new observations on the genus Tursiocola

Phytotaxa ◽  
2020 ◽  
Vol 453 (1) ◽  
pp. 1-15 ◽  
Author(s):  
ROKSANA MAJEWSKA
Keyword(s):  
Sea Turtles ◽  
Central Area ◽  
Sea Turtle ◽  
Dermochelys Coriacea ◽  
Eastern Coast ◽  
New Taxon ◽  
Freshwater Turtles ◽  
Diatom Genus ◽  
Leatherback Sea Turtles ◽  
Internal Side

Tursiocola, a presumably exclusively epizoic diatom genus, comprises species found on various aquatic animals such as cetaceans, manatees, and marine and freshwater turtles. The genus is characterised by linear or lanceolate valves with well-developed pseudosepta at both poles, a valvocopula with three pairs of siliceous tabs, and a butterfly-like structure extending from the central nodule on the internal side of the valve. The current study describes a novel species of Tursiocola, T. neliana Majewska sp. nov. that grows epizoically on leatherback sea turtles from the Eastern Coast of South Africa based on detailed observations using light and scanning electron microscopy. The new taxon resembles the other currently known sea turtle-associated Tursiocola species in possessing relatively small, slightly heteropolar valves with acute apices and a strongly reduced butterfly structure on the internal side. However, T. neliana differs from all other members of the genus in being distinctly dorsiventral, with a clearly bowtie-shaped central area, unequal stria density on two sides of the raphe-sternum, and up to 8 areolae per stria. The description of the new taxon brings the total number of the sea turtle-associated Tursiocola species known so far up to four. An emended description of Tursiocola is proposed based on the new observations presented in this and other recent reports. Furthermore, the current understanding of the genus ecology is summarised.

scholarly journals Marine leech Ozobranchus margoi parasitizing loggerhead turtle (Caretta caretta) in Rio Grande do Sul, Brazil

2012 ◽  
Vol 21 (3) ◽  
pp. 301-303 ◽  
Author(s):  
Carla Rosane Rodenbusch ◽  
Fernanda Simone Marks ◽  
Cláudio Wageck Canal ◽  
José Reck
Keyword(s):  
Infectious Diseases ◽  
Loggerhead Turtle ◽  
Rio Grande ◽  
Caretta Caretta ◽  
Sea Turtle ◽  
Pcr Analysis ◽  
Southern Brazil ◽  
Rio Grande Do Sul ◽  
Subtropical Zone ◽  
Official Record

This paper reports the finding of several Ozobranchus margoi (Annelida: Hirudinea) parasitizing a loggerhead turtle (Caretta caretta) that was found in the municipality of Tavares, state of Rio Grande do Sul, southern Brazil. Since this parasite is considered to be a vector of chelonid herpesvirus 5 (ChHV-5), the leeches collected were tested for the presence of this virus. All the specimens were negative on PCR analysis. Although O. margoi is considered to be a common sea turtle parasite, this is the first official record describing collection of this parasite from a loggerhead turtle in southern Brazil, within the country's subtropical zone. This finding draws attention to the presence of this parasite and to the risk of leech-borne infectious diseases among turtles found along the coast of southern Brazil.

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