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1
Winarto, Winarto, and Siva Devi Azahra. "Karakteristik dan Preferensi Habitat Penyu dalam Membuat Sarang Alami untuk Peneluran." BIOEDUSAINS:Jurnal Pendidikan Biologi dan Sains 5, no. 1 (June 22, 2022): 189–96. http://dx.doi.org/10.31539/bioedusains.v5i1.3655.
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This study aims to examine the characteristics and environmental factors of turtles' preferences in making their natural nests. The method used is the descriptive quantitative method. The results showed that there were two types of turtles found during the observation, namely the green turtle (Chelonia mydas) and the hawksbill turtle (Eretmochelys imbricata). Measurements and observations of the characteristics of the 14 nesting points showed that the diameter and depth of the green turtle's nest were larger than those of the hawksbill turtle. Both types of turtles have a preference for nesting areas on sloping beaches with temperatures of 28-30ºC and humidity of 76-89%, as well as being around vegetation in the form of sea pine (Casuarina equisetifolia), sea oyster (Gynura sp), sea pandanus (Pandanus odorifer), sea kangkung (Ipomea peltate) and sea hibiscus (Thespesia populnea). In conclusion, temperature, humidity and types of vegetation around the nest determine the turtle's preference in making natural nests for laying eggs.
Keywords: Nest Characteristics, Conservation, Turtle, Habitat Preference
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Harjiyatni, F. R., J. S. Murdomo, Sri Suwarni, Hartanti, Puji Prikhatna, Retno Lantarsih, and W. H. Putri. "Sea Turtle Protection: A Case Study of Protected Sea Turtle Capture in Gunungkidul Regency, Indonesia." IOP Conference Series: Earth and Environmental Science 1030, no. 1 (June 1, 2022): 012018. http://dx.doi.org/10.1088/1755-1315/1030/1/012018.
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Abstract This paper aims to discuss the legal process for capturing protected turtles in Gunungkidul Regency and the rescued green turtle’s background. This research uses a socio-legal approach. Data were collected using in-depth interviews and observation and analyzed qualitatively. The result shows: first, the process of catching turtles carried out by community members is strictly enforced. The Natural Resources Conservation Agency of Yogyakarta Special Region submitted the turtle arrest case to police investigators for further investigation. Whatever reasons people put forward, it doesn’t stop the police from strictly enforcing the turtle capture case. Second, the background of the capture of green turtles is due to the lack of public awareness and concern about the importance of turtles as endangered species that are protected and should not be caught. In this case, the regulations regarding the protection and prohibition of capturing turtles are complete, but the local communities often violate them. The results suggest a need to strengthen local communities to understand the importance of protecting turtles as endangered species and strict sanctions for turtle capture. It is not only to establish the education community but also to empower the community to provide the initial information to the investigators if it is found the violation of the Act on the turtles protection.
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Fadli, S. N., N. H. Idris, M. J. Osman, N. Othman, and M. H. I. Ishak. "Spatial Distribution and the Influence of Surface Temperature and Green Area on Sea Turtle Nesting Sites in Peninsular Malaysia." IOP Conference Series: Earth and Environmental Science 1240, no. 1 (September 1, 2023): 012012. http://dx.doi.org/10.1088/1755-1315/1240/1/012012.
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Abstract Malaysia is home to four of the seven sea turtles in the world, with Malaysian islands being one of the potential areas for sea turtle landing and nesting. However, sea turtles are classified as endangered species because they face extinction mainly due to land use changes, human marine activities, and environmental factors. As a result, they are now among the most important resources for ecotourism. Green turtles are the most prevalent species (endangered), while the hawksbill turtle is one of the world’s most seriously endangered marine turtle species today. Hence, considering the importance of improving turtle habitat in Malaysia, this study investigated the sea turtle’s nesting site preference in Peninsular Malaysia using spatial analysis. The objectives of this study are (1) to map sea turtle nesting sites in Peninsular Malaysia for five years (from 2017-2021) and (2) to identify the influence of surface temperature and landscape characteristics on sea turtle nesting habitats. This study used the binomial regression method to determine the significant environmental factors such as temperature, distance from the green area and the coastal line that could influence the preference for sea turtle habitat. The results show a positive relationship between temperature and that more sea turtles will nest and land in the area with the higher temperature. Also, more sea turtles prefer to land and nest near green areas. These findings confirmed the influence of green areas in turtle nesting sites in Peninsular Malaysia. It could assist the authorities in further understanding the importance of green areas in turtle nesting site preference and developing a mitigation plan to protect sea turtle habitat.
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Báez, José C., David Macías, Salvador García-Barcelona, and Raimundo Real. "Interannual Differences for Sea Turtles Bycatch in Spanish Longliners from Western Mediterranean Sea." Scientific World Journal 2014 (2014): 1–7. http://dx.doi.org/10.1155/2014/861396.
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Recent studies showed that regional abundance of loggerhead and leatherback turtles could oscillate interannually according to oceanographic and climatic conditions. The Western Mediterranean is an important fishing area for the Spanish drifting longline fleet, which mainly targets swordfish, bluefin tuna, and albacore. Due to the spatial overlapping in fishing activity and turtle distribution, there is an increasing sea turtle conservation concern. The main goal of this study is to analyse the interannual bycatch of loggerhead and leatherback turtles by the Spanish Mediterranean longline fishery and to test the relationship between the total turtle by-catch of this fishery and the North Atlantic Oscillation (NAO). During the 14 years covered in this study, the number of sea turtle bycatches was 3,940 loggerhead turtles and 8 leatherback turtles, 0.499 loggerhead turtles/1000 hooks and 0.001014 leatherback turtles/1000 hooks. In the case of the loggerhead turtle the positive phase of the NAO favours an increase of loggerhead turtles in the Western Mediterranean Sea. However, in the case of leatherback turtle the negative phase of the NAO favours the presence of leatherback turtle. This contraposition could be related to the different ecophysiological response of both species during their migration cycle.
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van der Geest, Nick van der, Lorenzo Garcia, Roy Nates, and Alberto Gonzalez-Vazquez. "Sea Turtles Employ Drag-Reducing Techniques to Conserve Energy." Journal of Marine Science and Engineering 10, no. 11 (November 17, 2022): 1770. http://dx.doi.org/10.3390/jmse10111770.
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Sea turtles are recognised as one of the ocean’s most remarkable migratory species, accomplishing journeys that cover thousands of kilometres. This fact is even more extraordinary when considering sea turtles consume mostly low-energy foods. The biology of sea turtles dominates the literature; however, the swimming strategies they employ to achieve their migratory success from a biomechanical and hydrodynamic viewpoint is relatively unexplored. In past research, the sea turtle’s upstroke has been debated among researchers as to whether it is passive or for thrust production. In this work, we recreate a model based on the green sea turtle (Chelonia mydas) and develop an ad hoc testing rig to uncover the secrets behind the sea turtle’s upstroke. Our findings suggest sea turtles utilise a passive upstroke that can substantially lower the animal’s drag coefficient to levels that cause insignificant losses in swim speed despite not developing any thrust force. This can conceivably save the animal a notable amount of energy as the upstroke is responsible for a large percentage of the overall limb beat cycle. These findings could potentially pave a path towards developing high-efficiency bioinspired underwater drone technologies.
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Lohmann, Kenneth J., and Catherine M. F. Lohmann. "Sea Turtle Navigation and the Detection of Geomagnetic Field Features." Journal of Navigation 51, no. 1 (January 1998): 10–22. http://dx.doi.org/10.1017/s0373463397007649.
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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.
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van der Geest, Nick, and Lorenzo Garcia. "Employing Robotics for the Biomechanical Validation of a Prosthetic Flipper for Sea Turtles as a Substitute for Animal Clinical Trials." Biomechanics 3, no. 3 (September 4, 2023): 401–14. http://dx.doi.org/10.3390/biomechanics3030033.
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Sea turtles are a keystone species for the ocean’s ecosystem, with all species currently being listed as endangered. Such a threat is mainly due to human factors such as fishing net entanglement. This entanglement often comes at the expense of turtles losing a pectoral flipper. The reduction in a sea turtle’s survival odds upon losing a flipper is a significant concern. This issue extends beyond individual animals, as the potential extinction of sea turtles could have detrimental effects on ocean health and subsequently disrupt our lifestyles. In this work, with the help of robotics, we tested the suitability of a prosthetic flipper for sea turtles that have lost a flipper. Testing with our sea-turtle-inspired robot helped to demonstrate the prosthetic flipper’s performance without clinical trials in live animals. The robot showed that the prosthetic could closely mimic the sea turtle’s downstroke and upstroke, allowing the animal to regain control in roll, pitch, and yaw, despite the absence of anatomical joints and related muscles. Additionally, swim speed tests provided an average swim speed of 0.487 m/s while dragging 6 m of cable to give a calculated maximum swim speed of 0.618 m/s, coming close to the average swim speed of wild sea turtles of 0.6 m/s. Our aspiration is that the findings from this study will pave the way for an open-source implant design, empowering veterinary professionals globally to aid injured turtles. Furthermore, this research promises to inspire additional animal-based robotic designs, advancing technologies geared towards assisting other animals in distress.
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Guimarães, Suzana Machado, Davi Castro Tavares, and Cassiano Monteiro-Neto. "Incidental capture of sea turtles by industrial bottom trawl fishery in the Tropical South-western Atlantic." Journal of the Marine Biological Association of the United Kingdom 98, no. 6 (March 27, 2017): 1525–31. http://dx.doi.org/10.1017/s0025315417000352.
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The five sea turtle species occurring in Brazilian waters are susceptible to threats, including incidental catches by fisheries. Studies on incidental captures in fishing gears are the main focus of several conservation actions due to high sea turtle fishery mortality worldwide. This study provides the first evaluation of incidental sea turtle catches by industrial bottom trawl fisheries operating in Brazilian waters. Four twin-trawler vessels were monitored between July 2010 and December 2011 by captains who voluntarily completed logbooks. Forty-four turtles were captured during the 1996 tows (8313 fishing hours), resulting in a catch of 5.3 ± 0.8 turtles per 1000 h per unit effort. Captured species included the loggerhead turtle (Caretta caretta, 22 individuals), olive ridley turtles (Lepidochelys olivacea, 21 individuals) and one green turtle (Chelonia mydas). Water depth was the only variable that significantly affected sea turtle captures according to Generalized Linear Models. The capture rates reported in this study ranked sixth in relation to other published studies of similar fisheries occurring worldwide. Considering the importance of this region for sea turtles, the increasing evidence of sea turtle mortality and the goals of the National Action Plan for Conservation of Sea Turtles in Brazil, it is essential to identify the main threats towards these animals and propose mitigating solutions to reduce sea turtle mortality induced by fishing activities. This study provides results that may guide future research and goals in meeting sea turtle conservation strategies.
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Papi, F., P. Luschi, S. Akesson, S. Capogrossi, and G. C. Hays. "Open-sea migration of magnetically disturbed sea turtles." Journal of Experimental Biology 203, no. 22 (November 15, 2000): 3435–43. http://dx.doi.org/10.1242/jeb.203.22.3435.
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Green turtles (Chelonia mydas) that shuttle between their Brazilian feeding grounds and nesting beaches at Ascension Island in the middle of the Atlantic Ocean are a paradigmatic case of long-distance oceanic migrants. It has been suggested that they calculate their position and the direction of their target areas by using the inclination and intensity of the earth's magnetic field. To test this hypothesis, we tracked, by satellite, green turtles during their postnesting migration from Ascension Island to the Brazilian coast more than 2000 km away. Seven turtles were each fitted with six powerful static magnets attached in such a way as to produce variable artificial fields around the turtle that made reliance on a geomagnetic map impossible. The reconstructed courses were very similar to those of eight turtles without magnets that were tracked over the same period and in the previous year, and no differences between magnetically disrupted and untreated turtles were found as regards navigational performance and course straightness. These findings show that magnetic cues are not essential to turtles making the return trip to the Brazilian coast. The navigational mechanisms used by these turtles remain enigmatic.
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Hossain, M. A., M. S. E. Mahfuj, S. M. A. Rashid, and M. N. Ahsan. "Present status of conservation and management of sea turtle in Cox’s Bazar district, Bangladesh." Mesopotamian Journal of Marine Sciences 28, no. 1 (April 18, 2022): 45–60. http://dx.doi.org/10.58629/mjms.v28i1.154.
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The study was conducted to know the present status of conservation and management of sea turtle in Cox’s Bazar district, Bangladesh. Two species of sea turtles have been making nest in Bangladesh. A total of 251 turtle individuals were found. The highest nesting frequency of Olive ridley (108) and Green turtles (10) were observed in February. About 21,942 hatchlings were produced and released by the hatcheries for conservational step. A total of one hundred people were selected randomly for taking interview to assess their knowledge and attitude towards sea turtle conservation and management. Most of the respondents were fishermen (55%), student and housewife were 20% and 8%, 5% were found involving in business and rest 12% were involved in others activities. About 45% of the respondents thought that turtles were beneficial while other 40% of the respondents thought turtles were harmful. The rest of the respondents (15%) answered that they were not sure whether sea turtle was beneficial or harmful. Most of the fishermen did not know about Turtle Excluder Devices (TEDs) or its uses. It was found that the nesting of sea turtles was reducing and there was lack of knowledge among the people of the study area about the importance of sea turtle conservation and management.
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van der Geest, Nick, Lorenzo Garcia, Roy Nates, and Fraser Borrett. "New Insights into Sea Turtle Propulsion and Their Cost of Transport Point to a Potential New Generation of High-Efficient Underwater Drones for Ocean Exploration." Journal of Marine Science and Engineering 11, no. 10 (October 9, 2023): 1944. http://dx.doi.org/10.3390/jmse11101944.
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Sea turtles gracefully navigate their marine environments by flapping their pectoral flippers in an elegant routine to produce the required hydrodynamic forces required for locomotion. The propulsion of sea turtles has been shown to occur for approximately 30% of the limb beat, with the remaining 70% employing a drag-reducing glide. However, it is unknown how the sea turtle manipulates the flow during the propulsive stage. Answering this research question is a complicated process, especially when conducting laboratory tests on endangered animals, and the animal may not even swim with its regular routine while in a captive state. In this work, we take advantage of our robotic sea turtle, internally known as Cornelia, to offer the first insights into the flow features during the sea turtle’s propulsion cycle consisting of the downstroke and the sweep stroke. Comparing the flow features to the animal’s swim speed, flipper angle of attack, power consumption, thrust and lift production, we hypothesise how each of the flow features influences the animal’s propulsive efforts and cost of transport (COT). Our findings show that the sea turtle can produce extremely low COT values that point to the effectiveness of the sea turtle propulsive technique. Based on our findings, we extract valuable data that can potentially lead to turtle-inspired elements for high-efficiency underwater drones for long-term underwater missions.
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Hossain, MA, MI Miah, KR Hasan, JJ Bornali, and M. Shahjahan. "Present status of conservation and management of sea turtle in Coxs Bazar district of Bangladesh." Bangladesh Journal of Animal Science 42, no. 2 (December 31, 2013): 131–38. http://dx.doi.org/10.3329/bjas.v42i2.18493.
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The study was conducted to know the present status of conservation and management of sea turtle in Coxs Bazar district. Data were collected by physical survey, interviewing people of the study area and from different non-government and government organizations during December 2010 to November 2011. In the present study, it was found that two species of sea turtles have been making nest in Bangladesh. Major nesting sites of turtles were St. Martin's Island, Teknaf, Bordal, Sonadia Island, Kutubdia Island, Pechardwip, Inani Beach, Moheskhali Island and Shahporirdwip. A total of 260 turtle individuals were found and the highest nesting frequency of Olive ridley (108) and Green turtles (10) were observed in February. About 21,942 hatchlings were produced and released by the hatcheries as a conservational step. Winter season was identified as nesting season for sea turtle. About 45% of the respondents thought that turtles were beneficial while other 40% of the respondents thought turtles were harmful. It was found that the nesting of sea turtles was reducing and there was lack of knowledge among the people of the study area about the importance of sea turtle conservation and management. DOI: http://dx.doi.org/10.3329/bjas.v42i2.18493 Bang. J. Anim. Sci. 2013. 42 (2): 131-138
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Febrinal, Febrinal, Azzahrah Khairunnisa Mardhiyah, Maysyarah Ardiana, Zultsatunni’mah Zultsatunni’mah, Pati Hariyose, and FITRA ARYA DWI NUGRAHA. "Sosialization of Sea Turtle Under Threatened in Pasir Jambak." Pelita Eksakta 2, no. 2 (November 30, 2019): 148. http://dx.doi.org/10.24036/pelitaeksakta/vol2-iss2/72.
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All sea turtles are listed as endangered and critically endangered by IUCN Red List due to human consumption and lifestyle. In West Sumatra, Pasir Jambak Beach is an important habitat for nesting of sea turtles, but human activities in this area becomes serious threats for sea turtles. Based on our interview, the local people of Pasir Jambak still consume the sea turtle eggs and mistaken for the effect of this egg to human. During our activity, we share our knowledge especially to the children of Pasir Jambak, hoping that they will not continue the habit of consuming the sea turtle egg, and become more concerned to the conservation of sea turtle around them. All of us were responsible for the rapid decline of sea turtle populations. We also take an action for cleaning the Pasir Jambak beach from the plastic trash and released the Tukik (juvenile) to help increasing the sea turtle population in nature.
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Antonio, Rene Abdulhamed, and Joie Matillano. "Nesting incidence, exploitation and trade dynamics of sea turtles in Balabac Strait Marine Biodiversity Conservation Corridor, Palawan, Philippines." Palawan Scientist 8 (August 2016): 31–46. http://dx.doi.org/10.69721/tps.j.2016.8.1.03.
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The study assessed the nesting incidence, threats to nesting habitats, exploitation and trade dynamics of sea turtles in the Balabac Strait Marine Biodiversity Conservation Corridor (MBCC). The most number of nests found belonged to the green sea turtle Chelonia mydas and only very few were of hawksbill sea turtle Eretmochelys imbricata. The shoreline vegetation was the most preferred nesting area, followed by beach forest and open beach. The eggs and meat of sea turtles in Balabac Strait MBCC are exploited for local consumption and trade. Information on trade route and local perception on conservation issues about sea turtles is also presented herein.
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Adi Eti Harnino, Taurus Zeno, I. Nyoman Yoga Parawangsa, Luthfiana Aprilianita Sari, and Sulastri Arsad. "Effectiveness of Sea Turtle Conservation Management at the Turtle Conservation and Education Center of Serangan, Denpasar Bali." Journal of Marine and Coastal Science 10, no. 1 (February 22, 2021): 18. http://dx.doi.org/10.20473/jmcs.v10i1.25604.
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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.
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TAUFIK, Muhammad, Fiki NAFILA, Sinki ANGGARAINI, Aisyah Hadi RAMADANI, and Muhammad Badrut TAMAM. "Enhancing Sea Turtle Conservation Efforts through Collaboration Approach: Case Study of ORI MA FALA Program, Ternate." International Journal of Environmental, Sustainability, and Social Science 5, no. 3 (May 29, 2024): 460–65. http://dx.doi.org/10.38142/ijesss.v5i3.1016.
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Internationally turtles are listed on the IUCN red list and Appendix I of CITES (Convention on International Trade in Endangered Species), which means that their existence in nature is threatened. Ternate is well known for its endemic flora and fauna. On this small island, for example, various types of sea turtles have lived. Promotion of knowledge about sea turtle conservation is lacking. As a result, commercial exploitation of sea turtles is rampant in Tobololo. This study describes the role of the local community in maintaining the existence of sea turtles and how collaboration between stakeholders can improve sea turtle conservation efforts more effectively. Sea turtle conservation at Tobololo beach in ternate has used a multi-stakeholder collaborative approach by PT Pertamina Patra Niaga DPPU Babullah. Conservation is primarily carried out by the ORI MA FALA group. The success of the program in releasing hatchlings was 74.11% and the success in hatching was 87.4%.
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Herrera, Candy, Evelyn Guerra, Andrea Rosas, Yingying Wei, Jack Pringle, Baltazar Espinoza, and Baojun Song. "The Impact of Temperature-Dependent Sex Determination on the Population Dynamics of Green Sea Turtles (Chelonia mydas)." Bionatura 5, no. 1 (February 15, 2020): 1029–38. http://dx.doi.org/10.21931/rb/2020.05.01.4.
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The sex of the turtles is determined by the incubation temperature of the eggs during the mid-trimester of development. In green sea turtles (Chelonia mydas), recent studies show that sex ratios are changing, producing a female-biased sex ratio within the population. We developed a novel continuous model to analyze the dynamics of the green sea turtle population long-term. We determine the safe operating space for the proportion of eggs that become male at which the population of green sea turtle can exist without going to extinction. When the proportion of male eggs leaves this range the overall turtles’ population collapses. Additionally, we examined how temperature changes affect the sex ratios of the green sea turtle population.
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Nguyen, Dang Ngai, and Van Chien Pham. "Status and impacts to sea turtles in Vietnam." Vietnam Journal of Marine Science and Technology 24, no. 2 (May 21, 2024): 141–51. http://dx.doi.org/10.15625/1859-3097/18763.
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Sea turtles face a great danger of extinction because of human impacts, and the number of turtle occurrence is decreasing. By interviewing fishermen, coastal residents and authorities combined with field surveys in some places where turtles regularly lay eggs, such as Con Dao and Ninh Thuan, the results show that 05 species of sea turtles were found in Vietnam: The Green (Chelonia mydas), Hawksbill (Eretmochelys imbricata), Olive Ridley (Lepidochelys olivacea), Loggerhead (Caretta caretta) and Leatherback (Dermochelys coriacea). Among them, Green turtles are the most abundant and distributed in all surveyed localities; Hawksbill and Olive Ridley were smaller in number; and Loggerhead and Leatherback were the two species with the least number. Only 03 species remaining to breed on the beaches: Green, Olive Ridley, and Leatherback. The Hawksbill turtles used to lay eggs in the past but have been no longer recorded. Con Dao is a home for the largest number of breeding Green turtles. The reasons for the decline of turtles in Vietnam were the collection of eggs and nesting turtles, fisheries bycatch, development of coastal infrastructure and waste pollution, habitat degradation, and illegal trade in sea turtle products.
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Page, Felicia M., James Manning, Lesley Howard, Ryan Healey, and Nancy E. Karraker. "Developing bottom drifters to better understand the stranding locations of cold-stunned sea turtles in Cape Cod Bay, Massachusetts." PeerJ 11 (August 30, 2023): e15866. http://dx.doi.org/10.7717/peerj.15866.
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Every fall, juvenile sea turtles in the Northwest Atlantic Ocean are threatened by rapidly declining water temperatures. When sea turtles become hypothermic, or cold-stunned, they lose mobility—either at the surface, subsurface, or the bottom of the water column—and eventually strand at the shoreline where rescue teams associated with the Sea Turtle Stranding and Salvage Network may search for them. Understanding the effects of ocean currents on the potential stranding locations of cold-stunned sea turtles is essential to better understand stranding hotspots and increase the probability of successful discovery and recovery of turtles before they die in the cold temperatures. Traditional oceanographic drifters—instruments used to track currents—have been used to examine relationships between current and stranding locations in Cape Cod Bay, but these drifters are not representative of sea turtle morphology and do not assess how bottom currents affect stranding locations. To address these knowledge gaps, we designed new drifters that represent the shape and dimensions of sea turtles—one that can float at the surface and one that sinks to the bottom—to track both surface and bottom currents in Cape Cod Bay. We found a marked difference between the trajectories of our new drifter models and those that were previously used for similar research. These findings bring us one step closer to identifying the transport pathways for cold-stunned sea turtles and optimizing cold-stunned sea turtle search and rescue efforts in Cape Cod.
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Zhang, Ting, Liu Lin, Daniel Gaillard, Fang Chen, Huaiqing Chen, Meimei Li, Shannan Wu, Zhao Wang, and Haitao Shi. "Rapid authenticity testing of artificially bred green turtles (Chelonia mydas) using microsatellite and mitochondrial DNA markers." PeerJ 9 (October 28, 2021): e12410. http://dx.doi.org/10.7717/peerj.12410.
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Sea turtles are threatened by climate change and human activity, and their global populations continue to decline sharply. The Chinese government encourages artificial breeding of sea turtles to reduce the use of wild populations. However, artificial breeding of sea turtles is still fairly difficult, and some facilities may illegally purchase wild turtle eggs and then sell incubated turtles by marketing them as artificially bred turtles, which adds another threat to an already endangered species. Therefore, it is necessary to find a reliable method to distinguish the authenticity of artificially bred individuals. In this study, we investigated a turtle farm in southern China, that contained more than 400 green turtles, which were claimed to have been bred in captivity. Parentage testing of turtles from this farm was successfully conducted using two nuclear microsatellites combined with a mitochondrial D-loop DNA marker. Genetic matching of all 19 adults and randomly selected 16 juvenile turtles revealed that none of the juvenile turtles had a matching parent combination among the adult turtles. Therefore, we speculated that the green turtles in this farm were from the wild and that their origin of birth was mainly the Sulu Sea. The methods and molecular markers used in this study could be a reference for rapid authenticity testing of green turtles in future forensic enforcement and population management.
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Azizan, Nor Hidayah, Nabilah Naharudin, Nurhanisah Hashim, and Mohd Uzair Rusli. "Site Suitability Analysis for Sea Turtle Nesting Area by using AHP and GIS." IOP Conference Series: Earth and Environmental Science 1217, no. 1 (July 1, 2023): 012031. http://dx.doi.org/10.1088/1755-1315/1217/1/012031.
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Abstract Sea turtles are among the endangered marine life not only in Malaysia but also in the world. There are various criteria required in finding a suitable turtle nest site, it may be necessary to suit the needs of the environment in the study area, and it was found that there are four (4) most important criteria in studying turtle nesting suitability site namely (1) sand temperature, (2) vegetation, (3) beach slope, and (4) sand particle size. The use of GIS with the help of AHP can get a better result in finding the site suitability for sea turtle nesting by using weighted overlay analysis. The highest weight value is sand particle size with 0.616, followed by beach slope with 0.220, sand temperature with 0.114, and vegetation with 0.049 was derived from the use of AHP techniques. As a result, the suitability index in the study area was measured and analyzed with the sea turtles’ activities. As a result, the suitability index in the study area was measured and analyzed with the sea turtles’ activities. It was found that there is a low correlation between the site suitability index and the sea turtles’ activities which matches the expert’s opinion that though the site is deemed suitable for sea turtles nesting, they may not be crawled up and nest due to other external factors. The sites with the highest index were verified to be the most suitable by the experts as it is true that sea turtles were ascending to the sites for nesting. In conclusion, integrating GIS with the help of AHP can be an important technique to find a suitable site for the sea turtle nesting area.
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Corsini-Foka, Maria, Gerasimos Kondylatos, and Elias Santorinios. "Increase of sea turtles stranding records in Rhodes Island (eastern Mediterranean Sea): update of a long-term survey." Journal of the Marine Biological Association of the United Kingdom 93, no. 7 (May 29, 2013): 1991–2002. http://dx.doi.org/10.1017/s0025315413000556.
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A total of 209 strandings of sea turtles (152 loggerhead turtles Caretta caretta, 42 green turtles Chelonia mydas, 15 unidentified) were recorded during the period 1984–2011 along the coasts of Rhodes (Aegean Sea, Greece). The proportion of dead to live individuals was different in the two species. Stranded Caretta caretta were larger than Chelonia mydas. The size range of stranded green turtles, usually juveniles, appeared to increase since 2000, including the largest specimens ever observed in Greek waters. For both species, a tendency to strand more frequently on the west coast of the island, along fishing ground areas, was noted. The higher incidence of loggerhead turtle strandings was observed in summer, while more green turtle strandings were documented in winter. Factors involved in the increased trend of stranding records of both species, along with the acceleration of this phenomenon in the last decade, are discussed. Data from Rhodes provide evidence that human activities detrimentally affect mainly larger-sized loggerhead turtles living in shallow waters.
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Gatto, Christopher R., and Richard D. Reina. "The ontogeny of sea turtle hatchling swimming performance." Biological Journal of the Linnean Society 131, no. 1 (August 3, 2020): 172–82. http://dx.doi.org/10.1093/biolinnean/blaa113.
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Abstract Sea turtle hatchlings experience high mortality rates during dispersal. To minimize time spent in predator-dense waters, hatchlings typically undergo a period of hyperactivity termed the ‘frenzy’, characterized by almost continuous swimming for ~24 h. Research has focused on swimming performance during the frenzy, but our understanding of changes in swimming performance post-frenzy is limited. Thus, we measured green turtle (Chelonia mydas) hatchling swimming performance during the frenzy and post-frenzy when the turtles were 4, 12 and 24 weeks old. Using load cells, we recorded thrust production, stroke rates and the time turtles spent performing various swimming gaits. We found that the proportion of time spent powerstroking and the thrust generation per powerstroke were the main determinants of overall swimming performance. Older, larger turtles generated more thrust per stroke, but the proportion of time spent powerstroking throughout the entire swimming trial did not differ among age groups. Hatchlings have been thought mainly to use currents to reach nursery foraging grounds, and our findings suggest that hatchling swimming might also play an important role in directing hatchlings to optimal nursery habitats, supporting recent studies. Additionally, turtle size is positively related to swimming performance in post-frenzy turtles, suggesting that faster-growing turtles might have fitness advantages over slower-growing turtles.
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Mansfield, Katherine L., Jeanette Wyneken, Warren P. Porter, and Jiangang Luo. "First satellite tracks of neonate sea turtles redefine the ‘lost years’ oceanic niche." Proceedings of the Royal Society B: Biological Sciences 281, no. 1781 (April 22, 2014): 20133039. http://dx.doi.org/10.1098/rspb.2013.3039.
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Few at-sea behavioural data exist for oceanic-stage neonate sea turtles, a life-stage commonly referred to as the sea turtle ‘lost years’. Historically, the long-term tracking of small, fast-growing organisms in the open ocean was logistically or technologically impossible. Here, we provide the first long-term satellite tracks of neonate sea turtles. Loggerheads ( Caretta caretta ) were remotely tracked in the Atlantic Ocean using small solar-powered satellite transmitters. We show that oceanic-stage turtles (i) rarely travel in Continental Shelf waters, (ii) frequently depart the currents associated with the North Atlantic Subtropical Gyre, (iii) travel quickly when in Gyre currents, and (iv) select sea surface habitats that are likely to provide a thermal benefit or refuge to young sea turtles, supporting growth, foraging and survival. Our satellite tracks help define Atlantic loggerhead nursery grounds and early loggerhead habitat use, allowing us to re-examine sea turtle ‘lost years’ paradigms.
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McNally, Kerry L., Jennifer L. Bowen, Jennifer O. Brisson, Adam Kennedy, and Charles J. Innis. "Evaluation of the Respiratory Microbiome and the Use of Tracheal Lavage as a Diagnostic Tool in Kemp’s Ridley Sea Turtles (Lepidochelys kempii)." Animals 11, no. 10 (October 10, 2021): 2927. http://dx.doi.org/10.3390/ani11102927.
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Respiratory disease is a common cause of morbidity and mortality in sea turtles, including the Kemp’s ridley sea turtle (Lepidochelys kempii). Although culture-dependent methods are typically used to characterize microbes associated with pneumonia and to determine treatment, culture-independent methods can provide a deeper understanding of the respiratory microbial communities and lead to a more accurate diagnosis. In this study, we characterized the tracheal lavage microbiome from cold-stunned Kemp’s ridley sea turtles at three time points during rehabilitation (intake, rehabilitation, and convalescence) by analyzing the 16S rRNA gene collected from tracheal lavage samples. We retrospectively developed a radiographic scoring system to grade the severity of lung abnormalities in these turtles and found no differences in diversity or composition of microbial communities based on radiographic score. We also found that the culture isolates from tracheal lavage samples, as well as other previously reported sea turtle pathogens, were present in variable abundance across sequenced samples. In addition to the tracheal microbial community of live turtles, we characterized microbial communities from other segments of the respiratory tract (glottis, trachea, anterior lung, posterior lung) from deceased turtles. We found a high degree of variability within turtles and a high degree of dissimilarity between different segments of the respiratory tract and the tracheal lavage collected from the same turtle. In summary, we found that the pulmonary microbial community associated with pneumonia in sea turtles is complex and does not correlate well with the microbial community as identified by tracheal lavage. These results underscore the limitations of using tracheal lavage for identification of the causative agents of pneumonia in sea turtles.
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Lubis, Adelia Maisyaroh, Sri Jayanthi, Setyoko Setyoko, Dini Fitria, Aini Munte, Danu Abian Latif, Muhammad Junaidi, and Haikal Muhaiminin. "The Environment Characteristics Habitat of Sea Tuntong’s (Batagur borneoensis) on Conservation Areas in Aceh Tamiang Regency's Coastal Waters." JURNAL PEMBELAJARAN DAN BIOLOGI NUKLEUS 9, no. 1 (March 21, 2023): 97–108. http://dx.doi.org/10.36987/jpbn.v9i1.3754.
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One of the endemic turtle conservation areas is the sea turtle conservation area on the coast of Aceh Tamiang Regency, Aceh Province (Batagur borneoensis). This animal is categorized as an endangered animals. The IUCN (International Union for Conservation of Nature and Natural Resources) designated sea turtles as Critically Endangered (CE) in 1996. The distribution of sea turtles is limited because the beach type must be suitable for spawning and survival. The goal of this study was to determine the physical, chemical, and biological characteristics of sea tuntong (Batagur borneonsis) habitat in a conservation area in Aceh Tamiang Regency. In this study, the descriptive method was used. The data collection process was completed. Data was gathered through direct observation in the field. Purposive sampling was used to identify observation stations. There are three research stations: Pusong Kapal (hatching hatchlings), Ujung Tamiang Beach (habitat for adult sea turtles), and Pusung Cium Beach (habitat for sea turtles) (nesting habitat). The study's findings revealed differences in physical, biological, and chemical characteristics at the three stations. It is possible to conclude that the water area off the coast of Aceh Tamiang Regency, Aceh Province, is suitable for sea turtle habitat (Batagur borneoensis)
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Louhichi, Maissa, Alexandre Girard, and Imed Jribi. "High Loggerhead (Caretta caretta) Bycatch Rate along with Several Endangered Target Species: Two Reasons to Look for Alternative to Traditional Large-Mesh Bottom-Set Gillnets (Garrasia) for More Sustainable Fisheries in the Gulf of Gabès (Tunisia)." Sustainability 16, no. 9 (April 29, 2024): 3713. http://dx.doi.org/10.3390/su16093713.
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Fishery bycatch poses a significant threat to sea turtles. This study provides an updated assessment of Loggerhead turtle (Caretta caretta) bycatch in the Gulf of Gabès, focusing on the impact of the Garrasia gillnets. Through 61 onboard observations conducted alongside fishermen in Zarzis deploying a bottom-set gillnet, called “Garrasia”, and targeting elasmobranch species, comprehensive data were collected, including the number of sea turtles captured, soak time, length of gillnets, location, and biometric data of sea turtles. Analysis revealed a catch per unit effort (CPUE) for sea turtles of 0.63 (95% CI [0.355–0.893]) turtles per kilometer per 24 h with a notably high mortality rate of 92.06% (95% CI [87.3–96.8]). In the Gulf of Gabès, 23 vessels are reported to use Garrasia, resulting in an estimated annual total capture of 3756.53 turtles with a 95% CI [1907.81–5902.30]. These findings underscore the significant impact of Garrasia on sea turtle populations in the Gulf of Gabès. The study calls for immediate collaborative efforts among researchers, local stakeholders, authorities and fishermen to elaborate balanced conservation strategies that consider both ecological sustainability and socio-economic factors, aiming to achieve a sustainable marine ecosystem.
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Louhichi, Maissa, Alexandre Girard, and Imed Jribi. "Fishermen Interviews: A Cost-Effective Tool for Evaluating the Impact of Fisheries on Vulnerable Sea Turtles in Tunisia and Identifying Levers of Mitigation." Animals 13, no. 9 (May 4, 2023): 1535. http://dx.doi.org/10.3390/ani13091535.
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Fisheries bycatch is considered one of the main threats to sea turtles. To provide an updated assessment of the bycatch impact on loggerhead turtles in Tunisia, 483 interviews were conducted with fishermen in 19 ports along the Gulfs of Gabes and Hammamet. The interview questions included data on vessel and fishing gear characteristics, monthly fishing effort, and monthly sea turtle bycatch of the last year. Results revealed that sea turtle bycatch per unit effort (BPUE) was the highest for ray nets (0.73 turtles/vessel/day, 95% CI [0.02–1.15]), followed by pelagic longlines (0.6 turtles/vessel/day, 95% CI [0–4.23]) and shark nets (0.4 turtles/vessel/day, 95% CI [0–2.12]). However, due to the trawlers’ high fishing effort, the cumulative impact of the trawl nets was the highest with an estimated number of 11,740 (95% CI [0–41,525.75]) turtles caught per year in Tunisia. Factors influencing the bycatch risk were gear characteristics (mesh size for nets, hook size for longlines, vertical opening for trawls), as well as season and location of operations. These factors will guide the research of mitigation solutions. The interviews with fishermen proved to be a cost-effective approach for the rapid assessment of sea turtle interactions with fisheries in the context of Tunisia.
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Nederlof, Remco A., Dion van der Veen, Justin R. Perrault, Robin Bast, Heather W. Barron, and Jaco Bakker. "Emerging Insights into Brevetoxicosis in Sea Turtles." Animals 14, no. 7 (March 22, 2024): 991. http://dx.doi.org/10.3390/ani14070991.
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This review summarizes the current understanding of how brevetoxins, produced by Karenia brevis during harmful algal blooms, impact sea turtle health. Sea turtles may be exposed to brevetoxins through ingestion, inhalation, maternal transfer, and potentially absorption through the skin. Brevetoxins bind to voltage-gated sodium channels in the central nervous system, disrupting cellular function and inducing neurological symptoms in affected sea turtles. Moreover, the current evidence suggests a broader and longer-term impact on sea turtle health beyond what is seen during stranding events. Diagnosis relies on the detection of brevetoxins in tissues and plasma from stranded turtles. The current treatment of choice, intravenous lipid emulsion therapy, may rapidly reduce symptoms and brevetoxin concentrations, improving survival rates. Monitoring, prevention, and control strategies for harmful algal blooms are discussed. However, as the frequency and severity of blooms are expected to increase due to climate change and increased environmental pollution, continued research is needed to better understand the sublethal effects of brevetoxins on sea turtles and the impact on hatchlings, as well as the pharmacokinetic mechanisms underlying brevetoxicosis. Moreover, research into the optimization of treatments may help to protect endangered sea turtle populations in the face of this growing threat.
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Kim, Il-Hun, Il-Kook Park, Daesik Park, Min-Seop Kim, In-Young Cho, Dongwoo Yang, Dong-Jin Han, et al. "Habitat use of loggerhead (Caretta caretta) and green (Chelonia mydas) turtles at the northern limit of their distribution range of the Northwest Pacific Ocean." PLOS ONE 19, no. 4 (April 4, 2024): e0290202. http://dx.doi.org/10.1371/journal.pone.0290202.
Full textAbstract:
Verifying habitats, including the foraging and nesting areas for sea turtles, enables an understanding of their spatial ecology and successful planning of their conservation and management strategies. Recently, the observation frequency and bycatch of loggerhead (Caretta caretta) and green (Chelonia mydas) turtles have increased in the northern limit of their distribution range, in the northern part of the East China Sea and East (Japan) Sea. We conducted satellite tracking to investigate the habitat use of seven loggerhead and eight green turtles from June 2016 to August 2022 in this area, where little is known about their spatial ecology. We applied a 50 percent volume contour method to determine their main foraging areas and analyzed 6 environmental variables to characterize their habitats. Loggerhead turtles mainly stayed in and used the East China Sea as a foraging area during the tracking period, while two individuals among them also used the East Sea as a seasonal foraging area. Most green turtles also used the East China Sea as a foraging area, near South Korea and Japan, with one individual among them using the lower area of the East Sea as a seasonal foraging area. Notably, one green turtle traveled to Hainan Island in the South China Sea, a historical nesting area. Our results showed that the two sea turtle species included the East Sea as a seasonal foraging area, possibly owing to the abundance of food sources available, despite its relatively lower sea temperature. Considering that loggerhead and green sea turtles were observed using the northern part of the East China Sea and East Sea more frequently than previously known and that the sea temperature gradually increases due to climate change, conservation and management activities are required for sea turtles in these areas.
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Aiba, Evander E., Billly Th Wagey, Ping A. Angmalisang, Anneke V. Loho, Deslie Kumampung, and Farnis B. Boneka. "PENYU DAN WARGA PULAU SIAU." JURNAL PESISIR DAN LAUT TROPIS 8, no. 1 (January 15, 2020): 65. http://dx.doi.org/10.35800/jplt.8.1.2020.27483.
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The study of the perception residents of the Siau island regarding the existence of sea turtles was carried out from June to December 2018. The survey method and direct observation were applied in data collection. The data collected then were analyzed descriptively. The results showed that 88 % of the residents are well acquainted with the life of sea turtles followed by 80 % of the residents knew of the sea turtles’ status as the protected animals through government regulations and international conventions. However, the proportion of residents involved in violating regulations are quite worrying to the survival of sea turtles. For it was found that 29% of the residents were catching sea turtles, 20 % were selling sea turtle meat and eggs, and 82 % were consuming sea turtle meat and eggs. Thefefore, law enforcement and conservation education are absolutely neccesary for the sustainability of sea turtles in North Sulawesi Indonesia. Keywords: Sea turtle, Siau Island, resident’s perception, law enforment. Conservation education AbstrakTelaah presepsi warga pulau Siau terhadap keberadaan penyu laut telah dilaksanakan pada Juni-Desember 2018. Metode survey dan observasi langsung diaplikasikan dalam pengumpulan data, dan data dianalisa secara deskripsif. Hasil menunjukkan bahwa warga mengenal dengan baik kehidupan penyu (88%) dan statusnya sebagai satwa yang dilindungi melalui regulasi pemerintah dan konvensi Internasional (80%). Namun proporsi warga yang terlibat dalam pelanggaran terhadap peraturan cukup mengkuartirkan akan keberlangsungan hidup penyu, yakni menangkap penyu (29%), menjual daging dan telur penyu (28%), mengkonsumsi daging dan telur penyu (82%). Penegakkan hukum dan edukasi diperlukan demi kelestarian penyu di Sulawesi Utara dan Indonesia pada umumnya.Kata kunci: Penyu laut, Pulau Siau, persepsi warga, penegakan hokum, pendidikan konservasi
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Chou, Wei-Rung, Po-Yu Wu, and Tsung-Hsien Li. "Assessing the Relationship between Sea Turtle Strandings and Anthropogenic Impacts in Taiwan." Journal of Marine Science and Engineering 11, no. 10 (October 11, 2023): 1962. http://dx.doi.org/10.3390/jmse11101962.
Full textAbstract:
Data acquired from stranded sea turtles can provide awareness of human activities that adversely affect sea turtle populations. We assessed strandings of five sea turtle species between 2017 and 2021. This study utilizes principal component analysis (PCA) and structural equation modeling (SEM) to reveal potential causes of sea turtle strandings linked to anthropogenic effects in Taiwan. Although our study did not observe a statistically significant impact of offshore wind turbines on sea turtle strandings, it did find evidence of a significant direct effect of coral colony density, heavy metals, and fishing disturbance on such strandings. For the conservation of endangered sea turtles, we recommend the incorporation of PCA and SEM in further contexts for validating anthropogenic impact assessments.
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Chrisman, Cheryl L., Michael Walsh, John C. Meeks, Heidi Zurawka, Richard LaRock, Larry Herbst, and Juergen Schumacher. "Neurologic examination of sea turtles." Journal of the American Veterinary Medical Association 211, no. 8 (October 15, 1997): 1043–47. http://dx.doi.org/10.2460/javma.1997.211.08.1043.
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Objective To determine whether neurologic examination techniques established for use on dogs and cats could be adapted for use on sea turtles. Design Prospective controlled observational study. Animals 4 healthy Green Turtles (Chelonia mydas), 1 healthy Kemp's ridley sea turtle (Lepidochelys kempi), and 6 Green Turtles suspected to have neurologic abnormalities. Procedure Neurologic examinations were performed while sea turtles were in and out of the water and in ventral and dorsal recumbency. Mentation, general activity, head and body posture, movement and coordination, thoracic and pelvic limb movement, strength and muscle tone, and tail movement were observed. Thoracic and pelvic limb flexor reflexes and nociception, righting response, cranial nerve reflexes, clasp and cloacal reflexes, and neck, dorsal scute, cloacal, and tail nociception were tested. Results Results of neurologic evaluations were consistent for healthy sea turtles. Sea turtles suspected to have neurologic abnormalities had abnormal results. Clinical Implications Many of the neurologic examination techniques used to evaluate dogs and cats can be adapted and used to evaluate sea turtles. A standardized neurologic examination should result in an accurate assessment of neurologic function in impaired sea turtles and should help in evaluating effects of rehabilitation efforts and suitability for return to their natural environment. (J Am Vet Med Assoc 1997;211:1043–1047)
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Godfrey, Matthew H., N. Mrosovsky, and R. Barreto. "Estimating past and present sex ratios of sea turtles in Suriname." Canadian Journal of Zoology 74, no. 2 (February 1, 1996): 267–77. http://dx.doi.org/10.1139/z96-033.
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Leatherback (Dermochelys coriacea) and green (Chelonia mydas) sea turtles in Suriname lay eggs over several months of the year. During this nesting season, changes in rainfall produce changes in sand temperature, which in turn influence the sexual differentiation of incubating sea turtle embryos. The overall sex ratio of leatherback and green sea turtle hatchlings produced at Matapica beach in Suriname was investigated. Estimates of the sex ratios of these turtles in 1993 (green turtles 63.8% female, leatherbacks 69.4% female) were roughly 10% more female-biased than those from an earlier study in 1982. For both species, a significant negative relationship was found between monthly rainfall and monthly sex ratios. Using this relationship and data on rainfall in the past, it was possible to estimate overall sex ratios for an additional 12 years. These estimates varied considerably among different years, ranging from 20 to 90% female in the case of green turtles. Nevertheless, males tended to be produced primarily in April and May, while some females were produced in all months. Such seasonal patterns of production of turtles of different sexes have implications for sea turtle conservation programs that involve manipulating or harvesting eggs.
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Yamani, Muhammad. "Harmonizing Conservation Values of National and Customary Laws on Turtles Conservation." Jambe Law Journal 2, no. 1 (November 3, 2019): 61–77. http://dx.doi.org/10.22437/jlj.2.1.61-77.
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Sea turtle populations on the Enggano Island are almost extinct as a result of over exploitation. This article aims to discuss harmonization of conservation values between national law and Enggano customary people in protectng sea turtles. It is found that the Enggano customary law norms have conservation values which stated prohibition of catching sea turtles by any means except for adat grandeur ceremonies (yakadea) use only. Sanctions are imposed to those who break the law with customary fines and a compulsary to apology to the chiefs and other Enggano Island communities. It is also learned that to harmonize conservation values between national law and Enggano customary law in protecting sea turtles can be conducted by implementing the norms of turtle protection in the national laws into the Village Regulation, which is an integral part of the hierarchical systems of laws and regulations in Indonesia. Harmonization of the conservation values of the sea turtles through the integration of legal substance is the best model in optimizing the protection of sea turtles without sacrificing the interests of traditional rituals that are still maintained for generations in the life of the Enggano community
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Jribi, Imed, Abderrahmen Bouain, Khaled Echwikhi, and Mohamed Nejmeddine Bradai. "Effect of bait on sea turtles bycatch rates in pelagic longlines: An overview." Amphibia-Reptilia 32, no. 4 (2011): 493–502. http://dx.doi.org/10.1163/156853811x601924.
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AbstractPelagic longline fishing has been identified as a significant threat to endangered sea turtle populations. Reducing sea turtle bycatch in pelagic longline fisheries, in concert with activities to reduce other anthropogenic mortality sources, may halt and reverse population declines. Here, we examine the effect of bait manipulation as a simple mitigation method that could reduce sea turtle interactions with longline fishing gear. We analyzed laboratory experiments and field trials conducted in the Mediterranean, the northeast Distant Area in the Atlantic and the Western North Pacific. Studies showed that turtles are more likely to feed on squid than on mackerel when both are used simultaneously as bait. The stingray, Dasyatis pastinaca, used as bait, was more effective than mackerel; this ray was vulnerable and stimulated much thought about other species to use as alternative bait. Effective in laboratory conditions with captive turtles, dyed and artificial bait did not seemed to be effective in reducing turtle bycatch in field conditions. Optimal mitigation measure must reduce incidence of hooking of threatened sea turtles to acceptable levels and also offer an economic advantage to fisheries. Studies concerning the effect of bait modification to reduce turtle bycatch highlight the importance of an integrated approach towards sensory deterrents, as both visual and chemical cues are likely to attract sea turtles to longline gear. Further research on the development of sensory-based deterrents can contribute to reduced sea turtle bait interactions and maintain catch rates of target species.
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Mohd Roslan, Ummu Atiqah, and Fatimah Noor Harun. "Modeling the Impact of Pollution on Sea Turtles." Malaysian Journal of Fundamental and Applied Sciences 19, no. 4 (August 27, 2023): 607–15. http://dx.doi.org/10.11113/mjfas.v19n4.2913.
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Human activities are currently threatening sea turtles at all life stages, both on nesting beaches and at sea. The debris and toxic waste dumped on the coast or at sea pollutes the sea and puts marine life in danger. In recent years, the number of global turtle population have noticeably decreased, and this is largely due to plastic pollution. However, how the sea pollution affects the sea turtles’ populations is not fully understood. Therefore, in this study, using the mathematical model, we will investigate the impact of pollution on sea turtle population. The model system is analyzed using standard mathematical techniques, including positivity of solutions and stability analysis. Our findings showed that there are two possible equilibrium points (i.e. steady-state solutions) for the model proposed, in which the stability analysis showed that only one of the solutions is asymptotically stable. Thus, the conditions of stability for both equilibrium points were also derived analytically based on their eigenvalues. As for the numerical simulations, the parameter of contamination rate is varied to investigate the effect of pollution on the population of sea turtles. The results suggested that if the contamination rate is high, then the population of sea turtles are expected to decrease and extinct approximately within 10 years. The comparison of survival and extinction of sea turtles are shown using the time series plots.
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Robinson, Nathan J., Eric A. Lazo-Wasem, Frank V. Paladino, John D. Zardus, and Theodora Pinou. "Assortative epibiosis of leatherback, olive ridley and green sea turtles in the Eastern Tropical Pacific." Journal of the Marine Biological Association of the United Kingdom 97, no. 6 (May 19, 2016): 1233–40. http://dx.doi.org/10.1017/s0025315416000734.
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Sea turtles host a diverse array of epibionts, yet it is not well understood what factors influence epibiont community composition. To test whether epibiont communities of sea turtles are influenced by the hosts’ nesting or foraging habitats, we characterized the epibiota of leatherback, olive ridley and green turtles nesting at a single location on the Pacific coast of Costa Rica. We also compared the epibiota of these turtles to conspecific populations nesting elsewhere in the East Pacific. If epibiont communities are influenced by nesting habitats, we predicted that sympatrically nesting turtles would have comparable epibiont taxa. Alternatively, if epibiont communities are influenced by foraging habitats, we predicted the diversity of epibiont taxa should reflect the type and diversity of the hosts’ foraging habitats. We identified 18 epibiont taxa from 18 leatherback, 19 olive ridley and six green turtles. Epibiont diversity was low on leatherbacks (four taxa), but higher for olive ridley and green turtles (12 and nine epibiont taxa respectively). The epibiont communities of olive ridley and green turtles were not statistically different, but both were different from leatherbacks. In addition, conspecific sea turtles from other nesting locations hosted more similar epibiont communities than sympatrically nesting, non-conspecifics. We conclude that epibiont diversity of nesting sea turtles is partially linked to the diversity of their foraging habitats. We also conclude that the surface properties of the skin and carapace of these turtles may contribute to the uniqueness of leatherback turtle epibiont communities and the similarities between olive ridley and green turtle epibiont communities.
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Limpus, CJ, D. Zeller, D. Kwan, and W. Macfarlane. "Sea-Turtle Rookeries in North-Western Torres Strait." Wildlife Research 16, no. 5 (1989): 517. http://dx.doi.org/10.1071/wr9890517.
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Deliverance Island, Kerr Islet and Turu Cay in north-western Torres Strait support a major nesting population and the most northerly recorded rookery of the flatback turtle, Natator depressa. Nesting occurs there year round, with a peak in the early months of the year. The islands are insignificant nesting sites for the green turtle, Chelonia mydas, and the hawksbill turtle, Eretmochelys imbricata. The N. depressa turtles that nest in western Torres Strait-north-eastern Gulf of Carpentaria are smaller and lay smaller eggs on average than the N. depressa turtles that breed in the southern Great Barrier Reef. On Deliverance Island, the inhabitants of nearby Queensland islands and Papua New Guinea coastal villages infrequently harvest N. depressa eggs as well as the green turtles that feed over the surrounding reef flats.
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Krismono, Adriani Sri Nastiti, Amula Nurfiarini, Ahmad Fitrianto, and Ngurah Nyoman Wiadnyana. "PRESENT STATUS OF NESTING HABITAT OF GREEN TURTLE (Chelonia mydas) lN WEST JAVA-INDONESIA." Indonesian Fisheries Research Journal 15, no. 1 (April 27, 2017): 49. http://dx.doi.org/10.15578/ifrj.15.1.2009.49-57.
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The coastal habitat condition much influences the moving of sea turtles to coast for nesting. In West Java Province there are some potential coasts as nesting habitat of sea turtles, but it has experiencing of many damage and has not been touched yet as the protected area for sea turtle nesting habitat.
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Dodge, KL, S. Landry, B. Lynch, CJ Innis, K. Sampson, D. Sandilands, and B. Sharp. "Disentanglement network data to characterize leatherback sea turtle Dermochelys coriacea bycatch in fixed-gear fisheries." Endangered Species Research 47 (February 24, 2022): 155–70. http://dx.doi.org/10.3354/esr01173.
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To characterize sea turtle bycatch in fixed-gear fisheries in Massachusetts, USA, we analyzed a 15 yr dataset of entanglement reports and detailed documentation from disentanglement operations. Almost all (272) of the 280 confirmed entanglements involved leatherback turtles Dermochelys coriacea. The majority of turtles were entangled in actively fished (96%), commercial (94%) pot/trap gear with unbroken/untriggered weak links, specifically the buoy lines marking lobster, whelk, and fish traps. Most reports came from recreational boaters (62%) and other sources (26%), rather than commercial fishers (12%). Leatherback entanglements occurred from May to November, with peak reporting in August, and included adult males, adult females, and subadults. All entanglements involved the turtle’s neck and/or front flippers, with varying degrees of visible injuries; 47 entangled leatherbacks were dead in gear, 224 were alive at first sighting, and 1 case was unknown. Post-release monitoring suggested turtles can survive for days to years after disentanglement, but data were limited. While the observed entanglements in our study are low relative to global bycatch, these numbers should be considered a minimum. Our findings are comparable to observed numbers of leatherbacks taken in Canadian fixed-gear fisheries, and represent just one of multiple, cumulative threats in the North Atlantic. Managers should focus on strategies to reduce the co-occurrence of sea turtles and fixed-fishing gear, including reductions in the number of buoy lines allowed (e.g. replace single sets with trawls), seasonal and area closures targeted to reduce sea turtle-gear interaction, and encourage the development of emerging technologies such as ‘ropeless’ fishing.
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Watson, John W., Sheryan P. Epperly, Arvind K. Shah, and Daniel G. Foster. "Fishing methods to reduce sea turtle mortality associated with pelagic longlines." Canadian Journal of Fisheries and Aquatic Sciences 62, no. 5 (May 1, 2005): 965–81. http://dx.doi.org/10.1139/f05-004.
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Changes in hook design and bait type were investigated as measures to reduce the bycatch of sea turtles on pelagic longlines in the western North Atlantic Ocean. Specifically, the effectiveness of 18/0 circle hooks and mackerel (Scomber scombrus) bait was evaluated with respect to reducing sea turtle interactions and maintaining swordfish (Xiphias gladius) and tuna (Thunnus spp.) catch rates. Individually, circle hooks and mackerel bait significantly reduced both loggerhead (Caretta caretta) and leatherback (Dermochelys coriacea) sea turtle bycatch. Circle hooks also significantly reduced the rate of hook ingestion by the loggerheads, potentially reducing postrelease mortality. The combination of circle hooks and mackerel bait was even more effective for loggerhead turtles and had no negative effect on swordfish catch. These modifications in fishing methods, in conjunction with tools developed to remove hooks and line from the turtles, significantly reduced the capture rate of sea turtles and potentially the post-hooking mortality of those that were caught and did not negatively impact the primary target species catch rate. In addition, these mitigation measures have the potential to reduce mortality of sea turtles and other bycatch species worldwide.
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Utama, Gwendolyn Ingrid, Shinta Pangesti, and Laura Cindy Vatresia. "Preserving the Existence of Sea Turtles: The Government Policies and Roles on Conservations." Law Review 22, no. 3 (March 30, 2023): 360. http://dx.doi.org/10.19166/lr.v22i3.7871.
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<p>Sea turtles are reptiles that live in the sea which have long been threatened, both from nature and human activities. Internationally, sea turtles are included in the 'red list' in the International Union for Conservation of Nature's (IUCN) and Appendix I of the Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES), which means that their existence in nature is threatened with extinction so that all the form of utilization and distribution must receive serious attention. Therefore, sea turtle conservation efforts are an important program to protect and save the populations, especially in Indonesia because there are 6 out of 7 sea turtles species still exist today in Indonesia. In order to support sea turtle conservation efforts in Indonesia, government roles are needed, both at the central and regional levels. This research focuses on the preserving sea turtles based in Indonesia through government policies and roles regarding conservations at Serangan Island and Tanjung Benoa, especially local government. The purpose of this research was to analyze government policies and their roles on sea turtle conservation efforts at Serangan Island and Tanjung Benoa. The research method used is normative using secondary data supported by primary data in the form of interviews with the management of the conservation centers. The research result shows that central government regulations are not always passed down to the regional level, but the government's awareness to protect the existence of turtles has been carried out together with the society even without regional regulations.</p>
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Hudgins, Jillian A., Emma J. Hudgins, Stephanie Köhnk, Enas Mohamed Riyad, and Martin R. Stelfox. "A brighter future? Stable and growing sea turtle populations in the Republic of Maldives." PLOS ONE 18, no. 4 (April 26, 2023): e0283973. http://dx.doi.org/10.1371/journal.pone.0283973.
Full textAbstract:
The Indian Ocean represents a significant data gap in the evaluation of sea turtle population status and trends. Like many small island states, the Republic of Maldives has limited baseline data, capacity and resources to gather information on sea turtle abundance, distribution and trends to evaluate their conservation status. We applied a Robust Design methodology to convert opportunistic photographic identification records into estimates of abundance and key demographic parameters for hawksbill sea turtles (Eretmochelys imbricata) and green sea turtles (Chelonia mydas) in the Republic of Maldives. Photographs were collected ad hoc by marine biologists and citizen scientists around the country from May 2016 to November 2019. Across 10 sites in four atolls, we identified 325 unique hawksbill turtles and 291 unique green turtles—where most were juveniles. Our analyses suggest that, even when controlling for survey effort and detectability dynamics, the populations of both species are stable and/or increasing in the short term at many reefs in the Maldives and the country appears to provide excellent habitat for recruiting juvenile turtles of both species. Our results represent one of the first empirical estimations of sea turtle population trends that account for detectability. This approach provides a cost-effective way for small island states in the Global South to evaluate threats to wildlife while accounting for biases inherent in community science data.
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Koeswiryono, Dika Pranadwipa, and I. Made Krisna Adi Chandra. "Developing English Module for Turtle Conservation Guides." SAGA: Journal of English Language Teaching and Applied Linguistics 2, no. 1 (February 1, 2021): 1–8. http://dx.doi.org/10.21460/saga.2020.21.73.
Full textAbstract:
Most of the six species of sea turtles in Indonesian waters have seen a decline, mainly due to human exploitation. One of the efforts to prevent the extinction of this pre-historic reptiles is the establishment of conservation centers. In Bali, one of the conservation centers actively involved in the efforts to conserve turtles is the Turtle Conservation and Education Center (TCEC). As more foreign tourists who are aware of turtle conservation come to this place, guides at TCEC are expected to able to provide sufficient explanation about turtles and their environment in English. They should provide a thorough insight of the turtle's anatomy, behavior, and reproductive cycle. This study aimed at developing English module for turtle conservation guides at TCEC. In developing the module, a framework of material development model was adopted. The framework consists of some stages namely, needs analysis, formulation of goals and objectives, development of English learning materials, and evaluation. The results of this study provide some implication and contributions for English language teaching.
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Werneck, M. R., and R. J. Da Silva. "Checklist of sea turtles endohelminth in Neotropical region." Helminthologia 53, no. 3 (September 1, 2016): 211–23. http://dx.doi.org/10.1515/helmin-2016-0045.
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SummaryThis paper presents a list of parasites described in sea turtles from the Neotropical region. Through the review of literature the occurrence of 79 taxa of helminthes parasites were observed, mostly consisting of the Phylum Platyhelminthes with 76 species distributed in 14 families and 2 families of the Phylum Nematoda within 3 species. Regarding the parasite records, the most studied host was the green turtle (Chelonia mydas) followed by the hawksbill turtle (Eretmochelys imbricata), olive ridley turtle (Lepidochelys olivacea), loggerhead turtle (Caretta caretta) and leatherback turtle (Dermochelys coriacea). Overall helminths were reported in 12 countries and in the Caribbean Sea region. This checklist is the largest compilation of data on helminths found in sea turtles in the Neotropical region.
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Di Bello, Antonio, Delia Franchini, Stefano Ciccarelli, Daniela Freggi, Francesco Caprio, Pasquale Salvemini, and Carmela Valastro. "Esophago-Gastric Tube (EG Tube) in Debilitated Sea Turtle Rehabilitation: Insight in 195 Loggerheads Caretta caretta, Southern Italy." Veterinary Sciences 11, no. 1 (January 15, 2024): 35. http://dx.doi.org/10.3390/vetsci11010035.
Full textAbstract:
Efficient nutritional support plays a pivotal role in the rehabilitation of sea turtles, ensuring a positive, swift, and successful recovery from clinical conditions for their reintroduction into the wild. For sea turtles in severely emaciated and underweight condition, the primary objective is to facilitate weight gain in terms of both muscle mass and fat reserves. Traditionally, many sea turtle rehabilitators have employed the practice of force-feeding, which also involves the daily insertion of an orogastric tube from the mouth to the stomach. However, this technique may be highly stressful for the animals, carrying the risks of regurgitation and potential harm, requiring the removal of the animal from the water, and subjecting it to uncomfortable and potentially dangerous handling. The procedure may also involve risks for operators. In this study, we explore the utilization of a permanent esophago-gastric tube (EG tube) in sea turtles as an alternative to force-feeding, providing a respectful and appropriate approach to meeting the nutritional needs of patients. The administration of food, essential medications, and fluids is performed directly with the turtle in its tank, minimizing the stress associated with handling, while ensuring the safety of operators. The study involves 195 marine turtles that underwent surgery for the placement of a permanent EG tube between 2008 and 2022. Of these, 116 animals were treated at the Sea Turtle Clinic of the Department of Veterinary Medicine at the University of Bari, South Adriatic Sea, Puglia (IT), and 79 patients were admitted to the Sea Turtle Rescue Center of Lampedusa, Central Mediterranean Sea, Sicily (IT). The loggerhead turtles (Caretta caretta) required EG tube placement due to their poor condition related to various diseases, which were systematically categorized. The duration of EG tube placement was analyzed regarding the specific condition of the animals and the nature of their injuries, considering any complications or differences between the two facilities. The results of the study will provide valuable information for the ongoing care and treatment of marine turtles in rehabilitation facilities.
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Putman, Nathan F., Jesse Hawkins, and Benny J. Gallaway. "Managing fisheries in a world with more sea turtles." Proceedings of the Royal Society B: Biological Sciences 287, no. 1930 (July 2020): 20200220. http://dx.doi.org/10.1098/rspb.2020.0220.
Full textAbstract:
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.
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Weir, Caroline R., Tamar Ron, Miguel Morais, and Agostinho Domingos C. Duarte. "Nesting and at-sea distribution of marine turtles in Angola, West Africa, 2000–2006: occurrence, threats and conservation implications." Oryx 41, no. 2 (April 2007): 224–31. http://dx.doi.org/10.1017/s003060530700186x.
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AbstractThe status of marine turtles in Angola, West Africa, is poorly known, and therefore during 2000–2006 a combination of both dedicated and opportunistic beach and at-sea turtle surveys were carried out, and interviews conducted with fishing communities and at markets. Green Chelonia mydas, olive ridley Lepidochelys olivacea, leatherback Dermochelys coriacea and loggerhead turtles Caretta caretta were recorded, and nesting of the first three species confirmed during September–March (peaking November–December). Green turtles nested mainly in the south, leatherback turtles in north and central Angola, and olive ridley turtle nesting was widespread. Olive ridley turtle nest density at Palmeirinhas averaged 32 nests km−1. At-sea surveys produced 298 turtle records, with peak occurrence during August. Significant anthropogenic-related mortality (including exploitation of meat and eggs and fishing bycatch) was recorded, in addition to natural predation and other threats. Maintenance of the long-term sustainability of these turtle populations should focus on the involvement of fishing communities and increasing awareness throughout Angola.
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REVUELTA, OHIANA, FRANCESC DOMÈNECH, STEPHEN KEABLE, and RAÚL MÍGUEZ-LOZANO. "First report of the scavenging isopod Natatolana neglecta (Crustacea: Isopoda: Cirolanidae) feeding on a sea turtle." Mediterranean Marine Science 20, no. 2 (May 28, 2019): 297. http://dx.doi.org/10.12681/mms.19058.
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A juvenile male loggerhead sea turtle (Caretta caretta) was found dead in April 2015, entangled in a trammel net on the Mediterranean coast of Spain. Post-mortem examination revealed the presence of ninety-five isopods dispersed in the coelomic cavity, and inside the oesophagus and skull. All individuals found scavenging on the sea turtle were identified as Natatolana neglecta (Hansen, 1890) (Isopoda: Cirolanidae). Genetic analysis of the isopod gut contents showed that they were feeding on turtle tissue, confirming that N. neglecta can also attack dead sea turtles. This study shows the value of cirolanids as potential indicators of the cause of death in stranded sea turtles.