Sea turtle

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...

The bone-eating worm Osedax is a speciose and globally distributed clade, primarily found on whale carcasses in marine environments. The earliest fossil evidence for Osedax borings was previously described in plesiosaur and sea turtle bones from the mid-Cretaceous of the United Kingdom, representing the only unequivocal pre-Oligocene occurrences. Confirming through CT scanning, we present new evidence of Osedax borings in three plesiosaur specimens and, for the first time, identify borings in two mosasaur specimens...

Currently, sea turtle habitats are being altered by climate change and human activities, with habitat loss posing an urgent threat to Indian sea turtles. Thus, the objective of this study is to analyze the dynamic shoreline alterations and their impacts on Olive Ridley Sea Turtle (ORT) nesting sites in Gahirmatha Marine Wildlife Sanctuary from 1990 to 2022. Landsat satellite images served as input datasets to assess dynamic shoreline changes. This study assessed shoreline alterations and their rates across 929 transects divided into four zones using the Digital Shoreline Analysis System (DSAS) software...

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...

Sand dunes are supported by the extensive root systems of dune plants that anchor the dune and protect it from erosion. While all plants that grow on the dunes support their structure, invasive plants can outcompete the native and non-native dune plants for resources such as nutrients, sunlight, and space to grow. During the summer, sea turtles lay nests on beaches and near dunes; however, their eggs and hatchlings are at risk of destruction and entrapment by dune plant root penetration. Dune plant roots can penetrate sea turtle nest cavities, thus decreasing hatch success of the eggs and emergence success of the hatchlings...

Fishing is one of the main threats to sea turtles due to the risk of entanglement in lost nets, vessel collision and mortality due to incidental catches. In Brazil, most of the studies regarding fishing interactions with sea turtles are focused on pelagic longline fisheries in the South and Southeast regions. However, their main reproductive areas in Southwest Atlantic RMU occur in Northeast Brazil, which overlaps small-scale coastal gillnet fisheries. Here, we aimed to use ethnobiology and participatory approaches as simple and cost-effective methods to identify areas for sea turtle conservation where impacts from small-scale fisheries are most likely...

This review summarises our two decades of polychlorinated biphenyl (PCB) monitoring in different marine organisms along the eastern Adriatic Sea. The aim was to gain an insight into the trends of PCB distribution in order to evaluate the effectiveness of past and current legislation and suggest further action. Here we mainly focus on PCB levels in wild and farmed Mediterranean mussels, wild and farmed bluefin tuna, loggerhead sea turtles, common bottlenose dolphins, and small pelagic fish. The use of artificial intelligence and advanced statistics enabled an insight into the influence of various variables on the uptake of PCBs in the investigated organisms as well as into their mutual dependence...

After hatching, sea turtles leave the nest and disperse into the ocean. Many years later, they return to their natal coastlines. The period between their leaving and their returning to natal areas, known as the "Lost Years", is poorly understood. Satellite tracking studies aimed at studying the "Lost Years" are challenging due to the small size and prolonged dispersal phases of young individuals. Here, we summarize preliminary findings about the performance of prototype microsatellite tags deployed over a three-year period on 160 neonate to small juvenile sea turtles from four species released in the North Atlantic Ocean...

We examined the probability of past sea turtle nesting as a function of light intensity and patterns of temporal changes of light along nesting beaches in the Egyptian Red Sea. Beaches had a lower probability of past sea turtle nesting as light intensity increased. Light has been significantly increasing on mainland nesting beaches between 1992 and 2021 except for temporary declines. Island beaches historically had lower light pollution, but there was a sudden increase of light starting in 2014 that continued through 2021, except for the precipitous decline in 2020 during the Covid 19 pandemic...

The Virtual Access to STEM Careers (VASC) project is an intertwined classroom and virtual reality (VR) curricular program for third through fourth graders. Elementary school students learn about and take on the roles and responsibilities of STEM occupations through authentic, problem-based tasks with physical kits and immersive VR environments. This article reports on a round of curriculum and virtual environment development and in-classroom experimentation that was guided by preliminary results gathered from our initial VASC prototyping and testing...

Population declines of vertebrates are common, but rebuilding marine life may be possible. We assessed trends in sea turtle numbers globally, building 61 time series of abundance extending beyond 2015, representing monitoring in >1200 years. Increases were widespread with significant upward trends, no significant change, and significant downward trends in 28, 28, and 5 time series, respectively. For example, annual nest numbers increased between 1980 and 2018 from around 4,000 to 16,000 for green turtles at Aldabra (Seychelles, Indian Ocean) and between 2008 and 2020 from around 500 to 35,000 for loggerhead turtles in Sal (Cape Verde, north Atlantic)...

The pharmacokinetics of florfenicol (FFC) in green sea and hawksbill sea turtles were evaluated following intramuscular (i.m.) administration at two different dosages of 20 or 30 mg/kg body weight (b.w.). This study (longitudinal design) used 5 green sea and 5 hawksbill sea turtles for the two dosages. Blood samples were collected at assigned times up to 168 h. FFC plasma samples were analyzed using validated high-performance liquid chromatography equipped with diode array detection. The pharmacokinetic analysis was performed using a non-compartment approach...

BACKGROUND: Biological invasions are a leading cause of reductions in global biodiversity. Islands are particularly sensitive to invasions, which often result in cascading impacts throughout island communities. Wild pigs (Sus scrofa) are globally invasive and pose threats to numerous taxa and ecosystems, particularly for islands where they have contributed to declines of many endemic species. However, the impacts of wild pig diet on the flora and fauna remain understudied in many island systems...

Anticipating and mitigating the impacts of climate change on biodiversity requires a comprehensive understanding on key habitats utilized by species. Yet, such information for high mobile marine megafauna species remains limited. Here, we compile a global database comprising published satellite tracking data (n = 1035 individuals) to spatially delineate foraging grounds for seven sea turtle species and assess their thermal stability. We identified 133 foraging areas distributed around the globe, of which only 2% of the total surface is enclosed within an existing protected area...

Sea turtles are critical components of marine ecosystems, and their conservation is important for Ocean Governance and Global Planet Health. However, there is limited knowledge of their ecology in the Gulf of Guinea. To fill this knowledge gap, this study presents the first integrative assessment of green and hawksbill turtles in the region, combining nesting surveys over 9 years and telemetry data, to offer insights into these population dynamics, and behaviours, including nesting preferences, morphological and reproductive parameters, diving patterns and inter-nesting core-use areas...

The underwater environment is filled with various sounds, with its soundscape composed of biological, geographical, and anthropological sounds. Our work focused on developing a novel method to observe and classify these sounds, enriching our understanding of the underwater ecosystem. We constructed a biologging system allowing near-real-time observation of underwater soundscapes. Utilizing deep-learning-based edge processing, this system classifies the sources of sounds, and upon the tagged animal surfacing, it transmits positional data, results of sound source classification, and sensor readings such as depth and temperature...

This study investigates the spatiotemporal trends of loggerhead turtles along the Croatian Adriatic coast by using stranding data and post-mortem analyses. Information on 620 loggerhead turtles ( Caretta caretta ), collected in the period between 2010 and 2022, has been analysed. Seasonal stranding variations reveal distinct patterns, indicating season-specific abundance and age-specific mortality in different areas, particularly in the key neritic habitat of the northern Adriatic. The analysis identifies four critical areas in the northeast and central Adriatic showing high stranding densities and provides regional managers with a tool with which to effectively conserve and manage this species...

Future climate change scenarios project that the increase in surface temperatures will affect ocean temperatures, inducing shifts in marine biodiversity. Sea turtles are species that are particularly vulnerable to the effects of climate change because temperature is a factor that influences embryonic development. We collected clutches of olive ridley turtles from a mass-nesting beach in the Mexican Pacific, which were incubated in ex situ conditions. When the hatchlings emerged, we measured the body condition index-which evaluates the weight-length relationship-and swim thrust, both were considered traits associated with fitness, termed "fitness proxies," and evaluated the effects of incubation temperature, maternal effects, and paternity on these fitness proxies...

Sea turtles are one of the most significant groups of marine species, playing a key role in the sustainability and conservation of marine ecosystems and the food chain. These emblematic species are threatened by several natural and anthropogenic pressures, and climate change is increasingly reported as one of the most important threats to sea turtles, affecting sea turtles at all stages of their life cycle and at both their marine and coastal habitats. The effect of climate change is expressed as global warming, sea-level rise, extreme storms, and alterations in predation and diseases' patterns, posing a potentially negative impact on sea turtles...

Eumycetoma, a subcutaneous infection caused by various fungi with pathognomonic discharging grain, is rarely reported in Malaysia. This case concerns a eumycetoma infection in an immunocompetent man who presented with progressive left foot swelling complicated with pustules, sinuses and pale grain discharge for the past year after recurrent thorn pricks. Histological findings of the grain and tissue showed foci of septate fungal hyphae. Tissue culture yielded no growth. Amplification and sequencing of the rDNA internal transcribed spacer 1 (ITS1), ITS4 and large subunit regions of the tissue identified the causative agent as Fusarium falciforme , highlighting the role of molecular diagnostic method in identifying fungal species in eumycetoma...