ISTS42 Program/Agenda

Trinidad is a vital location since it supports a third of one of the world's largest population of leatherback turtles, with over 10,000 turtles nesting on the island. This accounts for 80% of the leatherback turtle population in the Caribbean Region. This study identifies some of the challenges faced when conducting traditional beach monitoring and data collection campaigns in the ‘sea-turtle nesting’ Matura region of North-east Trinidad and evaluates a method to reduce them. A lack of funding during the critical ‘sea-turtle nesting’ months has led to a decline in patrolling efforts, resulting in limited data collection and turtle tagging exercises being conducted. In response to this challenge, this research focuses on an evaluation of the utility of the Matrice300 RTK Unmanned Aerial System (UAS) as a transformative technology to enhance the efficiency of turtle patrols along the extensive Matura beach coastline. The primary objectives include: 1) evaluating the capability of the Matrice300 RTK UAS in identifying nesting Leatherback turtles using a Thermal Infrared (TIR) camera, 2) assessing the feasibility of deploying the UAS to scout remote beach areas for nesting turtles, and 3) determining the UAS's efficacy in detecting unauthorized activities at the Matura Turtle Nesting Site (MTNS). Sea-turtles were identified from drone imagery based on their morphological features, heat signatures and track formation. After conducting numerous surveys, the UAS proved to be highly successful in identifying Sea turtles from an altitude of 45 meters. Different stages of nesting were also discernible, and the drone quickly became a critical part of a nightly patrolling regime, thereby optimizing the existing workforce. This study hopes to contribute insights into the integration of drone technology for sea-turtle conservation and provides guidelines for enhancing monitoring with UAS support on the island of Trinidad. Recommendations for the involvement of UAS in other conservation programs are also made.

In many low-income countries, the distribution and status of aquatic megafauna species, such as sea turtles, are poorly known, and their populations are mostly threatened by poaching, accidental catch, and habitat degradation. Without a good understanding of the population dynamics, distribution, and threats, these species may face local extinction. Surveys and monitoring in the aquatic environment can be time-consuming and demand skills that are often unavailable and unreliable locally, even for simple field observations. Many NGOs also lack the staffing and financial resources to patrol long distances of coastlines.

In response to this knowledge and skill gap, we developed the Siren mobile application to facilitate the acquisition of field observations of marine animals like sea turtles and enable researchers to streamline program operations and transform sightings into actionable conservation data.

Based on a citizen science approach since its inception in 2014, Siren has significantly improved our conservation strategy, making our program pertinent and economically viable:

(i) By putting Siren in the hands of local people, we increased the number of sightings to more than 20,000 observations of marine animals along the 400km coast of Cameroon. Out of those, the volunteering opportunistic sightings of female sea turtles and their nests that over 80 fishermen reported during their normal fishing activities allowed our team of just four observers to better target priority areas and optimal distribution of patrol effort along the beach. This resulted in an increased volume of sea turtle nesting data that otherwise would have been sparse, spaced over time and distance, and ultimately less relevant.

(ii) While we were initially patrolling 80kms of coastline to look for nests, Siren helped reduce the patrol distance to 15kms, resulting in a remarkable 81.25% gain in efficiency.

(iii) Reported observations of sea turtles now provide a trove of information that we can use as visual proof for our broader conservation and educational activities, such as the documentation of dead female turtles due to ingestion of plastics in our plea with The Minister of The Environment, Nature Protection and Sustainable Development (MINEPDED) of Cameroon.

(iv) Overall, the use of technology instead of paper forms is less error-prone and provides a more accurate estimate of patrol effort, particularly by ensuring that observers actually conduct patrols through the systematic collection of GPS coordinates.

Although similar technologies exist in the market, Siren is the first multi-language application (English, French, Spanish, Arabic, and Portuguese) maintained by a community of scientists and technologists through open collaboration. It is paired with a web interface for administrators of sea turtle monitoring programs to visualize and analyze aggregated data following scientific community standards.

Reliable access to remote marine turtle nesting sites remains a persistent challenge when attempting to monitor nester abundance and distribution. These difficulties are further increased where large areas across multiple locations need to be surveyed to accurately quantify population trends. Here, we present case studies demonstrating how unmanned aerial vehicles (UAVs) have been successfully used in Western Australia to monitor marine turtle nesting activity and adult orientation behaviour along remote sections of the mainland and at offshore islands of the Pilbara region. Specifically, we discuss the use of UAVs around industrial developments, and at locations where coastal access points may be over 50 km away from the survey area of focus. We discuss methodological and logistical considerations in flight planning, image capture, and survey frequency, as well as in post-processing and analysis procedures. Additionally, we highlight the financial, safety, and time-saving benefits of aerial surveys when compared to more traditional, boots-on-the-ground monitoring approaches, and future avenues of research arising from the latest wave of technological advancements, including three-dimensional modelling of nesting habitat. Finally, we demonstrate that short-term investment in UAVs can provide long-term value to monitoring programs, field studies, and management efforts for marine turtles.

Traditionally, satellite telemetry has been instrumental in tracking and studying sea turtles' movements, biology, and ecology in the Canary Islands. In parallel, research on the Canary Current and its Upwelling System has relied on a combination of in-situ measurements, remote sensing, and model data. Unfortunately, these two fields of research have largely remained isolated from each other.

ANIMAL MOCA-UP (ANIMAL telemetry to Monitor the Canary current and the UPwelling system) represents a newly established collaborative initiative that unites researchers from these disparate disciplines. Our goal is to leverage animal telemetry for monitoring the Canary Current and the Upwelling System, merging telemetry data with in-situ measurements from various platforms, remote sensing information, and model data. This multidisciplinary approach enables us to delve deeper into the study of climate change effects in this region.

Sea turtles possess two key attributes that make them ideal candidates for oceanographic research as ‘sentinels of climate change’: their impressive migratory behavior and their preference for spending a significant portion of their time in the upper meters of the water column. Capitalizing on these characteristics, we have successfully tagged five loggerhead sea turtles with devices capable of recording their position, seawater temperature, and depth (specifically, model Splash10-F-351 from Wildlife Computers).

These tagged turtles are providing us with invaluable insights, shedding light not only on sea turtle biology and ecology but also on the intricate workings of the Canary Current and the Upwelling System. Furthermore, we are gaining a deeper understanding of how climate change is impacting these oceanic phenomena.

Sex determination at early developmental stages in sea turtles continues to be an issue of primary interest and research priority. Despite recent advances in the field, determining the natural sex ratio of sea turtles remains a challenge for a variety of reasons, as does a complete understanding of the factors that influence embryonic sex determination. In the context of climate change, with global temperature increases, the description of a non-invasive, reliable, reproducible sexing method at different stages of development, applicable on a large scale, would represent a breakthrough in the study of populations and their ability to adapt to global warming. In this context, the use of traditional methods of measuring steroid hormones was re-evaluated as a tool for sexing 100 loggerhead sea turtles (Caretta caretta) of different age groups, post-neonates, juveniles, and adults, of known sex by endoscopy. At the same time, a metabolomic approach was applied to another group of 100 loggerhead turtles: 50 post-neonates and 50 juveniles (in the case of targeted metabolomics), and 24 neonates and 24 juveniles (in the case of untargeted metabolomics) with the aim of finding biomarkers of sex in plasma samples. The results obtained in both approaches have allowed us to identify the sex of the specimens according to those validated by endoscopic techniques. These results promote the development of useful tools for the study of sea turtle population dynamics and the impact of climate change on species with temperature-dependent sex determination.

The ingestion of hooks and/or lines, often resulting from sea turtles
interaction with fishing activities, frequently leads to severe injuries in
the digestive tract, ultimately resulting in fatality. In cases where
foreign objects become lodged in the cervical esophagus, their removal is
performed through the ventral surface of the neck. For hooks firmly wedged
in the intracoelomic portion of the esophagus, a supraplastron approach is
employed.
Injuries caused by lines tend to be more severe, often resulting in
intussusceptions and tears in the gastrointestinal tract. The development
of new surgical procedures for accessing the coelomic cavity has
significantly improved the survival rates of these patients. The preferred
approach allowing to reach the stomach is through the left axillary region;
hooks and lines in the intestine or pyloric area are removed by accessing
the coelomic cavity through the right or left prefemoral fossa.
Despite these advanced techniques, they may not always ensure access to all
portions of the digestive tract. Some segments may remain concealed by
vital organs, as it is the case with the caudal area of the esophagus
before reaching the cardias valve. In this specific tract, the esophagus is
surrounded by the left bronchus, near the subclavian artery, presenting
difficulties to be exposed for surgery.
A new surgical pprocedure here is presented to have access to this
challenging esophageal segment: the “gular approach” has been conceived for
the first time in a loggerhead sea turtle with a hook perforating the left
bronchus.
A skin incision of 8-10 cm is performed between neck and shoulder,
following the dorsal edge of the gular plate on the plastron. Subsequent to
the subcutaneous tissue dissection, the superficial deltoid muscle is
incised and the deep deltoid and supracoracoid muscles are then gently
parted along the dorsal side. This procedure exposes the end portion of the
subclavian artery, which is carefully cranio-laterally shifted and
safeguarded using a retractor. The procedure is finalized by an incision
into the antero-lateral portion of the coelomic cavity's dome in order to
reach the final portion of the esophagus.Through images and videos, step by step the novel procedure, complex and requiring advanced surgical skills, is described with the aim to provide guidance to expert surgeons looking to adopt this advanced technique in similar scenarios.

Traumatic injury to sea turtles can occur due several causes such as vessel strikes, interaction with dredges, fishing activity, inflicted by humans, natural predation. Among traumatic injuries, those involving the skull can be complicated by brain exposure; turtles with severe skull injuries that have nervous system impairment, emaciation and dehydration can’t often survive. Since July 2014 the Sea Turtle Clinic took in charge all cases of head injuries in sea turtles with the purpose of studying: 1) the incidence of head trauma in injured sea turtles in South Adriatic sea, 2) the severity and type of the injuries and the role of CT in these evaluation, 3) the neurological deficits and damages to the sense organs and whether there is a correlation between these deficits and the extent of head injuries, 4) the possible treatments, 5) the sequelae and complications of this condition and 6) the rate of mortality.

In this retrospective study 2081 Caretta caretta were evaluated, 36 of which showed head trauma. The severity of head injuries was assessed by clinical and neurological examination. Physical and neurological evaluations were performed to assess and grade the lesions and neurological deficits. CT examination was essential to evaluate impaired central nervous system and sense organs. In 25/36 sea turtles with more severe head trauma, computed tomography (CT) findings in combination with physical and neurological evaluation, enabled to evaluate whether there is a correlation between deficits and the extent of head injuries.

External head injuries were classified, and 6 turtles presented with mild, 8 with moderate and 22 with severe trauma. Mentation was classified as alert in 18 turtles, depressed in 10, and lethargic/comatose in 8. In 13 subjects, the head trauma involved the orbital, nasal, and squamosal bones with a possible compromise of the sensory organ (eyeball, nose, ear). A complete neurological examination, including observations made both in and out of the water, performed in all 36 traumatized sea turtles revealed that 48% had no impairment of the nervous system (NS) and mentation state was alert; in 31% the mentation state was depressed, and in 21% the mentation state was lethargic/comatose. In the present study, 28% of the turtles showed head damage related to severe neurological deficits. According to our scoring classification set for the grading of skull injuries, 65% were severe lesions, while 21% and 14% were moderate and mild wounds, respectively.

In animals that have survived, we observed a progressive recovery of neurological reflexes during or after complete healing of the head. All sea turtles underwent curettage of the skull wounds: the treatment protocol included the use of a plant-derived dressing (Neem oil and Hypericum perforatum). Twenty-seven out of 36 sea turtles were released after a time ranging from a few days to 1-8 months.