ISTS42 Program/Agenda

Bycatch is considered the most important threat to the survival of marine turtles. Most solutions to reducing bycatch focus on the effects of modified fishing gears on target species catch and marine turtle bycatch. However, for a population like the critically endangered East Pacific leatherback turtle, finding statistically significant solutions is practically impossible due to their low abundance and resulting low bycatch rate. One way to obtain data on modified fishing gears is to run trials where populations are abundant and then export the modifications that prove to be working to other areas with lower abundance levels but highly threatened species. However fishing gears and techniques are so unique in each community that those solutions might not work. For the past two years, we have been working with fishing communities to identify strategies that could work at individual community levels. Our methodology was based on 5 steps: 1) identify bycatch hotspots through surveys, 2) get an in-depth understanding of the bycatch in these areas, 3) work with members of fishing communities to design a strategy to reduce bycatch, 4) test the strategy in the field, and 5) assess if it was successful and eventually modify certain steps. This approach has led us to design a variety of strategies, some of which we are testing in the field and are providing positive results. As an example, in Barra de Tecoanapa, Guerrero, residents came up with the idea of creating a group of volunteers to protect an important sea turtle nesting ground. Through this initiative, not only have they protected nesting female leatherbacks from being killed for their eggs and meat, they are also contributing to increasing awareness to the point that now some of the fishermen are reporting incidental catches of marine turtles and filming their release from nets. In a nearby community, Punta Maldonado, removing abandoned nets from the beach has increased awareness such that volunteers are now willing to monitor endangered hawksbill turtles in their bay and find other solutions to reduce bycatch. In San Ignacio, Baja California Sur, projects aimed at diversifying the sources of income of local families have allowed to release some pressure from the fishery and have effectively reduced the fishing effort in that area. In Southern Sinaloa, monitoring understudied beaches has provided important info on mortality events and raised a lot of interest in fishery learning exchanges to discuss solutions among peers (fisherman to fisherman). Other strategies include setting up artificial reefs to create productive grounds where people are willing to fish with hook and line only, and restoring mangroves, to protect the land from extreme weather events and to protect important nursery grounds for commercially important species. Bycatch in artisanal fisheries is difficult to address, a one-size-fits-all solution is not realistic due to the incredibly high degree of diversity in fisheries and communities. Creating opportunities for fishing communities to work out their own, custom-made solutions is a just, equitable approach that shows promise in reducing marine turtle bycatch.

Sea turtle conservation in the Maldives archipelago is largely overseen by the central government, with national level legal protections implemented since the late 90s. Due to the geographically dispersed nature of ~1200 islands, of which only 188 are residential, community-based enforcement and the implementation of legislation remains difficult at island level, especially with a top-down approach where the central government develops conservation guidelines for the whole country. This disconnect between the local and central government often makes changing of behaviors and mindsets to support conservation a challenge. This was exacerbated when the central government imposed a ban on harvesting sea turtles and eggs, which had been a traditional source of food. The active participation of the community in conservation is recognized as pivotal for effective change at island-level to protect sea turtles in the country. In this regard the Environmental Protection Agency of Maldives (EPA) together with conservation charity Olive Ridley Project (ORP) piloted a project that re-integrates traditional conservation practices in managing the most significant green turtle nesting site in the country, Gaadhoo island located in Laamu Atoll. The island’s 500m strip of southwestern beach, known locally as ‘velaa heylhi’, is estimated to have recorded as much as 1,400 nests annually in the 1900s according to residents, who are known to be the only community to have monitored and managed a nesting beach prior to national level protections, implementing selective egg harvesting practices. Gaadhoo community relied on indigenous knowledge of sea turtle reproduction and nesting beach maintenance, and had actively defended the nesting beach against hunters. However, they were disempowered from continuing the practice in 2006, with the sudden ban on sea turtle egg harvesting enforced by the central government, which restricted access to the beach altogether. Without a tangible system in place for the government to enforce the ban, the island became a hotspot for illegal sea turtle hunting and egg take, which was further escalated when the residents were relocated in 2016. Anecdotal data suggests nesting had declined significantly after 2016, and ad hoc data collected between 2018-2022 indicated a high amount of illegal egg take. To address this issue, a ranger was hired to monitor Gaadhoo’s nesting beach in January 2023, with preliminary findings indicating a steep decrease in illegal egg take after the monitoring efforts began. The historical methods for sea turtle conservation and beach maintenance by Gaadhoo community were also documented, identifying gaps in the existing management framework that can be improved with feedback from the community. The project also identified stakeholders such as the police, local NGOs- some led by former Gaadhoo residents - that have shown willingness to take ownership of the program. Efforts are underway to build capacity thorugh shared learning in nesting beach management and move towards community-based monitoring. In the meantime, 161 nesting activity (91 true nests) have been recorded in 10 months of data collection, with only 2 poaching incidents recorded - suggesting hopeful signs for the protection and management of Gaadhoo’s sea turtle nesting beach.

On sea turtle nesting beaches, nesting females, eggs, and hatchlings are exposed to a variety of natural and anthropogenic threats. Even if the hatchlings manage to emerge from the nest, natural circumstances, mainly predation, results in only about one of 1,000 hatchlings reaching maturity. Sea turtle conservation projects around the world use a variety of methods to increase the survival probability of sea turtles and their offspring on their nesting beaches in order to contribute to the survival of the species.

The approach to focus on nesting beaches to protect sea turtles is close at hand, and one of the most favoured and effective methods is direct protection by patrolling. Other common activities are egg incubation in hatcheries, and sometimes also hatchling retention and headstarting.

Egg incubation in protected hatcheries is generally used to protect nests from flooding, predation, light pollution, and human egg collection. If nest relocation and hatchery management are following best practice procedures, they can be successful in terms of increasing hatching success. However, careful consideration is required because hatcheries are altering the natural behaviour of nesting sea turtles and may introduce risks, such as altered sex ratios, we don’t fully comprehend yet.

Sometimes hatchlings are not released immediately but are retained for several hours or even days for various reasons, including waiting for visitors to release them. The last step in this series of methods is headstarting, where hatchlings are kept in tanks for a longer period of time. We distinguish headstarting from hatchling retention once people start to feed the hatchlings. Headstarting is often based on the hypothetical assumption that a natural “1 in 1,000” chance of survival for sea turtle hatchlings can be increased by raising them in a protected environment and “making them stronger”.

In our presentation, we discuss the potential benefits and risks of these methods, based on lessons learned by various sea turtle conservation programs, relevant literature and our own observations, to help conservation groups make informed decisions about protecting sea turtles on their nesting beaches.

Jeen Yessa and Jeen Syuab beaches in Papua, Indonesia, have the highest leatherback nesting activity in the Pacific and form the Jeen Womom Coastal Park Marine Protected Area, designated in 2017. Previous research has identified that marine turtle nests at Wembrak Beach (6.4 km), one of three Jeen Yessa’s beaches, are threatened by high sand temperatures. Shading nests in situ using palm leaves (Cycas sp.) successfully reduces sand temperatures at nest depth and increases hatching success, but the availability of palm leaves is limited. We investigated the potential of cocomesh, woven coconut rope, as an alternative shading material that is also abundant locally, sustainable, and biodegradable at Wembrak Beach during the April-September 2023 nesting season. We compared two different cocomesh heights (60 and 120 cm) and two mesh size weaves (1 and 1.5 cm) with a control (no cocomesh) and placed the five treatments (120x1 cm, 120x1.5 cm, 60x1 cm, 60x1.5 cm, and control) at 5 locations 1 km apart within the westernmost 5 km of Wembrak Beach. We measured sand surface temperature within the different treatments at 06:00, 14:00, and 20:00 between mid-July and mid-September. Average sand temperatures without shading at 06:00 is 25.90 °C (range = 23.6 - 35.7°C), at 14:00 is 35.18°C (range = 25.2 - 42.50°C), and at 20:00 is 26.92°C (range = 22.9 - 29.20°C). At 06:00 and 20:00, sand surface temperatures under all cocomesh treatments do not differ from the control. At 14:00, a cocomesh with 120 cm in height and 1 cm in mesh size lowers the sand surface temperatures significantly more than other treatments, by 0.81°C on average. In conclusion, cocomesh, which is 120 cm in height and 1 cm in mesh size, is best at lowering sand surface temperatures. We will examine the effect of this size of cocomesh on the hatching success of leatherback nests in the April and September 2024 nesting season and compare the hatching success to other shading treatments and control (no shading).

The coast of the province of Palawan, Philippines hosts important foraging and nesting grounds for at least three species of marine turtles: olive ridley turtles (Lepidochelys olivacea), green turtles (Chelonia mydas), and hawksbill turtles (Eretmochelys imbricata) currently listed as vulnerable, endangered, and critically endangered respectively. Many anthropogenic activities still threaten these populations, and most of the nearly 2000 km of coastline across 1700+ islands, remain unmanaged. In the last ten years, several conservation initiatives have been initiated and implemented by local communities, people organisations, government agencies, NGOs and private groups, across many of the 23 municipalities and the one city, with a wide range of successes, failures and impacts. Here, we present preliminary nesting data and threats information collected by the different stakeholders during the last 10 years from 10 municipalities and the capital city. Between 2014-2022, a total of 1,030 marine turtle nests were reported, consisting of 614 (59.6%) olive ridley nests, 254 (24.7%) green turtle nests, 40 (3.9%) hawksbill turtle nests and 122 (11.8%) unidentified nests (species was not reported/identified). Additional data from other Municipalities are available but not yet included yet in this preliminary study. Olive ridley nesting season occurs from November to February, occasionally extending into October and March, with temporal and geographical variation. A significant increase in olive ridley nest reporting in the last 5 seasons has been observed, thanks to the increased effort and participation in beach patrolling along the West Philippines Sea coast. This, paired with the geographical distribution of the reporting and extent of unsurveyed beaches, further highlight the need to expand this work and stakeholders involvement. Threats distribution and frequency vary across the province, with nest depredation from stray dogs and wildlife (i.e. monitor lizards), eggs poaching for local consumption and trade, habitat modification, and poor hatchery management being the most significant. Currently regulated but unmanaged, the population of stray dogs has been reported by many stakeholders as one of the main threats to wildlife in the province, often at a scale similar to illegal wildlife trade. Based on three months of dedicated survey effort in (January-March) 2023, over 150 nests were depredated by dogs and an additional 100 incidents were reported by local partners in one single municipality. In conclusion, despite the lack yet, of a comprehensive assessment, these preliminary data highlight Palawan as one of the most important nesting and migratory habitats for olive ridley turtles in the region and the critical role of community-based conservation initiatives for their survival. Furthermore, when augmented with nesting data from the islands of Luzon and Mindanao, the Philippines as a whole, plays a vital role for the conservation of this species across Southeast Asia and West Pacific. Addressing the stray dog situation, training more local stakeholders in accurate data collection, centralising and digitising data collection and reporting, and designing a roadmap for the sustainable management of hatchery programs in the province should be the highest priorities within the next five years.