Sea Turtle Nesting: What Is Known and What Are the Challenges under a Changing Climate Scenario

The rate of climate change experienced globally in recent decades may compromise sea turtles’ survival;especially temperature increase, which is particularly fast, impacts life history characteristics, such as temperature-dependent sex determination (TSD), late maturity and sea turtles highly migratory nature. This review aims to identify and summarize the information that has been collected from 2009-2020 in order to aid future empirical studies that seek to fill these and other knowledge gaps, and subsequently assist conservationists in making multilevel decisions to protect sea turtle populations and species. In a summarized way the general knowledge acquired so far on the influence of environmental abiotic and biotic factors on nesting behaviour and hatching, emergence and survival successes of sea turtle hatchlings, was gathered. To accomplish this work, a search on Web of Science, Science Direct, NCBI/PubMed, and Google Scholar was carried out using the terms “sea turtles + climate change”. Published articles in the period 2009-2020 were selected, related to the nesting ecology of 5 species of sea turtles: Caretta caretta, Eretmochelys imbricata, Dermochelys coriacea, Chelonia mydas, Lepidochelys olivacea. Emphasis was also placed on geographical information and on population location (e.g. climatic conditions during the nesting season). These articles (N = 126) were analysed giving relevance to researcher’s data interpretations, comparisons with other researches, and the reached conclusions. An attempt was made to represent all 5 species of sea turtles when selecting articles on each of the environmental factors that influence sea turtle nesting: temperature, humidity, nesting substrate, gases, depth of the nest, sea surface temperature (SST), nest location on the beach, nesting phenology and geographic distribution of nesting habitats. The interaction between these parameters and their consequences on the terrestrial phase of reproduction are presented and discussed.

From the Challenges Imposed by Climate Change to the Preservation of Ecosystem Processes and Services

Today, especially in countries that offer a satisfactory quality of life, it is easy to forget that we depend directly and indirectly on services provided by ecosystems such as quantity and quality of water, energy, food, health, and shelter. In less developed countries, the daily struggle for essential goods makes this dependency more real, despite the lack of knowledge, organization and/or financial resources to deal with the problems imposed on ecosystems by climate and anthropogenic changes. Protecting ecosystems by ensuring the services they provide has become highly dependent on our management capacity, our understanding of its functioning, and our capacity for persuasion. Demographic pressure and individualism compromise the survival of various species, including our own, and create pressures under governments and the stability of nations. The notion of facing a global challenge has awakened in the scientific community the need to focus on developing global strategies that change the mind-sets of decision makers, industry, governments and markets. Global knowledge networks and experts are being built to mitigate problems on a global scale. In this mini review, the authors make a brief visit to documents, intergovernmental initiatives, and platforms that have been built with the aim of contributing to promote a resolution for the global problems.

Spy out to Protect: Sensing Devices for Wildlife Virtual Fencing

To avoid wildlife-human conflict several solutions are used, like electrical fences, the most expensive solution. Nowadays, technology enables alternative and cheaper approaches for conservation projects. A technological device was developed to detect elephants, moving on their habitat, and predict and react by avoiding confrontation with man. The devices were tested in field experiments, and proved to be efficient in capturing floor vibration, and air-sound signals. Collected data also enabled the estimation of the vibration-source by calculus (using triangulation), revealing the importance of the methodology for real-time location and tracking of high mass animals (e.g. elephants). Building up a mesh of devices, separated 25 m from each other, is estimated as possible to monitor and identify different animals (by discriminating patterns) in an area, like a virtual fencing system. Though the devices may be effective for animal behaviour research, or even animal communication analysis, or other Biology field, other applications outside Biology are possible for them, like monitoring of: rock-falling, micro seismic railway, infrastructures, and people movements.

A Piece of a Puzzle of Haplotypes for the Indian Ocean Hawksbill Turtle

The Indian Ocean basin has much to reveal in what concerns marine turtles. Its regional management units (RMUs) are still lacking molecular data to define conservation strategies and priorities. Vamizi Island is one of the best known rookeries in the north of the Mozambique Channel. A mitochondrial DNA analysis revealed 14 haplotypes for the hawksbill turtle’s nesting and foraging in/near Vamizi, twelve of which were new in 2011. Though more studies inside the Channel are needed, Vamizi Island possibly contributes with hatchlings for other locations. More knowledge is important to define priorities for management units inside the Indian Ocean.

The Poorly Known Northeast Atlantic Regional Management Unit for Loggerhead (Caretta caretta)

Loggerheads are distributed by ten Regional Management Units (RMUs) worldwide. The Atlantic Ocean houses three of these: the Northwest, Southwest and Northeast RMUs. The most studied is, so far, the Northwest RMU, but the other two have focused attention of researchers. In contrast, marine turtles from the African Atlantic region (Southeast) belong to a complex but little-known region. What is their role in the Atlantic? Are these RMUs connected? To understand these questions, research was made of reports and publications concerning the Northeast Atlantic (NEA) RMU. The asymmetry in information and available knowledge about NEA is high when compared to other RMUs. This demonstrates that there is still a lack of conservation programs besides Cape Verde, and that there is difficulty in transforming data (nesting ecology, molecular, telemetry, etc.) into publications. However, this issue is evident for other marine turtle species of East African Atlantic. There is a need for better scientific support, to enable local conservation programs to deliver data in reports, and even scientific publications. There are so many aspects of loggerhead’s life cycle that will only be unravelled by more and better supported studies. This is a paper that, by analysing the available information of the NEA loggerhead RMU, reflects the following steps to address in loggerhead conservation for the African Atlantic coast.

Eretmochelys imbricata:Lessons to Learn from a Monitoring Program in the North of Mozambique

Monitoring programs for nesting turtles around the world have been important to build up a matrix of information for better comprehension of their behaviour and dispersion. The Western Indian Ocean has several monitoring programs that are being used to reveal migration routes, phylogenetic interconnections and nesting behaviour patterns. We determined the nesting parameters for 69 records of hawksbill turtles collected during the Vamizi Island monitoring program. We also determined carapace measurements parameters of the turtles caught by fishermen in the area and give some considerations to improve the conservation of this species. Results show that the island receives hawksbill females all year long. Vamizi is a small nesting ground for this species, with an incubation period of 60.9 ± 10.6 days and a high reproductive rate. The turtles’ carapace measurements (SCL 42.0 ± SD 9.0 cm) revealed the existence of young individuals, foraging near the island, and their vulnerability to the fishing practices. This study strongly defends the need to identify more developmental and nesting spots, to be protected near Vamizi, to establish a solid network of marine reserves and corridors in the north of the Mozambique Channel.