In this study, multi-tissue (yolk and carapace) stable isotope analysis was used to assess individual isotopic niche trajectories of nesting green turtles on Rocas Atoll, off northeastern Brazil, and to reveal a diet shift in the temporal dimension. The diet trajectories of individual green turtles were highly directional, with a stronger component towards decreasing values of δ15N from carapace to yolk. When the green turtles are in their foraging sites (temporal window measured by the yolk samples), they are more herbivores. Conversely, in a broader temporal window, the green turtles demonstrate a carnivore-omnivore strategy, such as represented by heavier δ15N values in the carapace. This finding confirms a temporal diet shift. This is the first study that applies trophic niche trajectories for sea turtles, adding a new isotopic tool to understand the trophic ecology of these migrant animals.

The study analysed the niche breadth of nesting green turtles, Chelonia mydas, on Rocas Atoll, Brazil, through stable isotopes (δ15N and δ13C), comparing samplings of egg yolk and carapace collected from two nesting groups (2017 and 2019). The mean δ15N values in egg yolk and carapace were 7.1‰ (2017) and 6.8‰ (2019), and 7.8‰ (2017) and 7.3‰ (2019), respectively. For δ13C, the mean values were -17.4‰ (2017) and -17.5‰ (2019) in egg yolk, and -18.4‰ (2017) and -17.9‰ (2019) in carapace. The results suggest herbivory in coastal-benthic environments as the main feeding pattern in this nesting population. The niche breadth was similar between 2017 and 2019 in both tissues.  In general, the trophic diversity (NR, CR, CD and SEA) was comparable between years as well as the trophic redundancy (MNND and SDNND), which was overall high. The niche metrics pointed to a homogeneous feeding pattern in the two nesting groups (2017 and 2019). This study adds a piece to solve the puzzle of adult green turtle trophic ecology.

No abstract

For decades, the Brazilian north-east coast has been a recognized feeding area for five sea turtle species. However, it still lacks information about stranding patterns. A decade of a beach monitoring programme (from 2010–2019) provided information on the composition, abundance and spatio-temporal distribution of stranded sea turtle species along a semiarid coast in the western equatorial Atlantic. A total of 905 individuals of four species were recorded in a route of ~130 km. The most stranded group was the juvenile green turtles (Chelonia mydas), followed by Lepidochelys olivacea, Eretmochelys imbricata and Caretta caretta. The strandings present a seasonal and geographic pattern, and therefore any conservation measure to be implemented must consider these patterns. Also, the possible occurrence of fibropapillomatosis tumours calls for additional studies to understand its causes. Lastly, stranded sea turtles eventually show marks of fishery interaction, which indicate the need for environmental education programmes with fishing communities.

A educação oceânica é uma estratégia de transformação socioambiental frente as rápidas e profundas mudanças ambientais das últimas décadas. No presente estudo, foi desenvolvido um jogo voltado à educação oceânica denominado “Tarta Certo”, como uma proposta de inovação didática que tem como público alvo crianças e adolescentes. O jogo possui 120 cartas com perguntas que envolvem educação oceânica usando tartarugas marinhas como bandeira, com aspectos da sua biologia, comportamento, ameaças e interações nos ecossistemas marinhos e terrestres. O jogo foi desenvolvido para ser aplicado de forma remota e presencial e os interagentes são incentivados a responder as perguntas podendo acionar as dicas que são as cartas com desenhos que induzem a resposta correta. Com o objetivo de elaborar um material didático acessível e eficiente na sensibilização ambiental, o jogo foi avaliado por 20 professores, os quais apontaram seu caráter inovador, criativo e de potencial interesse e adesão dos alunos para otimizar o processo de ensino-aprendizagem. As inovações nos processos de ensino-aprendizagem são uma das formas de otimizar a educação como plataforma de modificação do atual cenário de ameaças aos ecossistemas. O “Tarta Certo” foi desenvolvido para ser uma alternativa nas práticas ambientais, intermediando os processos de construção cidadã e socioambiental.