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Knowledge of life history parameters is essential for the effective management of species of conservation concern. For migratory marine vertebrates such as hawksbill sea turtles Eretmochelys imbricata, feeding aggregations are important developmental habitats, allowing the study of population dynamics. Here, we used data from a 31 yr mark-recapture study of juvenile hawksbill sea turtles in the Fernando de Noronha Archipelago, Brazil, to estimate key demographic parameters. Turtles recruit to the neritic habitat at similar sizes to those of other Atlantic hawksbill aggregations. The curved carapace length (CCL) at the first capture ranged from 28 to 84 cm (mean ± SD: 44.6 ± 9.8 cm). Median minimum residence time of turtles captured at least twice was 3.2 yr, whilst long-term minimum residence of up to 14 yr was also observed, with turtles showing site fidelity within the archipelago. The mean size of turtles captured was constant throughout time. Turtles grew on average 3.4 ± 2.2 cm yr-1 , with a monotonic expected growth rate function generally decreasing with increasing size. At these rates, hawksbill turtles in Fernando de Noronha would need to spend ca. 14−18 yr to reach minimum adult breeding size (~74 cm CCL). This mark-recapture study has been essential to understanding the ecology and demographic parameters of this regional hawksbill turtle neritic foraging ground.

The worldwide population of the leatherback turtle (Dermochelys coriacea) encompasses seven subpopulations among the Pacific, Atlantic and Indian Oceans. It has experienced declines across parts of its distribution, with the subpopulation of the South-west Atlantic listed as critically endangered by the IUCN Red List. The main threats to this subpopulation include its interaction with fisheries, coastal development, pollution and climate change. In this study, we sequenced mitochondrial DNA from 52 leatherback turtles in Brazil and combined these with published data from other Atlantic Ocean rookeries. The haplotype diversities of the Atlantic population rookeries ranged from 0.112 to 0.533 and are not directly proportional to current rookery sizes. The Brazilian rookery, despite recording low nest numbers per year, had the second-highest haplotype diversity among all Atlantic rookeries (h = 0.532). A mixed-stock analysis revealed that the South American pelagic aggregate is primarily composed of individuals from West Africa (84%), with contributions from the North Atlantic rookeries (14%). Leatherback turtles appear to have a complex phylogeographic pattern, showing evidence of multiple colonization events and a lack of isolation by distance. Our novel dataset, based on DNA sequences of 695 base pairs, will provide baseline data needed to understand population dynamics in the region, building comprehensive population assessments to support and develop management strategies. Having both the only known regular rookery in the South-west Atlantic, and a mixed-origin foraging area for the species along its coast, Brazil has a key role in the conservation of the leatherback turtle.

In the southwestern Atlantic Ocean, leatherback turtles Dermochelys coriacea are only known to regularly nest in eastern Brazil, on the coast of the state of Espírito Santo. Here, we present an analysis of the nesting ecology, population trends and conservation status of this leatherback turtle colony between 1988 and 2017. We observed an increasing, although variable, trend in the annual number of nests, with the mean increasing from 25.6 nests in the first 5 yr of the study to 89.8 in the last 5 yr. Concurrently, there was also a significant decrease in the mean curved carapace length of the population, which we hypothesize was caused by recruitment of new females to the nesting population. Throughout the study period, nests were concentrated in the southern part of the 160 km long study area. No change was observed in the annual median nesting date. Mean annual hatching success was 66.0% and no significant variation in hatching success was detected after a major spill of mining tailings into the nesting area in 2015. We postulate that local conservation actions that started in the 1980s have contributed to the gentle recovery of this population; however, given the small population size and restricted nesting geographical distribution alongside the persistence of various threats-fisheries bycatch, climate change, pollution and coastal development-this population continues to be of conservation concern.

Coastal areas provide critical nesting habitat for marine turtles. Understanding how artificial light might impact populations is key to guide management strategies. Here we assess the extent to which nesting populations of four marine turtle species-leatherback (Dermochelys coriacea), olive ridley (Lepidochelys olivacea), hawksbill (Eretmochelys imbricata) and two subpopulations of loggerhead (Caretta caretta) turtles-are exposed to light pollution across 604 km of the Brazilian coast. We used yearly night-time satellite images from two 5-year periods (1992-1996 and 2008-2012) from the US Air Force Defense Meteorological Satellite Programme (DMSP) to determine the proportion of nesting areas that are exposed to detectable levels of artificial light and identify how this has changed over time. Over the monitored time-frame, 63.7% of the nesting beaches experienced an increase in night light levels. Based on nest densities, we identified 54 reproductive hotspots: 62.9% were located in areas potentially exposed to light pollution. Light levels appeared to have a significant effect on nest densities of hawksbills and the northern loggerhead turtle stock, however high nest densities were also seen in lit areas. The status of all species/subpopulations has improved across the time period despite increased light levels. These findings suggest that (1) nest site selection is likely primarily determined by variables other than light and (2) conservation strategies in Brazil appear to have been successful in contributing to reducing impacts on nesting beaches. There is, however, the possibility that light also affects hatchlings in coastal waters, and impacts on population recruitment may take longer to fully manifest in nesting numbers. Recommendations are made to further this work to provide deeper insights into the impacts of anthropogenic light on marine turtles. Keywords Artificial light • Coastal development • Remote sensing • Loggerhead turtle • Hawksbill turtle • Olive ridley turtle • Leatherback turtle Communicated by David Hawksworth.

The French angelfish Pomacanthus paru (Pomacanthidae) is recognised as an important cleaner in tropical reef environments, yet its clients remain relatively undescribed in the literature. Here, we report observations of their cleaning behaviour when interacting with different species of cryptobenthic fish clients. The study was conducted in Bahia state, northeast Brazil. In this region, French angelfish were seen cleaning four different species of cryptobenthic species, respectively, Coryphopterus glaucofraenum, Scorpaena plumieri, Labrisomus cricota, and Scartella cristata. These records show the broad spectra of clients that cleaners interact with in coral reef systems, as well as give important insights into the poorly known cryptobenthic fishes habits and ecology.