Bjorndal K.A.,University of Florida |
Chaloupka M.,University of Queensland |
Saba V.S.,Princeton University |
Van Dam R.P.,Chelonia Inc. |
And 39 more authors.
Ecosphere | Year: 2016
Somatic growth dynamics are an integrated response to environmental conditions. Hawksbill sea turtles (Eretmochelys imbricata) are long-lived, major consumers in coral reef habitats that move over broad geographic areas (hundreds to thousands of kilometers). We evaluated spatio-temporal effects on hawksbill growth dynamics over a 33-yr period and 24 study sites throughout the West Atlantic and explored relationships between growth dynamics and climate indices. We compiled the largest ever data set on somatic growth rates for hawksbills - 3541 growth increments from 1980 to 2013. Using generalized additive mixed model analyses, we evaluated 10 covariates, including spatial and temporal variation, that could affect growth rates. Growth rates throughout the region responded similarly over space and time. The lack of a spatial effect or spatio-temporal interaction and the very strong temporal effect reveal that growth rates in West Atlantic hawksbills are likely driven by region-wide forces. Between 1997 and 2013, mean growth rates declined significantly and steadily by 18%. Regional climate indices have significant relationships with annual growth rates with 0-or 1-yr lags: positive with the Multivariate El Niño Southern Oscillation Index (correlation = 0.99) and negative with Caribbean sea surface temperature (correlation = -0.85). Declines in growth rates between 1997 and 2013 throughout the West Atlantic most likely resulted from warming waters through indirect negative effects on foraging resources of hawksbills. These climatic influences are complex. With increasing temperatures, trajectories of decline of coral cover and availability in reef habitats of major prey species of hawksbills are not parallel. Knowledge of how choice of foraging habitats, prey selection, and prey abundance are affected by warming water temperatures is needed to understand how climate change will affect productivity of consumers that live in association with coral reefs. © 2016 Bjorndal et al.
Marcovaldi M.A.,Fundacao Pro Tamar |
Lopez-Mendilaharsu M.,Fundacao Pro Tamar |
Santos A.S.,Fundacao Pro Tamar |
Lopez G.G.,Fundacao Pro Tamar |
And 7 more authors.
Journal of Experimental Marine Biology and Ecology | Year: 2016
Concern over the potential impacts of increased temperature on marine turtles, which have temperature dependent sex determination, has resulted in an increase in research that predicts the sex ratio of marine turtle hatchlings under various scenarios of climate change. To accurately understand the projected impacts from global warming, it is necessary to understand the sex ratio baseline in advance of climate change. To address this, the primary sex ratio of loggerhead hatchlings, Caretta caretta, was estimated from incubation duration of 27,697 in situ nests from 21 nesting beaches used by two subpopulations of loggerhead turtles in Brazil over the last 25. years. A strong female bias (94%) was observed in all the areas used by the northern loggerhead stock, Sergipe (SE) and Bahia (BA), whereas a more balanced sex ratio (53% female) was estimated at the regions used by the southern loggerhead stock, Espirito Santo (ES) and Rio de Janeiro (RJ). Both inter-annual (SE: 83% to 99%, BA: 79. % to 98%, ES: 33% to 81%, RJ: 18% to 81%) and inter-beach variabilities (SE: 91% to 98%, BA: 89% to 96%, ES: 47% to 69%, RJ: 28% to 55%) in mean female offspring were observed. These findings provide evidence of persistent female bias in Brazil, and importantly identify male producing beaches and months, which will guide management decisions. © 2016 Elsevier B.V.
Sforza R.,Federal University of Espirito Santo |
Sforza R.,Centro TAMAR ICMBio |
Nalesso R.C.,Federal University of Espirito Santo |
Joyeux J.-C.,Federal University of Espirito Santo
Journal of Crustacean Biology | Year: 2010
The portunid crab Callinectes danae is abundant in Brazilian estuaries and coastal areas and is an important item to artisanal fisheries. This study investigated the distribution and population structure by sex and size, the size at sexual maturity, and sex-ratio of the species in Vitria Bay, Esprito Santo, southeastern Brazil. Crabs were collected monthly by nocturnal trawling during one year in six sampling stations distributed along an estuarine gradient and an independent depth gradient. Physico-chemical parameters of water were measured in situ on each station. A total of 3876 individuals were collected: 2537 females (1147 adults, 318 ovigerous, and 1072 juveniles), and 1339 males (444 adults and 895 juveniles). The mean carapace width (including lateral spines) at sexual maturity was 91.3 mm for males and 80.5 mm for females; the female-to-male sex ratio was 1.891. Adult females occurred throughout the bay and year-round, but egg-bearing females were almost exclusively caught in deep and high salinity areas. Adult males and juveniles of both sexes occurred mainly in internal areas of the estuary, nearest river mouths; highest captures were registered in November. Both the scarcity of males, probably resulting from size-selective catch, and the low proportion of ovigerous females, compared with that observed in other Brazilian estuaries, suggest that the population has been overexploited. © 2010 The Crustacean Society.
da Silva V.R.F.,Fundacao Pro Tamar |
Mitraud S.F.,SEPS EQ 709 909 Lote A CMJA |
Ferraz M.L.C.P.,Fundacao Pro Tamar |
Lima E.H.S.M.,Fundacao Pro Tamar |
And 16 more authors.
Environment, Development and Sustainability | Year: 2015
In the 35 years since its inception, the Brazilian National Program for the Conservation of Marine Turtles (TAMAR) has had great success in protecting the five species of sea turtles that occur in Brazil. It has also contributed significantly to worldwide scientific data and knowledge about these species’ biology, such as life cycles and migration patterns. TAMAR’s conservation strategies have always relied on a variety of environmental education and social inclusion (EESI) activities highly adapted to the socio-environmental evolving contexts of its 25 locations distributed across nine states. Diversity and flexibility are critical to enable timely and effective local responses to existing or potential threats to sea turtles. The intuitive, locally adapted, decentralized, and independent way EESI activities have been carried out have generated positive results in the resolution of specific and evolving local problems through the course of the project. This article brings EESI under the same conceptual framework that underlies its conservation approach by adopting an adaptive threat management framework to organize and qualify its educational and social inclusion interventions according to the main categories of threat addressed by TAMAR. © 2015 Springer Science+Business Media Dordrecht
Fiedler F.N.,Vale do Itajai University |
Sales G.,Centro TAMAR ICMBio |
Giffoni B.B.,Fundacao Pro TAMAR |
Port D.,Vale do Itajai University |
And 3 more authors.
Brazilian Journal of Oceanography | Year: 2015
In the presente study, cluster analysis was performed to classify 1080 interviews with captains of national pelagic longline fleet (2000 to 2011), and 38 trips of the chartered fleet (2003 to 2008), in relation to the composition of species landed. For the national fleet 4 groups were identified: 1 - Albacores, 2 - Blue shark, 3 - Swordfish, and 4 - Dolphinfish. For the chartered fleet 3 groups were identified: 1 - Swordfish, 2 - Blue shark, and 3 - Albacores. The results indicated that part of the national fleet change their strategies according to the availability of the target species and market demand (internal and external). A part of the fleet from Espírito Santo state operates in the region between December and March, exclusively to capture dolphinfish. The chartered fleet differed from the national one as regards the fishing areas of each target species, mainly as regards swordfish and blue shark. Despite the great difference in the data sets, it is evident that both the national and the chartered fleets operated in accordance with their peculiarities and technological development, adopting strategies that optimize catches and net profits per trip. © 2015, Universidade de Sao Paulo. All rights reserved.