Ana Cristina Vigliar Bondioli

Green turtle (Chelonia mydas) genetic diversity at Paranaguá Estuarine Complex feeding grounds in Brazil

Sea turtles are marine reptiles that undertake long migrations through their life, with limited information regarding juvenile stages. Feeding grounds (FGs), where they spend most of their lives, are composed by individuals from different natal origins, known as mixed stock populations. The aim of this study was to assess genetic composition, natal origins and demographic history of juvenile green turtles (Chelonia mydas) at the Paranaguá Estuarine Complex (PEC), Brazil, considered a Natural World Heritage site. Tissue samples of stranded animals were collected (n = 60), and 700 bp mitochondrial DNA sequences were generated and compared to shorter sequences from previously published studies. Global exact tests of differentiation revealed significant differences among PEC and the other FGs, except those at the South Atlantic Ocean. Green turtles at PEC present genetic signatures similar to those of nesting females from Ascension Island, Guinea Bissau and Aves Island/Surinam. Population expansion was evidenced to have occurred 20–25 kYA, reinforcing the hypothesis of recovery from Southern Atlantic refugia after the last Glacial Maximum. These results contribute to a better understanding of the dynamics of green turtle populations at a protected area by providing knowledge on the dispersion patterns and reinforcing the importance of the interconnectivity between nesting and foraging populations.

Effects of Lead in white shrimp (Litopenaeus schmitti) metabolism regarding salinity

Penaeid shrimps are important resources for worldwide fisheries and aquaculture. In Brazil, Litopenaeus schmitti is an important commercially exploited species, and the ideal animal for studying the impairment caused by the effects of heavy metals often detected in coastal areas. The main purpose of the present study was to detect the acute toxicity of lead (Pb) in L. schmitti and to investigate its effect on oxygen consumption and ammonia excretion for different salinities. This has not been studied in this species before. Lead was significantly more toxic at salinity 8 than at 20 and 33. The oxygen consumption and ammonia excretion were estimated through experiments performed on each of the fifteen possible combinations of three salinities (33, 20 and 8), at the temperature of 21 °C. Cadmium showed a significant improvement in oxygen consumption at salinity 8, and results show that the oxygen consumption increases with respect to the lead concentration. At the highest lead concentration employed (2.12 10 -2 mg/L), the salinity 8 and the temperature at 21 °C, oxygen consumption increases 131% in relation to the control. In addition, after separate exposure to lead, elevation in ammonia excretion was obtained, which was 88.2% higher than the control. The results show that lead is more toxic to L.

Microbiological quality of cultivation water used for oysters marketed in Cananeia-SP, Brazil

Bivalves represent the environment conditions where oysters are farmed, thus is vital that these organisms are not contaminated because they can represent a serious risk to the public health. This study aimed to assess the microbiological quality of water for the cultivation of oysters of Cooperostra (cooperative of producer) in Cananeia-SP, Brazil. The total and fecal coliforms were analyzed. The results showed that water quality were not satisfactory, according to Brazilian legislation, except for some months. The seasonal interference was analysed and a high positive correlation was verified, with low coliforms concentration in winter. The pluviometric index showed a high positive correlation to the microorganisms analysed.

Mixed-stock analysis in green turtles Chelonia mydas: mtDNA decipher current connections among west Atlantic populations.

Abstract The green turtle Chelonia mydas undertakes wide-ranging migrations between feeding and nesting sites, resulting in mixing and isolation of genetic stocks. We used mtDNA control region to characterize the genetic composition, population structure, and natal origins of C. mydas in the West Atlantic Ocean, at one feeding ground (State of Rio de Janeiro, Brazil), and three Caribbean nesting grounds (French Guiana, Guadeloupe, and Suriname). The feeding ground presented considerable frequency of common haplotypes from the South Atlantic, whereas the nesting sites presented a major contribution of the most common haplotype from the Caribbean. MSA revealed multiple origins of individuals at the feeding ground, notably from Ascension Island, Guinea Bissau, and French Guiana. This study enables a better understanding of the dispersion patterns and highlights the importance of connecting both nesting and feeding areas. Effective conservation initiatives need to encompass these ecologically and geographically distinct sites as well as those corridors connecting them.

Effects of low salinity on juvenile pink shrimp Farfantepenaeus paulensis (Perez-Farfante 1967, Crustacea)

It is of paramount importance to study salinity tolerance of commercially important crustaceans, such as the pink shrimp Farfantepenaeus paulensis to determine possible mortality causes in the wild and in aquaculture in oligohaline waters. The aim of this study was to determine the lethal salinity concentration (LC50) for juvenile pink shrimp F. paulensis and measure its oxygen consumption and ammonia excretion at different salinity levels. Shrimp of two length classes (49.4 ± 4.3 and 78.5 ± 5.5 mm) were placed in 10-L containers and exposed to salinity levels of 35, 30, 25, 20, 15, 10 and 5. The experiments were tripled, with seven shrimp in each container. The average lethal concentration (LC50s) for an exposure of 24 h was 13.33 (11.26–15.78) and 10.26 (8.60–12.64), respectively, for the two classes of juveniles. For an exposure of 48 h, LC50s were 12.71 (10.68–15.12) for the larger animals and 9.20 (7.34–11.52) for the smaller ones. There was an inverse relationship between salinity and rates of oxygen consumption and ammonia excretion. The average reduction in specific oxygen consumption in salinities 20, 25 and 30 showed a decrease in metabolic rate of 63, 80 and 82%, respectively, in relation to salinity level 0. The same occurred for the averages of ammonia excretion at salinity levels of 15, 20, 25, 30 and 35, which represented low metabolic rates of 57, 61, 70, 71 and 74% respectably in relation to salinity level 0.

Seasonal Variation in the Behavior of Sea Turtles at a Brazilian Foraging Area

Abstract This study was conducted in São Sebastião Channel, along the Southern Brazil Platform, and describes the occurrence of 3 species of sea turtles in the area, their main behavioral patterns, and the anthropogenic-related threats. Green turtles (Chelonia mydas) showed a preference for a site covered by Halodule spp. seagrass and hawksbill turtles (Eretmochelys imbricata) showed a preference for a sheltered bay with little wave action and the presence of rocks covered with Palythoa caribaeorum. These sites exhibited different characteristics due to the presence of ocean currents and variable habitat types in the Channel. This study enabled the description of the São Sebastião Channel as a foraging and resting area for sea turtles. We also suggest changing the category of the local marine protected area to enable better protection of turtles.