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Occurrence of multiple whitetip reef sharks Triaenodon obesus in the Atlantic Ocean is reported for the first time from near a sunken ferry off the Paraná coast in south-eastern Brazil. This occurrence is hypothesized to have been caused by either a human introduction or a remarkably long oceanic displacement., (© 2018 The Fisheries Society of the British Isles.)

Sharks are very sensitive to stress and prone to a high mortality rate after capture. Since approximately 50 million of sharks are caught as bycatch every year, and current recommendations to reduce the impact of commercial fishing strongly support immediate release, it is imperative to better understand post-release mortality caused by the stress of capture and handling. Blood samples allow the assessment of stress levels which are valuable tools to reduce mortality in commercial, recreational and scientific fishing, being essential for the improvement in those conservation measures. Biochemical analyses are widely used for sharks as stress indicators, with secondary plasma parameters (lactate, glucose and ions) being the most often employed assays. However, it is virtually impossible to determine baseline plasma parameters in free-ranging sharks, since blood withdrawal involves animal capture and restrain, which are stressful procedures. This study aims at analyzing secondary parameters of five healthy tiger sharks captured with circular hooks and handlines in Fernando de Noronha (Northeastern Brazil) and comparing them with secondary parameters of three dead tiger sharks caught off Recife (also Northeastern Brazil). The results showed that the analysis of some plasma constituents in dead animals may be an efficient tool to assess stress and lethality. However, traditional parameters such as glucose and calcium, need to be used with caution. The results also demonstrated the extreme importance of urea and phosphorus for assessing stress response and mortality in tiger sharks, both parameters frequently neglected and of utmost importance for shark's homeostasis.

The diets of six shark species, Sphyrna lewini, Sphyrna zygaena, Carcharhinus obscurus, Carcharhinus limbatus, Rhizoprionodon lalandii and Galeocerdo cuvier, were investigated in a subtropical coastal ecosystem of southern Brazil. Stomach content data were obtained to assess foraging niche segregation and ontogenetic shifts in the diets of these sharks. Five of the shark species off the Paraná coast were ichthyophagous, with the exception of S. zygaena, which was teutophagous. With the exception of G. cuvier, which had a generalist diet, the other five species displayed specialization in their feeding. Ontogenetic shifts were observed in C. obscurus and S. lewini with large individuals consuming elasmobranchs. Owing to the diet overlap between C. obscurus and S. lewini, C. obscurus and C. limbatus and R. lalandii and C. limbatus, future studies on the spatial and temporal distributions of these species are needed to understand the extent of competitive interactions., (© 2014 The Fisheries Society of the British Isles.)

Brazil currently ranks as the 11th producer and 1st importer of shark meat around the world. Data available from the FAO software FishStatJ along with data from regional sources, such as governmental bulletins, scientific papers, gray literature and internet were revisited to identify the main issues surrounding pelagic shark fisheries, trade and consumption in the largest country in South America. Among the main findings, it was noted that Brazil has not properly collected fishery statistics since 2007, that many species of threatened sharks are freely landed and traded even though it is prohibited by local legislation and/or international recommendations (regional fisheries management organizations). The blue shark ( Prionace glauca ) is the most frequently recorded shark in the official bulletins and is currently a locally targeted species. Additionally, the significant imports of this species from 23 other countries that also provide fins for Asia has drawn attention in recent decades. Regarding consumption, shark is considered to be low-value seafood compared to more common fish, such as groupers and snappers, and most Brazilians actually do not know that they are eating sharks. At present, the proportion of threatened elasmobranchs (in which sharks are included) in Brazil (33%, of 145 species) exceeds the global rate identified for the group (25%), and, until the present moment, no measure related to the management of species has been implemented. As advice, Brazil urgently needs to restructure its fishery information collection systems, management strategies and to tighten sanitary and labeling regulations for the marketing of fish. [ABSTRACT FROM AUTHOR]