Here, we report trading of endangered shark species in a world hotspot for elasmobranch conservation in Brazil. Data on shark fisheries are scarce in Brazil, although the northern and northeastern regions have the highest indices of shark bycatch. Harvest is made primarily with processed carcasses lacking head and fins, which hampers reliable species identification and law enforcement on illegal catches. We used partial sequences of two mitochondrial genes (COI and/or NADH2) to identify 17 shark species from 427 samples being harvested and marketed on the northern coast of Brazil. Nine species (53%) are listed under some extinction threat category according to Brazilian law and international authorities (IUCN – International Union for Conservation of Nature; CITES – Convention on International Trade of Endangered Species of Wild Fauna and Flora). The number increases to 13 (76%) if we also consider the Near Threatened category. Hammerhead sharks are under threat worldwide, and composed 18.7% of samples, with Sphyrna mokarran being the fourth most common species among samples. As illegal trade of threatened shark species is a worldwide conservation problem, molecular identification of processed meat or specimens lacking diagnostic body parts is a highly effective tool for species identification and law enforcement.

Nursery areas are critical to the survival of many marine species, and it is widely accepted that elasmobranch species use nursery areas where they improve species fitness. A 2007 review proposed an approach to identify elasmobranch nursery areas to help clarify their location and use. Here we examine progress towards defining elasmobranch nurseries in the intervening ≥10 years. Many studies have used these criteria, and some have tested their effectiveness, but it is apparent that there is still much to learn. Our current understanding of elasmobranch nurseries is biased towards tropical coastal shark species with few studies of temperate, pelagic, deep-water or batoid species. Recent research has used the criteria to more accurately identify nursery areas, determine that some species may not use them and, at times, improve conservation and management. Results are also revealing that some areas considered to be nurseries do not meet the criteria. Although we have learned a great deal about the location and use of elasmobranch nurseries, there are still several questions to be answered and species to be considered. Continued application of nursery criteria and improved knowledge of nursery areas will lead to improved conservation and management systems.

Nursery areas are crucial for many elasmobranch species, providing benefits that increase fitness and survival. Shark nurseries are well studied and our knowledge of their function and importance has expanded over the past few decades. However, little attention has been given to batoid nurseries, with studies covering less than 6% of the 663 currently described species. Threats of extinction faced by batoids reinforce the importance of defining these critical habitats. This review synthesises current knowledge of batoid nursery areas to provide a better understanding of their ecological roles and importance. Historically, different criteria have been used to define viviparous and oviparous batoid nurseries, causing confusion that could lead to failure of conservation and management strategies by under-or overestimating the importance of areas and delaying effective action. We suggest the criteria used to identify shark nurseries be applied to juvenile batoids, standardizing this nursery definition for all elasmobranchs, but we also advocate for a second set of criteria that identifies egg case nurseries. Batoids are thought to play 3 main ecological roles in nursery areas: energetic links, bioturbators and mesopredators. Biotic and abiotic features affect abundance and distribution of batoids within nurseries and likely play a key role in their habitat use. However, analysis of batoid ecological roles in nursery areas is limited by the lack of research on their early life history stages. Thus, identification of areas that support sensitive life stages and an improved understanding of early life history are crucial for the efficient management and conservation of batoid species and their nurseries.

Animal tracking provides integral spatiotemporal information that contributes to the growing field of movement ecology.AT is one of the main approaches to track the movements of aquatic animals.

Increasing fishing effort has caused declines in shark populations worldwide. Understanding biological and ecological characteristics of sharks is essential to effectively implement management measures, but to fully understand drivers of fishing pressure social factors must be considered through multidisciplinary and integrated approaches. The present study aimed to use fisher and trader knowledge to describe the shark catch and product supply chain in Northeastern Brazil, and evaluate perceptions regarding the regional conservation status of shark species. Non-systematic observations and structured individual interviews were conducted with experienced fishers and traders. The demand and economic value of shark fins has reportedly decreased over the last 10 years while the shark meat trade has increased slightly, including a small increase in the average price per kilogram of meat. Several threatened shark species were reportedly often captured off shore and traded at local markets. This reported and observed harvest breaches current Brazilian environmental laws. Fishing communities are aware of population declines of several shark species, but rarely take action to avoid capture of sharks. The continuing capture of sharks is mainly due to a lack of knowledge of environmental laws, lack of enforcement by responsible authorities, and difficulties encountered by fishers in finding alternative income streams. National and regional conservation measures are immediately required to reduce overfishing on shark populations in Northeastern Brazil. Social and economic improvements for poor fishing communities must also be implemented to achieve sustainable fisheries.

No abstract

Sawfishes are the most endangered cartilaginous fishes on the planet. Their external morphology facilitates entanglement in fishing nets and their K-selected life history hinders the recovery of exploited populations. The Eastern Amazon coast (EAC) is known to be an area where sawfishes occur in Brazil, but few studies have been conducted in the area to better understand their biology and ecology. The present study reports sawfish captures along the coast of Brazil's second largest state. Data were collected from interviews with fishermen, a literature review, and media reports. In total, 23 captures were recorded between 1984 and 2016. Records include adults, a pregnant female with near-term embryos, juveniles, and young-of-the-year specimens. Most catches were reported in the Canal do Navio, an area under strong human pressure. Sawfish saws are valuable items and, for many anglers in precarious economic and social situations, high market prices eclipse the fishing prohibitions laid down under federal laws. Urgent research is required to understand sawfishes' life history, identify their critical habitats, and effectively manage and conserve these species along the EAC.

Stingrays are thought to play important ecological roles in coral reef ecosystems. However, little is known about juvenile stingray movement patterns and habitat use in coral reefs. This study used active acoustic telemetry to determine fine-scale diel movement patterns and habitat use of juvenile cowtail stingrays (Pastinachus ater) in a coral reef flat environment. Seven cowtail stingrays (4 males and 3 females) were manually tracked between April and December 2016. Each individual was tracked over 2 days, generating a total of 14 active tracks ranging from 4.91 to 9 h. Specimens moved at an average speed of 2.44 m min -1 ± 0.87 SE, with minimum distances travelled ranging from 546 to 1446 m. Tracking data showed that juvenile cowtail stingrays move in response to tidal cycles, moving faster and in straighter pathways during incoming and outgoing tides. Juvenile cowtail stingrays also showed a strong affinity to sand flat areas and mangrove edge areas. These areas provide food resources and potential refuges for juvenile rays to avoid predators. Coral reef flats were identified as secondary refuge for juveniles during the lowest tides. Future research is necessary to fully unveil the major drivers of juvenile cowtail stingray seasonal and ontogenetic movement patterns and habitat use within coral reef flat environments. This information is important to establish a full understanding of juvenile cowtail stingray ecology, but could also improve management and conservation policies.