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The movement and activity patterns of the nurse shark, Ginglymostoma cirratum, a vulnerable species off Brazil, were investigated using mark-recapture and acoustic telemetry at an oceanic insular Marine Protected Area, the Fernando de Noronha Archipelago, Brazil. A total of 93 sharks were captured and tagged, ranging from 82 to 265 cm of total length (TL). Nurse sharks were captured throughout the year, and all life-stages used the insular shelf. Fifteen sharks (16% of the total) were recaptured after periods at liberty ranging from 3.5 h to 705 days, and the distances between tag and recapture locations ranged from 0.07 to 3.5 km. Site fidelity and movements of 10 sharks ranging from 107 to 265 cm TL were investigated for 18 months with an array of automated telemetry receivers. The mean period of detection of the monitored sharks was 66 days, ranging from 13 to 119 days. One individual 158 cm TL was monitored with active tracking for 17 days, with distances between daily locations ranging from 0.84 to 3.32 km, exhibiting movements similar to those of sharks monitored by automated telemetry. Despite remaining motionless or exhibiting short range movements for several hours or days, nurse sharks can be relatively wide-ranging, and protected areas alone cannot be the only conservation measure used to protect this species, which requires a set of protective measures, including fisheries management. [ABSTRACT FROM AUTHOR]

Although many skates possess life history characteristics that may make them vulnerable to exploitation, the detailed biological information needed to enact effective management schemes is lacking for most species. The objectives of this study were to provide age, growth, and maturity estimates for the roughtail skate, Bathyraja trachura, from the eastern Bering Sea. Maximum age was estimated at 36 yr based on band pair counts in vertebral centra. Of the four growth models applied, the logistic model provided the best description of growth (asymptotic total length = 911 mm; growth coefficient = 0.131 yr−1). There was no evidence of difference in growth between males and females. Females attained maturity at larger sizes and older ages than males. The median size-at-maturity was estimated at 741 mm total length (TL) for males and 796 mm TL for females; median age-at-maturity was estimated at 21.1 yr and 24.7 yr for males and females, respectively. The results of this study may indicate a latitudinal pattern in size and growth, with individuals from the eastern Bering Sea growing more slowly and reaching higher maximum ages than previously reported for specimens collected off the western coast of the continental United States. [ABSTRACT FROM PUBLISHER]

In Tunisia, elasmobranch landings have decreased substantially in recent years. Generally, species-specific information is largely unavailable for artisanal fisheries, but it is essential to increase knowledge and to ensure proper management of these species. This study analysed elasmobranch catches with longline fishery in the Gulf of Gabès. In total, 21 and 20 pelagic and bottom longline fishing trips were conducted, respectively, from July to September in 2007 and 2008. A total of eight elasmobranch species were caught: four batoids and four sharks. Pelagic longline captures were hooked externally while a high number of individuals captured with bottom longline were hooked internally. Discards due essentially to low commercial value and size represented 7.6% of total number of elasmobranch specimens caught. Longline landings in the Gulf of Gabès were principally composed of sandbar shark, Carcharhinus plumbeus, representing, respectively, 94.14% and 21.17% in number of pelagic and bottom longline captures. The importance of rhinobatids and Mustelus capture with bottom longline reflect their abundance in this area compared to other Mediterranean zones. Juveniles, including neonates with umbilical scars, dominated carcharhnids specimens, while smoothhound and guitarfish captures were dominated by mature individuals. Mitigation measures based on gear modifications, size limits and delineated nursery areas in the Gulf of Gabès should be developed to protect these vulnerable species. [ABSTRACT FROM PUBLISHER]