This article has been peer reviewed and accepted for publication. It is in production and has not been edited, so may differ from the final published form.
Contrasting patterns of residency and space use of coastal sharks within a communal shark nursery
The benefits of marine protected areas are difficult to estimate for mobile species, but their effectiveness can be increased if essential habitats such as nursery areas are protected. We examined movements of juvenile blacktip reef Carcharhinus melanopterus and sicklefin lemon sharks Negaprion acutidens in a coastal nursery in northern Australia. Telemetry-derived data were modelled using Brownian bridges and overlaid with maps of habitats and no-take zones. Juvenile N. acutidens were typically residents (â¥ 30 days) of the nursery with small areas of core space use (< 1.3 km2), while juvenile C. melanopterus were non-residents (< 30 days) and used larger areas (< 3.6 km2). Both species displayed positive selection for sandflats and mangroves, and avoidance of deeper lagoonal and slope habitats. Monthly patterns were examined only for resident N. acutidens, and residency decreased with increasing shark length and varied seasonally for males but not females, while space use showed weak declines with increasing tidal range, and slight increases with mean air pressure, rainfall and shark length. Protecting sandflat and vegetated habitats can increase the efficacy of no-take zones for juvenile N. acutidens as they display residency and affinity to these features, but will be of limited benefit for juvenile C. melanopterus as they display low residency and broader movements.
MF16131 Accepted 30 January 2017
© CSIRO 2017