Home range has been estimated for a limited number of marine fishes; however, the use of space and timing of activities within the home range has rarely been studied. In addition, understanding movement patterns of exploited fish species has been identified as a crucial science gap, impeding informed marine reserve design. We used a radio-acoustic positioning telemetry (VRAP) system to monitor detailed movements of 10 blue rockfish Sebastes mystinus around shallow rock pinnacles and stands of bull kelp Nereocystis leutkeana in central California in September 2002. The mean home range was 8783 m 2 ± 1137 SE; however, activity was highly concentrated in 1 to 3 core areas within each home range. Mean core areas measured 1350 m 2 ± 286 SE, but accounted for ~83% of activity. All core areas were centered over rock pinnacles where rockfish were highly aggregated. Individuals exhibited high site fidelity and made only brief radial excursions away from these centers or moved directly from one pinnacle to the next along defined corridors. Patterns of diel activity and nocturnal sheltering corresponded closely with nautical twilight. Cores overlapped, but estimated locations of nocturnal shelters differed significantly among individuals. Movement patterns were correlated with wind velocity, upwelling index, water temperature and habitat structure. KEY WORDS: Sebastes mystinus · Rockfish · Movement · Home range · Tagging · Core areas Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 327: [157][158][159][160][161][162][163][164][165][166][167][168][169][170] 2006 among terrestrial animals has been attributed to patterns of refuging (e.g. Hamilton & Watt 1970) and foraging (Samuel et al. 1985, Kenward et al. 2001. Patterns of core area use in marine fishes are also likely to have important implications for understanding the ecological determinants of space use; however, very little is known other than that core areas are increasingly detected as tracking technologies improve. Holland et al. (1993) identified core areas within which juvenile hammerhead sharks Sphyrna lewini restricted their diurnal movements to a small portion of their total home range (a turbid portion of an island bay), suggesting an anti-predation function. In the oceanic environment, adult S. lewini aggregate at oceanic seamounts during the day, and from these refuging cores make nocturnal foraging movements into a much broader pelagic environment (Klimley & Nelson 1984). Parsons et al. (2003) identified core areas for 4 individual snapper Pargus auratus that were relatively stable over a period of 4 lunar cycles, while a fifth individual gradually changed the number and location of occupied cores. The location and timing of core area use was not, however, attributed to particular activities or habitat resources. While the quality of habitat is likely to influence the extent (Mathews 1990, Lowe et al. 2003 and the shape (e.g. Holland et al. 1996, Topping et al. 2005) of the home range, the extent ...

Over the past 4 decades there has been a growing concern for the conservation status of elasmobranchs (sharks and rays). In 2002, the first elasmobranch species were added to Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Less than 20 yr later, there were 39 species on Appendix II and 5 on Appendix I. Despite growing concern, effective conservation and management remain challenged by a lack of data on population status for many species, human−wildlife interactions, threats to population viability, and the efficacy of conservation approaches. We surveyed 100 of the most frequently published and cited experts on elasmobranchs and, based on ranked responses, prioritized 20 research questions on elasmobranch conservation. To address these questions, we then convened a group of 47 experts from 35 institutions and 12 countries. The 20 questions were organized into the following broad categories: (1) status and threats, (2) population and ecology, and (3) conservation and management. For each section, we sought to synthesize existing knowledge, describe consensus or diverging views, identify gaps, and suggest promising future directions and research priorities. The resulting synthesis aggregates an array of perspectives on emergent research and priority directions for elasmobranch conservation.

Underwater visual surveys represent an essential component of coastal marine research and play a crucial role in supporting the management of marine systems. However, logistical and financial considerations can limit the availability of survey data in some systems. While biologging camera tag devices are being attached to an increasing diversity of marine animals to collect behavioral information about the focal species, the ancillary imagery collected can also be used in analytical techniques developed for diver-based surveys. We illustrate this approach by extracting ancillary data from shark-borne camera tag deployments focused on the behavior of a White shark (Carcharodon carcharias) off Gansbaai, South Africa, and a Grey Reef shark (Carcharhinus amblyrhynchos) within the Chagos Archipelago. Within the giant kelp forest environment of Gansbaai we could determine the spatial density of kelp thali and underlying substrate composition. Within the coral reef environment, the animal-borne video allowed us to determine the approximate percent and type of benthic cover, as well as growth form and genus of corals down to the upper mesophotic zone. We also enumerated fish species-level abundance over reef flat and wall environments. We used established dive-survey methods to analyze video data and found the results to be broadly comparable in the two systems studied. Our work illustrates the broad applicability of ancillary animal-borne video data, which is analogous in type and quality to diver-based video data, for analysis in established marine community survey frameworks. As camera tags and associated biologging technologies continue to develop and are adapted to new environments, utilising these data could have wide-ranging applications and could maximise the overall cost–benefit ratio within biologging deployments.