Population organisation in reef sharks: new variations in coastal habitat use by mobile marine predators

2016 ◽  
Vol 544 ◽  
pp. 197-211 ◽  
Author(s):  
A Chin ◽  
MR Heupel ◽  
CA Simpfendorfer ◽  
AJ Tobin
2007 ◽  
Vol 344 ◽  
pp. 271-275 ◽  
Author(s):  
DD Chapman ◽  
EK Pikitch ◽  
EA Babcock ◽  
MS Shivji

Waterbirds ◽  
2002 ◽  
Vol 25 (4) ◽  
pp. 429-435 ◽  
Author(s):  
A. L. Bryan ◽  
K. F. Gaines ◽  
C. S. Eldridge

2021 ◽  
Vol 8 (10) ◽  
Author(s):  
Cassie N. Speakman ◽  
Andrew J. Hoskins ◽  
Mark A. Hindell ◽  
Daniel P. Costa ◽  
Jason R. Hartog ◽  
...  

The highly dynamic nature of the marine environment can have a substantial influence on the foraging behaviour and spatial distribution of marine predators, particularly in pelagic marine systems. However, knowledge of the susceptibility of benthic marine predators to environmental variability is limited. This study investigated the influence of local-scale environmental conditions and large-scale climate indices on the spatial distribution and habitat use in the benthic foraging Australian fur seal ( Arctocephalus pusillus doriferus ; AUFS). Female AUFS provisioning pups were instrumented with GPS or ARGOS platform terminal transmitter tags during the austral winters of 2001–2019 at Kanowna Island, south-eastern Australia. Individuals were most susceptible to changes in the Southern Oscillation Index that measures the strength of the El Niño Southern Oscillation, with larger foraging ranges, greater distances travelled and more dispersed movement associated with 1-yr lagged La Niña-like conditions. Additionally, the total distance travelled was negatively correlated with the current year sea surface temperature and 1-yr lagged Indian Ocean Dipole, and positively correlated with 1-yr lagged chlorophyll- a concentration. These results suggest that environmental variation may influence the spatial distribution and availability of prey, even within benthic marine systems.


2020 ◽  
Vol 653 ◽  
pp. 191-204
Author(s):  
S Bennington ◽  
W Rayment ◽  
S Dawson

Species distribution models (SDMs) often rely on abiotic variables as proxies for biotic relationships. This means that important biotic relationships may be missed, creating ambiguity in our understanding of the drivers of habitat use. These problems are especially relevant for populations of predators, as their habitat use is likely to be strongly influenced by the distribution of their prey. We investigated habitat use of a population of a top predator, bottlenose dolphins Tursiops truncatus, in Doubtful Sound, New Zealand, using generalised additive models, and compared the results of models with and without biotic predictor variables. We found that although habitat use by bottlenose dolphins was significantly correlated with abiotic variables that likely describe foraging areas, introduction of biotic variables describing potential prey almost doubled the deviance explained, from 19.8 to 39.1%. Biotic variables were the most important of the predictors used, and indicated that the dolphins showed a preference for areas with a high abundance of a reef fish, girdled wrasse Notolabrus cinctus. For the dolphins of Doubtful Sound, these results show the importance of prey distribution in driving habitat use. On a broader scale, our results indicate that making an effort to include true biotic descriptors in SDMs can improve model performance, resulting in better understanding of the drivers of distribution of marine predators.


2009 ◽  
Vol 32 (2) ◽  
pp. 360-374 ◽  
Author(s):  
Stephen T. Ross ◽  
W. Todd Slack ◽  
Ryan J. Heise ◽  
Mark A. Dugo ◽  
Howard Rogillio ◽  
...  

2018 ◽  
Vol 285 (1875) ◽  
pp. 20172456 ◽  
Author(s):  
Jessica J. Williams ◽  
Yannis P. Papastamatiou ◽  
Jennifer E. Caselle ◽  
Darcy Bradley ◽  
David M. P. Jacoby

Animal movements can facilitate important ecological processes, and wide-ranging marine predators, such as sharks, potentially contribute significantly towards nutrient transfer between habitats. We applied network theory to 4 years of acoustic telemetry data for grey reef sharks ( Carcharhinus amblyrhynchos ) at Palmyra, an unfished atoll, to assess their potential role in nutrient dynamics throughout this remote ecosystem. We evaluated the dynamics of habitat connectivity and used network metrics to quantify shark-mediated nutrient distribution. Predator movements were consistent within year, but differed between years and by sex. Females used higher numbers of routes throughout the system, distributing nutrients over a larger proportion of the atoll. Extrapolations of tagged sharks to the population level suggest that prey consumption and subsequent egestion leads to the heterogeneous deposition of 94.5 kg d −1 of nitrogen around the atoll, with approximately 86% of this probably derived from pelagic resources. These results suggest that sharks may contribute substantially to nutrient transfer from offshore waters to near-shore reefs, subsidies that are important for coral reef health.


2011 ◽  
Vol 68 (12) ◽  
pp. 2029-2045 ◽  
Author(s):  
Nigel E. Hussey ◽  
Sheldon F.J. Dudley ◽  
Ian D. McCarthy ◽  
Geremy Cliff ◽  
Aaron T. Fisk

Understanding the role of predators is challenging but critical for ecosystem management. For community dynamics, predator-specific size-based variation in diet, trophic position, and habitat use are rarely accounted for. Using two applied tools (stable isotopes and stomach content data), we examined inter- and intra-species ontogenetic variability in diet (stomach contents), trophic position (TPSIA for δ15N and TPSCA for stomach contents), and habitat use (δ13C) of two large sharks, the scalloped hammerhead ( Sphyrna lewini ) and the dusky ( Carcharhinus obscurus ). Stomach contents identified size-based and gender-specific shifts in diet indicating resource partitioning for and between species. Calculated TP for the two sharks varied by method, either TPSIA or TPSCA and with species, size, and gender, but were complicated by differing baselines and broad functional prey groups, respectively. TP increased with size for S. lewini, but was low in large C. obscurus compared with small sharks. Size-based δ13C profiles indicated habitat partitioning by sex in S. lewini and a movement to shelf edge foraging in large C. obscurus. These results demonstrate that predators exert proportional size-based effects on multiple components of the marine system that are further complicated by species- and gender-specific strategies.


Author(s):  
Rebecca S Lipscombe ◽  
Julia L Y Spaet ◽  
Anna Scott ◽  
Chi Hin Lam ◽  
Craig P Brand ◽  
...  

Abstract Understanding the movement of marine predators is vital for effective conservation and management. Despite being targeted by shark control programs, the tiger shark, Galeocerdo cuvier, is poorly studied off eastern Australia. To investigate the horizontal movement and habitat use in this region, 16 sharks (157–384 cm total length) were tagged with MiniPAT pop-up satellite archival tags in 2018 and 2019. Eleven of these individuals were also fitted with satellite-linked radio transmitting tags. After release, most sharks moved off the continental shelf and headed north, associating with seamounts as they moved towards Queensland. During their time at liberty they transited through temperate, sub-tropical and tropical waters and spent the majority of time in the upper 50 m of the water column and at temperatures between 22 and 25˚C. Horizontal movement was focused in waters off the continental shelf. Increased movement over shelf waters occurred during the austral spring and summer when the East Australian Current is at its strongest and warm waters encroach the continental shelf. Broad latitudinal movement along the east coast of Australia was evident and highlights the connectivity between tropical and warm-temperate regions.


PLoS ONE ◽  
2013 ◽  
Vol 8 (1) ◽  
pp. e53348 ◽  
Author(s):  
Kelly J. Benoit-Bird ◽  
Brian C. Battaile ◽  
Scott A. Heppell ◽  
Brian Hoover ◽  
David Irons ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document