Flapping about: trends and drivers of Australian cownose ray (Rhinoptera neglecta) coastal sightings at their southernmost distribution range DOI Creative Commons
Alysha J. Chan, Fabrice R. A. Jaine,

Francisca Maron

et al.

Frontiers in Fish Science, Journal Year: 2024, Volume and Issue: 1

Published: Jan. 11, 2024

The Australian cownose ray ( Rhinoptera neglecta ) is an understudied batoid that occurs along Australia's north and east coasts. Currently classified as Data Deficient on the IUCN Red List of Threatened Species, major knowledge gaps exist regarding species' geographic range, habitat use drivers influencing its presence in coastal waters. Sightings R. were collected during systematic aerial surveys conducted 980 km (~47%) New South Wales (NSW) coastline between 2017 2019. North-bound flown 500 m offshore, whilst return beach/sea interface (inshore or nearshore). Using generalized additive models a set nine predictors, we examined relationship spatio-temporal occurrence , their group size biophysical environment at southernmost extent distribution. Results for presence/absence (44.20% deviance explained) observed offshore inshore (42.58 41.94% explained, respectively) highlighted latitude, day year, sea surface temperature, rainfall, wind speed, direction common influences to three models. indicated more likely be present northern half NSW spring summer months. However, larger sizes southern regions same seasons, regardless whether they inshore. Group also influenced by localized conditions, such SST tidal flows. This study represents largest attempt date decipher spatial ecology provides insights into distribution relative abundance species full coastline, extending known over 70 southward.

Language: Английский

Improving white shark detection capabilities in an Australian bather protection programme using environmental DNA DOI Creative Commons

Zach Clark,

Adam D. Miller, Craig D. H. Sherman

et al.

ICES Journal of Marine Science, Journal Year: 2025, Volume and Issue: 82(4)

Published: March 29, 2025

Abstract Bather protection programmes rely heavily on surveillance tools capable of detecting the presence shark species that are known to physically interact with humans. This study investigates potential for environmental DNA (eDNA) technologies improve detection capabilities and complement current survey methods. We conducted a 14-month monitoring programme at two white (Carcharodon carcharias) visitation hotspots in eastern Australia assessed spatio-temporal patterns near-shore using species-specific eDNA assay, SMART (Shark-Management-Alert-in-Real-Time) drumline captures, acoustic telemetry data from tagged sharks. observed higher frequencies across both locations compared Specifically, surveys provided relatively constant rates period, whereas detections were highly seasonal largely restricted austral winter–spring period. Findings consistent assumptions about spatial ecology year-long sharks subtropical habitats but suggest during summer–autumn months is possibly more prevalent than currently assumed. Overall, this highlights value as tool enhancing capabilities, importance adopting multiple complementary methods when assessing rates. discuss implications these findings bather mitigation overseas.

Language: Английский

Citations

0
Shifts in the incidence of shark bites and efficacy of beach-focussed mitigation in Australia DOI Creative Commons
Charlie Huveneers, Craig Blount, Corey J. A. Bradshaw

et al.

Marine Pollution Bulletin, Journal Year: 2023, Volume and Issue: 198, P. 115855 - 115855

Published: Dec. 2, 2023

Shark-human interactions are some of the most pervasive human-wildlife conflicts, and their frequencies increasing globally. New South Wales (Australia) was first to implement a broad-scale program shark-bite mitigation in 1937 using shark nets, which expanded late 2010s include non-lethal measures. Using 196 unprovoked shark-human recorded since 1900, we show that bites shifted from being predominantly on swimmers 79 % surfers by 1980s increased 2-4-fold. We could not detect differences interaction rate at netted versus non-netted beaches 2000s, partly because low incidence high variance. Although continued occur with tagged-shark listening stations, there were no while SMART drumlines and/or drones deployed. Our effect-size analyses small increase difference between mitigated non-mitigated indicate reductions interactions. Area-based protection alone is insufficient reduce interactions, so propose new, globally transferable approach minimise risk bite more effectively.

Language: Английский

Citations

10
Hooking efficiencies of SMART drumlines and their possible deployment rates vs gillnets for bather protection DOI Creative Commons
Paul A. Butcher, Matt K. Broadhurst, Victor M. Peddemors

et al.

Frontiers in Marine Science, Journal Year: 2025, Volume and Issue: 11

Published: March 6, 2025

Introduction For 87 years, gillnets have been deployed off up to 51 beaches in New South Wales, Australia, reduce bites on humans by white ( Carcharodon carcharias ), bull Carcharhinus leucas and tiger Galeocerdo cuvier ) sharks. Recently, minimise unwanted fishing mortalities, baited drumlines with electronic catch sensors, called ‘shark management alert real time’ (SMART) trialled. The SMART are more selective than because catches quickly removed (with target sharks spatially displaced), nearly all survive. Nevertheless, important questions remain unanswered, including (1) the required number of at a beach (2) their risk not being due adverse weather—which doesn’t affect gillnets. Methods To answer first question, we analysed 22,025 diurnal drumline deployments across 1637 days for frequency proximal captures (i.e. ≥two caught similar space time) dependence drumlines. second question was investigated collating weather conditions during 31 years target-shark (290 93 sharks) correlating these known operational limitations Results Among 494 hooked sharks, 71% were targets (298 whites, 43 tigers, 9 bulls). No multiple daily recorded or but there 46 instances where five same day, twenty occurrences within km 60 min initial capture. Proximal remained independent region. historical gillnet data revealed would restricted deploying 67–83% period deployed, ~75% those occasions when gillnetted. Conclusion While acknowledge be fewer water users sea conditions, if replace gillnets, greater catching efficiency, selectivity, survival released animals need rationalised against temporally comparable deployments. If latter is acceptable, recommend least two three per ensure hook remains while others checked.

Language: Английский

Citations

0
High-resolution mapping of shark movements from drone footage at Queensland beaches improves risk assessment for beach safety DOI
Maddison C. Cross, J. D. Mitchell,

Tracey B. Scott-Holland

et al.

Marine Policy, Journal Year: 2025, Volume and Issue: 179, P. 106737 - 106737

Published: April 26, 2025

Language: Английский

Citations

0
From little things big things grow: enhancement of an acoustic telemetry network to monitor broad-scale movements of marine species along Australia’s east coast DOI Creative Commons
Adam Barnett, Fabrice R. A. Jaine, Stacy L. Bierwagen

et al.

Movement Ecology, Journal Year: 2024, Volume and Issue: 12(1)

Published: April 23, 2024

Abstract Background Acoustic telemetry has become a fundamental tool to monitor the movement of aquatic species. Advances in technology, particular development batteries with lives > 10 years, have increased our ability track long-term patterns many However, logistics and financial constraints often dictate locations deployment duration acoustic receivers. Consequently, there is compromise between optimal array design affordability. Such can hinder marine animals over large spatial temporal scales. Continental-scale receiver networks study large-scale movements, but significant gaps coverage remain. Methods Since 2007, Integrated Marine Observing System’s Animal Tracking Facility (IMOS ATF) maintained permanent installations on eastern Australian seaboard. In this study, we present recent enhancement IMOS ATF tracking infrastructure Queensland collect data movements species northeast extent national array. Securing relatively small initial investment for expanding tagging activities served as catalyst, bringing together diverse group stakeholders (research institutes, universities, government departments, port corporations, industries, Indigenous ranger groups tourism operators) create an extensive collaborative network that could sustain extended into future. To fill existing maximise monitoring footprint, new initiative atypical design, deploying single receivers spread across 2,100 km waters. Results The approach revealed previously unknown broad-scale some highlights clusters are not always required enhance collection. designs using predominantly deployments more vulnerable when lost or fail, therefore “redundancy” critical consideration designing type Conclusion Initial results suggest enhancement, if sustained will uncover range assist addressing ecological, fisheries, conservation questions multiple

Language: Английский

Citations

2
Global genetic diversity and historical demography of the Bull Shark DOI
Bautisse Postaire, Floriaan Devloo‐Delva, Juerg M. Brunnschweiler

et al.

Journal of Biogeography, Journal Year: 2023, Volume and Issue: 51(4), P. 632 - 648

Published: Dec. 11, 2023

Abstract Aim Biogeographic boundaries and genetic structuring have important effects on the inferences interpretation of effective population size ( N e ) temporal variations, a key genetics parameter. We reconstructed historical demography divergence history vulnerable coastal high‐trophic shark using genomics assessed our ability to detect recent bottleneck events. Location Western Central Indo‐Pacific (IPA), Tropical Atlantic (WTA) Eastern Pacific (EPA). Taxon Carcharhinus leucas (Müller & Henle, 1839). Methods A DArTcap™ approach was used sequence 475 samples assess global structuring. Three demographic models were tested each population, an ABC‐RF framework coupled with coalescent simulations, investigate within‐cluster structure. Divergence times between clusters computed, testing multiple scenarios, fastsimcoal . variations STAIRWAYPLOT. Coalescent simulations performed determine detectability under estimated trend for datasets this size. Results corresponding IPA, WTA EPA regions identified, agreeing previous studies. The IPA presented highest diversity consistently identified as oldest. No significant detected. increased globally, earlier onset in during last glacial period. showed that weak bottlenecks could not be detected dataset, while old and/or strong would erase observed ancestral expansion. Main Conclusions This study further confirms role marine biogeographic breaks shaping large mobile predators. increases are potentially linked extended habitat availability. limited suggests can monitored over ocean basins. Due insufficient amount available data, it cannot concluded whether overfishing is impacting Bull Shark diversity, calling whole‐genome sequencing.

Language: Английский

Citations

4
Flapping about: trends and drivers of Australian cownose ray (Rhinoptera neglecta) coastal sightings at their southernmost distribution range DOI Creative Commons
Alysha J. Chan, Fabrice R. A. Jaine,

Francisca Maron

et al.

Frontiers in Fish Science, Journal Year: 2024, Volume and Issue: 1

Published: Jan. 11, 2024

The Australian cownose ray ( Rhinoptera neglecta ) is an understudied batoid that occurs along Australia's north and east coasts. Currently classified as Data Deficient on the IUCN Red List of Threatened Species, major knowledge gaps exist regarding species' geographic range, habitat use drivers influencing its presence in coastal waters. Sightings R. were collected during systematic aerial surveys conducted 980 km (~47%) New South Wales (NSW) coastline between 2017 2019. North-bound flown 500 m offshore, whilst return beach/sea interface (inshore or nearshore). Using generalized additive models a set nine predictors, we examined relationship spatio-temporal occurrence , their group size biophysical environment at southernmost extent distribution. Results for presence/absence (44.20% deviance explained) observed offshore inshore (42.58 41.94% explained, respectively) highlighted latitude, day year, sea surface temperature, rainfall, wind speed, direction common influences to three models. indicated more likely be present northern half NSW spring summer months. However, larger sizes southern regions same seasons, regardless whether they inshore. Group also influenced by localized conditions, such SST tidal flows. This study represents largest attempt date decipher spatial ecology provides insights into distribution relative abundance species full coastline, extending known over 70 southward.

Language: Английский

Citations

1