Estuaries and Coasts, Journal Year: 2023, Volume and Issue: 47(3), P. 880 - 893
Published: Dec. 14, 2023
Language: Английский
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
Biology, Journal Year: 2023, Volume and Issue: 12(9), P. 1189 - 1189
Published: Aug. 31, 2023
Unprovoked shark bites have increased over the last three decades, yet they are still relatively rare. Bull sharks globally distributed throughout rivers, estuaries, nearshore areas and continental shelf waters, capable of making long distance movements between tropical temperate regions. As this species is implicated in their range, knowledge environmental drivers bull important for better predicting likelihood occurrence at ocean beaches potentially assist reducing bites. Using largest dataset acoustically tagged world, we examined spatial ecology 233 juvenile large (including sub-adult adult) monitored a 5.5-year period (2017-2023) using an array real-time acoustic listening stations off 21 along coast New South Wales, Australia. were detected more coastal northern NSW (<32° S) but travelled southwards during austral summer autumn. Juveniles not on until reached 157 cm stayed north 31.98° S (Old Bar). Intra-specific diel patterns observed, with juveniles exhibiting higher presence 20:00 03:00, whilst was greatest from midday through to 04:00. The results generalised additive models revealed that often found when water temperatures than 20 °C, after >45 mm rain swell heights 1.8 2.8 m. Understanding influence variables will facilitate education could drive smart behaviour amongst users.
Language: Английский
Citations
6
Frontiers in Marine Science, Journal Year: 2023, Volume and Issue: 10
Published: Nov. 29, 2023
Information on how the trophic ecology of predators shapes their movement patterns and space-use is fundamental to understanding ecological processes across organisational levels. Despite this, studies combining spatial determine prey preference and/or resource availability shape space use are lacking in marine as these can occur at low density often difficult track over extended periods. Furthermore, many exhibit behavioural variability within species among closely related, sympatric adding further complexity. We applied a context-focused, multi-method approach understudied great hammerhead shark ( Sphyrna mokarran ) test if home ranges relate availability. Movement data from satellite acoustic telemetry Queensland, Australia, were combined with stable-isotope analysis, drone surveys, videos hunting behaviour. Limited dispersal, small S. linked specialisation stingray prey. Drone surveys showed predation events stingrays demonstrated high, year-round this shallow, inshore habitats, which may allow majority remain resident. This affinity for habitats suggests that critical life-history requirements performed local or regional scales, although some larger movements evident. These results interpreted comparison well-studied bull Carcharhinus leucas ), reliance pelagic food webs. had high individual movement, both large-scale migrations residency. could indicate only individuals locally sustained dynamic, webs, while others undergo excursions distant habitats. The specialised foraging indicates they play an apex predator role potentially shaping space-use, behaviour batoids. As disproportionately affected by anthropogenic stressors, mokarran’s limited demographic connectivity make particularly vulnerable threats.
Language: Английский
Citations
4
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
Ecology and Evolution, Journal Year: 2024, Volume and Issue: 14(12)
Published: Nov. 28, 2024
Animal movements are typically influenced by multiple environmental factors simultaneously, and individuals vary in their response to this heterogeneity. Therefore, understanding how aspects, including biotic, abiotic, anthropogenic factors, influence the of wild animals is an important focus wildlife research conservation. We apply Exponential Random Graph Models (ERGMs) analyze movement networks a bull shark population network acoustic receivers identify effects environmental, social, or other types covariates on movements. found that intra- interspecific often had stronger than variables. ERGMs proved be potentially useful tool for studying animal data, especially context spatial attribute
Language: Английский
Citations
1
Frontiers in Marine Science, Journal Year: 2022, Volume and Issue: 9
Published: Sept. 21, 2022
Coastal pelagic ecosystems are highly variable in space and time, with environmental conditions the distribution of biomass being driven by complex processes operating at multiple scales. The emergent properties these their interactive effects result dynamic mosaics referred to as “seascapes”. Mechanisms that link large-scale oceanographic ecological variability coastal environments remain poorly understood, despite importance for predicting how will respond climate change. Here we assessed seascape along path rapidly intensifying East Australian Current (EAC) Southern Extension southeast Australia, a hotspot ocean warming ecosystem tropicalisation. Using satellite situ measures temperature, salinity current velocity coupled contemporaneous measurements from nine boat-based active acoustic surveys five consecutive years, investigated relationships between physical environment (zooplankton fish) timescales. Survey periods were characterised high conditions, variation influenced meso-to-large scale occurring offshore, including position strength eddies. Intra-annual was often similar or greater magnitude inter-annual variability, suggesting important scales days weeks. Two categories identified (A) warmer, less saline water (B) cooler, more water, former indicating influence EAC on processes. Warmer waters also associated fewer, deeper dense biological aggregations. As continues warm penetrate further south, it is likely this have substantial activity ecosystems, potential reduction accessibility prey aggregations surface-feeding predators fisheries. These results highlight import role offshore driving region undergoing rapid oceanic
Language: Английский
Citations
7
Fisheries Research, Journal Year: 2022, Volume and Issue: 257, P. 106501 - 106501
Published: Sept. 23, 2022
There is increasing support for shark bite mitigation measures, such as SMART (Shark-Management-Alert-in-Real-Time) drumlines that minimise impacts on target sharks and other marine animals. On the east coast of Australia, are used in a management program to catch relocate white (Carcharodon carcharias), tiger (Galeocerdo cuvier), bull (Carcharhinus leucas; herein referred sharks). This study examines effect bait position relative seabed drumline catches eastern Australian waters, aiming optimise while reducing bycatch. Over 17 months, were deployed at Ballina Evans Head, New South Wales. Trace extensions attached 3.2 m standard traces test height above an experimental design alternated every fortnight. White accounted 67% total catch, whereas infrequently caught (3%). Bait did not significantly influence probability sharks. However, Critically Endangered grey nurse (Carcharias taurus) false alarm events increased when baits closer seabed. Catches varied throughout year linked seasonal water temperature changes. The effectively species whilst events, highlighting trace length currently NSW deployments optimal.
Language: Английский
Citations
7
Animal Behaviour, Journal Year: 2024, Volume and Issue: 215, P. 227 - 239
Published: July 29, 2024
While wildlife tourism may impact the animals it targets, plays a critical role in public education and conservation awareness. Understanding changes animal behaviour response to activities can inform trade-offs between negative impacts socioeconomic benefits. There are claims that cage-diving condition white sharks, Carcharodon carcharias, interact with boats, potentially increasing risk of shark bites. We tracked fine-scale movements 73 sharks relation boats using acoustic telemetry 2018 2022 at Neptune Islands, Australia, investigate associative factors influencing residency time spent proximity boats. White gradually less near throughout their site. This was consistent across individuals, years, sexes sizes. Sharks, however, resumed natural behaviours (i.e. initial amount boats) each they returned suggesting observed habituation loss stimulus used attract sharks) did not last for long periods. These trends support lack long-term learnt increasingly interacting Our results indicate current management strategies such as regulating number days industry operate site food-based attractant used, reducing bait consumed limit while enabling continued opportunities tourism. how associate humans help ensure best practices place both targeted people involved, particularly case threatened dangerous species.
Language: Английский
Citations
1
Biology, Journal Year: 2022, Volume and Issue: 11(10), P. 1456 - 1456
Published: Oct. 4, 2022
There is still limited information about the diversity, distribution, and abundance of sharks in around surf zones ocean beaches. We used long-term large-scale drone surveying techniques to test hypotheses relative occurrence off beaches New South Wales, Australia. quantified 36,384 flights across 42 from 2017 2021. Overall, there were 347 chondrichthyans recorded, comprising 281 (81.0%) sharks, with observations occurring <1% flights. Whaler (Carcharhinus spp.) had highest number (n = 158) recorded. 34 individuals observed for both white (Carcharodon carcharias) critically endangered greynurse (Carcharias taurus). Bull leucas), leopard (Stegostoma tigrinum) hammerhead species (Sphyrna recorded 29, eight three individuals, respectively. Generalised additive models identify environmental drivers detection probability white, bull, greynurse, whaler sharks. Distances nearest estuary, headland, island, as well water temperature wave height, significant predictors shark occurrence; however, this varied among species. we provide valuable evidence-based species-specific conservation management strategies coastal
Language: Английский
Citations
6
Aquatic Conservation Marine and Freshwater Ecosystems, Journal Year: 2023, Volume and Issue: 34(1)
Published: Oct. 20, 2023
Abstract Identifying the species response to changing environments can contribute towards proactive and adaptable resource management and, although obtaining observations be logistically challenging for aquatic species, postulated through monitoring. A network of acoustic tracking receivers ( n = 93) across south‐eastern Australia was used identify effects environmental conditions on activity yellowtail kingfish Seriola lalandi , 63), an economically important with a crucial role in pelagic ecosystems. Activity (measured via tri‐axial acceleration) provides insight into energetic expenditure animals, which is linked movement, behaviour, physiological processes. Kingfish strongly influenced by sea surface temperature hour day, smaller from distance nearest landmass bathymetry. also decreased during higher tides periods greater moon fraction. Findings show that responses are sensitive long‐ short‐term changes, regulate behaviours Changes movement (residency space use) were further investigated at seasonal aggregation small temperate estuary (approx. 120 km 2 ; Coffin Bay, South Australia), where individuals remained austral spring summer (September–April), complete exodus winter. Fifty per cent tagged fish returned this three consecutive years, indicating its importance aggregating kingfish. While residing varied between interconnected areas, temperature, tide height, fraction again identified as explanatory variables. These findings have implications budgets large subtropical regions, facing rapidly climates. results understanding accounting potential impacts future climatic migratory species.
Language: Английский
Citations
2