Spatial connectivity of reef manta rays across the Raja Ampat archipelago, Indonesia

Royal Society Open Science, Journal Year: 2024, Volume and Issue: 11(4)

Published: April 1, 2024

The reef manta ray Mobula alfredi is present throughout most island groups that form the Raja Ampat archipelago, Indonesia. species protected regionally and nationally currently managed as a single homogeneous population within 6.7 million ha archipelago. However, scientific evidence lacking regarding spatial connectivity structure of M. this Using network analysis an array 34 acoustic receivers deployed between February 2016 September 2021, we examined movements 72 subadult adult tagged in seven regions Ampat. A total 1094 were recorded primarily concentrated nearby receiver stations, highlighting frequent local within, limited long-distance regional arrays. Network revealed highly connected nodes acting hubs important for movements. community detection algorithm further indicated clusters network. Our results suggest existence metapopulation comprising three demographically geographically distinct subpopulations They also reveal importance Eagle Rock critical node movement network, justifying urgent inclusion site marine area

Language: Английский

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Natural and Artificial Structures Influence the Movement and Habitat Connectivity of Whale Sharks (Rhincodon typus) Across Seascapes

Diversity and Distributions, Journal Year: 2025, Volume and Issue: 31(1)

Published: Jan. 1, 2025

ABSTRACT Aim To understand how natural geomorphological features and oil gas platforms (OG platforms) influence the habitat use seascape connectivity of whale shark ( Rhincodon typus ). Location East‐Indian Ocean North‐West Australia. Methods We compiled a satellite tracking dataset 78 sharks tagged across 14‐year period at Ningaloo Reef Shark Bay World Heritage Areas in Western Australia to develop spatial networks for regions then applied Bayesian modelling framework assess effects OG on patterns connectivity. Results Geomorphological such as pinnacles, canyons, seamounts promoted strongly influenced both regional (1000's km; Ocean) local (100's Australia) scales. In Australia, had similar feature types also enhanced The most visited by were situated close edge continental shelf near that likely enhance productivity. Main Conclusion Our work identified oceanic coastal seascapes. Sharks routinely platforms, which acted migratory stepping stones further Protection promote could assist conservation management sharks. suggest their movement beyond individual structures, should be considered environmental impact assessments during operation decommissioning phases.

Language: Английский

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Occurrence of mobulid rays in Northwest Madagascar

Environmental Biology of Fishes, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 5, 2025

Language: Английский

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Potential nursery area for the endangered oceanic manta ray in the Gulf of California, México

Environmental Biology of Fishes, Journal Year: 2025, Volume and Issue: unknown

Published: April 22, 2025

Language: Английский

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Preliminary insights into manta ray (Mobula alfredi and M. birostris) population demographics and distribution in South Africa

Environmental Biology of Fishes, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 8, 2025

Abstract Both the reef manta ray, Mobula alfredi and oceanic ray M. birostris , are repeatedly observed in South Africa, yet little is known about distributions of either species. In this study, we collated citizen science observations since 2003 to reveal six areas KwaZulu-Natal (KZN) Eastern Cape provinces, where rays have been sighted across multiple years. Using their unique ventral spot patterning, 184 individuals were photo-identified, comprising 139 45 . Most photo-identified encountered iSimangaliso Wetland Park (IWP) KZN (89%; n = 119) for Aliwal Shoal (48%; 22). We identified 32 new transboundary records 28 also photographed Inhambane Province, Mozambique, demonstrating connectivity, specifically Závora ( 27). One individual traveled times between IWP Závora, totaling 1305 km, another from Pondoland MPA a distance over 600 km. Further, extend southern range Africa by 500 km Mdumbi Beach Port Ngqura, Cape. These collective findings represent Africa’s first in-water assessment aggregations, showing particular be critical habitat movements documented here suggest population one most mobile globally. hope baseline data provided will drive increased research management along coastlines.

Language: Английский

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Staying Close to Home: Horizontal Movements of Satellite-Tracked Reef Manta Rays Mobula alfredi (Krefft, 1868) in the World’s Largest Manta Sanctuary

Fishes, Journal Year: 2025, Volume and Issue: 10(2), P. 66 - 66

Published: Feb. 5, 2025

Indonesia is home to significant populations of globally vulnerable reef manta rays (Mobula alfredi) in at least four key regions: Berau, Nusa Penida, Komodo, and Raja Ampat. Despite detailed population studies each these regions, little known about their horizontal movement patterns. Our study used satellite telemetry investigate rays’ habitat use ranges. A total 33 were tagged with SPLASH10F-321A tags across the Berau (n = 5), Penida 8), Komodo 6), Ampat 14), yielding usable data from 25 tags. The tracked for 7 118 days (mean ± SD 50 30) July 2014 2022. results showed localized movements, strong residency near tagging sites, high site fidelity as evidenced by area-restricted search (ARS) behaviors frequent revisitations. Most restricted ranges region, no connectivity between regions. Across individuals, range (95% utilization distributions) varied significantly, ranging 19 48,294 km2 4667 10,354). These findings offer important insights into spatial patterns Indonesia, allowing formulation more effective management strategies.

Language: Английский

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Movements and habitat use of reef manta rays around the Mozambique Channel Island of Mayotte, Southwestern Indian Ocean

Environmental Biology of Fishes, Journal Year: 2025, Volume and Issue: unknown

Published: April 29, 2025

Language: Английский

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Identifying spatial movements and residency of pelagic thresher sharks (Alopias pelagicus) using satellite and passive acoustic telemetry to inform local conservation in central Indonesia

Frontiers in Fish Science, Journal Year: 2024, Volume and Issue: 2

Published: May 22, 2024

The pelagic thresher shark ( Alopias pelagicus ) is globally endangered, threatened by bycatch, and targeted in industrial artisanal fisheries Indonesia. However, a lack of information about their ecology, particularly movement habitat use, hinders the development science-based conservation measures to protect species. Here, we report our research, which first use combination satellite passive acoustic telemetry investigate residency within Indonesia's waters, especially areas impacted local fisheries. A total 24 sharks were tagged with archival tags n = 9), internal 10), both 5) Selat Pantar Marine Protected Area (MPA). sharks, dominated females (71%) ranged size from 125–180 cm FL (mean ± SD: 161 13). Seven fifteen acoustically detected receivers, while twelve fourteen reported data. stayed attached for 81–181 days, tag detection periods 44–175 days. Horizontally, found satellite-tagged moved broadly, mainly offshore, approximately 90 km tagging locations. They between Banda, Flores, Savu Sea regions, where unregulated unreported longline gillnet are known operate. Meanwhile, showed distinct diel patterns around MPA's coastal indicating potential philopatric behavior. Vertically, spent significantly p < 0.001) more time deeper water during day shallower at night. deepest dive recorded was 1,889.5 m, ever Our results suggest that area-based protection can be an effective nearshore tool as individuals appear remain relatively restricted MPA extended periods. regulation aimed restricting illegal fishing also necessary when they move offshore. findings have been communicated relevant governments, resulting increased political will new legislation them connected waters East Nusa Tenggara.

Language: Английский

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Insights into the visitations of oceanic manta rays at cleaning stations on coral reefs in the Bird's Head Seascape, eastern Indonesia

Frontiers in Fish Science, Journal Year: 2024, Volume and Issue: 2

Published: Aug. 16, 2024

The globally endangered oceanic manta ray Mobula birostris is believed to spend significantly more time in the open ocean than coastal areas. Nonetheless, Bird's Head Seascape (BHS) eastern Indonesia hosts a large population of this species (over 850 individuals), frequently sighted at coral reef cleaning stations and forming vital asset for marine tourism region. Despite this, detailed understanding movements habitat use wide-ranging within shallow (< 30 m) ecosystems remains limited. Addressing knowledge gap urgently required sustainable management ray-focused Here, we report results an initial passive acoustic telemetry study investigating by rays. Forty-one rays were acoustically tracked from February 2016 August 2019 array 28 receivers deployed known hypothesized transit points across BHS (including regions Raja Ampat, Fakfak, Kaimana). A total 5,822 detections recorded 16 all tagged individuals, 421 visitation events documented 37 out 41 providing valuable insights into their patterns stations. Tagged individuals detected receiver durations ranging 0.2 427.0 min (mean ± SD = 48 64 min). Notably, 94% during daylight hours (reaching peak noon), underscoring apparent diurnal pattern spent around frequent short-range between adjacent (5–12 km apart), with two-thirds 191 occurring neighboring southern Ampat. repeatedly three which previously only hosting rays, suggesting likely also utilize these Our provides important visitations local stations, will inform effective conservation efforts BHS.

Language: Английский

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Half a century of citizen science tag-recapture data reveals stock delineation and cross-jurisdictional connectivity of an iconic pelagic fish

Reviews in Fish Biology and Fisheries, Journal Year: 2024, Volume and Issue: 34(4), P. 1433 - 1449

Published: Aug. 6, 2024

Abstract Tag-recapture programs to monitor the movements of fish populations are among some longest-running citizen-science datasets date. Here, using half a century yellowtail kingfish ( Seriola lalandi, Carangidae) tag-recapture data collected through projects, we report novel insights into population connectivity in Australia and New Zealand (NZ). Despite importance commercial recreational fisheries, substantial knowledge gaps about their stock structure between jurisdictions hinder current management efforts. Between 1974 2022, 63,432 releases 4636 recaptures (7.3%) tagged were NZ. Most individuals (51.4%) recaptured within 10 km original release location up 14 years post-release (mean: 225 days), indicating degree site fidelity. However, 656 (14.2%) over 100 from location, with one travelling at least 2834 702 days. Seasonal variability was evident for recaptures, more occurring summer autumn most jurisdictions. Network analysis revealed no western eastern Australia, supporting genetic delineation. By contrast, extensive exists across NZ, 87 moving five Australian state jurisdictions, 316 15 bioregions six Our findings provide important new suggest increased collaboration international fisheries may support improved assessment management.

Language: Английский

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