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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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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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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Estimating the abundance and population trends of reef manta rays (Mobula alfredi) in Nusa Penida, Bali, Indonesia

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

Published: Feb. 28, 2025

Language: Английский

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Genomic evidence indicates small island-resident populations and sex-biased behaviors of Hawaiian reef Manta Rays

BMC Ecology and Evolution, Journal Year: 2023, Volume and Issue: 23(1)

Published: July 8, 2023

Abstract Background Reef manta rays ( Mobula alfredi ) are globally distributed in tropical and subtropical seas. Their life history traits (slow growth, late maturity, low reproductive output) make them vulnerable to perturbations therefore require informed management strategies. Previous studies have reported wide-spread genetic connectivity along continental shelves suggesting high gene flow continuous habitats spanning hundreds of kilometers. However, the Hawaiian Islands, tagging photo-identification evidence suggest island populations isolated despite proximity, a hypothesis that has not yet been evaluated with data. Results This island-resident was tested by analyzing whole mitogenome haplotypes 2048 nuclear single nucleotide polymorphisms (SNPs) between M. (n = 38) on Hawaiʻi Island Maui Nui (the 4-island complex Maui, Molokaʻi, Lānaʻi Kahoʻolawe). Strong divergence Φ ST 0.488) relative genome-wide SNPs (neutral F 0.003; outlier 0.186), clustering mitochondrial among islands provides robust female reef strongly philopatric do migrate these two groups. Combined restricted male-mediated migration, equivalent male moving every 2.2 generations (~ 64 years), we provide significantly demographically isolated. Estimates contemporary effective population size N e 104 (95% CI: 99–110) 129 122–136) Nui. Conclusions Concordant from photo identification studies, results indicate small, genetically-isolated resident populations. We hypothesize due Mass Effect, large sufficient resources support populations, thereby making crossing deep channels separating groups unnecessary. Small size, diversity, k-selected region-specific anthropogenic threats, which include entanglement, boat strikes, habitat degradation. The long-term persistence Islands will island-specific

Language: Английский

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First Documented Courtship Behavior between Mobula birostris and M. alfredi at a Coral Reef Cleaning Station in Misool, Raja Ampat

Diversity, Journal Year: 2024, Volume and Issue: 16(6), P. 319 - 319

Published: May 27, 2024

Though a previous study in Sudan confirmed the existence of living hybrid an oceanic manta ray (Mobula birostris) and reef (M. alfredi), courtship behaviors between two closely related species have never been documented. Here we report first observation male M. birostris female alfredi at cleaning station on shallow coral seamount Misool, Raja Ampat, Indonesia. The observed event lasted for approximately 45 min involved one actively chasing mature around repeatedly bumping her left wing tip with his right cephalic lobe, while second continuously flanked to seemingly prevent retreat from potential evasion pursuing male. Notably, exhibited rapid coloration change, likely indicative courtship-related stress, transitioning striking pale hue she throughout activity normal chevron pattern once males departed.

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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Characteristics, residency and site fidelity of photo-identified reef manta rays (Mobula alfredi) population in New Caledonia

Marine Biology, Journal Year: 2024, Volume and Issue: 171(8)

Published: June 28, 2024

Language: Английский

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