Nursery habitat use of neonate blacktip reef sharks at Chagar Hutang Bay, Malaysia, insights from integrated mark-recapture and acoustic telemetry
Journal Publication ResearchOnline@JCUAbstract
Identifying nursery habitats for threatened reef-associated sharks is essential for understanding their early life-stage ecology and for guiding spatial conservation. In Malaysia, such information remains scarce for blacktip reef sharks. We present a preliminary assessment of neonate site use and site fidelity using complementary mark–recapture surveys and passive acoustic telemetry at Chagar Hutang Bay (CHB), Redang Island, a newly designated Important Shark and Ray Area and potential nursery site. Thirty neonates (38–62 cm in total length) were externally tagged during 2023–2024 across 78 one-hour gillnet / hook-and-line deployments (fishing effort); five were additionally implanted with acoustic transmitters in 2024. Overall catch-per-unit-effort was 0.67 sharks per hour of fishing effort. Mark–recapture yielded a 33.3% recapture rate and a mean time at liberty of 56.4 ± 42.5 days. Acoustic detections revealed a mean detection period of 46.2 ± 43.4 days, including two individuals detected ≥ 90 days. Integrating both methods increased the mean detection period from 48.7 ± 44.2 days (mark–recapture alone) to 65.5 ± 38.0 days when acoustic data were included. Acoustically tagged sharks showed stronger site fidelity to the west side of the bay (4 of 5 individuals), with diel detections peaking in early morning and late afternoon. Collectively, our findings highlight CHB as a candidate nursery for neonate blacktip reef sharks and provide important insight into their spatial patterns of site use within Malaysia’s Marine Park network, providing empirical support for CHB’s designation as an ISRA.
Journal
Regional Studies in Marine Science
Publication Name
Regional Studies in Marine Science
Volume
99
ISBN/ISSN
2352-4855
Edition
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Issue
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Pages Count
12
Location
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Publisher
Elsevier
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EISSN
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DOI
10.1016/j.rsma.2026.105119