Exploitation status and stock assessment of daisy parrotfish (Chlorurus sordidus) in Karimunjawa Marine National Park, Central Java, Indonesia

DIAN WIJAYANTO (Department of Capture Fisheries, Faculty of Fisheries and Marine Sciences, Universitas Diponegoro. Jl. Prof. Jacub Rais, Tembalang, Semarang 50275, Central Java, Indonesia)
ALHADI BUSTAMAM (Department of Mathematics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia. Jl. Lingkar, Pondok Cina, Beji, Depok 16424, West Java, Indonesia)
YANDRA ARKERMAN (Department of Computer Science, Faculty of Mathematics and Science, Institut Pertanian Bogor. Jl. Raya Dramaga, Kampus IPB Dramaga, Bogor 16680, West Java, Indonesia)
KHAIRUL AMRI (Research Center for Fishery, National Research, and Innovation Agency. B.J. Habibie Building, Jl. M.H. Thamrin No. 8, Central Jakarta 10250, Jakarta, Indonesia)
TIRTADANU TIRTADANU (Research Center for Fishery, National Research, and Innovation Agency. B.J. Habibie Building, Jl. M.H. Thamrin No. 8, Central Jakarta 10250, Jakarta, Indonesia)
GATHOT WINARSO (Research Center for Fishery, National Research, and Innovation Agency. B.J. Habibie Building, Jl. M.H. Thamrin No. 8, Central Jakarta 10250, Jakarta, Indonesia)
IRMAN HERMADI (Department of Agroindustrial Technology, Faculty of Agricultural Technology, Institut Pertanian Bogor. Jl. Raya Dramaga, Kampus IPB Dramaga, Bogor 16680, West Java, Indonesia)
SARI INTAN KAILAKU (Research Center for Agroindustry, National Research, and Innovation Agency. Jl. Raya Jakarta-Bogor KM 46, Sentul, Cibinong 16911, Bogor 16680, West Java, Indonesia)
FAIK KUROHMAN (Department of Capture Fisheries, Faculty of Fisheries and Marine Sciences, Universitas Diponegoro. Jl. Prof. Jacub Rais, Tembalang, Semarang 50275, Central Java, Indonesia)
MUHAMMAD REYHAN PUTRANTO (Department of Capture Fisheries, Faculty of Fisheries and Marine Sciences, Universitas Diponegoro. Jl. Prof. Jacub Rais, Tembalang, Semarang 50275, Central Java, Indonesia)
DITA JUNI KURNIA (Department of Capture Fisheries, Faculty of Fisheries and Marine Sciences, Universitas Diponegoro. Jl. Prof. Jacub Rais, Tembalang, Semarang 50275, Central Java, Indonesia)

Biodiversitas Journal of Biological Diversity
Vol. 26 No. 9 (2025)

Abstract. Wijayanto D, Bustamam A, Arkerman Y, Amri K, Tirtadanu, Winarso G, Hermadi I, Kailaku SI, Kurohman F, Putranto MR, Kurnia DJ. 2025. Exploitation status and stock assessment of daisy parrotfish (Chlorurus sordidus) in Karimunjawa Marine National Park, Central Java, Indonesia. Biodiversitas 26: 4831-4837. Daisy parrotfish (Chlorurus sordidus) play a crucial ecological role in maintaining coral reef health and resilience by grazing on algae, which prevents algal overgrowth and promotes coral recruitment. This study evaluated the exploitation status of C. sordidus in the Karimunjawa Marine Protected Area, Central Java, Indonesia, using biological indicators, including length at first capture (Lc??%), growth parameters, and mortality rates. Field sampling was conducted from March 2024 to February 2025, involving fisher interviews and morphometric measurements of 1,032 individuals. Results showed a Lc??% of 24.8 cm and an asymptotic length (L?) of 51 cm, exceeding the size of first maturity but below the sex-change size range, potentially affecting reproductive dynamics. Further analysis revealed total mortality (Z) of 4.31 year-¹, with fishing mortality (F = 2.33) higher than natural mortality (M = 1.20), reflecting intensive fishing pressure on the stock. The exploitation rate (E: 0.54) indicates that the species is currently overexploited, which may reduce herbivory functions, weaken coral reef resilience, and threaten long-term fishery benefits. These findings highlight the urgent need for effective management measures, including minimum size limits, seasonal fishing restrictions, and community-based compliance, to ensure population sustainability. Continuous monitoring and further research on reproductive biology and critical habitats, particularly nursery grounds and spawning aggregations, are essential for informed conservation strategies, ensuring not only population sustainability but also the maintenance of ecosystem services that support local livelihoods and marine ecotourism in Karimunjawa.