Encourages submission of manuscripts dealing with all aspects of maritime and marine resources in estuaries, coastal zones, continental shelf, the seas and oceans, including marine biodiversity and fisheries resources, biochemistry, physiology, behaviour, and genetics of marine life, socio-economic and cultural aspects, conservation and management, as well as biogeochemistry, marine pollution, and climate change.
Distribution and photo-physiology of bleached and non-bleached Sarcophyton sp. in Rodrigues reefs, Mauritius
Abstract. Ramkalam MK, Korimbocus AM, Jogee SY, Gerzer F, Nundlall Y, Chatoolsingh D, Anansamy M, Kaullysing D, Casareto BE, Suzuki Y, Reimer J, Wijayanti DP, Nascimento B, Bhagooli R. 2025. Distribution and photo-physiology of bleached and non-bleached Sarcophyton sp. in Rodrigues reefs, Mauritius. Indo Pac J Ocean Life 9: 163-171. Soft corals are key contributors to reef ecosystems, especially where hard coral cover is declining, yet their responses to bleaching stress remain poorly understood in the Indian Ocean. This study investigated the distribution and abundance of soft corals, alongside the photosynthetic performance of bleached and non-bleached Sarcophyton sp. around Rodrigues Island, Republic of Mauritius. Field surveys were carried out using Line Intercept Transects (LIT) across four sites: Ti Trou, Plateau Benitiers, Var Brulee, and Pate Reynieux, revealing significant variations in the soft coral communities. For healthy and bleached Sarcophyton colonies, chlorophyll fluorescence was measured using a JUNIOR Pulse-Amplitude-Modulated (J-PAM) to assess the photo-physiology (Y(II), rETRmax, NPQmax). Results showed that soft corals flourished at shallow southern sites (65.00±0.26% and 51.67±4.72%) with lower levels of nitrate and phosphate. The photo-physiological analyses showed that healthy Sarcophyton sp. had higher Y(II) (0.509±0.004) and rETRmax values (15.23±4.2) compared to bleached Sarcophyton sp. (Y(II); 0.163±0.05, rETRmax; 0.97±0.42), while NPQmax values remained similar (healthy looking; 0.09±0.02, bleached; 0.06±0.008). The retention of quenching activity suggests that even bleached the Sarcophyton samples still had some protective mechanisms hence the possibility of remaining symbionts. These findings demonstrate the physiological plasticity and resilience of Sarcophyton sp., which may contribute to adaptation and resilience to stress conditions and contributes to shifts in reef communities.
Bleaching, chlorophyll fluorometery, coral distribution patterns, Rodrigues Island, Sarcophyton
Copyright (c) 2026 Indo Pacific Journal of Ocean Life
Decadal variation in the Tridacna population at two marine protected areas in Rodrigues Island, Republic of Mauritius
Abstract. Ramah S, Kaullysing D, Soondur M, Taleb-Hossenkhan N, Bhagooli R. 2025. Decadal variation in the Tridacna population at two marine protected areas in Rodrigues Island, Republic of Mauritius. Indo Pac J Ocean Life 9: 172-178. Giant clams (Tridacninae) are largely threatened worldwide, but information regarding their distribution and abundance is limited in the Western Indian Ocean, especially in the waters of the Republic of Mauritius, including the island of Rodrigues. This study provides the first decadal assessment (2015-2024) of the population density of Tridacna maxima and T. squamosa within two marine protected areas: Southeast Marine Protected Area (SEMPA) and English Bay Marine Reserve (EBMR) found in Rodrigues Island. Annual surveys were carried out by placing five permanent belt transects of 50 m × 5 m (250 m²) at both sites. The data were extrapolated to individuals per hectare (ind./ha), and Mixed-effect models were used to assess temporal and spatial differences. Across the 10 years, SEMPA consistently supported higher Tridacna densities than EBMR, particularly for T. maxima (peak 640 ind./ha vs. 360 ind./ha). Species identity and interactions were significant, with T. squamosa occurring only in SEMPA, ranging from 13 to 120 ind./ha, and was absent from EBMR throughout the study. Statistical analyses revealed significant effects of site and species identity, as well as strong site × species and year × species interactions, indicating that temporal dynamics differed remarkedly between species and between MPAs. Surveys revealed significant site- and species-specific variations in giant clam densities in Rodrigues. Mean densities of T. maxima and T. squamosa were significantly higher in SEMPA compared to EBMR (p<0.001). Both species persisted across survey years in SEMPA, whereas densities in EBMR remained consistently low with no significant increase over time (p=0.01). These results indicate spatial heterogeneity in population trajectories and identify SEMPA as a key area of persistence. The findings of this study provide baseline evidence of site- and species-specific variation in giant clam populations in Rodrigues, contributing to broader understanding of spatial heterogeneity and long-term dynamics for future comparative research in the Western Indian Ocean.
Giant clams, density, Tridacna maxima, T. squamosa, Rodrigues
First record of Annella mollis (Octocorallia) from Rodrigues Island, Western Indian Ocean
Abstract. Brihatee M, Marwyn A, Shakeel JY, Ashfaaq K, Maria RA, Homesha B, Ramkalam M, Deepeeka K, Beatriz CE, Yoshimi S, Hakim AA, Lalas JAA, Reimer JD, Wijayanti DP, Nascimento B, Ranjeet B. 2025. First record of Annella mollis (Octocorallia) from Rodrigues Island, Western Indian Ocean. Indo Pac J Ocean Life 9: 140-146. Gorgonians octocorals inhabit environments ranging from shallow tropical reefs to deep and polar waters. A habitat-forming species, they contribute significantly to habitat structural complexity and biodiversity, yet their occurrence in the Western Indian Ocean (WIO) remains poorly documented. Rodrigues Island, in particular, has lacked formal records in gorgonian species. To address this gap, ecological surveys were conducted in April 2024 at seven fore-reef sites around Rodrigues using triplicate 10×5 m belt transects surveyed by SCUBA. Results showed that only one species, Annella mollis, was recorded and was restricted to two outer reef slope sites, Tombant Coco and Ti Paté, at depths of approximately 27 m. Mean densities were low (0.17±0.01 and 0.15±0.01 individuals m⁻², respectively), and colonies were dominated by medium size classes (76-150 cm), with few larger individuals. Colonies were attached to consolidated rocky substrates on steep slopes associated with higher coral cover relative to other surveyed sites. No gorgonians were observed at the remaining five, shallower sites. These findings provide the first baseline record of gorgonians from Rodrigues Island and contribute to the limited knowledge of octocorals in the WIO. Our observations highlight the apparent restriction of A. mollis to deeper reef slope habitats around the island and underscore the need for broader surveys, temporal monitoring, and complementary morphological and genetic analyses to better understand gorgonian diversity and ecological roles in the region.
Gorgonian, habitat preferences, marine ecology, species distribution, zonation
Conservation under warming ocean conditions for endemic corals and reef fishes of Rodrigues Island, Mauritius
Abstract. Munbodhe V, Bhagooli R. 2025. Conservation under warming ocean conditions for endemic corals and reef fishes of Rodrigues Island, Mauritius. Indo Pac J Ocean Life 9: 147-162. Ocean warming has accelerated coral-algal phase shifts, threatening reef biodiversity and ecosystem functions. This study assessed coral reef conditions across 14 sites around Rodrigues Island, Mauritius, including four Marine Protected Areas (MPAs) and ten Non-Protected Areas (NPAs), surveyed from November 2019 to December 2020. Coral cover, macroalgae, and substrate covers were quantified using underwater visual censuses and 15 quadrats per site (~4 m² each). Live coral cover in MPAs was 2.5 times higher than in NPAs, with significant differences in benthic composition (GLM–Poisson, p<0.001). Significant differences in live corals, macro-algae, and soft coral covers were observed between MPAs and NPAs, GLM-Poisson Distribution, p<0.001. The MPA harbored 2.5-fold more live corals than NPAs. Relatively low coral genera richness was noted in the no-take marine reserves (Pielou's Evenness Index, J=0.31 and Simpson Dominance, D=0.65) as compared to multiple use MPAs (0.65<J<0.96) and NPAs (0.94<J<0.83). Of the 150 coral species recorded, 47 were from the genus Acropora, which mostly occurred in the MPAs. The MPAs demonstrated significantly higher reef structural complexities than the high macroalgal and rubble covers in the NPAs, ANOVA Post-hoc, p<0.007. No endemic coral, Acropora rodriguensis, was observed at the surveyed sites, while Pomacentrus rodriguensis, the endemic reef fish, was dominant in algal-dominated NPAs. The presence of regionally and nationally endemic species highlights Rodrigues as a biodiversity hotspot requiring strengthened reef management. This study provides critical baseline data for coral reef resilience and underscores the need for genetic and long-term ecological monitoring to support ecosystem-based conservation in a warming ocean.
Acropora, coral species, endemic and rare, reef fishes, marine protected area
Biological traits of corals under electro-mineral accretion at a coral restoration site in Indonesia
Abstract. Taylor ACF. 2026. Biological traits of corals under electro-mineral accretion at a coral restoration site in Indonesia. Indo Pac J Ocean Life 10 (1): o100102. https://doi.org/10.13057/oceanlife/o100102. Coral reef restoration efforts risk creating habitats that appear functional yet lack key ecological roles. Electro-Mineral Accretion (EMA)—a method applying low-voltage current to promote calcium carbonate deposition—has been used to enhance coral growth, but its effects on other biological traits remain poorly understood. This study investigated whether corals grown under EMA exhibit trade-offs between growth, reproduction, and skeletal structure compared to natural colonies. At restoration sites in Lombok, Indonesia, colonies of Stylophora pistillata were assessed for fecundity, polyp density, skeletal density, and growth. Growth comparisons of Acropora muricata were also measured between EMA treatments and naturally growing corals. EMA-treated corals showed significantly higher skeletal growth rates but reduced reproductive output, with fecundity 40% lower than natural colonies. Skeleton density was also reduced, suggesting lighter, less robust structures, while differences in polyp density were minor. These patterns indicate that enhanced growth under EMA may occur at the expense of reproduction and structural strength. The findings highlight a key ecological trade-off: faster-growing EMA corals may contribute to short-term reef cover but potentially compromise long-term population viability and resilience. Coral restoration success depends not only on promoting rapid growth but also on preserving reproductive capacity and skeletal integrity. This study underscores the importance of evaluating multiple biological traits when assessing restoration methods and cautions against relying solely on growth enhancement as a measure of ecological success.
Artificial reef, biorock, coral biology, coral restoration, electro-mineral accretion
Copyright (c) 2026 ANDREW C. F. TAYLOR https://creativecommons.org/licenses/by-nc-sa/4.0
Species composition and seasonal dynamics of tongkol fishes (Thunnini Tribe) landed at TPI Kranji, Lamongan, Indonesia
Abstract. Saputri RRL, Paricahya AF. 2026. Species composition and seasonal dynamics of tongkol fishes (Thunnini Tribe) landed at TPI Kranji, Lamongan, Indonesia. Indo Pac J Ocean Life 10 (1): o100103. https://doi.org/10.13057/oceanlife/o100103. Tongkol fisheries potential in East Java, Indonesia, including at TPI Kranji, Lamongan, is highly dependent on the policies and management of the area. Identification of tongkol species, tongkol-associated species, data on fishing grounds, annual catch, and fishing season are necessary for policy making and sustainable management. This study was conducted from April 2022 to July 2024, with catch data collection and participatory mapping methods. Identification of tongkol at TPI Kranji leads to three species: Auxis thazard, Euthynnus affinis, and Thunnus tonggol. The tongkol fishing ground during the fishing season ranged around 20 to 40 miles from the landing base. When not during the tongkol fishing season, fishers catch more tongkol-associated species dominated by Hilsa keele at distances around 10 to 20 miles from the landing base. Tongkol-associated species identified 38 species from 13 families. The annual catch of tongkol fluctuated annually, but the trend of A. thazard catch declined. The increase in catch of T. tonggol since 2013 could potentially decline if not appropriately managed, considering that T. tonggol dominates the catch of tongkol commodity at TPI Kranji up to 77.11%, followed by E. affinis with 18.98% and A. thazard with 3.91%. The average annual catch of tongkol commodity at TPI Kranji from 2013 to 2023 is 1,641.13 tons per year. TPI Kranji has to avoid additional fishing effort in the peak fishing season due to the decreasing stock trends.
Indopacific, monsoon cycle, multispecies fishery, neritic tuna, participatory mapping
Copyright (c) 2026 RENGGA RETNO LAILA SAPUTRI, AKHSAN FIKRILLAH PARICAHYA https://creativecommons.org/licenses/by-nc-sa/4.0
Photo-physiological thermal stress responses of Echinopora forskaliana from shaded and light-exposed environments around Rodrigues Island, Western Indian Ocean
Abstract. Jeetun S, Ricot M, Jogee SY, Taleb-Hossenkhan N, Ramah S, Perrine JS, Kaullysing D, Bhagooli R. 2025. Photo-physiological thermal stress responses of Echinopora forskaliana from shaded and light-exposed environments around Rodrigues Island, Western Indian Ocean. Indo Pac J Ocean Life 9: 111-123. Corals in shaded and exposed habitats experience variable heat and light stresses, impacting their photosynthetic performance and resilience to thermal stress. This study examined bleaching, photosynthetic performance, and growth patterns of Echinopora forskaliana (Milne Edwards & Haime, 1849) in shaded and exposed environments at St. François, Rodrigues Island. Bleaching prevalence and colony sizes were recorded using three belt transects. Field observations in 2018 revealed healthy-looking colonies in shaded habitats, while colonies in exposed habitats showed bleaching. Responses of healthy-looking E. forskaliana colonies from both habitats were assessed under exposure to 29 and 32°C. Effective quantum yield at Photosystem II (?PSII), maximum relative electron transport rate (rETRmax), and maximum non-photochemical quenching (NPQmax) were measured at the start, and after 3 and 12 hours of exposure. Field bleaching surveys showed that 93.3% of exposed colonies were pale/bleached, while shaded ones remained unaffected and were significantly larger (42.1±9.0 cm). Thermal stress at 32°C and 206.5±27.0 Lux caused steep declines in ?PSII (99.7%), rETRmax (93.5%), and NPQmax (97.37%) in exposed colonies after 12 hours, while shaded colonies maintained their photosynthetic performance. These findings suggest that shaded habitats may act as refugia for corals under climate-induced thermal stress, highlighting the need for adaptive conservation and management approaches. The urgency of adaptive conservation and management approaches is underscored, as these findings highlight the need for immediate action to protect these crucial habitats.
Bleaching susceptibility, climate change, coral, Echinopora forskaliana, PAM, Rodrigues, thermal stress
Copyright (c) 2025 Indo Pacific Journal of Ocean Life
Aggregation behavior of suspension-feeding sea cucumbers in a tropical lagoon system of Rodrigues Island, Western Indian Ocean
Abstract. Gerzer F, Kaullysing D, Ramah S, Bhagooli R. 2025. Aggregation behavior of suspension-feeding sea cucumbers in a tropical lagoon system of Rodrigues Island, Western Indian Ocean. Indo Pac J Ocean Life 9: 124-132. Suspension-feeding holothurians exhibit unique behavioral and ecological adaptations when compared to deposit-feeding sea cucumbers. Their population drivers, habitat preferences, and niche partitioning, however, remain poorly understood. In this study, we document a high-density aggregation of Holothuria cinerascens (Brandt, 1835) (16.9 ± 3.11 ind/m²), which was substantially higher than the coexisting deposit-feeders' density (Holothuria atra Jaeger, 1833: 0.8 ± 0.9 ind/m²; Stichopus horrens Selenka, 1867: 0.3 ± 0.5 ind/m²). The study site in Torrent, located on Rodrigues Island's east coast, is characterized by sandy flats and occasional limestone structures that clearly indicate habitat partitioning. The limestone structure along the transect showed 100% niche occupation by H. cinerascens, and the sandy flat had a composition of 72.7% H. atra and 27.3% S. horrens. The limestone's structural complexity provides a variety of crevices, access to water flow, predatory refuge, and attachment opportunities, ultimately creating a suitable habitat for suspension-feeding holothurians. Additionally, trade wind-generated hydrodynamics on Rodrigues Island likely enhance suspended nutrient flux on the east coast, favoring suspension-feeding plasticity of the sometimes trophically facultative H. cinerascens. These findings give insights into holothurian niche specialization, driven by microhabitat structure, hydrodynamic conditions, and trophic plasticity, delivering possible implications on conservation and mariculture strategies, as well as enhancing the overall understanding of holothurian ecology.
Biogeograph aggregation behavior, high density occurrence, Holothuria cinerascens, niche differentiation, suspension-feeding sea cucumber
Short Communication: First Indian records and range expansion of three epitoniid gastropods in the Gulf of Mannar, India
Abstract. Kumar RR, Ardovini R, Venkatraman C, Pakchirajan P, Rajappa B. 2026. Short Communication: First Indian records and range expansion of three epitoniid gastropods in the Gulf of Mannar, India. Indo Pac J Ocean Life 10 (1): o100101. https://doi.org/10.13057/oceanlife/o100101. The Gulf of Mannar, located along the southeast coast of India, is recognized as a global biodiversity hotspot, yet several molluscan groups remain poorly documented. By documenting their occurrence, this study provides evidence of range expansion and contributes to understanding the biogeographical patterns of the family in the Indo-Pacific region. This study reports the first confirmed Indian records of three epitoniid gastropods: Epitonium angustum and Epitonium zatrephes, and the first distributional record of Epidendrium aureum from the Gulf of Mannar thereby extending their known distributional ranges into the northern Indian Ocean. A key aspect of this study was the careful examination and comparison of morphological characters, including shell sculpture, coloration, and protoconch features, which were carefully examined and compared with authoritative taxonomic descriptions for accurate species identification. These new records provide essential baseline data for further investigations on taxonomy, systematics, and ecological interactions of Epitoniidae in Indian waters. Considering the ecological roles of epitoniids as specialized ectoparasites of sea anemones, their presence may also have implications for understanding trophic relationships in coral reef ecosystems.
Distribution, Epidendrium aureum, Epitonium angustum, Epitonium zatrephes, marine biodiversity
Copyright (c) 2026 RUPAVATH RAJENDAR KUMAR, ROBERTO ARDOVINI, CHINNADURAI VENKATRAMAN, PADMANABAN PAKCHIRAJAN, BABU RAJAPPA https://creativecommons.org/licenses/by-nc-sa/4.0
Coral diseases and associated photosynthetic responses around Rodrigues Island, Western Indian Ocean
Abstract. Jogee SY, Anasamy M, Jeetun S, Ricot M, Ramkalam M, Korimbocus A, Kaullysing D, Nascimento B, Casareto BE, Suzuki Y, Wijayanti DP, Bhagooli R. 2025. Coral diseases and associated photosynthetic responses around Rodrigues Island, Western Indian Ocean. Indo Pac J Ocean Life 9: 100-110. The coral reefs of Rodrigues Island are among the most biodiverse ecosystems in the Western Indian Ocean (WIO) but are increasingly threatened by coral diseases. While disease prevalence has been documented, its physiological impacts remain poorly understood. This study assessed the photo-physiological responses of four reef-building coral species (Montipora sp., Platygyra sp., Acropora sp., Favia sp.) affected by Black Band Disease (BBD), Skeletal Eroding Band (SEB), White Band (WB), and White Syndrome (WS). Coral fragments containing both diseased and visually healthy tissues were collected from four sites and analyzed in situ using a Junior-Pulse-Amplitude-Modulated (PAM) fluorometer. Parameters measured included maximum quantum yield (Fv/Fm), maximum relative electron transport rate (rETRmax), maximum non-photochemical quenching (NPQmax), initial slope before saturation (?), post-saturation slope (?), and minimum saturating irradiance (Ik), derived from rapid light curves. Diseased tissues generally exhibited reduced photosynthetic performance, with BBD in Montipora sp. and SEB in Favia sp. showing the most pronounced declines in Fv/Fm and ?, along with altered ? and NPQmax values. In contrast, WB and WS had limited or non-significant effects on the measured parameters. These results highlight disease and species-specific vulnerabilities, indicating that some coral-algal symbioses are more susceptible to functional impairment. In the context of climate change, disease-driven stress could accelerate reef degradation, especially in isolated islands like Rodrigues. Integrating photo-physiological monitoring into routine reef health surveys can enhance early detection of functional decline, guide species-targeted restoration, and strengthen adaptive management strategies to safeguard the resilience of Rodrigues’ reefs and other WIO coral ecosystems.
Chlorophyll fluorescence, coral disease, PAM, photo-physiology, Rodrigues Island, species-specific vulnerability
Spatio-temporal density patterns of corallivorous invertebrates around Rodrigues Island, Western Indian Ocean
Abstract. Priest JS, Ramah S, Ramkalam M, Korimbocus AM, Bhagooli R, Kaullysing D. 2025. Spatio-temporal density patterns of corallivorous invertebrates around Rodrigues Island, Western Indian Ocean. Indo Pac J Ocean Life 9: 92-99. Coral reef ecosystems globally are subject to multiple stressors making them targets for corallivore predation by organisms such as the crown-of-thorns starfish (COTS), Acanthaster (Gervais 1841) and gastropods, mainly Drupella (Thiele 1925). Around Rodrigues Island, little is known about COTS and gastropod corallivory. Surveys to assess COTS and Drupella cornus (Röding 1798) density were conducted using the belt transect method and random quadrat sampling, respectively, around Rodrigues Island from 2017 to 2020 at least once at six lagoon sites (1-2 m). In April 2024, additional surveys were carried out at nine lagoon sites (1-2 m) and seven dive sites (9-28 m), including previously surveyed locations. During this study, no COTS were observed along the surveyed transects, however, suspected COTS feeding scars were spotted on some coral colonies at two lagoonal sites. Significant spatio-temporal variations in D. cornus density were observed, with considerable increases at Rivière Banane from 0.07 ± 0.07 ind/m2 in 2018 to 0.93 ± 0.48 ind/m2 in 2024 and Var Brûlée from 0.40 ± 0.16 ind/m2 in 2017 to 2.07 ± 0.89 ind/m2 in 2024. Two-way ANOVA test revealed significant interaction between site and year (p < 0.01), suggesting that both spatial (site) and temporal (year) factors interact in influencing D. cornus densities. These findings suggest potential reef stress, possibly caused by fishing pressure, predator loss, and/or rising sea temperatures, and highlight the necessity for corallivore monitoring and intervention to protect the health and resilience of the coral reefs of Rodrigues. The study revealed that D. cornus, rather than COTS, poses a potential threat to Rodrigues reefs, particularly at Var?Brûlée and Rivière?Banane. Further research is warranted to gather additional data on corallivore distribution and their impact on the coral reefs of Rodrigues.
Acanthaster, corallivory, crown-of-thorns starfish, Drupella cornus, Rodrigues
Herbivorous fish biomass and benthic composition around Rodrigues Island, Western Indian Ocean
Abstract. Ricot M, Jeetun S, Jogee SY, Anasamy M, Kaullysing D, Taleb-Hossenkhan N, Bhagooli R. 2025. Herbivorous fish biomass and benthic composition around Rodrigues Island, Western Indian Ocean. Indo Pac J Ocean Life 9: 79-89. Herbivorous reef fish play a critical role in maintaining coral reef resilience by controlling algal growth and facilitating coral recovery. This study assessed the biomass of herbivorous fish and benthic composition across coral-dominated (high live hard coral cover >20%) and non-coral-dominated (low live hard coral cover <20%) habitats at five sites, namely, Aquarium, Plateau Bénitier, Ti Trou, Antonio's Finger, and Couzoupa around Rodrigues Island, Western Indian Ocean. Fish biomass was estimated using triplicate belt transects, focusing on key herbivorous families (Acanthuridae and Scaridae), while benthic composition was quantified to identify habitat-specific patterns. Results revealed higher herbivorous fish biomass in coral-dominated habitats (1028.54±847.78 kg/ha) compared to non-coral-dominated habitats (728.34±229.36 kg/ha). No significant differences (p>0.05) were observed in the biomass of the Acanthuridae (p=0.56) nor Scaridae (p=0.36) fish families between coral-dominated and non-coral-dominated habitats. Coral-dominated habitats exhibited higher live hard coral cover (64.03±9.55%) compared to non-coral-dominated habitats (7.3±1.32%). Additionally, a significant interaction between protection status and live coral cover was observed, indicating that both protection measures and coral cover levels jointly influence herbivorous fish biomass. These findings underscore the importance of benthic habitat structure, particularly coral cover, in shaping herbivorous fish communities and supporting higher fish biomass in coral-dominated habitats.
Coral reef, functional groups, marine protected areas, reef fish, reef fish assemblages, reef resilience, tropical islands
Structure and composition of mollusks (Gastropoda and Bivalvia) in the coastal karstic ecosystems of Gunung Kidul, Yogyakarta, Indonesia
Abstract. Alghifari ZA, Nur FA, Sari YD, Anam ZK, Chairunisa S, Yap CK, Setyawan AD. 2025. Structure and composition of mollusks (Gastropoda and Bivalvia) in the coastal karstic ecosystems of Gunung Kidul, Yogyakarta, Indonesia. Indo Pac J Ocean Life 9: 64-78. Karstic coastal ecosystems in southern Java remain underexplored in terms of intertidal biodiversity, particularly mollusks. This study examines the structure, composition, and ecological traits of mollusk assemblages across five karst beach sites in Gunung Kidul, Yogyakarta, Indonesia: Pringjono, Torohudan, Ngrawah, Dadap Ayam, and Ngrenehan. A total of 28 valid mollusks species were identified from two classes—Gastropoda (23 species) and Bivalvia (5 species)—representing 17 families. Species richness and density varied across sites, shaped by substrate heterogeneity, tidal exposure, and anthropogenic influence. Gastropods dominated rocky and tide pool microhabitats, while bivalves were more abundant in sediment-rich, sheltered areas. Functional guilds included grazers, filter feeders, and predators, indicating a complex trophic structure. Microhabitat specificity and patchy distribution suggest that environmental filtering and habitat fragmentation play major roles in community assembly. Taxonomic verification was essential, leading to the exclusion of 17 misidentified taxa initially reported. This study highlights the ecological importance and vulnerability of molluscan communities in tropical karst ecosystems. It underscores the need for site-specific conservation strategies, such as protecting rocky and tide pool microhabitats for gastropods and sediment-rich, sheltered areas for bivalves, and improved taxonomic rigor in coastal biodiversity assessments.
Bivalvia, Gastropoda, karst beach, mollusca, species richness
Short Communication: Spatial distribution and diversity of intertidal crustaceans in karstic beaches of southern Java, Indonesia
Abstract. Hartono DAN, Widowati D, Saputra EF, Wicaksono FR, Pramadaningtyas PS, Yap CK, Setyawan AD. 2025. Short Communication: Spatial distribution and diversity of intertidal crustaceans in karstic beaches of southern Java, Indonesia. Indo Pac J Ocean Life 9: 26-35. Karstic coastal systems in tropical regions are often overlooked in biodiversity assessments despite their ecological complexity and vulnerability. This study investigates the species composition, diversity, and environmental drivers of intertidal crustacean communities across five karstic beaches in Gunungkidul, Indonesia. A total of 18 crustacean species were recorded, with Coenobita scaevola emerging as the most dominant and widely distributed taxon. Species richness and the Shannon-Wiener diversity index (H?) varied significantly among sites, with Ngrenehan Beach exhibiting the highest diversity (H?=2.18) and Ngrawah the lowest (H?=1.23). Among the measured abiotic parameters, dissolved oxygen (DO) showed the strongest positive correlation with H? (r=0.92, p<0.05), indicating its critical role in structuring crustacean assemblages. Cluster analysis revealed two distinct site groups, reflecting spatial heterogeneity in species composition likely shaped by microhabitat features. The findings underscore the importance of karstic intertidal habitats as localized biodiversity reservoirs and emphasize the need for site-specific conservation strategies and long-term ecological monitoring in tropical coastal regions.
Bray-Curtis similarity, Coenobita scaevola, crustacean diversity, dissolved oxygen, Gunungkidul, karst beach
Review: Bioactive compounds and therapeutic potentials of coral reef organisms
Abstract. Syamsi RN, Rosyida SH, Allysa TN, Hanifah W, Izdihar RS, Naim DM, Setyawan AD. 2025. Review: Bioactive compounds and therapeutic potentials of coral reef organisms. Indo Pac J Ocean Life 9: 46-63. Coral reef ecosystems harbor an extraordinary diversity of marine organisms that are increasingly recognized as rich sources of bioactive compounds. This review examines the biodiversity, chemical composition, and pharmacological activities of coral reef organisms, with a particular focus on soft corals, macroalgae, sponges, and their associated microorganisms. Key classes of compounds—including terpenoids, alkaloids, steroids, and sulfated polysaccharides—have demonstrated potent antibacterial, antiviral, anti-inflammatory, anticancer, and immunomodulatory properties in both in vitro and in vivo studies. Beyond laboratory findings, this study highlights the ethnopharmacological significance of coral-derived organisms in traditional healing systems across Southeast Asian coastal communities. It also explores the continuity and erosion of these practices, and discusses their potential integration into modern complementary medicine frameworks. The final sections address critical challenges in coral-based drug discovery, such as taxonomic underrepresentation, unsustainable harvesting, and regulatory constraints. At the same time, the review identifies emerging opportunities facilitated by omics technologies, synthetic biology, and interdisciplinary collaboration. By synthesizing biomedical and cultural perspectives, this review underscores the immense therapeutic potential of coral reef biodiversity and calls for integrated conservation and research strategies that ensure both ecological integrity and equitable innovation.
Complementary medicine, drug discovery, ethnopharmacology, pharmacological activity, traditional medicine
Plastic waste characteristics and community responses in mangrove-influenced coastal villages of Kampung Laut, Cilacap, Indonesia
Abstract. Astuti AR, Putri DS, Arlysia V, Santika YE, Safitri FE, Setyawan AD. 2025. Plastic waste characteristics and community responses in mangrove-influenced coastal villages of Kampung Laut, Cilacap, Indonesia. Indo Pac J Ocean Life 9: 36-45. Plastic pollution presents a significant threat to coastal and mangrove ecosystems, particularly in low-income and infrastructure-deficient regions of Southeast Asia. This study investigates the composition of plastic waste and the perceptions and behaviors of local communities in three mangrove-influenced villages of Kampung Laut Sub-district, Cilacap, Indonesia. Field surveys conducted in 33 sampling plots revealed that plastic waste was predominantly composed of single-use items, especially polypropylene (PP), low-density polyethylene (LDPE), and polyethylene terephthalate (PET), reflecting both domestic consumption and livelihood-related activities such as fisheries and aquaculture. A structured questionnaire grounded in the Knowledge-Attitude-Practice (KAP) framework was administered to 91 respondents. Statistical analyses, including Principal Component Analysis, Pearson correlation, and Partial Least Squares Structural Equation Modeling (PLS-SEM), were employed to explore the relationships among cognitive and behavioral variables. The results indicated that knowledge significantly influenced attitudes, which were positively associated with pro-environmental behavior; however, knowledge alone did not directly predict action. Sociodemographic constraints—particularly low education and income levels—further limited behavioral change despite moderate awareness. Comparisons with regional and global studies suggest that such gaps are common in coastal communities. These findings underscore the need for integrated waste governance strategies that combine education, infrastructure, and locally adapted regulations, alongside stronger integration between plastic waste management and mangrove conservation efforts.
Coastal village, KAP model, mangrove ecosystem, plastic pollution, waste behavior
Identification and diversity analysis of rabbitfish (Acanthuriformes: Siganidae) from Sedayu Lawas Coastline, Lamongan District, Indonesia
Abstract. Paricahya AF, Harahap MAR, Amalia E, Hidayat AN, Hidayati DA. 2026. Identification and diversity analysis of rabbitfish (Acanthuriformes: Siganidae) from Sedayu Lawas Coastline, Lamongan District, Indonesia. Indo Pac J Ocean Life 10 (1): o100104. https://doi.org/10.13057/oceanlife/o100104. The Siganidae family has been widely studied, but the previous study still focused on a limited number of species, such as Siganus canaliculatus. Consequently, the potential distribution and diversity of other Siganidae species in specific regions remain poorly documented, placing their populations at high risk of overexploitation due to limited data collection and their incidental capture as bycatch. In this study, specimens were collected using several types of fishing gear, each adapted to one of three habitat types in Sedayu Lawas Coastline, Lamongan District, Indonesia: Mangrove Estuary (MaE), Muddy Beach (MuB), and Coral Beach (CoB). Data on fish catches were collected once a week for three months (January-March 2025). Species were identified using key morphological characteristics, resulting in the identification of a total of 1,046 specimens. Four of the seven recorded Siganidae species were captured, including Siganus guttatus, which exhibited two distinct variants. Diversity was assessed using Species Abundance (Sa), the Shannon-Wiener Index (H′), and the Simpson Dominance Index (C). The highest Sa values were 35.2% for Siganus javus at the CoB site, 38.4% for S. canaliculatus at the MaE site, and 43.4% for S. canaliculatus at the MuB site. The mean H′ and C values varied among sites, with 0.97, 0.99, and 1.09 for H′, and 0.39, 0.41, and 0.36 for C at MaE, MuB, and CoB, respectively. These values also differed across months, with H′ values of 1.12, 0.69, and 1.24 and C values of 0.35, 0.50, and 0.31 for January, February, and March, respectively. The results indicate that the highest abundance was observed in CoB, however, the presence of other habitats also contributes to supporting populations of various Siganidae species. Implementing habitat based management, strengthening ecological conservation, and centralizing species specific catch data are essential to enhance the sustainability of Siganidae fisheries.
Diversity study, habitats, morphology, rabbitfish, Siganidae
Copyright (c) 2026 AKHSAN FIKRILLAH PARICAHYA, MUHAMMAD ALFIANDI RACHMAD HARAHAP, ELOK AMALIA, AHMAD NUR HIDAYAT, DESY AMALIA HIDAYATI https://creativecommons.org/licenses/by-nc-sa/4.0
Diversity of soil macrofauna in the coastal karst area of Gunung Sewu, Paranggupito Sub-district, Wonogiri District, Indonesia
Abstract. Pramono CL, Ramadhani G, Zahra JA, Wahyuningtyas J, Nugroho GD, Indrawan M, Setyawan AD. 2025. Diversity of soil macrofauna in the coastal karst area of Gunung Sewu, Paranggupito Sub-district, ??Wonogiri District, Indonesia. Indo Pac J Ocean Life 9: 1-11. As a region with unique characteristics of limestone formations and a complex drainage system, the karst region faces environmental challenges that affect its macrofauna diversity. This study aims to identify soil macrofauna and analyze the relationship between abiotic factors that influence their presence in agroforestry land in a coastal karst area of Gunung Sewu, a United Nations Educational, Scientific and Cultural Organization (UNESCO) Global Geopark, including Paranggupito Village, Gudangharjo Village, and Gunturharjo Village of Paranggupito Sub-district, Wonogiri District, Central Java, Indonesia, that was conducted in October 2024. To achieve the study's objectives, we measured abiotic factors, including physical and chemical elements of the environment, such as temperature, air humidity, soil humidity, light intensity, altitude, soil pH, and soil temperature. This study involved two types of plantation patterns in each village, namely woody and intercropping vegetation, with 18 research points divided into 2 stations in each area, each consisting of 3 sub-stations with 90 pitfall traps. Soil macrofauna samples were collected using the pitfall trap method, and data were analyzed using a diversity index and Pearson correlation between the diversity of soil macrofauna and its abiotic factors. The results showed that 16 different species were found in all three villages, and the sugar ant (Camponotus consobrinus) species dominated the intercropping vegetation, with a total of 347 individuals and 104 individuals in woody vegetation. The diversity of macrofauna at each station was relatively low. In contrast, the relationship between abiotic factors and diversity showed varying correlations, such as soil moisture, light intensity, and air humidity were negatively correlated by -0.59, -0.41, and -0.39, respectively, which means when the values increase, then the diversity tends to decrease and vice versa; In contrast, pH soil, soil temperature and air temperature were positively correlated by 0.79, 0.62, 0.78, respectively showing a moderately strong relationship whereas the soil values increase, the diversity also tends to increase. The discovery of soil macrofauna species in this study shows that macrofauna are able to survive in karst areas, which have an important role in maintaining soil health and fertility, so their existence must be maintained and preserved, highlighting their resilience and the importance of preserving their habitats to maintain soil health and fertility.
Coastal, intercropping, karst, pitfall trap, vegetation, woody
Structure and composition of Ophiuroidea (Echinodermata) at three beaches in Gunungkidul, Yogyakarta, Indonesia
Abstract. Yap CK, Putri RRA, Manullang RH, Andrianto R, Salsabila S, Nugroho GD, Setyawan AD. 2024. Structure and composition of Ophiuroidea (Echinodermata) at three beaches in Gunungkidul, Yogyakarta, Indonesia. Indo Pac J Ocean Life 8: 112-121. Ophiuroidea (Echinodermata) contribute significantly to species diversity, abundance, and biomass of the world's marine fauna. The study aimed to determine the composition structure of Ophiuroidea in the coastal area of Gunungkidul, Yogyakarta, Indonesia. It was conducted in March 2024 at Pringjono Beach, Torohudan Beach, and Dadap Ayam Beach, at low tide with a sampling area of about 1,000 m2 on each beach. We recorded the name of the species, the number of individuals, and description of visible characteristics as well as pH, Dissolved Oxygen (DO), and seawater temperature. The data were analyzed using the density, Shannon-Wiener diversity index (H'), evenness index (E), and richness index (R). We found five species from two families, Ophiocomidae, with Breviturma dentata (Müller and Troschel, 1842); Ophiocoma schoenleinii (Müller and Troschel, 1842); Ophiocoma scolopendrina (Lamarck, 1816); Ophiocoma erinaceus (Müller and Troschel, 1842); and Ophiomyxidae, with only one species, Ophiarachna affinis (Lütken, 1869). Breviturma dentata was the most dominant species, with 495 individuals. Pringjono Beach had the highest density, followed by Torohudan Beach and Dadap Ayam Beach. Then, for H' and E were low, but R was moderate. Water temperature, pH, and DO may affect species density in these areas.
Echinodermata, ecosystem, environment, Gunungkidul, Ophiuroidea
Potential and strategy for ecotourism development in the coastal area of Paranggupito Sub-district, Wonogiri District, Indonesia
Abstract. Afifah RN, Alfiyah LK, Bernadetta MP, Simanjuntak MPD, Setyaningrum M, Sunarto, Setyawan AD. 2025. Potential and strategy for ecotourism development in the coastal area of Paranggupito Sub-district, Wonogiri District, Indonesia. Indo Pac J Ocean Life 9: 12-25. Ecotourism emphasizes environmental conservation while supporting nature preservation and local community welfare. It arose as a response to the harmful effects of conventional tourism, such as ecosystem damage, biodiversity loss, and community disruption, aiming instead for responsible tourism that protects nature. This study aims to determine the management conditions of Karang Payung, Nampu, and Klothok Beaches in Paranggupito Sub-district, Wonogiri District, Central Java, Indonesia and the potential of TAO (Tourist Attraction Objects) that have been operating, as well as beach development strategies. Data collection was carried out by observation and interviews using simple random sampling method to 102 people throughout the beach, which was then analyzed by ADO ODTWA (Analysis of Operational Areas of Objects and Natural Tourism Attractions) method to determine the potential feasibility of the area, then continued with SWOT (Strengths, Weakness, Opportunity, and Threats) analysis as a development recommendation. The results of the ADO ODTWA analysis show that the accessibility aspect of Nampu Beach has a feasibility index on the facilities aspect of 59.50% (not feasible). The accessibility index of Karang Payung Beach is 60.29% (not feasible), and the facility index is 65.71% (not feasible). The results of this analysis indicate the necessity for improvement and development of attractions and accessibility. The results of the SWOT analysis on Nampu Beach and Karang Payung Beach necessitate the formulation of a strategic plan.
ADO-ODTWA, nature tourism, SWOT, tourist attraction
Mangrove dynamics on the Madura Island coast, Indonesia, analyzed through NDVI: Balancing degradation and restoration efforts
Abstract. Ramadhani G, Wahyuningtyas J, Arifiandita DM, Ayuningtyas HR, Deristani A, Ulumuddin YI, Setyawan AD. 2024. Mangrove dynamics on the Madura Island coast, Indonesia, analyzed through NDVI: Balancing degradation and restoration efforts. Indo Pac J Ocean Life 8: 101-111. Mangrove ecosystems are plant communities that thrive at the interface between land and sea, but they face significant threats, particularly from land conversion. The mangrove forests along the coast of Madura have experienced a decline in coverage due to such conversion. This study offers valuable insights into changes in mangrove areas and uses NDVI analysis to assess these changes from 2019 to 2024. The study focuses on monitoring mangrove forest distribution and changes in the Bangkalan, Sampang, Pamekasan, and Sumenep coastal areas. Primary data were obtained from Sentinel-2A - 2A satellite imagery of Madura. Data analysis used the Kappa Analysis method to validate mangrove density classification. Results showed an increase in mangrove coverage in Bangkalan between 2019 and 2024, with the moderately dense category rising from 348.9 to 355.3 hectares and the dense category increasing from 114.7 to 150.1 hectares. Similarly, in Pamekasan, the moderately dense classification grew from 305.4 to 409.3 hectares. However, overall, the reduction in mangrove forest area was more significant than the increase. The Kappa accuracy of 70% indicated moderate reliability, with data discrepancies in 14 out of 40 points. In Madura's mangrove forests, conservation efforts include education, conservation initiatives, and community empowerment through sustainable environmental communication strategies.
Density, Health, Kappa Coefficient, Mangrove, NDVI
Water resource sustainability in the coastal-karst area of Paranggupito Sub-district, Wonogiri, Indonesia
Abstract. Aryanto AEP, Herbowo ACF, Aftsari AI, Maharani MP, Worokinkkin SPDA, Setyawan AD. 2024. Water resource sustainability in the coastal-karst area of Paranggupito Sub-district, Wonogiri, Indonesia. Intl J Trop Drylands 8: 94-100. The karst region, with its unique geological landscape characterized by barren limestone hills, presents a significant challenge for the local population in processing clean water. Therefore, sustainable water source management is of utmost importance. This study aims to examine the water usage in Gunturharjo, Gudangharjo, and Paranggupito Villages and identify the water sources used to meet daily needs. The method used in this research is a descriptive-qualitative approach. Primary data were obtained from interviews and surveys conducted in the villages. In comparison, secondary data were obtained through a literature review of scientific articles, books, and websites related to water management. This study shows that in the three villages of Paranggupito Sub-district, Wonogiri District, most water sources are heavily influenced by the seasons. Based on interviews, 46% of the community obtains water for daily needs from communally managed water sources, while the remaining 54% manage their water or rely on privately owned dug wells. Otherwise, the regulations or applicable rules have not yet been implemented, so the management and sustainability of water resources are at risk. In terms of sustainability, the management of water resources can meet daily water needs for the next few years. Still, it does not guarantee the sustainability and quality of water, especially for drinking purposes.
Karst, Paranggupito, springs, sustainability, water management
Species diversity of mangrove at tree and pole level in Sampang and Pamekasan Districts, Madura Island, Indonesia
Abstract. Lathifah MN, Muazulfa TI, Nisa WK, Raharjo YAA, Arta YPA, Setyawan AD. 2024. Species diversity of mangrove at tree and pole level in Sampang and Pamekasan Districts, Madura Island, Indonesia. Indo Pac J Ocean Life 8: 84-93. Madura Island, Indonesia, located northeast of Java Island, features naturally occurring mangrove vegetation along its coastline. Mangrove forests encompass approximately 75% of the coastlines in tropical and subtropical regions. The diversity of mangrove species needs to be assessed to determine the current situation and provide an evaluation of biodiversity conservation. In this research, the mangrove species diversity at both tree and pole level in the coast of Taddan Village, Sampang District (7°13'7.53"S, 113°16'15.93"E), Song Osong Beach, Sampang District (7°13'19.55"S, 113°12'10.63"E), Branta Tinggi Village, Pamekasan District (7°13'19.53"S, 113°27'12.45"E) and Tlanakan Village, Pamekasan District (7°13'16.24"S, 113°26'11.68"E), Madura Island, East Java, Indonesia were determined. A 150 m long transect plot was established at each station, yielding 40 plots for 4 stations. Abiotic factors, including temperature, salinity, pH, and soil moisture at the study location, were also measured. The Shannon-Wiener Index (H') is used to analyze the species diversity index; Pielou's Evenness and Margalef's Richness index analysis are also calculated in this research. The results indicated that there are 3 species consisting of Rhizophora stylosa, Avicennia marina, and Sonneratia alba. The diversity analysis showed a moderate category (H' range: 1.85-2.56), with the highest values at both tree and pole levels recorded at Song Osong Beach (H' tree: 2.56, H' pole: 2.19). Meanwhile, the lowest value at the tree level was recorded at Taddan Village (H': 1.99), and the pole level is at Branta Tinggi Village (H': 1.85). The Margalef's richness values obtained range from D: 39.34-95.58 (high) at the tree level and D: 13.61-98.00 (high) at the pole level. The results of Pielou's evenness calculations indicate low evenness at all stations (J' tree: 0.05-0.27: J' pole: 0.02-0.48. In an ecosystem with a medium-level diversity index, vegetation can grow with sufficient support but also faces significant threats. In this instance, the threats arise from anthropogenic activities, such as illegal logging and land conversion for aquaculture purposes. The implementation of mangrove maintenance efforts can be achieved through protection and rehabilitation initiatives that collaborate with local governments and engage indigenous communities.
Diversity index, Madura Island, mangrove, Shannon-Wiener Index
Copyright (c) 2024 Indo Pacific Journal of Ocean Life
Review: The nutritional value and health benefits of kawakawa (Euthynnus affinis)
Abstract. Rahma HS, Ayuningtyas HR, Nabila I, Annafi DN, Nurwulandari M, Indrawan M, Dadiono MS, MD Naim D, Setyawan AD. 2024. Review: The nutritional value and health benefits of kawakawa (Euthynnus affinis). Indo Pac J Ocean Life 8: 72-83. Kawakawa (Tuna), or Euthynnus affinis (Cantor, 1849), is a species of pelagic fish of the Scombridae family with a vast habitat and distribution in tropical and subtropical waters in the Indo-Pacific region. This literature review aims to provide an understanding of the habitat, morphological characteristics, nutritional content, and benefits of kawakawa for health. Kawakawa prefer warm waters with a temperature of 20-30°C. As a pelagic fish, kawakawa spends most of its life in the open water column and away from the seabed. Kawakawa morphologically has unique characteristics, namely oblique and curved black stripes on the ribs and the presence of a pattern of black stripes between the abdomen and fins. This fish can grow to a maximum weight of 14 kg and a maximum fork length (FL) of 100 cm. The nutritional content of kawakawa is diverse, and it includes protein, omega-3, omega-6, selenium, vitamin D, and DHA. The protein content of kawakawa ranges from 20 to 25%, with 0.87% fat, which is lower than that of other fish species. With its high protein, low fat, and strong omega-3 fatty acid profile, kawakawa has a high overall nutritional value, making it a nutrient-dense food choice. The nutritional content in kawakawa has health benefits, namely preventing stunting, reducing heart risk, preventing cancer, maintaining eye health, increasing body immunity, preventing anemia, and maintaining bone health.
Diversity and composition of Crustacean and Mollusk in mangrove area in Sampang and Pamekasan Districts, Madura Island, Indonesia
Abstract. Haqqi MRA, Sholichah DM, Ashila J, Reza AD, Indrawan M, Dadiono MS, Yap CK, Rahim KABA, Setyawan AD. 2024. Diversity and composition of Crustacean and Mollusk in mangrove area in Sampang and Pamekasan Districts, Madura Island, Indonesia. Indo Pac J Ocean Life 8: 59-71. Mangrove ecosystem in Indonesia is the largest in the world and contains various biota with a great interest to study. An example of mangrove ecosystems can be found in Sampang and Pamekasan Districts, Madura Island which have a high potential for biodiversity, such as Crustacean and Mollusk. However, information regarding the diversity of Crustaceans and Mollusks in that territory is still very limited. Therefore, this research was conducted to assess the diversity of Crustaceans and Mollusks in the mangrove area of Sampang and Pamekasan Districts. The study was conducted in December 2023 with data collection located at four stations: (i) Taddan, Camplong Sub-district and (ii) Song-Osong Beach, Sampang Sub-district, both in Sampang District; (iii) Branta Tinggi and (iv) Raya Ambat Street both in Tlanakan Sub-district, Pamekasan District. Data on biotic and abiotic environmental parameters was collected and sampling of Crustacean and Mollusk was conducted using Visual Encounter Survey (VES) and direct catching. The results showed that mangrove ecosystem in Sampang and Pamekasan Districts had certain similarities, i.e. both were composed by vegetation of Sonneratia alba, Avicennia marina, Sonneratia caseolaris, and Rhizophora mucronata. The environmental parameters measurement showed that the study area location has warm temperatures, wet soil, neutral pH, and relatively low salinity compared to Madura Strait. There were 32 Crustacean species with the mostly found was Balanus sp. (barnacle), followed by Clibanarius longitarsus (common hermit crab). The number of Mollusks obtained was 24 species with the mostly found was Pirenella alata and Pirenella cingulata. Based on ecological indices calculation, Crustacean on study area location had moderate diversity, high species richness, high evenness or stable community, and indicates no dominant species. While the Mollusk on study area location had moderate diversity, moderate species richness, high evenness or stable community, and indicates no dominant species. Station 3 (Branta Tinggi) had the highest number of Crustacean species, diversity, species richness, and evenness, while Station 4 (Raya Ambat Street) had the highest number of Mollusk species, diversity, species richness, and evenness.
Crustacean, diversity, environment, Mollusk, mangrove
Diversity of reef fish in the littoral zone of the south coast of Gunungkidul District, Yogyakarta, Indonesia
Abstract. Rahma HS, Ayuningtyas HR, Nabila I, Annafi DN, Dianti, Yap CK, Dadiono MS, Setyawan AD. 2024. Diversity of reef fish in the littoral zone of the south coast of Gunungkidul District, Yogyakarta, Indonesia. Indo Pac J Ocean Life 8: 43-51. Diversity in the intertidal zone plays an important role in the marine ecosystem. The balance of the intertidal zone's ecosystem and environmental health can be inferred from the diversity of fish. This study aims to identify reef fish species diversity in the intertidal zone of the south coast of Gunungkidul, Yogyakarta, Indonesia. The research was conducted on five beaches, i.e., Pringjono, Ngrenehan, Ngrawah, Torohudan, and Dadap Ayam, each with its own distinct ecological features. Survey and exploratory methodologies were utilized to analyze and reveal field findings. Observation and sampling were conducted using the random sampling approach. Data were analyzed using the Shannon Diversity Index (H'), the Evenness Index (E), and the Richness Index (Dmg). The study identified 1,378 individuals comprising 45 species and 28 families. The highest number of individuals was caught at Pringjono Beach, with 369 individuals. Asterropteryx semipunctata and Bathygobius fuscus from the Gobiidae family dominated most stations. The Diversity Index (H') indicated high species diversity across all stations, with the highest value of 3.562 and the lowest of 3.023. For the Evenness Index, most of the five stations were classified as almost evenly distributed, as the lowest value was 0.92 and the highest was 0.97. Meanwhile, the richness index of the fish species at the five research locations is a high category. In sampling stations, there are some differences in abiotic factors, such as salinity, water pH, water temperature, and Dissolved Oxygen (DO), which can affect the composition and distribution of reef fish in the littoral zone in Gunungkidul beach areas.
Diversity Index, Evenness Index, fish abundance, reef fish population
Analysis of mangrove forest ecosystem sustainable management by coastal communities in Sampang District, Madura Island, Indonesia
Abstract. Koesdaryanto NSR, Wijayanti M, Simanjuntak MPD, Fathoni MFM, Sulton MN, Lillo EP, Setyawan AD. 2024. Analysis of mangrove forest ecosystem sustainable management by coastal communities in Sampang District, Madura Island, Indonesia. Indo Pac J Ocean Life 8: 33-42. The mangrove forest ecosystem is important in a coastal area to improve the welfare of coastal villages and increase the productivity of coastal ecosystems. This ecosystem has indicators of sustainability efforts, including ecological, economic, and social dimensions. This study aims to determine the sustainability status of mangrove forest ecosystems and compile recommendations in Taddan and Aeng Sareh Villages, Sampang Sub-district, Sampang District, East Java, Indonesia. This research and data collection was carried out in December 2023. The methods used in data collection are interview techniques and questionnaire distribution. The primary data is processed with the Multidimensional Scaling (MDS) method through Rapid Appraisal for Fisheries (Rapfish), which displays Monte Carlo analysis, and the data results are aligned with previous literature studies. The results of the analysis showed that the sustainability index of mangrove ecosystem management in the two villages was included in the less sustainable category, including ecological dimensions (sustainability index of Taddan and Aeng Sareh Villages respectively namely 62.88 and 21.05), economic (sustainability index of Taddan and Aeng Sareh Villages respectively 35.78 and 40.14), and social (sustainability index of Taddan and Aeng Sareh Villages respectively 42.94 and 39.51). Alternative strategy recommendations that can be applied for sustainable mangrove ecosystem management in Taddan and Aeng Sareh Villages, Sampang, are improving coordination between stakeholders, making patented regulations, training on creativity and productivity of village communities, formulating mangrove ecosystem management programs, routinely carrying out rehabilitation efforts, and increasing awareness from researchers.
Coastal, mangrove ecosystems, Rapfish, strategy, sustainability
Diversity and first record of Porifera (sponges) from Gujarat Coast, India
Abstract. Sabapara Z, Poriya P. 2024. Diversity and first record of Porifera (sponges) from Gujarat Coast, India. Indo Pac J Ocean Life 8: 18-32. The present study represents a significant milestone in understanding sponge diversity in the Gujarat Coastal area. This investigation identified 51 sponge species and classified them into 3 classes and 28 families. Amongst the reported species, 47 species belong to class Demospongiae, followed by Calcarea and Homoscleromorpha, with 2 species, respectively. Remarkably, 24 of these species were previously undocumented along the Gujarat Coastline, while two species, Sycon grantioides Dendy, 1916 and Halichondria (Halichondria) tenuiramosa Dendy, 1922 only reported from the Gujarat Coast in India. Our research involved exploring 11 sites along the coast, with the primary objective of documenting intertidal sponges and exploring valuable insights into their habitat preferences. The study also includes information on the distribution patterns of these species within the region. Except for a few bio-eroding boring sponges, most of the recorded sponge species exhibit an encrusting growth habit. They are typically found in habitats beneath the rocks, zoanthid beds, shallow rock pools, coralline beds, caves-crevices and in close association with other macrofauna and seaweeds. This diverse range of habitats suggests the adaptability and resilience of these sponges in various ecological niches along the Gujarat Coast. The finding of many new records highlights the necessity of ongoing study and conservation initiatives to protect the diverse marine biodiversity of the Gujarat Coastline.
Diversity, first record, Gujarat, India, intertidal, Porifera, sponges
Diversity of waterbirds around Ekasoghi mangrove area, Sumenep, with the first record of Australian tern (Gelochelidon macrotarsa) from Madura Island, Indonesia
Abstract. Andrimida A, Sonhaji A, Hardiyan FZ. 2024. Diversity of waterbirds around Ekasoghi mangrove area, Sumenep, with the first record of Australian tern (Gelochelidon macrotarsa) from Madura Island, Indonesia. Indo Pac J Ocean Life 8: 10-17. Mangrove forests provide an essential habitat for a lot of organisms, and they also provide an important habitat for waterbirds. This study aims to provide an overview of waterbirds' diversity and abundance around Ekasoghi mangrove area situated on the eastern coast of Sumenep, Madura Island on East Java, Indonesia. This research was conducted at three stations, each representing a different habitat type around Ekasoghi mangrove area. Waterbird data was collected using the exploration method, and waterbird species were determined by examining their morphological characteristics. Waterbirds' diversity was determined using the Shannon-Wiener diversity index, and the abundance was determined using the abundance index. Moreover, 38 individuals belonging to 15 species from 4 orders and 6 families were recorded during this study, with more than half belonging to the Charadriiformes order; the waterbird diversity index ranged from the highest 1.97 to the lowest 1.33. Three species with the highest abundance index value are striated heron (Butorides striata) with an abundance index value of 18.42, followed by Javan plover (Anarhynchus javanicus) and common sandpiper (Actitis hypoleucos) as the second with an abundance index value of 13.16. This research also provides the first record of the migrating seabird Australian tern (Gelochelidon macrotarsa) from Madura Island.
Charadriiformes, distribution extension, new record, waterbirds
Enabling conditions toward the rehabilitation and preservation of mangrove ecosystem in Sampang, Madura Island, Indonesia
Abstract. Aftsari I, Pramono CL, Alyodya DA, Nurwulandari M, Sujarta P, Dadiono MS, Yap CK, Setyawan AD. 2024. Enabling conditions for the rehabilitation and preservation of mangrove ecosystem in Sampang, Madura Island, Indonesia. Indo Pac J Ocean Life 8: 1-9. Mangroves are a very productive ecosystem that is important to the environment and human welfare. Rehabilitation activities need to be carried out to restore mangrove forests that have experienced degradation. In doing so, local communities have an important role because their involvement can minimize human disturbance and realize sustainable mangrove management. This research aims to determine the circumstances that can facilitate or prohibit local communities in the rehabilitation of mangrove forests in Sampang District, Madura Island, East Java Province, Indonesia. This research was conducted in two villages in Sampang District, i.e.: Taddan and Gulbung in December 2023 using two methods, namely remote sensing analysis to determine changes in mangrove cover from 2008 to 2023 and in-depth interviews to determine the role and strategies of the community in mangrove rehabilitation. The remote sensing analysis shows significant increase in mangroves in Taddan Village from 54.7757 ha in 2008 to 101.718 ha in 2023 (+46.9422 ha). During the same period, mangroves in Gulbung Village increased from 21.6928 ha to 30.6723 ha (+8.9795 ha), although there was a decreasing trend during the period of 2013-2023. There is a difference in situation between the two villages, where in Taddan there are rehabilitation and conservation activities, increasing mangroves, while in Gulbung some mangroves have been converted into salt ponds, especially during the last decade. The results of the interviews revealed that public knowledge and awareness regarding the benefits and importance of mangrove management are still low. We also found that the facilitation from governments and the formation of community groups might enable the preservation and rehabilitation of mangrove forests.
Mangrove, rehabilitation, remote sensing