Ade Yamindago

Bathymetry plays a crucial role in supporting navigation routes within Indonesian waters. Given the highly dynamic nature of the marine environment, continuous bathymetric mapping is essential. Particularly in Prigi Bay, which holds considerable potential in terms of natural resources, tourism, and serves as the location of the Nusantara Fisheries Port (PPN Prigi). Conventional methods such as echosounders still face limitations in terms of spatial coverage and operational efficiency. A more advanced alternative is Satellite Derived Bathymetry (SDB), which utilizes satellite imagery combined with digital processing algorithms. This study employs Landsat 8 imagery to map seafloor depth and topography using the Stumpf algorithm. The analysis involves comparing band ratio outputs from the Landsat 8 imagery with in-situ depth measurements to evaluate the accuracy of depth estimation. Results indicate that actual water depths in Prigi Bay range from 4.92 m to 67.61 m, while estimations derived from Landsat 8 imagery range from 7.05 m to 57.10 m. The regression model between Landsat 8-derived depths and in-situ measurements produced a coefficient of determination (R²) of 0.6287, a correlation coefficient (r) of 0.792, a Root Mean Square Error (RMSE) of 12.697, and a Normalized Mean Absolute Error (NMAE) of 28.48, indicating a reasonably reliable level of accuracy for satellite-based bathymetric estimations in coastal waters.

Desa Sidoasri, Kabupaten Malang, memiliki potensi ekowisata bahari yang tinggi namun menghadapi tekanan ekologi dan kelembagaan lokal yang terbatas. Program ini bertujuan memberdayakan Pokmaswas dan masyarakat pesisir agar bertransformasi dari pengguna pasif menjadi pengelola aktif ekowisata berkelanjutan. Metode yang digunakan adalah pendekatan partisipatif berbasis komunitas melalui survei awal, FGD, pelatihan Training Ecodiver (selam dasar, identifikasi biota, pemantauan terumbu, dokumentasi), sarasehan desa, pendampingan intensif, serta evaluasi formatif–sumatif. Hasil menunjukkan: (i) penilaian potensi wisata (panorama pantai, trekking, snorkeling–diving, canoeing, GT fishing) memperoleh skor tinggi pada keunikan ekosistem, keterkaitan antarhabitat, dan keterwakilan ekosistem pesisir; (ii) partisipasi, motivasi, dan kapasitas kelembagaan masyarakat meningkat, tercermin dari keterlibatan dalam pemantauan terumbu, pengelolaan homestay, promosi digital, serta penguatan rencana kerja Pokmaswas; (iii) jejaring komunitas–pemerintah–akademisi menguat dan membuka peluang tindak lanjut. Disimpulkan bahwa konservasi harus menjadi prasyarat pengembangan ekowisata, dengan paradigma “konservasi sebagai investasi” untuk menjaga daya tarik destinasi dan manfaat ekonomi lokal. Ke depan disarankan institusionalisasi SOP dan insentif konservasi, monitoring jangka panjang berbasis komunitas, perluasan kemitraan lintas sektor, serta integrasi adaptasi iklim dan pengendalian spesies invasif dalam paket ekowisata Sidoasri.

Marine macroinvertebrates are essential organisms that contribute significantly to the structure and function of aquatic ecosystems such as coral reef. This study examined the relationship between substrate types and macroinvertebrate communities in the Sempu Strait, Malang, to understand the...

Isdianto A, Gibran K, Yamindago A, Sari SHJ, Yanuar AT, Setyoningrum D, Setyanto A, Hidayah LN, Marsela K, Haykal MF, Fathah AL, Putri BM, Supriyadi, Luthfi OM, Pratiwi DC. 2024. Environmental determinants of reef fish community structure in Sempu Strait, East Java, Indonesia. Biodiversitas 25: 4781-4789. The Rumah Apung located in Sempu Strait, Malang District, East Java, Indonesia, is home to diverse coral reef ecosystems that provide vital ecological services and support local livelihoods. However, these ecosystems face significant threats from both natural environmental changes and anthropogenic activities. Understanding how environmental factors influence reef fish communities is critical to inform effective conservation strategies. This study investigated the influence of environmental factors on the community structure of coral reef fish in the Sempu Strait waters, East Java, using Underwater Visual Census (UVC) and Principal Component Analysis (PCA). Conducted from August 2023 to May 2024 at the Sempu Strait Floating House Station, this study aimed to assess the impact of water quality, substrate type, and food availability on the diversity and abundance of coral reef fish. The main results revealed a significant correlation between the community structure of coral reef fish and environmental variables such as water clarity, salinity (r = 0.65, p<0.01), pH (r = 0.55, p<0.05), dissolved oxygen (r = 0.70, p<0.01), and sediment type. Seasonal variations significantly affected water quality, with cold nutrient-rich water during the east monsoon increasing fish biomass by about 30%. Human activities, especially recreational diving and fishing activities, were correlated with a 20% decline in coral reef fish populations, highlighting the anthropogenic pressure on this ecosystem. PCA provides insight into the complex interdependencies within coral reef ecosystems, illustrating how multiple environmental factors combine to influence reef fish dynamics. The study concludes that effective management and conservation strategies, such as establishing marine protected areas, implementing community-based monitoring programs, and promoting sustainable tourism practices, are essential, supported by regular environmental monitoring, are essential to maintain the biodiversity and ecological integrity of coral reefs in the Sempu Strait. These strategies should address both natural environmental changes and anthropogenic impacts to mitigate their adverse effects on coral reef ecosystem conditions.

Isdianto A, Ishaq SY, Yamindago A, Iranawati F, Yanuar AT, Hidayah LN, Marsela K, Adhihapsari W, Lelono TD, Fathah AL, Atikawati D, Putri BM, Wardana NK, Supriyadi, Luthfi OM. 2024. Population and distribution patterns of juvenile scleractinian corals in Sempu Island Nature Reserve, East Java, Indonesia. Biodiversitas 25: 3480-3490. Coral reefs, which play a vital role in tropical marine ecosystems, are threatened by anthropogenic and natural stressors, despite their important ecological and economic roles. This study examines the resilience of coral ecosystems through the lens of juvenile coral populations at Floating House Beach, which is part of the Sempu Island Nature Reserve, East Java, Indonesia. Using the Underwater Photo Transect (UPT) method along a 100-meter reference line with a 1 × 1-meter transect, our study found that coral cover was severely damaged, with live coral cover of only 18.67% and 17.61% at two observation stations, which was dominated by the life form CM (Coral Massive) at both stations. However, twelve juvenile coral genera were identified that showed potential for natural recovery, namely Acropora, Favia, Favites, Galaxea, Leptoseris, Montipora, Mycedium, Platygyra, Pocillopora, Porites, Stylophora, and Turbinaria. Juvenile coral densities were low, at 0.55 and 0.88 colonies/m², indicating a very low coral recruitment category with Pocillopora being the most common. Spatial distribution, analyzed using the Morisita Index, showed a predominantly clumped arrangement (Ip>0), indicating non-random aggregation of juveniles. The results of this study highlight the significant impact of environmental stressors on juvenile coral communities and underscore the urgent need for targeted conservation efforts to support coral resilience and recovery.

Marine debris significantly impacts coral ecosystems, especially in regions with high biodiversity like the Sempu Island Nature Reserve in Malang, Indonesia. According to the guidelines of ReefCheck and KLHK 2020, this in-depth study looked at the types, amounts, and impacts of marine debris on...

Invertebrata laut umumnya ditemukan di wilayah perairan laut terutama area intertidal. Namun, seiring dengan kebutuhan akan makanan dan tempat berlindung, invertebrata laut juga dapat ditemukan di sampah laut organik di daerah pesisir. Penelitian ini bertujuan untuk menganalisis jenis invertebrata yang berasosiasi dengan sampah laut organik dan struktur komunitasnya. Penelitian ini dilakukan di Pesisir Kabupaten Malang khususnya Pantai Sendang Biru dan Pelabuhan Perikanan Pantai Pondokdadap. Sampah organik laut dikumpulkan dari transek garis yang telah ditentukan dengan pengulangan waktu, kemudian dilanjutkan dengan menganalisis komposisi jenis sampah dan invertebrata laut asosiasinya. Komposisi jenis tertinggi sampah organik laut yaitu daun sebesar 67,80% di Pantai Sendang Biru dan 48,29% di Pelabuhan Pondokdadap. Komposisi berat tertinggi sampah organik laut yaitu sabut kelapa sebesar 46,02% di Pantai Sendang Biru dan 68,08% di Pelabuhan Pondokdadap. Sebanyak empat genus invertebrata laut (Melampus, Littoraria, Ligia, dan Platorchestia) ditemukan berasoasi dengan sampah laut organik di Pantai Sendang Biru, sedangkan sebanyak enam genus (Melampus, Ellobium, Littoraria, Nerita, Ligia, dan Platorchestia) ditemukan berasosiasi dengan sampah laut organik di Pelabuhan Pondokdadap. Indeks keanekaragaman invertebrata yang ditemukan pada kedua wilayah bernilai sedang, komunitas dalam kondisi stabil, dan tidak terdapat spesies yang mendominasi. Analisis korelasi menunjukkan hubungan yang positif antara kepadatan jenis sampah organik laut dengan kelimpahan invertebrata laut. Penelitian ini menunjukkan pentingnya pengelolaan sampah organik di daerah pesisir untuk kelangsungan hidup invertebrata laut.

Isdianto A, Ariefandi MF, Asadi MA, Yamindago A, Setyawan FO, Bintoro G, Setyanto A, Lelono TD, Tumulyadi A, Adhihapsari W, Setyoningrum D, Fathah AL, Putri BM, Supriyadi, Luthfi OM. 2024. Community structure and biomass of reef fish concerning coral cover in Sempu Strait, East Java, Indonesia. Biodiversitas 25: 3376-3385. Reef fishes were used as bioindicators of biodiversity in coral reef ecosystems. However, coral cover and reef fish abundance around Sempu Strait tended to decrease. The study aims to obtain reef fish's community structure and biomass and their correlation to coral cover. We observed significant variability in reef fish populations through bi-monthly monitoring using an underwater visual census and underwater photo transect conducted from December 2022 to April 2023. Based on these observations, the average range of coral fish abundance was 0.453 to 0.577 individuals per square meter, with the highest value at Rumah Apung station (0.577 ind/m2). The community structure included 81 reef fish species, categorized into major (50 species), indicator (10 species), and target (21 species) groups, demonstrating a community with moderate diversity, stable evenness, and low dominance across the observed stations. Further, the research quantified fish biomass, recording an average of 0.0207 kg/m2 or 207.571 kg/Ha, categorized as low, with the highest biomass measurements at Rumah Apung station (0.0054 kg/m2). Strong correlations were identified between coral cover and both fish abundance (correlation coefficient = 0.741) and biomass (correlation coefficient = 0.666). These results emphasize the profound impact of coral health on the conditions and sustainability of reef fish populations. These findings underscore the critical dependency of reef fish on coral ecosystems and provide essential data for conservation efforts to maintain and restore these vital marine habitats.

The Christmas Tree Worm (Spirobranchus sp.) is a biota that lives in association with hermatypic corals. This bioeroder damages the structural integrity of corals, making them susceptible to breakage. Therefore, further investigation is required to determine the distribution, diversity,...