Understanding the impact of Indian Ocean Dipole (IOD) on fishery around Indonesia is important as the fishery resources are small compared to the demand. In this study, we analyzed the effect of positive and negative phases of IOD on chlorophyll-a concentration and the catch of Sardinella lemuru in the Bali Strait. Data are based on field surveys in the Bali Strait during the positive and negative phase of IOD and Sea Surface Temperature (SST) and Sea Surface Chlorophyll (SSC) obtained from the analysis of satellite images. The results suggest that SSC concentration in the strait significantly correlates with the positive and negative phase of IOD, possibly through a change of upwelling and downwelling there. It is suggested that the change of phytoplankton biomass due to positive IOD would result in an increase of Sardinella lemuru in the Bali Strait. This research has direct implications as important information for the government in planning lemuru fisheries management in the Bali Strait based on oceanographic studies and climate phenomena.

Accretion and erosion, which are natural geological phenomena in mangrove areas, provide interesting views that have implications for sustainable area management. This research aims to analyze the ecosystem that exists in the cold lava sedimentation of Mount Bromo and explore aspects of...

Arfiati D, Zakiyah U, Anitasari S, Inayah ZN, Orchida K, Pratiwi RK. 2024. Plankton diversity in the Rowo Klampok Swamp, Malang District, East Java, Indonesia. Biodiversitas 25: 1846-1855. Wetlands are a productive ecosystem and have high biodiversity, including plankton. Plankton can be used to assess the health status of wetlands. This research aims to determine the diversity and abundance of phytoplankton and zooplankton and to analyze the water quality conditions of the tropical wetland (Rowo Klampok Swamp, Malang District, East Java, Indonesia). This research was conducted from May to June 2023 and it's a survey research. The research results show that the phytoplankton found in Rowo Klampok Swamp consists of 4 divisions with 13 genera, while there are 3 divisions with 3 genera in zooplankton. Phytoplankton divisions are Bacillariophyta, Chlorophyta, Cyanophyta, and Dinoflagellate, while zooplankton divisions are Arthropoda, Ciliophora, and Rotifera. The average value of total phytoplankton abundance reached 2,618,684 cells/L, while zooplankton was 10,504 Ind/L. The Chlorophyta division is the most commonly found phytoplankton, with a percentage ranging between 32.5 and 53.1%, respectively. Dictyosphaerium is a phytoplankton genus often found with the highest average abundance of 1,922,929 cells/L. The diversity index, uniformity index, and dominance index of phytoplankton ranged between 1.965-2.439, 0.945-1.173, and 0.125-0.213, respectively, while those of zooplankton were 0.496-0.529, 0.317-0.593 and 0.458-0.684, respectively. Rowo Klampok Swamp has a medium trophic level (mesotrophic) and shows moderate pollution. The water quality conditions are considered suitable for aquatic organisms, but we need to monitor and reduce phosphorus input into the bodies of water.

Kelimpahan serta biodiversitas zooplankton sangat tergantung pada keberadaan fitoplankton sebagai makanan utamanya. Fitoplakton berperan penting sebagai produsen primer di perairan. Keberadaan fitoplankton sendiri selain bergantung faktor fisika-kimiawi perairan, juga nutrien seperti nitrat dan fosfat. Penelitian ini bertujuan untuk memetakan sebaran biodiversitas zooplankton serta faktor yang mempengaruhinya di pesisir utara dan selatan Madura, Jawa Timur. Lokasi pengambilan sampel dilakukan secara purposive di Pantai Pasongsongan, Sumenep dan pantai Pantai Branta Pamekasan di tiga stasiun yang berbeda. Pengukuran parameter kualitas air dilakukan secara in situ dan ex situ, dan analisis biodiversitas zooplankton dilakukan dengan indeks biologi meliputi indeks keanekaragaman, indeks dominansi dan juga dilakukan analisis distribusi spasial menggunakan QGIS Las Palmas 3.10.2 untuk mengetahui peta distribusi kelimpahan nitrat, fosfat, fitoplankton dan zooplankton. Hasil penelitian menunjukkan bahwa kandungan nitrat di pesisir utara Madura berkisar 0,0973 - 0,1124 ppm, sedikit lebih rendah dari pantai selatan Pamekasan yang berkisara antara 0,008 - 0,11 ppm. Konsentrasi fosfat berkisar antara 0,0388 - 0,0685 ppm di pantai utara dan 0,05 - 0,06 ppm di pantai selatan. Selama penelitian ditemukan zooplankton sebanyak 19 genera dari 7 filum. Sub kelas yang paling banyak ditemukan adalah Copepoda dari filum Arthopoda. Densitas zooplankton berkisar antara 48,408 - 57,325 Ind./L di pesisir utara Madura dan antara 210,191 - 314,650 Ind./L di pesisir selatan. Sebaran tertinggi zooplankton didapatkan pada stasiun satu di setiap lokasi sampling baik di pesisir utara maupun selatan Madura. Hal ini sesuai dengan data densitas fitoplankton yang juga menunjukkan nilai yg tinggi di stasiun tersebut. Nilai indeks keanekaragaman yang diperoleh di pesisir selatan sedikit lebih tinggi yaitu berkisar antara 1,6 - 2,05, dibandingkan nilai di pesisir utara berkisar antara 1,2 - 1,4 meskipun nilai tersebut termasuk kedalam kategori keanekaragaman sedang. Hal ini diikuti nilai indeks dominansi berkisar antara 0,17 - 0,39 di pesisir utara dan selatan berkisar antara 0,3 – 0,4 atau dengan kata lain tidak ada genus zooplankton yang mendominasi. Berdasarkan peta sebaran biodiversitas zooplankton disimpulkan bahwa pesisir selatan memiliki biodiversitas zooplankton yang relatif lebih rendah dengan dominansi relatif lebih tinggi dibandingan dengan pesisir utara Madura yang memiliki biodiversitas lebih tinggi dan dominansi spesies yangg lebih rendah.

Banyuurip Mangrove Center (BMC) is a form of mangrove ecosystem conservation and utilization in Banyuurip Village that still faces obstacles in its ecotourism sector management. This study aims to determine the condition of mangroves in BMC, identify Internal Factor Analysis Summary (IFAS) and External Factor Analysis Summary (EFAS), and develop the best strategies for BMC management based on its mangrove condition. This research uses a survey method that includes the data obtained from respondents and the in-situ data on mangrove conditions. Analysis of mangrove data includes identification of species, density, and relative density. Meanwhile, data from the respondents, including tourists and management staff, were analyzed using SWOT analysis. Based on research results, it was known that mangroves in BMC are in relatively good condition. From the respondent questionnaire using SWOT analysis, the best strategy to be suggested is the SO strategy. These strategies must include government support by maximizing its advantages, utilizing social media for promotion, developing mangrove nurseries to produce quality mangrove seedlings, collaborating with Perlindungan Masyarakat (LINMAS) or Community Protection to improve security, and their economic sector by involving the society in another factor of the ecotourism management such as mangrove processing.

Arfiati D, Zakiyah U, Anitasari S, Inayah ZN, Pratiwi RK. 2023. Community structure of periphyton on bamboo substrate in whiteleg shrimp (Litopenaeus vannamei Boone, 1931) pond with semi-biofloc system. Biodiversitas 24: 5080-5087. Periphyton is one aquatic organism that attaches to the substrate and can be used as a bioindicator. This study analyzes the community structure and dynamics of periphyton on bamboo substrates in whiteleg shrimp ponds with a semi-biofloc system. The study was conducted from May to July 2022. The bamboo substrate was placed in the ponds, and the samples were taken every seven days to 8 weeks. Identification and calculation of periphyton using Lackey Drop Micro transect Counting Method. The periphyton was found on a bamboo substrate in whiteleg shrimp ponds with a semi-biofloc system consisting of phyto-periphyton and zoo-periphyton. The phyto-periphyton group contains 4 phylum, 21 species, including the Bacillariophyta, Chlorophyta, Cyanophyta, and Ocrophyta. The zoo-periphyton group has 4 phylum, 10 species consisting of Arthropoda, Ciliophora, Nematoda, and Rotifera. The abundance of periphyton found changes every week. The relative abundance of phyto-periphyton includes phylum Bacillariophyta (17-69%), Chlorophyta (1-22%), Cyanophyta (30-65%), and Ocrophyta (0-25%), while zoo-periphyton includes phylum Arthropoda (0-3%), Ciliophora (69-99%), Nematodes (0-2%) and Rotifers (0-28%). The total abundance of phyto-periphyton on bamboo substrate ranged from 223,806-989,398 cells/L, while zoo-periphyton ranged from 396-1,924 individual/L. The diversity, uniformity, and dominance index of phyto-periphyton and zoo-periphyton are moderate. Water quality parameters during the study were relatively good for aquatic organism growth, except for very high total organic matter levels in several weeks.