The Java Sea with a surface area about 467.000 km2, is located in the South East Sunda Shelf with the average of depth is 40 meters, affected by several phenomena, whether physical or meteorological. This research aims to analyze the characteristics of water masses in the Java Sea and its relationship with the periodicity of the monsoon and Indonesian Throughflow Water (ITF) phenomenon. Then analyze the exchange of water masses in the Java Sea. The data used are temperature and salinity to identify the characteristics of the water masses. Ocean currents data to identify ITF patterns and winds data to identify the monsoon patterns. The data used in 2015 from the Infrastructure Development of Space Oceanography (INDESO) sites with a resolution of 1/12°. The method used is a descriptive analysis of spatially and temporally. The results show that averaging seasonal found that southeast monsoon period salinity is higher (31-34 psu) than northwest monsoon period (29.5-33 psu), and southeast monsoon period temperature is lower (27-30.5°C) than northwest monsoon period (28.5-30.5°C). ITF phenomenon occurs in May through September and reaches its peak in June, July, and August. ITF strengthened in southeast monsoon and weakened in the northwest monsoon. ITF and monsoon have similar impacts on salinity and temperature in the Java Sea. The water masses in the Java Sea comes from the South China Sea and Makassar Strait. In the northwest monsoon, Java Sea filled by water masses of the South China Sea, while in the southeast monsoon phenomenon which coincides with ITF phenomenon, Java Sea water masses is filled by water masses from Makassar Strait. In the transition monsoon I and II, the Java Sea filled by the South China Sea and the Makassar Strait water masses. Laut Jawa dengan luas permukaan sekitar 467.000 km2, terletak dibagian tenggara paparan Sunda dengan kedalaman rata-rata adalah 40 meter dipengaruhi oleh beberapa fenomena, baik fisikal maupun meteorologikal. Penelitian ini bertujuan untuk mendapatkan informasi mengenai karakteristik massa air di Laut Jawa dan hubungannya dengan periodisitas monsun serta fenomena arlindo dan menganalisis pertukaran massa air di Laut Jawa. Data yang digunakan adalah suhu dan salinitas untuk mengidentifikasi karakteristik massa air. Arus untuk mengidentifikasi pola arlindo dan angin untuk mengidentifikasi pola monsun. Data yang digunakan tahun 2012 dari situs infrastructure development of space oceanography (INDESO) dengan resolusi 1/12°. Metode yang digunakan adalah deskriptif dengan pendekatan analisis secara spasial dan temporal. Berdasarkan hasil perata-rataan musiman didapatkan bahwa salinitas saat monsun timur lebih tinggi (31-34 psu) daripada saat monsun barat (29,5-33 psu), dan suhu saat monsun timur lebih rendah (27-30,5°C) daripada saat monsun barat (28,5-30,5°C). Fenomena arlindo terjadi pada bulan Mei sampai September dan mencapai puncaknya pada bulan Juni, Juli, dan Agustus. Arlindo menguat pada monsun timur dan melemah pada monsun barat. Monsun dan arlindo memiliki pengaruh yang sama terhadap salinitas dan suhu di Laut Jawa. Massa air di Laut Jawa berasal dari Laut Cina Selatan dan Selat Makassar. Pada monsun barat, Laut Jawa diisi oleh massa air Laut Cina Selatan, sedangkan pada monsun timur yang bertepatan dengan fenomena arlindo, massa air Laut Jawa diisi oleh massa air Selat Makassar. Pada monsun peralihan I dan II, Laut Jawa diisi oleh massa air Laut Cina Selatan dan juga Selat Makassar.

Understanding the mechanisms that determine the critical habitat of commercial species is one of the significant challenges in marine science, particularly for species that inhabit the vast ocean worldwide. Previous investigations primarily focused on determining skipjack habitats without considering the feasible size for sustainable fisheries. To define habitat hotspots and movement patterns for decently sized skipjack tuna (≥50 cm) in Indonesia Fisheries Management Area (IFMA) 713, Indonesia, we examined the remote sensing of synoptic sea surface temperature (SST) and chlorophyll-a concentration (Chl-a) measurements with catch data from 2007 to 2016. A new skipjack tuna habitat model was developed based on the link between the key satellite-based environmental data and the best tuna fishery performance using a combination of generalized additive models (GAMs) and kernel density estimates. The findings reveal that feasible skipjack catch sizes were found in approximately 27% of total fishing grounds and were significantly captured in areas with a Chl-a of 0.15–0.28 mg m⁻³ and an SST of 29.5–31.0 °C, corresponding with an elevated skipjack habitat index (SHI). The habitat hotspots for the commercial skipjack were particularly produced by favorable Chl-a and SST, in association with Chl-a front and anticyclonic and cyclonic eddies, especially in October, which coincided with the highest skipjack catch per unit effort (CPUE). Skipjack distributions were mostly found within 10 km of favorable feeding habitats. They used the hotspot area as an indicator of their dynamics and movement pattern in the environment. The observed CPUEs cross-validated the predicted SHI values, suggesting that the model provided a reliable proxy for defining the potential habitats and the spatial movement of mature skipjack schools. Our findings have global significance for locating ecological hotspots, monitoring sustainable skipjack fisheries, and tracking skipjack migration, especially within the western tropical Pacific.

The Makassar Strait (MS) is characterized by water mass from the Pacific Ocean and is one of the ITF (Indonesia Throughflow) branches. It carries warm water masses from the Pacific Ocean to the Indian Ocean. This research aims to analyze the relationship between CPUE of Eastern Little Tuna (Euthynnus affinis) and oceanographic variables, likewise predict the fishing area using the Generalized Additive Model (GAM). The research method used is spatial and temporal analysis. The data was used from 2015 to 2020. The data processed were sea surface temperature, chlorophyll-a, salinity, currents, sea level as predictor variables, and Eastern Little Tuna production as a response. Eastern Little Tuna catch data were normalized into Catch per Unit Effort, while the oceanographic data were extracted using ArcGIS. Based on the results of the GAM model, it was found that the model with five variables is the most suitable predictive model, with 16.4% CDE. Salinity is the most influential parameter on the catch of Eastern Little Tuna with a significance value of <2.00 × 10⁻¹⁶ ***. The optimum value for SST is 30–31 °C, chlorophyll-a is 1–2 mg/m³, salinity is 29–30 ppt, current velocity is 0.3–0.5 m/s and sea level is between 0.6–0.7 m. Based on the GAM prediction results, a high CPUE value will be obtained in the southwest monsoon (March to May). Fishing activity carried out in the best season will implement the adoption of harvest control measures.

Symbiodiniaceae species is a dinoflagellate that plays a crucial role in maintaining the symbiotic mutualism of reef-building corals in the ocean. Reef-building corals, as hosts, provide the nutrition and habitat to endosymbiotic Symbiodiniaceae species and Symbiodiniaceae species transfer the fixed carbon to the corals for growth. Environmental stress is one of the factors impacting the physiology and metabolism of the corals-dinoflagellate association. The environmental stress triggers the metabolic changes in Symbiodiniaceae species resulting in an increase in the production of survival organelles related to storage components such as lipid droplets (LD). LDs are found as unique organelles, mainly composed of triacylglycerols surrounded by phospholipids embedded with some proteins. To date, it has been reported that investigation of lipid droplets significantly present in animals and plants led to the understanding that lipid droplets play a key role in lipid storage and transport. The major challenge of investigating endosymbiotic Symbiodiniaceae species lies in overcoming the strategies in isolating lesser lipid droplets present in its intercellular cells. Here, we review the most recent highlights of LD research in endosymbiotic Symbiodiniaceae species particularly focusing on LD biogenesis, mechanism, and major lipid droplet proteins. Moreover, to comprehend potential novel ways of energy storage in the symbiotic interaction between endosymbiotic Symbiodiniaceae species and its host, we also emphasize recent emerging environmental factors such as temperature, ocean acidification, and nutrient impacting the accumulation of lipid droplets in endosymbiotic Symbiodiniaceae species.

In order to determine how the El Niño Southern Oscillation (ENSO) affects Eastern Little Tuna catch rates in the Makassar Strait (MS), satellite-derived oceanographic variables, including sea surface temperature (SST), chlorophyll-a, salinity, sea surface height (SSH), ocean current, Niño index 3.4, and Eastern Little Tuna (Euthynnus affinis) catch data were used. Analyses were conducted for a seven-year period (January 2015-December 2021), which included the El Niño (2015) and La Niña (2021) events. A higher CPUE value is obtained in 2021 when La Niña occurs with a CPUE value of 3973 kg/trip, compared to the El Niño event. Based on seasonal variations, the highest catch was recorded during the northwest monsoon (706.02 kg/trip) with 2789 fishing points, while the lowest occurred during the southeast monsoon (700 kg/trip) with 2942 fishing points. The CPUE was 16.25 kg/trip with 1133 fishing points during El Niño and 23.56 kg/trip with 1027 fishing points during La Niña, respectively. The fishing grounds area was wider during the La Niña period, at 2 - 8°S and 115 - 120°E. This study revealed a strong impact of the La Niña events, significantly increasing Eastern Little Tuna catch in the MS.