Mangrove ecosystems play a pivotal role in climate change mitigation due to their exceptional carbon sequestration capacity and the vital ecosystem services they provide. This study examines changes in mangrove cover and estimates carbon stocks on Gilibakau Island, Saleh Bay, Indonesia, utilizing Pleiades satellite imagery and drone-derived data. Analysis of Pleiades imagery from 2020 and 2022 identified an increase in mangrove area from 6.53 hectares to 6.71 hectares, attributed primarily to rehabilitation initiatives, including replanting programs. Biomass was quantified using drone-based data collected in 2024, employing a tree height-based allometric model. The estimated biomass ranged from 23.63 to 192.69 tonnes per hectare, reflecting the high-density mangrove cover and its significant carbon storage potential. Regression analysis revealed a strong correlation (R² = 0.863) between Normalized Difference Vegetation Index (NDVI) values and biomass, validating NDVI as an effective proxy for mangrove biomass estimation.

The formation of coral cays in the Kepulauan Seribu Marine Parks, Jakarta Special Capital Region, is the result of patch reef evolution which linked to the geology of sediment accretion, including the ecology of coral growth and competition of benthic community. This study aims to map the level of reef complexity in Pamegaran Island using Benthic Terrain Modeler. Field observation to monitor benthic communities in four stations at 3- and 5- meter depth was combined with SPOT-7 image processing to evaluate in situ rugosity, 3-dimensional bathymetry and benthic habitat classification. The results of this study revealed low degree of terrain complexity as results of habitat degradation and dominant benthic class of sand. Classification of reef benthic habitat resulted in five classes, namely sand (Sd= 126.65 ha), seagrass (Sg= 35.29 ha), bare rubble (Rb= 32.68 ha), reefs dominated by dead corals (DC=3.16 ha) and dead coral with algae (DA= 20.50 ha); with 67.21% score of overall accuracy (OA). In situ rugosity at 5 m was higher than 3 m, as result of higher coverage of live corals particularly in the east site. Similar profile was shown for rugosity index, which reflects ratio between surface to planar area and seafloor gradient along the reef slope. Finally, positive correlation between reef surface and in situ rugosity implies the importance of live coral communities in supporting complex terrain and benthic habitat in the patch reef environment.

Coastal flooding driven by sea-level rise and land subsidence poses severe risks to low-lying communities. This study evaluates the causes and impacts of coastal sinking in Sayung, Demak, Central Java, using multi-temporal Landsat imagery (1977, 2024), tidal gauge data, and GPS measurements. A set of spectral indices—Normalized Difference Vegetation Index (NDVI), Weighted Modified Normalized Difference Water Index (WMNDWI), Land Surface Water Index (LSWI), and Normalized Difference Built-up Index (NDBI)—were calculated and integrated as input features for a Random Forest machine learning model to detect and classify environmental changes. Results indicated an average land subsidence rate of approximately 6 cm/year ± 0.8 cm/year, validated against InSAR-based measurements, and a classification accuracy of 91% (RMSE of 0.8 cm/year). A substantial decline in vegetation indices was observed, reflecting the conversion of agricultural land into built-up areas and water bodies. Extensive flooding and shoreline retreat were documented, with high-risk zones concentrated along densely developed coastlines. These findings highlight the urgent need for integrated management strategies, including stricter groundwater regulation, continuous remote-sensing-based monitoring, and large-scale mangrove restoration, to safeguard ecological functions and enhance the socio-economic resilience of coastal communities in the face of accelerating climate change impacts.

Coral reefs are essential ecosystems, providing ecological and socioeconomic benefits globally, including habitat for marine life, coastal protection, and support for fisheries and tourism. However, these reefs face significant threats due to overfishing, destructive fishing practices, pollution,...