Revegetation of abandoned aquaculture regions should be a priority for any integrated coastal zone management (ICZM). This paper examines the potential of a matchless time series of 20 very high spatial resolution (VHSR) optical satellite images acquired for mapping trends in the evolution of mangrove forests from 2001 to 2015 in an estuary fragmented into aquaculture ponds. Evolution of mangrove extent was quantified through robust multitemporal analysis based on supervised image classification. Results indicated that mangroves are expanding inside and outside ponds and over pond dykes. However, the yearly expansion rate of vegetation cover greatly varied between replanted ponds. Ground truthing showed that only Rhizophora species had been planted, whereas natural mangroves consist of Avicennia and Sonneratia species. In addition, the dense Rhizophora plantations present very low regeneration capabilities compared with natural mangroves. Time series of VHSR images provide comprehensive and intuitive level of information for the support of ICZM.

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Plastic debris has become an acute marine pollution concern worldwide in modern times. Indonesia is particularly impacted because of its high population density, heavy rainfall rate and numerous coastlines. A Lagrangian analysis was performed to simulate the fate of fictive marine debris drifting along surface currents, including tides and Stokes drift. The fictive particles were released according to the discharge rate of 21 Indonesian rivers and advected over 4 years. Most of the particles were stranded along Indonesian coasts (60%), before 6 months had elapsed (84%) and within a range of 1000 km (76%). The time variability exhibited two seasonal peaks, one centered on January-February and one on June-July, consistent with in situ observations. However, the results underline the complexity of performing direct comparisons between in situ observations and numerical simulations for stranded waste due to limited measurements and the heterogeneity of field methods and protocols.

Indonesia is an archipelagic country with more than 17,000 islands scattered across the country. Unique ecosystems, such as mangrove and coral reefs that have a very important ecological function, can be found in coastal area along with highly diverse species. Coastal area is also place for many major cities, while small islands became tourist destination. Human activities in these areas have generated pressure to the coastal resources and environment sustainability, (e.g.: the emerging unmanaged waste in major cities and tourist destination, which leaked to the ocean, then drifted, dispersed, and stranded in other shores). This study aims to identify various waste management practices in selected sites of small islands (e.g.: Pulo Aceh, Seribu, Karimunjawa, Wakatobi), where they have limited resources to managed waste. The result indicated that waste management practices in each place are vary, adjusted with their specific condition (e.g.: total population, daily waste generation, and availability of waste processing technology). Local community have adopted number of techniques to manage domestic waste, as well as stranded marine debris in their island. Based on the field observation, the key success factors of waste management in small islands will depend on the involvement of local community, good collaboration among stakeholders, also output of waste processing practice should bring direct and indirect benefit for the society, low-cost, and eco-friendly.

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Indonesia has lost 30% of the area over the past two decades due to anthropogenic activities. To overcome this problem, mangrove rehabilitation-which is generally interpreted as mangrove planting program - become the most popular option. These efforts could enhance the quantitative function (increasing mangrove areas extent and number of trees planted), yet the quality functions (biodiversity and ecological function) remain unclear. This analysis was carried out simultaneously with medium to high-resolution satellite image analysis to differentiate mangrove canopy pattern of these sites. The results showed that beta diversity value of mangroves in rehabilitation sites was lower than mangroves in natural area, which was characterized in satellite imagery as more uniform canopy and finer texture. Rehabilitation efforts that are mostly done through monoculture, are unable to produce an equal mangrove ecosystem function as natural mangroves do. This paper aims to examine the effectiveness of rehabilitation efforts whether they can develop an equal ecological function as good as natural mangrove ecosystem, by comparing the difference of beta diversity in two study sites which representing the natural (north Sulawesi) and rehabilitated mangrove (West Bali).

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Banten Bay is a 150 km2 sea area which includes the waterfront of Serang City in Banten Province, Indonesia with several large rivers flowing into the Bay. The rapid development of industrial and commerce surrounds this bay added with population growth in Serang City have caused environmental problems. For instance, there has been a surge in the volume of domestic and industrial waste that has been dumped along several rivers and finally leaked into Banten Bay. This study aimed to spatially visualize the existing waste flow from residential area to the location of landfills in order to assist the local government in evaluating their waste management system, and to help prevent the waste leaking into Banten Bay and even further beyond. By using hydrodynamic modelling and ground truthing, we can predict the potential waste hotspots and the seasonal patterns of marine debris around Banten Bay and its surroundings. The results show that plastic litter originating from the Cibanten River will drift to the west during the east monsoon and will move to the east during the west monsoon. Based on this evidence, plastic litter from the Cibanten River estuary has the potential to spread further towards the Sunda Strait during the east monsoon and into Jakarta Bay during the west monsoon. We encourage cooperation among local governments in Banten and West Java throughout the watershed as well as with the Jakarta Provincial Government to establish an integrated waste management system to prevent the waste leakage.