Coastal zones are considered to be highly vulnerable to the effects of climate change, such as erosion, flooding, and storms, including sea level rise (SLR). The effects of rising sea levels endanger several nations, including Indonesia, and it potentially affects the coastal population and natural environment. Quantification is needed to determine the degree of vulnerability experienced by a coast since measuring vulnerability is a fundamental phase towards effective risk reduction. Therefore, the main objective of this research is to identify how vulnerable the coastal zone of Bali Province by develop a Coastal Vulnerability Index (CVI) of areas exposed to the sea-level rise on regional scales using remote sensing and Geographic Information System (GIS) approaches. This study was conducted in Bali Province, Indonesia, which has a beach length of ~640 km, and six parameters were considered in the creation to measure the degree of coastal vulnerability by CVI: geomorphology, shoreline change rate, coastal elevation, sea-level change rate, tidal range, and significant wave height. The different vulnerability parameters were assigned ranks ranging from 1 to 5, with 1 indicating the lowest and 5 indicating the highest vulnerabilities. The study revealed that about 138 km (22%) of the mapped shoreline is classified as being at very high vulnerability and 164 km (26%) of shoreline is at high vulnerability. Of remaining shoreline, 168 km (26%) and 169 km (26%) are at moderate and low risk of coastal vulnerability, respectively. This study outcomes can provide an updated vulnerability map and valuable information for the Bali Province coast, aimed at increasing awareness among decision-makers and related stakeholders for development in mitigation and adaptation strategies. Additionally, the result may be utilized as basic data to build and implement appropriate coastal zone management.

Mangrove vegetation is one of the forest ecosystems that offers a potential of substantial greenhouse gases (GHG) emission mitigation, due to its ability to sink the amount of CO2 in the atmosphere through the photosynthesis process. Mangroves have been providing multiple benefits either as the source of food, the habitat of wildlife, the coastline protectors as well as the CO2 absorber, higher than other forest types. To explore the role of mangrove vegetation in sequestering the carbon stock, the study on the use of remotely sensed data in estimating carbon stock was applied. This paper describes an examination of the use of remote sensing data particularly Landsat-data with the main objective to estimate carbon stock of mangrove vegetation in Perancak Estuary, Jembrana, Bali. The carbon stock was estimated by analyzing the relationship between NDVI, Above Ground Biomass (AGB) and Below Ground Biomass (BGB). The total carbon stock was obtained by multiplying the total biomass with the carbon organic value of 0.47. The study results show that the total accumulated biomass obtained from remote sensing data in Perancak Estuary in 2015 is about 47.20±25.03 ton ha-1 with total carbon stock of about 22.18±11.76 tonC ha-1and CO2 sequestration 81.41±43.18 tonC ha-1.

Perancak estuary is a productive ecosystem and has important role in the balance of nature and the life of local communities. However, research about water quality and organisms in Perancak estuary is still low, especially on plankton abundance and distribution. The aim of this research was to analyze the abundance and spatial distribution of plankton communities. The research was conducted by field surveys in November 2015, samples were taken from 3 stations representing upstream (S1), stream (S2) and downstream (S3). Plankton sampling was carried out by filtering water samples as much as 100 liters of plankton net with mesh size 25?m, diameter 31 cm, and length 80 cm. Filtered samples were stored in the sample bottle and the preserved with 1 ml of 4% formaldehyde. The result showed, an abundance of phytoplankton ranged between 33,600 ? 3,002,400 cell/m³ and zooplankton between 6,000-57,000 ind/m³. Total of 6 genera of phytoplankton and 14 genera of zooplankton was recorded during the research period. The ecological index showed that species diversity of plankton in Perancak estuary was categorized as low diversity. Plankton abundance in S1 which located in Loloan River is higher than others. Its caused by anthropogenic waste from agriculture, households and industrial waste.

Water quality in the environment is influenced by anthropogenic activity and natural process. Anthropogenic activities such as fishing activities, fish ponds, fishing ports, residential waste provide the greatest contribution to water quality conditions. The condition of water quality is very important in supporting the survival of the organisms living on it. Determination of the status of water quality should be done as a reference for pollution monitoring in an aquatic system for both marine tourism development and biota life purposes, especially in the mangrove ecosystem. This study aims to assess the status of water quality in Perancak Estuary Jembrana Bali for marine tourism and the mangrove ecosystem. Water quality measurement was conducted from January to March 2018 at 10 observation stations which divided into 3 zones based on the representation of area characteristics. These zones include: zone I represent water quality conditions close to residential areas, zone II represent water quality conditions close to mangrove and aquaculture ecosystems, and zone III represent sea water quality transition conditions. The sampling procedure was based on APHA standard method. The water quality data then analysed using the STORET method. Stored index for marine tourism and marine biota (mangrove) in zone I, II, III showed lightly contaminated to moderately polluted (-10 until -16) for physical parameters, heavily polluted (-40 until -80) for chemical parameter and biology parameters is still in accordance with quality standards until lightly contaminated (0 until -6). Based on the value of the pollution index shows the water quality status of Perancak Estuary from January-March is classified as bad/severe pollution both for marine tourism and the mangrove ecosystem. Chemical parameters (nitrate, phosphate, ammonia) contribute the most to the level of pollution.

During Marine Science Summer Course 2017, a continuous 24-h conductivity-temperature-depth (CTD) “yoyo” measurement has been carried out at the entrance of Padangbai Lombok Strait to investigate seawater properties variations on semidiurnal tidal-scale which is dominant in the strait. The SBE CTD 19 plus is equipped with optional sensors such as pH, turbidity and chlorophyll-a derived-fluoro. During 24-h field observation, 15 CTD casts from sea surface to about 60 m depth have been acquired. It is shown that observed seawater properties fluctuate strongly four times a day, following semidiurnal-tide period with two flood-tide and two ebb-tide conditions. During flood-tide, water mass is derived from open strait with colder, saltier, denser and low dissolved oxygen characteristics. In contrast, during ebb-tide, local water mass is recirculated back from the inner bay to the open strait. It is interesting to note that fluctuation of chlorophyll-a indicates a diurnal signal. In addition, fluctuation of pH, turbidity and dissolved oxygen showed a weak semidiurnal signal.

Land areas in the territorial waters will often be affected by sea-level flooding or commonly referred to as rob. This research was conducted to see the physical condition of the waters and to do a hydrodynamic model (2D) in the waters of the Tembesi Reservoir, Batam, Indonesia. This research was conducted using primary and secondary data to produce physical conditions of waters and hydrodynamic (2D) models. The results showed the depth of waters has a minimum value of depth of -1.05 meters and a maximum value of depth of -5.95 meters. The percentage of wind speed below 1 Knot is 3.23%, and the independent variable in the percentage of wind data processing is 1.61%, with the lowest wind speed in the range of 0.1-1 Knots. Water level models produced in conditions during the filling process before the water discharge from the outlet is 0.023 meters and relatively small currents range from 0.0012 cm/s. Elevation of the final water level to the final flow when the conditions during the filling process before the water is discharged, resulting in highest water elevation, compared to when the water condition in the reservoir has been discharged from the outlet into the sea.