The Lombok Strait, as one of the outlet straits, is part of the ITF route, which is directly adjacent to the Indian Ocean. There is a sill in the Lombok Strait, which is a place for internal wave generation. Leg-1 data from the Japan Agency for Marine-Earth Science and Technology in collaboration with the Agency for the Assessment and Application of Technology which is part of the Tropical Ocean Climate Study Expedition including CTD Yoyo and ADCP taken using ship vehicles R/V Kaiyo. CTD Snapshot from PUSHIDROSAL using the KRI Spica 934 vehicle part of the Opssurta Baruna Jaya 2 Expedition. Determination of seawater mass stratification with the criteria for the thermocline layer is ≥ 0.05 °C.m-1. Four types of water masses were identified, Java Sea, mixed seawater mass (Java Sea - ITF) which occurred diapycnal mixing, North Pacific Subtropical Water (NPSW) and North Pacific Intermediate Water (NPIW). The seawater mass stratification in the Lombok Strait based on temperature, salinity and density which are seen to follow the internal tidal pattern. The average values for energy dissipation and vertical diffusivity for each layer and replication were 5.73 x 10-7 W.Kg-1 and 3.67 x 10-2 m2.s-1 for CTD Yoyo and 2.25 x 10-6 W.Kg-1 and 7.38 x 10-2 m2.s-1 for CTD Snapshot. The value obtained is greater than the open ocean and straits in other studies. The high shear value confirms this in the thermocline layer. The Richardson gradient value> 0.25 is relatively constant in the thermocline layer.

Pollution is a threat to coral reefs in Indonesian waters. The number of coral reefs that are in very good condition denies very little compared to the total area of ??coral reefs in Indonesia. One form of pollution that can threaten coral reefs is marine debris. This study aims to identify potential sources of marine debris that can disrupt the health of coral reefs. the research was carried out in the waters of Kelapa Island, Kelapa Dua Island and Harapan Island, DKI Jakarta. The data used includes current data obtained using secondary data, data on the amount of marine debris,and the water base data substrate obtained using the LIT method. The results showed that the waste was thought to come from community activities, tourism and fisheries. The location that can be a source of marine debris in the research location comes from the mainland of Jakarta Bay. The bottom substrate conditions are in the "bad" to "medium" category. The range of the lowest proportion of live coral cover is 10,8% and the highest live coral cover at 31.1%. The coral reefs in the research location are in a state of worry  and their existence is threatened by pollution of marine debris.

Musi estuary is the mouth of the Telang and Musi rivers directly adjacent to the Bangka Strait. During flood (ebb) we see the distribution of salinity increases (decreases) which is known through the vertical distribution using CTD. The TS diagram is used to see the water mass characteristics the study area. Data-Interpolating Variational Analysis (DIVA) method is used to interpolate and visualize data from vertical and spatial temperature, salinity and density data. The classification of the Musi estuary zone is identified based on the value of the distribution of salinity, which considers the exchange of circulating salinity at flood and ebb. The density of the water mass is significantly affected by the proven graded salinity. While the temperature distribution does not change significantly with depth, the spatial distribution indicates that the temperature in the estuary is lower than in the upstream and ocean areas. The spatial distribution of salinity indicates that high salinity enters the estuary towards the river further at flood than at ebb. Salinity distribution ranges from 0.5 to 30 psu and temperatures between 29 and 33 oC from horizontal and vertical sections. The pattern of salinity distribution in the Musi river estuary was identified, consisting of three zones representing salinity conditions in the study area, namely the Polyhaline, Mesohaline, and Olygohaline zones.

The waters of the Bangka Belitung islands are shallow waters that are affected by tides. The tides in these waters originate from the propagation of the Natuna and Java Seas, so they have unique characteristics. This study aims to analyze the amplitude and phase difference at 2 stations representing Bangka and Belitung Islands with the final output of LAT and HAT information as marine cadastral recommendations at Tanjung Pesona and Tanjung Tinggi stations and safe depths for ports in PPN Sungailiat and PPN Tanjung Pandan. . Tidal data for 1 year with time intervals of 1 hour in 2015 were used to extract the harmonic components to determine the type of tide and calculate the tidal level at each station. The results obtained are 19 harmonic components with a diurnal tide type. The water level at Tanjung Pesona is higher than the high Tanjung, which is described by tidal levels with HAT 2.64 and 1.72 m. Safe depth of harbor pond. In the LAT condition (lowest recess), the water level at Tanjung Pesona station is above the Sungailiat PPN pool's maximum depth; on the other hand, the Tanjung Pandan PPN LAT is 0.44 m below the maximum depth of the port pool.Key Word: Bangka Belitung, chart datum, LAT, HAT, tidal level

The Indonesian Throughflow (ITF) via its western path conveys mainly North Pacific water origin with Smax thermocline water and Smin intermediate water from its entry portal in Sangihe-Talaud arcs to the main outflow straits in Lombok, Ombai and Timor passage. Along its route, the throughflow water characteristics transforms significantly due to strong diapycnal mixing forced by internal tidal waves interaction along complex topography such as passages, sill, straits, and shallow islands chains. This paper reports a brief estimate of turbulent mixing profiles in Sangihe chains, and Makassar Strait. The CTD dataset are obtained from the year of maritime continent (YMC) Cruise in August 2019 on board the R.V. Baruna Jaya I. The Thorpe method is used to analysis dissipation energy ( ε ) and vertical diffusivity (Kz ) from CTD dataset. It is shown that the highest ε epsilon 5.87 × 10−7 Wkg −1 and Kz 4.42 × 10−3 m2s 1 are found in the Sangihe area. In Labani Channel and Dewakang Sill the averaged vertical diffusivity is much weaker at the order of 10−4 m 2s1. Thus, Sangihe Chains station have the highest values compared to other stations at depth 950-1000 meters.