This paper provides an overview of the upwelling processes and the controlling factors as an effort to reveal the characteristics and the intensities of upwelling events in several parts of the world. This review aimed at identifying the characteristics of upwelling and how the global climate controlling this physic phenomenon such as ENSO, IOD and Kelvin Wave. Several places in the Southeast Asia experienced high intensities of upwelling when El Nino events such as in South of Java, East Coast of Malaysia Peninsula and in Vietnam Coastal area. The results of this review found that area with the most intensive and productive upwelling in the world is South American waters and Banguela Upwelling System (BUS) in the African Coast. However, several other areas also show intensive and high productivity of upwelling, such as off the southern coast of Java Island in Indonesia and the Banda Sea and its surroundings. It is found that upwelling with stronger intensity can result in increase of mortality of certain organisms such as scallops. Additionally, increase of nutrients in a waters is often accompanied by an increase in several species of toxic algae that are harmful to the local fishery system (harmful algae blooms, HABs).

The modeling uses a software-based numerical model DHI MIKE user interface developed by The Danish Hydraulic Institute (DHI) Water and Environment, Denmark. Simulation of current uses a 2-dimensional model (averaging to depth) with a finite element approach. Modeling of currents was conducted to know current dynamics by tidal cycle and seasonal variation (west and east monsoon). The models were validated using correlation coefficient value (r) by comparing direct measurement and model output. The r-value for current velocity during west monsoon was 0.653 and east monsoon was 0.697 and for current direct during west monsoon was 0.887 and the east monsoon was 0.857. While the r-value for the tide was 0.858. All these r values showed a strong correlation and these indicated the models were valid. The result of the simulation of the current models showed that the surface currents were strongly influenced by the tidal cycles. The currents direct flowed to the south at flood tide and to the eastern at ebb tide. The maximum current velocity during the west monsoon was 0.50 m/sec and during the east monsoon was 0.40 m/sec. The averages of currents direct were more dominant eastward of Jeneberang estuary.

Research on the occurrence and the characteristics of microplastics (MPs) sedimentary in seagrass meadows at the area of Mare Island conservation is the very first study in this region. The objectives of this work is to determine the abundance and the characteristics of MPS and its diversity in the two villages namely Maregam and Marekofo at the Island. Samples are collected using sediment core, then dried and extracted using NaCl to separate the density. MPs were identified under a microscope after going through the filtering process. The abundance of MPs particles ranges from 17,000 - 37,000 particles. kg-1dry weight (dw) sediment at Station 1 (Maregam) and 13.839 - 30,666 particles.kg-1 dw sediment at Station 2 (Marekofo). In general, the average value of MPs abundance at station 1 higher than station 2 were 27.090 ± 13.908 particles.kg-1 dw of sediment and 18,368 ± 10,625 particles.kg-1 dw of sediment, respectively. Statistically there no significance difference of the MPs abundance between the two station Furthermore, the predominance of MPs types were fiber and fragments, while the majority of colors of particles were blue. While the results of the microplastic diversity test indicated that MPS particles at Mare Island were not too complex and were in unstable conditions. Even though the less density of the population at the island, MPs were quite high compared to other areas in the world. This finding is allegedly that those MPs were supplied from the distance which transmitted by hydro-oceanographic and meteorology factors, beyond of local contribution.Keywords: Microplastic, seagrass bed, sediment, conservation area, Mare Island

Despite the research on PCBs occurrence in the various matrices in the world, no review has been carried out on the status of these substance contaminations in marine and freshwater sediments during the current periods throughout the globe. The objectives of this paper are to briefly discuss the occurrence of PCBs concentrations within marine and freshwater sediments in several places in the world and to determine which part of marine and freshwater sediments are the most contaminated in the world. The emphasis is on the last three decades namely from 1985 to 2020. The results suggested that during 1985 to 2010, the PCBs concentrations in the sediments ranged between 2 μg.kg−1 and 1648 μg.kg−1. The most elevated was found in Ionian Sea, Italia as the site where connected with high activities of industries, urban and harbor. The lowest one was reported in Bering sea and the Gulf of Alaska as the uncontaminated site during this era. Subsequently, a decade later which was recorded from 2011 to 2020 found the PCBs concentrations in the sediments ranged from 0.036 to 3730 μg.kg−1. The highest concentration was reported at coastal area at the center of Vietnam where linked with the urban and industries sites. Conversely, the lowest one was found at Chao River sediments where connected with the agriculture field. The evaluation of sediments guide lines quality through ERL (Effects Ranged Low) and ERM (Effects Ranged Medium) showed that the most contaminated marine and freshwater sediment in the world during 1985 to 2010 was at Ionian Sea, Italy, whereas in the recent period (2011 to 2020) was found in the Coastal area of Vietnam. According to this evaluation, these locations are high risk to the toxic effect particularly to the benthic organisms. Therefore, these places are high concerned in terms of protection and conservation of some marine biotas.

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