Cua Dai is one of the major estuarine areas in Central Vietnam that plays a significant role in local maritime transport, fisheries, and tourism activities. This paper presents a study that monitored the shoreline dynamics of the Cua Dai estuary over a period of 50 years by using field survey data, geographic information systems techniques, and multi-temporal satellite remote sensing images (ALOS-AVNIR2 and Landsat imageries). The assessment of shoreline changes was divided into three phases: 1964-1980, 1981-2000, and 2001-2014. The results revealed that over the last 50 years, shoreline changes dramatically occurred between 1964 and 1980. The general trends of erosion and accretion at the Cua Dai estuary show that the river mouth moved towards the south due to the erosion of shorelines in the north and the river bank in the south of the Cua Dai estuary. The study outcomes can provide essential information for planning, zoning, and sustainable development activities of the coastal zones in the context of climate change.

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We presented a low-cost and simple method to synthesize carbon nanodots (CDs) from waste wine cork using hydrothermal synthesis.  The structural and optical properties of the CDs are characterized by TEM, FTIR, Raman, UV-Vis absorption, and photoluminescence (PL) spectra. The analysis results indicated the average diameter of CDs ⁓ 6.2 ± 2.7 nm. Optical measurements showed the phenomenon of excitation-dependent PL and the formation of functional groups on the surface of the particles. CDs with a quantum yield of 1.54% was calculated using quinine sulfate as reference. Furthermore, a probe of wine cork-derived CDs in bioimaging has been successfully applied in living mesenchymal stem cells (MSCs). After treatment with CDs, MSCs exhibited fluorescence including green, yellow, and red colors under the excitation wavelengths in the range 330–385 nm, 450–480 nm, and 510–550 nm, respectively. The achievement demonstrated potential applications of fluorescent CDs in the field of the fluorescent image.

This study was conducted to provide a comprehensive database of shoot density and biomass characteristics of seagrass beds in several coastal waters in Central Vietnam. The survey process of the characteristics related to shoot density and biomass of seagrass beds was carried out mainly in the dry season (from April to September) during the period from 2017-2019. The data were collected at six sampling locations in Lang Co lagoon, Thua Thien Hue Province; five sampling locations at Cua Dai estuary in Quang Nam Province and Van Phong bay, Khanh Hoa Province; and finally in Ly Son MPA (Marine Protected Area) with nine sampling locations. The characteristics of shoot density collected through the field surveys obtained the difference in the Central Coast region. DW (Dry Weight) biomass of seagrass in Lang Co lagoon and Cua Dai estuary reached 76.56 ± 52.38 (g DW)/m 2 ) and 53.21 ± 57.66 (g DW/m 2 ), respectively dominated by Thalassia hemprichii and Halodule pinifolia in Lang Co lagoon and Cua Dai Estuary, respectively. The rate of above-and below-ground biomass was different. Seagrass species tended to grow below-ground part compared to above-ground part. The study results would be a significant database on environmental informatics to promote the sustainable management of seagrass resources in the central coastal areas of Vietnam.