No abstract

Từ khóa: Du lịch, lượng giá, hệ sinh thái, biển đảo, dịch vụ, Bạch Long Vĩ. MỞ ĐẦUHệ sinh thái (HST) biển là một hợp phần trong hệ thống tài nguyên. Trong các HST, hàng hoá và dịch vụ là sản phẩm của tự nhiên, được sản sinh trong suốt quá trình tiến hoá lâu dài. Một trong những dạng hàng hóa, dịch vụ được cung cấp từ các hệ sinh thái biển là giá trị du lịch. Giá trị du lịch thường mang lại lợi ích kinh tế rất to lớn cho cộng đồng dân cư ven biển. Phát triển đảo BLV thành một đảo du lịch đang được thành phố Hải Phòng định hướng xây dựng. BLV được biết đến như là một hòn đảo du lịch mới nằm trong lòng VBB với cảnh quan thiên nhiên độc đáo, là một hòn đảo xanh, nổi trên mặt biển xanh, sạch đầy hấp dẫn và quyến rũ du khách. Đặc biệt có HST rạn san hô ngầm là một dạng tài nguyên quý giá. Đánh giá tiềm năng phát triển du lịch của đảo BLV và lượng giá kinh tế giá trị du lịch có thể mang lại từ các hệ sinh thái biển của đảo BLV là việc làm rất cần thiết giúp chính quyền có được

Intertidal and larger marine ecosystems surrounding the islands of Bach Long Vi (Northern Vietnam), Con Co (Central Vietnam) and Tho Chu (Southernmost Vietnam) which have typical and valuable ecosystems are planned as marine protected areas. They are the study area of this paper on identification and estimation of these ecosystem services. The total economic valuation concept is used to estimate the total value of the ecosystems during the period March 2014 to October 2015. The marine ecosystems surrounding Bach Long Vi Island were estimated servicing 599,047.8 million VND (Vietnam Dong)/year in total (corresponding to 26.62 million USD (US dollar-1 USD = 22,503.68 VND (rate May 1, 2015)); calculated per hectare; this value corresponds with 94 million VND/year. The marine ecosystems surrounding Con Co Island provide a total monetary service of 267,518 million VND/year (approximately, 12 million USD/year); this corresponds with 307 million VND/ha/year. The marine ecosystems surrounding the Tho Chu archipelago were worth 565,236 million VND/year (approximately, 25 million USD/year); this corresponded with 125.47 million VND/ha/year. These figures show the most significant service value of marine ecosystems, particularly around the three islands. Palabras claveMarine ecosystem service, Island, Coral reef, Tidal wetland, Tropical region.

Grain sizes and minerals from Gulf of Tonkin sediments were evaluated from 30 surface samples and 50 samples in two cores, distribution of grain sizes and minerals to help understand sediment characteristics, origins, and environmental dynamics. There were five sediment types: Fine and very fine sands were found nearshore where land-sea interactions were stronger than offshore, whereas very coarse, coarse, and medium silts were found offshore, in small bays, river mouths with weak land-sea interactions, or near source sediment supplies. Minerals in sediment were identified as decreasing in the content of quartz, illite, kaolinite, chlorite, feldspar, goethite, halite, calcite, gibbsite, aragonite, and montmorillonite. Content of major minerals such as quartz, illite, kaolinite, and chlorite varied from nearshore to offshore; quartz was higher nearshore than offshore; illite, kaolinite, and chlorite nearshore were lower than offshore; calcite and aragonite were low nearshore and high in offshore; goethite was lower offshore and higher nearshore, while halite was high offshore and low nearshore. Surface sediments were divided into three groups based on sedimentary environment characteristics: group 1 was distributed nearshore with strong dynamics, group 2 in bays and nearshore with weak dynamics, and group 3 was distributed offshore with quiet dynamics. The origin of the sediments is weathering and erosion from the mainland and islands under the river and sea processes in the Gulf of Tonkin with quartz, illite, kaolinite, feldspar, chlorite and montmorillonite presenting in the sediment. Geochemical processes produced goethite, gibbsite, halite and pyrite in the sediments. Biological substances produced calcite and aragonite.

Grain sizes and minerals from Gulf of Tonkin sediments were evaluated from 30 surface samples and 50 core samples in two cores, distribution of grain sizes and minerals to help understand sediment characteristics, origins, and environmental dynamics. There were five sediment types: Fine and very fine sands were found nearshore where land-sea interactions were stronger than offshore, whereas very coarse, coarse, and medium silts were found offshore, in small bays, river mouths with weak land-sea interactions, or near source sediment supplies. Minerals in sediment were identified as decreasing in the content of quartz, illite, kaolinite, chlorite, feldspar, goethite, halite, calcite, gibbsite, aragonite, and montmorillonite. Content of major minerals such as quartz, illite, kaolinite, and chlorite varied from nearshore to offshore; quartz was higher nearshore than offshore; illite, kaolinite, and chlorite in nearshore were lower than offshore; calcite and aragonite were low nearshore and hight in offshore; goethite was lower offshore and higher nearshore, while halite was high in offshore and low in the nearshore. The origin of the sediments is weathering and erosion from the mainland and islands under the river and sea processes distributed in the Gulf of Tonkin with quartz, illite, kaolinite, feldspar, chlorite and montmorillonite present in the sediment. Geochemical processes produced goethite, gibbsite, halite and pyrite in the sediments. Biological substances produced calcite and aragonite.