tailieunhanh - Biogeochemical Variability of Vietnamese Coastal Waters Influenced by Natural and Anthropogenic Processes

Phân tích những đặc điểm chính của chu trình sinh địa hóa vật chất trong vùng biển ven bờ Việt Nam trong đó thảo luận về sự biến đổi theo không gian và thời gian của các yếu tố hàm lượng sắc tố thực vật nổi năng suất sinh học dinh dưỡng nito và phospho | Asian Journal of Water Environment and Pollution Vol. 4 No. 1 pp. 37-46. Biogeochemical Variability of Vietnamese Coastal Waters Influenced by Natural and Anthropogenic Processes Nguyen Tac An and Phan Minh Thu Institute of Oceanography 01 Cau Da Nha Trang Vietnam ngtacan@ Received January 15 2006 revised and accepted November 5 2006 Abstract The paper focuses on an analysis of the main characteristics of Vietnamese coastal zones and their biogeochemical cycles. Spatial and temporal variability in the distribution of chlorophyll primary production carbon nitrogen and phosphorus are discussed. Biogeochemistry depends on hydrodynamics especially on the upwelling from the seas and on anthropogenic processes from the land. Key words Biogeochemical processes coastal zone Vietnam chlorophyll primary production balance. Introduction More than 50 of a population of about 82 million live in Vietnam s coastal provinces that cover of the country s total area GDS 2004 . Their activities especially those that are related to food production such as the development of aquaculture and fishing have brought enormous pressure on Vietnam s coastal environment. For example the accumulation of waste from aquaculture has caused soil degradation pollution and eutrophication in water bodies in general and red tide blooms in coastal waters. Agricultural run-off and inputs of domestic and industrial waste have further contributed to changes in the distribution and behaviour of elements and cycling of carbon and other nutrient elements in coastal waters. Thus not just the socioeconomic but also the regulatory functions of the coastal waters are under threat. A better knowledge on the processes involved and their interactions with the overall structure and functioning of coastal ecosystems is a prerequisite for developing management measures towards the wise use and the protection of coastal marine Corresponding Author resources. This paper gives a brief overview of the .