Low nutrient and high chlorophyll a coastal upwelling system – A case study in the southern Taiwan Strait

摘要: Using the field data during four summer cruises of 2005, 2006, 2008 and 2013, an interesting phenomenon low nutrient high Chl.a (LNHC) was observed in coastal upwelling system off Dongshan southern Taiwan Strait. The results indicated that region dominated by cold ( 33.9 psu) upwelled water, concentration nitrate (<1 μM) phosphate (<0.1 very low, while with content (mean 1.98–3.56 μg L−1, maximum 8.3 L−1) stronger cruise 2006 2008. water originated from 50–100 m layer Shanwei a (<7.5 μmol·L−1) (<0.5 μmol·L−1), which transported to Shantou-Dongshan northeastward bottom current. During time moved long-distance (150–300 km) through euphotic zone alongshore, phytoplankton grew rapidly due favorable temperature, N/P ratio illumination, consumed most nutrients water. These unique physical, chemical biological processes are main reasons for formation nutrients/high chlorophyll this