Phân bố muối dinh dưỡng vùng nước trồi mạnh Ninh Thuận - Bình Thuận tại thời điểm dự báo có hiện tượng El Nino, tháng 7/2016 [Nutrient distribution of Ninh Thuan - Binh Thuan - a strong affected area from upwelling, in the time of El Nino Forcasting, July 2016]

Abstract

Ninh Thuan - Binh Thuan marine area is strongly affected from upwelling operation, especially from June to July annually. Moreover, the El Niño phenomenon was forecasted in such period in 2016. This study’s objective was to understand the features of nutrients in studied area in July 2016, the moment that was annual peak upwelling time as well as El Niño phenomenon prediction. The results showed that DIN concentration at surface was lower and distributed increasing from offshore area to shore, while that at the bottom was higher and increasingly from North to South. The highest value at surface is 3.95 µM and at bottom is 4.2 µM. DIP distribution was quite different between surface and bottom, the trend at surface was not obvious while that at bottom was increasing from North to South and from offshore area to shore. The highest values were recorded at both layers of the same site (0.39 µM and 0.42 µM). DSi distribution trends at both surface and bottom were almost the same, increasing from North to South and from offshore area to coast. There were not so many anomalies of nutrient parameters in the area during survey time, all of the highest values were near shore and at coastal sites. Generally, vertical distribution of nutrients in water column was uneven and not obvious. There was no detection of either similarity in nutrients content or mutant layers down to 50 m depth. Together with temperature and salinity data, it can be said that the upwelling operation in studied area in survey time was not obvious. The calculation of Oceanic Nino Index also showed that El Niño did not take place in the survey time.