Characteristics of Nutrients Distribution and Limitation of Miaodao Archipelago Sea Area from 2018 to 2019

Abstract

This paper analyzed the horizontal distribution and limitation of DIN, PO4-P and SiO3-Si based on the four surveys of Miaodao Archipelago sea area in August and October of 2018, April and June of 2019. The results showed that the concentration of DIN ranged from 0.82 μmol/L to 95.14 μmol/L with an average value of 5.27 μmol/L and the maximum was in August of 2018. The concentration of PO4-P ranged from "not detected" to 2.12 μmol/L with an average value of 0.19 μmol/L and the maximum was in October of 2018. The concentration of SiO3-Si ranged from 0.25 μmol/L to 48.93 μmol/L with an average value of 5.38 μmol/L and the maximum was in August of 2018. In general, the concentration of nutrients was higher in summer and was relatively scarce in spring. PO4-P was the limiting factor in August and October of 2018, June of 2019, while SiO3-Si and PO4-P were the limiting factors in April of 2019. The PO4-P limitation would limit the primary productivity of sea area and the aquaculture could be influenced. The low content of SiO3-Si was not conducive to the growth of diatoms, which indirectly promoted the reproduction of dinoflagellates, so that this area was easy to cause red tide in spring.

Keywords

• miaodao archipelago
• horizontal distribution of nutrients
• nutrients structure
• nutrients limitation