What is the red tide in Bohai Bay?

At the end of 2006 10, a large-scale red tide appeared in the waters near Tianjin and Huanghua in Bohai Bay, and its biological species was identified as Phaeocystis globosa. According to experts, this is the first time in recent years that Phaeocystis has appeared in this season in Bohai Sea.

The so-called red tide refers to the abnormal reproduction of a large number of plankton, which makes the sea water discolored.

Most plankton in natural waters have certain colors, such as noctiluca scintillans is red, Chlorella viridis is green, and diatoms are mostly brown. In general, due to the small number, it is not easy to detect. However, when the eutrophication of water makes it multiply rapidly, they gather in large numbers on the water surface and float in various forms such as blocks and ribbons, making the water surface appear in various colors. The main reason of red tide is that the ocean is polluted, and the nutrients such as nitrogen and phosphorus that can be used by organisms accumulate in large quantities, resulting in eutrophication of the ocean, which provides rich nutrients for the mass reproduction of red tide organisms. Strong sunlight, rising water temperature, stagnant seawater and stable airflow over the sea surface are natural conditions conducive to the aggregation of red tide organisms.