There are many kinds of organisms that can glow in seawater, from unicellular dinoflagellate to coelenterates such as luminous jellyfish, annelids such as marine polychaetes, mollusks such as luminous cephalopods, and even arthropods such as krill and fireflies. From the phenomenon of "fluorescent beach", we can rule out the larger jellyfish and cephalopods, while arthropods such as fireflies can't produce such strong fluorescence, so it is most likely that dinoflagellate unicellular organisms reproduce.
For dinoflagellate, this bioluminescence phenomenon may be a defensive measure. When disturbed by predators such as zooplankton, the emitted fluorescence can attract predators with higher nutrition such as fish with more sensitive senses, thus driving away their direct predators.
Because dinoflagellates, represented by Noctiluca scintillans, proliferate in large numbers, so that there is a strong fluorescence phenomenon, which indicates that the contents of phosphorus, potassium, iron and other nutrients in seawater in this sea area increase, which makes the number of bacteria, cyanobacteria and unicellular algae as dinoflagellates increase.
Description of fluorescent beach phenomenon
The "fluorescent beach" phenomenon has become a hot topic. This strange phenomenon has been reported in seven places in the world, including three in Puerto Rico, two in Australia, 1 in Maldives and 1 in Dalian, China. Marine biologists generally believe that "fluorescent beach" is actually a spectacular scene formed by countless plankton with deep blue light washed up on the beach with the waves.
There are two colors of "fluorescent beach", one is blue spots, and the other is green spots that keep flashing. In contrast, the blue dot is more beautiful and dazzling. At night, there are stars on the winding beach, and couples walk hand in hand, which is extremely romantic. However, such beautiful scenery is hard to last. It will fade quickly in a quiet environment, and only by stirring the sea or throwing stones will it shine again.
Baidu encyclopedia-fluorescent beach