It's a by-product of a biochemical reaction that was triggered by the microorganisms just off the shore of the Puerto Marqués beach in Acapulco.
While those who've seen it online have been quick to say this strange sight has been caused by a lack of human activity due to the coronavirus lockdown allowing nature to flourish once again, marine biologists have said this is not the case.
One such biologist called Enrique Ayala Duval explains the real science behind it.
He told Sabersfin.com: "Bio-luminescence is the light produced as a result of a biochemical reaction in which most of the time luciferin [protein], molecular oxygen and ATP [adenosine triphosphate] take part, which react by means of the enzyme luciferase in the following way: oxygen oxidizes luciferin, luciferase accelerates the reaction, and ATP provides the energy for the reaction, producing noticeable water and light at night."
Righto, that clears that up, then.
He continued: "There is a hypothesis that the bio-luminescence that exists today is the result of evolution.
"Initially, when the Earth's atmosphere had an almost zero concentration of oxygen and oxygen was gradually increasing due to the increasing presence of photosynthetic organisms, organisms were released from oxygen, which was then toxic to them with the bio-luminescence reaction producing water."
Of course, not all the humans are gone. One person couldn't resist jumping straight into the waves and getting among the plankton.
Putting aside the fact that bathing in the ocean is currently banned in Mexico, that's a pretty dumb move, and they've been rightly called out on social media for their actions.
One person said: "The phytoplankton natural spectacle in Puerto Marqués #Acapulco is impressive, it is an effect created by microorganisms from the sea. What is bad is that the human being will always be there to ruin everything."
Anyway, let's just try to enjoy the spectacle. It could be another 60 years before it returns to this particular beach.