Did you see a jellyfish on a recent trip to the seaside? UK beachgoers are more likely to spot one now than in the past, as rising sea temperatures due to climate change have ushered more of these gelatinous animals into the waters around northern Europe.
Jellyfish don’t swim like fish. They belong to the plankton: a diverse group of marine creatures that drift through the sea, floating wherever the currents take them. Jellyfish are among the few types of plankton visible to the human eye. Most plankton are tiny (smaller than 2mm) and can only be seen with a microscope.
Although largely invisible, plankton are the base of the ocean food web, eaten by fish, seabirds and even whales. Species that don’t eat plankton, like seals, will eat organisms that do. Globally, phytoplankton (single-celled algae which, like trees and shrubs on land, are mostly green in colour and use chlorophyll to photosynthesise) produce half of the oxygen we breathe.
— source weforum.org | Aug 25, 2022