Plankton: this is the ๐ฏ๐ฎ๐๐ฒ ๐ฎ๐น๐ถ๐บ๐ฒ๐ป๐๐ฎ๐ถ๐ฟ๐ฒ of any body of water. Without phytoplankton, we would have neither ๐๐ผ๐ผ๐ฝ๐น๐ฎ๐ป๐ฐ๐๐ผ๐ป, nor small ๐ฝ๐ผ๐ถ๐๐ผ๐ป๐, nor large ๐ฝ๐ฟ๐ฒฬ๐ฑ๐ฎ๐๐ฒ๐๐ฟ๐ in the ocean; underwater and sub-lake life would be extinct. This is the principle of ๐ฐ๐ต๐ฎ๐ถฬ๐ป๐ฒ ๐ฎ๐น๐ถ๐บ๐ฒ๐ป๐๐ฎ๐ถ๐ฟ๐ฒ ; if zooplankton can no longer feed on phytoplankton, they disappear, and small fish find themselves without zooplankton and decline in turn, which in turn causes the large predators to disappear. Carnage!
But what are these microscopic organisms, without which we would have no life underwater? Just one example: ๐น๐ฒ๐ ๐ฎ๐น๐ด๐๐ฒ๐! According to a 2003 CIPEL study, there are ๐ญ๐ฐ๐ฌ ๐๐ฎ๐ ๐ผ๐ป๐ (families) of phytoplankton in ๐ฑ๐ฎ๐ป๐ ๐น๐ฒ ๐๐ฒฬ๐บ๐ฎ๐ป alone! Despite their small size, phytoplankton make up the ๐บ๐ฎ๐ท๐ผ๐ฟ๐ถ๐๐ฒฬ of the ๐ฏ๐ถ๐ผ๐บ๐ฎ๐๐๐ฒ ๐๐ฒฬ๐ด๐ฒฬ๐๐ฎ๐น๐ฒ in virtually any body of water.
Phytoplankton live in the ๐ฒ๐ฎ๐๐ ๐ฝ๐ฒ๐ ๐ฝ๐ฟ๐ผ๐ณ๐ผ๐ป๐ฑ๐ฒ๐ of the lake. Since they are photosynthetic organisms - which use the sun's energy to feed themselves - they must be found in the zone known as '๐ฒ๐๐ฝ๐ต๐ผ๐๐ถ๐พ๐๐ฒ', i.e. the zone in which light still penetrates (between 10 and 15m deep). Often unicellular, phytoplankton float freely in the euphotic zone. Many species can form ๐ฐ๐ผ๐น๐ผ๐ป๐ถ๐ฒ๐, making them ๐๐ถ๐๐ถ๐ฏ๐น๐ฒ๐ ๐ฎฬ ๐น'ล๐ถ๐น ๐ป๐.
Phytoplankton numbers ๐ณ๐น๐๐ฐ๐๐๐ฎ๐๐ถ๐ผ๐ป๐ ๐๐ฎ๐ถ๐๐ผ๐ป๐ป๐ถ๐ฒฬ๐ฟ๐ฒ๐ are impressive; one litre of water can contain ๐ฏ๐ฌ ๐ฎฬ ๐ฑ๐ฌ ๐ณ๐ผ๐ถ๐ ๐ฝ๐น๐๐ more plankton in ๐ณ๐ถ๐ป ๐ฑ๐ฒ ๐ฝ๐ฟ๐ถ๐ป๐๐ฒ๐บ๐ฝ๐ than during the winter! Every year in May, the phytoplankton population collapses, due to its overconsumption by zooplankton. The zooplankton population in turn collapses when it has eaten all the available phytoplankton. Finally, a ๐ฒฬ๐พ๐๐ถ๐น๐ถ๐ฏ๐ฟ๐ฒ is found between the phyto and zooplankton in Lake Geneva.
Phytoplankton also has another role; it is the second ๐ฝ๐ผ๐๐บ๐ผ๐ป ๐ฑ๐ฒ ๐น๐ฎ ๐ฝ๐น๐ฎ๐ป๐ฒฬ๐๐ฒ. We hear a lot about the Amazon, but phytoplankton produces ๐ฑ๐ฌ% ๐ฑ๐ฒ ๐น'๐ผ๐ ๐๐ด๐ฒฬ๐ป๐ฒ which we breathe, whereas ๐๐บ๐ฎ๐๐ผ๐ป๐ถ๐ฒ ๐ฒ๐ป ๐ฝ๐ฟ๐ผ๐ฑ๐๐ถ๐ ๐ฒ๐ป๐๐ถ๐ฟ๐ผ๐ป ๐ฎ๐ด%. Sylvia Earl, a great oceanographer and explorer, has calculated that just one species of plankton, Prochlorococcus, provides the oxygen for one in five breaths for every human being on Earth!
Although tiny, phytoplankton is perhaps the living organism on which the most responsibility rests. ๐๐ฒ ๐ฝ๐น๐ฎ๐ป๐ฐ๐๐ผ๐ป, ๐ฐ'๐ฒ๐๐ ๐น๐ฎ ๐๐ถ๐ฒ. Enough to study, cherish and protect!
Information from the CIPEL and National Geographic
Photo credit: Patrice Simon, Arielle Cordonier
