The Web of Life (40) Plankton


Plankton┬átypify the protist’ classification dilemma, in being characterized only as teeny critters that can’t swim against a current.

Bacterioplankton are waterborne bacteria and archaea, rendering the term bacterioplankton an incomplete misnomer. A more inclusive and descriptive term would be saproplankton, because these plankton remineralize organic material.

Phytoplankton practice photosynthesis. Among them are prokaryotes (cyanobacteria) and eukaryotes (diatoms, coccolithophores, and dinoflagellates).

Phytoplankton alter their biochemical composition according to nutrient availability. ~ American biochemist Patrick Martin

 Husbanding Phosphorus

Phosphorus is essential to all organisms. It can be extremely scarce in open-ocean surface waters. Phytoplankton compensate by tucking away a reserve of phosphorus when it is available.

Conversely, phytoplankton take various measures to access phosphorus when supply is scant. They reduce their inventory of phosphorus-containing biochemicals, increase their affinity and uptake rate of phosphorus, and produce enzymes to hydrolyze extracellular dissolved organic phosphorus molecules.