All Hail Plankton!


Plankton run the world. Plankton’s absence would forever change the world.

Plankton is divided into two main groups; Phytoplankton, the plant plankton, and Zooplankton, the animal plankton. Phytoplankton, like plants on land, contain pigments, such as chlorophyll for photosynthesis.

Phytoplankton first appeared around 3 billion years ago and helped create the ozone layer. We can thank phytoplankton for more than 50% of the oxygen in our atmosphere and basically supporting life on this planet. Phytoplankton feed just about everything in the ocean, either directly or indirectly, even whales. Without plankton we would not have some of our most iconic Northwest species like salmon or orcas, these animals rely on phytoplankton further down the food chain. One meal for a humpack whale may represent 400 billion diatoms, a type of phytoplankton. Phytoplankton is the “Green Machine” of Puget Sound, accounting for Puget Sound’s emerald green color in the spring and summer and resulting in the amazing biodiversity and productivity we see here.

Zooplankton are the animal plankton and are divided into two groups, holoplankton and meroplankton. Meroplankton only spend part of their life as plankton, usually the larval stage. Examples of meroplankton are sea stars, crabs, clams, and fish. Holoplankton spend their entire life as plankton, examples include arrow worms, krill, and our favorite; copepods.

Why do we love copepods so much? Aside from being adorable, they are numerous and considered the insects of the sea, likely outnumbering the insects with an estimated population of one quintillion (1,000,000,000,000,000,000). They are also an important link in the food chain, linking phytoplankton to fish and whales. Over 60,000 copepods were found in the stomach of a herring. In 2005, upwelling occurred later in the year than usual, resulting in a low copepod biomass that effected recruitment of juvenile rockfish, salmon, and breeding failure in Auklets, a marine bird.

Plankton really do run the world and deserve the attention they get on board; the Marine Science Afloat™ program devotes 3 of 5 classes to plankton.



Pat Maxwell

Executive Director

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