Map of zooplankton biomass (averaged over all seasons), found in the upper 200 meters of the ocean, represented as the amount of carbon (milligrams) in a cubic meter (m3) of seawater.

https://www.st.nmfs.noaa.gov

A Coccolith bloom off the coast of Cornwall and Devon taken by Landsat in 1999.

https://en.wikipedia.org

Shown here is the Continuous Plankton Recorder (CPR), a robust and reliable instrument designed to capture plankton samples over huge areas of ocean. The CPR is usually towed from the stern of volunteer merchant ships such as RoRo and Container Ships. However this versatile recorder has also been deployed from large sailing vessels, fishing boats and super tankers.

https://www.sahfos.ac.uk

A variety of zooplankton

https://en.wikipedia.org