How You Catch Zooplankton and More...
Dr. Carin Ashjian’s group (from Woods Hole) are studying what zooplankton species composition,including where the different types are located, and how their distributions are associated with currents or water types. The currents are like a species relocation service; for example, the baby (nauplii) barnacles appear in different locations along Hanna Shoal due to currents. How are they caught? The zooplankton are caught in a bongo net (two plankton nets in tandem). (Ring net plankton samples are shared with the Dunton and Trefry groups.)
Types of Zooplankton
Zooplankton are animals that live all or part of their life as plankton floating freely throughout the seas and other bodies of water. Most copepods in different parts of the world's oceans have a life span of a few months, but a species in the Arctic can live for two years. This copepod (Calanus glacialis) is a favorite food source for birds. For those of you that have watched the Sponge Bob cartoon; the character called "plankton" is a cartoon version of a copepod. In the picture below is my favorite copepod (top) in the arctic, Calanus glacialis. I like the red pigments, which are lipid stores. The second picture is a barnacle nauplii.
Picoplankton...Very Tiny Plankton
Picoplankon can be counted using a flow cytometer. The instrument shines a beam of light at the plankton. Each type of plankton emits light of different wavelength in response.
Red Tide Part 2
A type of phytoplankton is also responsible for causing red tides in the Gulf of Mexico. The organism is the dinoflagellate Noctiluca which produces a neurotoxin when it dies, causing fish kills. The red tide pictured in the journal called "Heading Out" is not a phytoplankton, but a ciliate (Mesodinium rubrum) with an endosymbiotic (endo - inside and symbiotic - cooperating) alga. It is not toxic!