Naming conventions for living marine tracers

[jessluo]

As we begin adding in additional plankton functional types, we need to decide on an appropriate naming convention for these PFTs.

For example, do we use autotroph vs heterotroph? Or phytoplankton vs zooplankton? Right now it is autotroph and zoo, which seems inconsistent.

Additionally, since our phytoplankton groups are sp, diat, and diaz, it would make sense to name zooplankton groups by some sort of name that represents their size/function, e.g. microzoo, mesozoo or macrozoo rather than zoo1, zoo2, and zoo3.

Alternatively, we can decide that zooplankton should have a different naming convention than phytoplankton.