Theoretical reasons are given to show that midwater chlorophyll maxima may be due to an increase in the chlorophyll content of the plants rather than to an accumulation of plants due to sinking. Data from the Gulf of Mexico are used to support this explanation.
Steele, J. H.. 1964. "A study of production in the Gulf of Mexico." Journal of Marine Research 22, (3). https://elischolar.library.yale.edu/journal_of_marine_research/1031