Comparisons of different oceanic regions often suggest that in the largest sense there is a direct relationship between phytoplankton and zooplankton-that is, banks and coastal areas with large concentrations of phytoplankton are likely to be rich in zooplankton, while sparser crops of both occur in deep oceanic waters. On the other hand, surveys of particular areas often show an inverse relationship, with local swarms of zooplankton occurring in phytoplankton-poor waters, alternating with dense patches of phytoplankton containing few animals....
Riley, Gordon A., and Dean F. Bumpus. 1946. "Phytoplankton-zooplankton relationships on Georges Bank." Journal of Marine Research 6, (1). https://elischolar.library.yale.edu/journal_of_marine_research/623