Question: Which of these describes a situation where the standing crop of primary producers is likely to be high? Need Assignment Help? The phytoplankton are growing faster than zooplankton, or anything else in the marine community. The phytoplankton are growing more slowly than zooplankton, or anything else in the marine community. The phytoplankton are growing at the same rate as the zooplankton. The zooplankton were already very abundant, but then the phytoplankton became also very abundant.