Understanding the dynamics of the relationship between phytoplankton and higher trophic levels is necessary for understanding the transfers of matter and energy through planktonic food webs. There have been several suggestions in the literature that copepods were more strongly associated with the subsurface productivity maximum than the chlorophyll maximum (Herman, 1983; Herman and Platt, 1983; Napp et al., 1988). Zooplankton have been shown to respond to microscale (centimeters) patches of phytoplankton in the lab (Tiselius, 1992; Saiz et al., 1993), however, except for Tiselius et al. (1994), who found correlations to 15 cm, there have been few data to confirm these results in situ. Zooplankton behavioral response to their food environment is therefore a critical factor to consider in trying to predict the relationship between phytoplankton and zooplankton in the ocean.