Regressions Between Biological Oceanographic Measurements in the Eastern Tropical Pacific and Their Significance to Ecological Efficiency1

Simple regressions of various standing stocks on each other and on primary productivity were compared by covariance analysis for different seasons, latitudes, and longitudes in the eastern tropical Pacific. The stock of zooplankton varies significantly with that of chlorophyll a to a power <1.0 in all seasons and areas, and it is shown that a similar relation probably exists between the corresponding rates of daily production. A similar relation holds in the regression of standing stock of fish‐cephalopod micronekton, suitably lagged, on stock of zooplankton. Thus the relative amount of organic matter transferred from one trophic level to another probably decreases with an increase of stock and production at the lower level, so that ecological efficiency is higher in oligotrophic than in eutrophic situations, in tropical oceans. Standing stock of chlorophyll a varies significantly with primary productivity to a power <1.0. The stock of crustacean micronekton sometimes varies with the stock of chlorophyll a to a power >1.0, which is interpreted as a feeding aggregation.