Abstract

Traditionally, diatoms have been associated with productive pelagic food chains that lead, through suspension-feeding planktonic copepods, to top consumers and important fisheries. Here, 15 laboratories located worldwide in 12 different countries and representing a variety of marine, estuarine and freshwater environments present strong evidence that diatom diets are in fact inferior for copepod reproduction. When fed to females of 16 copepod species, all but 1 of the 17 diatoms examined significantly reduced egg production rates or egg viability compared to non-diatom controls. These effects are hypothesized to influence copepod recruitment patterns and the flow of energy in marine food webs.