In coastal and estuarine waters, the traditional paradigm of production is that a spring algae bloom - dominated by diatoms - supports the reproduction of crustacean zooplankton - mostly copepods - which provide food for larval predatory and piscivorous fish (e.g. gadids, salmonids, etc.) as well as for planktivorous fish (clupeids). 

However, laboratory work over the last decade has begun to question the link between diatoms and copepods.  A number of studies have unequivocally shown that female copepods that are fed high concentrations of diatoms have a reduced reproductive success compared with female copepods that are fed other algal food types.  These findings have been ascribed to either toxins in the diatoms or nutritional deficiencies in the diatoms. 

In spite of the laboratory evidence, field observations of a direct effect of diatom diets on copepod reproduction are rare.  The goal of our study was to unambiguously determine if diatoms can affect copepod reproduction in situ.  To do this we embarked upon a three-year, NSF funded research project, headed by researchers here at the University of Washington. 

 UW School of Oceanography

  NOAA NMFS Pacific Fisheries Environmental Lab

 National Science Foundation