Science activity
Science activity #49851, updated 29 April 2022

Nutritional Quality of Zooplankton as Prey for Fish in the Sacramento-San Joaquin Dalta

Description / purpose

Primary consumers (zooplankton) are a critical trophic link for energy transfer to upper trophic levels and a key food source for threatened and endangered fish species in the Delta. The zooplankton community was shaped by large spatial and temporal changes in both abundances and species composition that affected quantity of zooplankton carbon. It is also expected that taxonomic shifts affected quality of zooplankton carbon for fish due to altering biomass transfer at the base of the food web that can profoundly influence nutritional quality and population dynamics at higher trophic levels. Yet the biochemical composition of plankton remains largely unstudied in this system despite the fact that the importance of zooplankton nutritional quality for fish is one potential major component for the long-term decline and more recent collapse of pelagic fish species. The proposed research aims to measure essential nutritional status (stoichiometry, fatty acids, sterols) for zooplankton taxa and will calculate food-quality indices for fish. On the basis of nutritional plankton and biomass values, spatial patterns as well as long-term and recent changes in plankton quality associated with compositional shifts will be estimated. We propose that through integrating plankton food-quality into the management and restoration plan for the Delta, the dynamics of the ecosystem can be viewed from a new perspective that has key implications for understanding the decline in pelagic organisms.

Linked science activities

None specified


Monika Winder, Principal investigator - Stockholm University

Activity status

  • Awarded / Initiating (2011)
  • In progress / Ongoing (2011 - 2014)
  • Complete

Funding summary

Total allocated funding: $312,566

Label Value
Contract # or labor code 2047
Implementing organization University of California - Davis [UC Davis]
Funding organization Delta Stewardship Council
Funding Source Delta Stewardship Council - General Fund
Date of award 2011
Date of fiscal year-end Not provided
Total award amount $312,566
State type of obligation Not provided
Federal type of obligation Not provided
Reimbursability Not provided
Procurement mechanism Not provided


Delta regions

Geographic tags

None specified

Type and context

Science action area
Management themes
Science themes
Science functions
Management actions
None specified
Science Topics
Lead implementing organization
Partner implementing organizations
None specified
Funding organizations
Funding programs
Funding sources