Primary food resources in the Sacramento-San Joaquin Delta

Interagency Ecological Program Newsletter
By:  and 



The Sacramento-San Joaquin River Delta, a complex mosaic of tidal freshwater habitats, is now a focus of ecosystem rehabilitation because of changes in critical functions associated with its geographic location at the landestuary interface. One of these functions is the production, transport, and transformation of organic matter that constitutes the “primary food supply,” that is, the food supply to the base of the food web. Interest in the primary food supply is motivated by evidence for sub-optimal food quantity or quality at trophic levels that support fish recruitment, including primary consumers such as clams, mysids, cladocerans, rotifers, and native copepods. We used the historical data set to examine the magnitudes of the most important organic matter sources for the Delta, the factors underlying their interannual and longer-term variability, and the implications of ecosystem rehabilitation actions for these sources. Here, we present a summary of the first phase of the analysis, including the quantitative importance of different organic matter sources and some of the hydrological controls on their year-to-year variability. The full report of this first phaseincluding data sources, the methods of calculation, and references, is in press elsewhere (Jassby and Cloern forthcoming). The historical data analysis is part of a larger project in which measurements of stable isotopes and biogeochemical markers, and experiments on organic matter biodegradation and zooplankton growth rates, are being used collectively to define the primary food resources and their quality.

Publication type Article
Publication Subtype Journal Article
Title Primary food resources in the Sacramento-San Joaquin Delta
Series title Interagency Ecological Program Newsletter
Volume 13
Issue 3
Year Published 2000
Language English
Publisher Interagency Ecological Program for the San Francisco Estuary
Contributing office(s) California Water Science Center
Description 5 p.
First page 21
Last page 25
Country United States
State California
Other Geospatial Sacramento-San Joaquin Delta
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