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January 10, 2022

In the Sacramento-San Joaquin Delta, phytoplankton populations that make up the bottom of the aquatic food web have been declining in recent decades. To better understand this problem, more thorough information and data on aquatic ecosystems are necessary.

Microscopic view of a phytoplankton cell collected in San Francisco Bay
Microscopic view of a phytoplankton cell collected in Sacramento-San Joaquin Delta

One of the primary ways of determining the health of an aquatic ecosystem is to understand its hydrodynamics, that is the movement of water and impact it has on the environment, including the food web. This allows water managers to make better decisions affecting the preservation of natural resources.

An area of interest in this effort has been the Sacramento River Deep Water Ship Channel, a terminal channel known to support native fish populations, where conditions may be favorable to enhance primary production of phytoplankton.

In an article for the journal San Francisco Estuary and Watershed Science scientists discuss their research related to this issue. This work included studying the mixing in the channel driven by tidal currents and wind, and the resulting effect on the strength and duration of thermal stratification in the upper channel and its influence on phytoplankton production. Information from this research will be useful for habitat-restoration efforts being made to increase phytoplankton production.

To learn more, read the full article.