In aquatic systems, primary productivity is a measure of algal community activity. Primary production and the amount of algae generally increase with increased nutrient input, higher temperatures, and additional light.
2023 Evaluation
Status
Insufficient Data to Determine Status or No Target Established
WQ5: Attain 1967-71 mean values for phytoplankton primary productivity in the littoral zone.
Key Points
The focus of UC-Davis's nearshore algae monitoring in Lake Tahoe for last 30 years has been on biomass (or amount of algae) and not its productivity. That data is analyzed in the nearshore attached algae threshold standard.
Work in the nearshore areas of Tahoe found that primary production increased by 40 percent in 2021 when the lake was blanketed in smoke from the Caldor, Tamarack, and Dixie fires (Smits et al., 2024)
No lake-wide trend in periphyton biomass has been observed since monitoring began.
About the Threshold
Rationale Details
Status Rationale
Insufficient data to determine status. Monitoring of nearshore algae shifted towards monitoring total biomass of algae rather than the rate specified in the standard (Attain 1967-71 mean values for phytoplankton primary productivity in the littoral zone).