Temperature trends at several sites in the upper San

This report is a brief examination of water temperature trends in Suisun Bay and the Delta. Water temperature trends are of particular interest because the success of both desirable and undesirable species can be highly temperature-sensitive. For example, the nuisance cyanobacterium Microcystis aeruginosa, which has been spreading in the estuary since 1999, has a high optimum temperature over 25◦C, depending on the strain (Nalewajko and Murphy, 2001). In contrast, the endangered native delta smelt Hypomesus transpacificus appears to have a lethal limit near 25◦C (Swanson et al., 2000). The analysis is based primarily on hourly time series data collected by the Californi