In a March 2020 post, I described the status of the Delta smelt through 2019. This post updates the status with the most recent 2020 information. Delta smelt continue to be absent from the standard long-term surveys and their related indices. However, some Delta smelt were collected in 2020 in selected locations of the Bay-Delta during focused intensive special surveys designed to find remaining survivors. Larval and juvenile Delta smelt were collected in low numbers in the Bay and north Delta (Figure 1). Pre-adult Delta smelt were also collected in summer trawl surveys (Figure 2).
The north Delta habitats where a few Delta smelt persevere continue to be plagued by constant stressful if not lethal water temperatures (Figures 3 and 4).
As I stated in a prior post, Delta smelt would benefit from increased net flows through the north Delta during the spring and summer.