Synthesis of the effect of drought on the distribution and movement of a non-native predator (striped bass) in the Sacramento-San Joaquin River Delta

Start/End: April, 2016 to March, 2018

Within the Sacramento-San Joaquin River Delta, predation may be a contributing factor to low survival of endangered Chinook salmon. To fully understand the potential impacts of striped bass, a non-native species and predator of Chinook and other fishes, requires understanding their population size and spatial distribution through time at time scales relevant to management. Drought and water flow may influence the amount of time striped bass spend in freshwater, which may impact their encounters and predation on Chinook salmon smolt.

This project will explore how drought and water runoff influence the distribution of striped bass between fresh and salt water in the Delta, using combination of existing datasets and new information gained from microchemistry analysis. Specifically, it will examine:

  • Whether yearly annual runoff influences the use of freshwater by striped bass over different spatial and temporal scales;
  • Whether sub-adult striped bass have different freshwater distributions than adult fish;
  • Whether introduced striped bass in California mimic distribution patterns in their native range.