Emerging scientific consensus increasingly points to a complex puzzle of factors or “stressors” that are responsible for the Delta's decline. When addressing problems in the Delta, it is important to remember that every piece of the puzzle is important. No single piece holds the answer; no one piece should be ignored.
Predation
Predation and competition for food from non-native species in the Delta greatly reduces survival of native fishes. MORE
CLIMATE CHANGE
Warmer temperatures, changing patterns of precipitation and run-off and rising sea levels are likely to have a profound effect on the Delta ecosystem. MORE
DIVERSIONs and in delta pumping
Upstream diversions and unscreened in-Delta pumping directly impact the quantity and quality of Delta water available for fisheries and the ecosystem. MORE
Ocean conditions
Poor ocean feeding conditions and commercial fishing have been identified as key causes of the collapse of fall run salmon. MORE
Development Impacts on Habitat
As California’s population has grown, so have demands on the Delta. This increase in human activity has clearly accelerated natural changes in the Delta and will continue to increase pressure on the estuary in the future. MORE
MUNICIPAL Wastewater and Industrial Discharges
Each day up to 1 billion gallons of partially treated sewage along with discharges from abandoned mines and other industrial facilities are flushed into the Delta, adding daily to the degradation of water quality. MORE
STATE AND FEDERAL PUMPS
The state and federal pumps clearly impact the Delta, but increasing evidence suggests the pumps are one of many stressors. MORE
Invasive Species
The Delta is considered one of the most invaded estuaries in the world. Many non-native species have gained a foothold and are currently inhabiting - and altering - the Delta’s ecosystem. MORE
POWER PLANT DIVERSIONS
Power plants operating directly in the Delta entrain fish and impact endangered species. MORE
Stormwater and Agricultural Runoff
Highly contaminated stormwater run-off from cities, along with salinity, pesticides and other toxic chemicals and pollutants from Delta cities and farms are having major impacts on water quality and fisheries. MORE