This project measures and compares ecological productivity in two types of river systems in the Upper Sacramento River watershed. The project's team of ecologists, geologist and biologists is comparing the food-web dynamics of three spring-fed systems - Hat Creek, Fall River and tributaries of the upper Sacramento River - with those of rivers that receive mainly snowmelt and stormwater runoff in the same watershed.

The study aims to improve understanding of spring systems and their role in sustaining salmonids in California. Spring systems are expected to become increasingly more important for the survival of these and other cold-water fishes as the climate changes and the runoff-fed rivers run low and warm.

Spring rivers are more resilient to long-term warming and changes in precipitation because they receive a constant source of cold water from underground. They often have unique water chemistry that promotes the growth of aquatic plants and insects.