Climate change is warming up water all over the world, including in the San Francisco Estuary. This has caused fish who live there to change their behavior in unexpected ways. All animals, including fish, have regular and specialized behaviors that help them to survive. Fish swim, by themselves or in groups, to move to safer habitats, to find food or mates, or just to avoid danger. Scientists worry that changes to these behaviors brought on by warming water will make estuaries less safe for rare and endangered fish like the delta smelt. In the San Francisco Estuary, we found that warmer waters caused delta smelt to swim faster and further away from their neighbors, and to be eaten more often by predators. All these changes could hurt the ability of delta smelt to survive in the future.
