- Reduced water levels result in less habitat space and less food for juvenile salmon.
- Higher water temperatures reduce their oxygen levels and increase their susceptibility to disease.
- Poor water quality caused by drought can also harm salmon.
Drought can result in the death of salmon eggs and juveniles, reduced adult survival, and population declines.
- Drought can cause river flows to diminish and create barriers to migration for adult salmon returning to their natal streams.
- Low water levels can also concentrate salmon in smaller areas, making them vulnerable to predators and competition.
- Warmer water temperatures can cause salmon to become stressed, reduce their ability to feed, and develop diseases.
- Warmer water also holds less dissolved oxygen, making it difficult for salmon to breathe.
- Drought can reduce the amount of zooplankton and other food sources for juvenile salmon.
- This can lead to malnutrition, reduced growth, and increased susceptibility to predators.
- Drought-related stress can make salmon more susceptible to diseases such as Bacterial Kidney Disease (BKD), Ichthyophthirius multifiliis (Ich), and Ceratomyxa Shasta (Ceratomyxosis).
- Drought-induced habitat reductions can force different salmon species to compete for limited food and space.
- Reduced water levels can also make salmon more vulnerable to predators, such as birds and mammals.
Drought poses a significant threat to the survival and recovery of endangered California salmon populations. Prolonged and severe droughts can cause substantial population declines and impede conservation efforts.
Water management strategies that prioritize instream flows and habitat conservation during drought are critical for the long-term protection of these iconic fish.
