Sampling will be conducted a minimum of twice annually during the summer (June, August). Collecting fish community samples during the summer months is important, as a primary constraint of the Index of Biotic Integrity (IBI) developed for the Sacramento-San Joaquin Drainage (Moyle et al. 1986) is that it be applied to summer fish populations.

Decisions to sample outside of the summer index period to obtain supplemental assemblage information will depend on 1. any funding limitations, or 2. contaminant loading in biota from the Mud Slough corridor reaching established ecological risk toxicity thresholds for selenium.