Fish bioenergetics models estimate relationships between energy budgets and environmental and physiological
variables. This study presents a generic rockfish (Sebastes) bioenergetics model and estimates energy
consumption by northern California blue rockf ish (S. mystinus) under average (baseline) and El Niño conditions.
Compared to males, female S. mystinus required more energy
because they were larger and had greater reproductive costs. When El Niño conditions (warmer temperatures;
lower growth, condition, and fecundity) were experienced every 3−7 years, energy consumption decreased on an individual and a per-recruit basis in relation to baseline conditions, but the decrease was minor (<4% at the individual scale, <7% at the per-recruit scale) compared to decreases in female egg production (12−19% at the individual scale, 15−23% at the per-recruit scale). When mortality in per-recruit models was increased by adding fishing, energy consumption in El Niño models grew more similar to that seen in the baseline model. However, egg production decreased significantly — an effect exacerbated
by the frequency of El Niño events. Sensitivity analyses showed that energy consumption estimates were most sensitive to respiration parameters, energy density, and female fecundity, and that estimated consumption
increased as parameter uncertainty increased. This model
provides a means of understanding rockfish trophic ecology in the context of community structure and environmental change by synthesizing metabolic, demographic, and
environmental information. Future research should focus on acquiring such information so that models like the bioenergetics model can be used to estimate the effect of climate change, community shifts, and different harvesting
strategies on rockfish energy demands