Effects of temperature change on demersal fishes in the California Current: a bioenergetics approach

Abstract

Diverse fish assemblages should feature a range of biological and ecological responses to temperature change. Using preliminary bioenergetics models, I simulated growth and maturation of three California Current groundfish (yelloweye rockfish ( Sebastes ruberrimus ), sablefish ( Anoplopoma fimbria ), and spiny dogfish ( Squalus acanthias )) at fixed temperatures ranging from 5 °C to 11 °C. I examined three response variables (size at age 1 (W1), age at 50% maturity (τ50%), and total prey consumption (C)). Yelloweye rockfish responded most strongly for W1, which increased 496% as temperature increased from 5 °C to 11 °C. Spiny dogfish τ50%was highly sensitive, declining from >48 years at 5 °C to <13 years at 11 °C. Age-specific C was most responsive in yelloweye rockfish, increasing by more than fivefold over the range of temperatures, although sablefish likely have greater community-wide impact because their trophic level and absolute feeding rates are higher. Regime shifts, temperature anomalies, or global climate change may directly affect fish energy budgets, elicit range shifts, or produce complex ecological interactions. Studies like this will help managers to identify temperature-sensitive species and anticipate potential changes in populations and diverse communities.