Assessing the intrinsic resilience of a particularly fast-growing teleost prey species (red cod, Pseudophycis bachus)

Abstract

Understanding the life-history parameters that influence productivity is important in assessing the intrinsic resilience of a species to exploitation. The life-history characteristics of red cod, Pseudophycis bachus, were investigated to assess the intrinsic resilience of this important prey species to increased predation pressure by a range of high trophic-level predators. Red cod has a particularly short longevity; in Australian shelf waters it is uncommon to encounter individuals older than 2+ years. There are few shelf-water species that exhibit the rapid rate of growth that was observed where females and males attained ~300-mm total length in the first year. A particularly rapid growth rate, and a reproductive strategy characterised by early maturity and high fecundity, suggests that the species is relatively resilient. However, red cod is short lived, which exposes populations to large shifts in biomass. Harvesting of this species by predators, particularly during years of poor recruitment, may be significant in shaping the dynamics of red cod populations.