Bridging the Gap between Ornithology and Fisheries Science: Use of Seabird Data in Stock Assessment Models

Seabirds and marine fish share habitats and food webs, but there is too little contact between the disciplines that study them. Fish stock assessment models, designed for use on teleost fishes with high fecundity, high recruitment variability, and continued growth throughout life, may be strengthened by inclusion of seabird data. In some circumstances seabird-based indices of prey abundance could assist in calibration of sequential population analysis of fish stocks. Seabird energy acquisition rates, equivalent to fisheries catch per unit effort, are the most promising avian indicators of stock size. Seabird data may be useful in predicting recruitment of commercial fisheries and in improving estimates of natural fish mortality. The impact of seabird predation on fish stocks depends on the age of targeted fish and their subsequent growth and mortality. Yield-per-recruit analyses, derived from fisheries science, suggest that under plausible conditions the impact of seabird predation on fish stocks may be amplified by avian preference for small prey. Increased collaboration between seabird biology and fisheries science will benefit conservation of both birds and fish.