North Pacific Anadromous Fish Commission

Technical Report 15

Table of Contents

A Model of Smolt-to-adult Survival in Terms of Salmon Growth through the Size Distribution of Predators

Authors:
James J. Anderson

Abstract Excerpt:
As a general rule, survival of juvenile salmon to adult spawners is thought to be determined by growth during the first year in the marine environment through size-selective removal of the smaller fish by predation and overwinter starvation (Beamish and Mahnken 2001). Numerous studies support this hypothesis (e.g., Beamish et al. 2004; Moss et al. 2005). However, other populations do not fit the “bigger is better” rule (Claiborne et al. 2014; Miller et al. 2013), nor does the estimated magnitude of size selection mortality account for the observed mortality (Beacham et al. 2018). Additionally, studies indicate significant ocean mortality on adult salmon (Seitz et al. 2019). However, studies on individually tagged salmon clearly indicate that large smolts have higher adult survival (Passolt and Anderson 2013). This paper explores a possible basis for the conflicting studies through a model that describes mortality of fish growing through a range of predator gape sizes.

*This is the first paragraph of an extended abstract. Download the full abstract below.

DOI:
https://doi.org/10.23849/npafctr15/65.68.

Citation

Anderson, J.J.  2019.  A model of smolt-to-adult survival in terms of salmon growth through the size distribution of predators.  N. Pac. Anadr. Fish Comm. Tech. Rep. 15: 65–68.  https://doi.org/10.23849/npafctr15/65.68.