North Pacific Anadromous Fish Commission

Technical Report 11

Table of Contents

Critical Size and Period for Pacific Salmon: A Review and Response to Beacham et al. (2018)

Authors:
Edward V. Farley, Jr., Ellen Yasumiishi, Jamal Moss, Jim Murphy, and Katie Howard

Abstract Excerpt:
For Pacific salmon, their early marine residence and first winter at sea are hypothesized as “Critical Periods” where mortality within a cohort can be large. Sogard (1997) suggests that mortality acts on a cohort in three possible ways: 1) indiscriminately—there is the same probability of mortality for all individuals (i.e., larval life history stage); 2) randomly—mortality is inconsistent or unpredictable; and 3) non-random—traits within a cohort reduce “relative” risk of mortality. For juvenile salmon, mortality is hypothesized to be “non-random” where the traits used to define “critical periods” include size and lipid storage that juveniles attain during their first summer at sea. These traits are a reflection of the marine ecosystems that the juvenile salmon experience. This concept of a critical period (summer growth and energy storage) has also recently been developed for young of the year pollock and Pacific cod within the Bering Sea (Hunt et al. 2011; Coyle et al. 2011; Heintz et al. 2013; Farley et al. 2015).

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

DOI:
https://doi.org/10.23849/npafctr11/59.63

Citation

Farley, E.V. Jr., E. Yasumiishi, J. Moss, J. Murphy, and K. Howard.  2018.  Critical size and period for Pacific salmon: a review and response to Beacham et al. (2018).  N. Pac. Anadr. Fish Comm. Tech. Rep. 11: 59–63.  https://doi.org/10.23849/npafctr11/59.63