|Document Type:||Journal Article|
|Title:||Estimating common growth patterns in juvenile Chinook salmon (Oncorhynchus tshawytscha) from diverse genetic stocks and a large spatial extent|
|Author:||Pascale A. L. Goertler, M. D. Scheuerell, Charles A. Simenstad, Daniel L. Bottom|
|Keywords:||Dynamic factor analysis, juvenile Chinook salmon, diversity, estuary, habitat, otolith microstructure ,|
Life history variation in Pacific salmon (Oncorhynchus spp.) supports species resilience to natural disturbances and fishery exploitation. Within salmon species, life-history variation often manifests during freshwater and estuarine rearing, as variation in growth. To date, however, characterizing variability in growth patterns within and among individuals has been difficult via conventional sampling methods because of the inability to obtain repeated size measurements. In this study we related otolith microstructures to growth rates of individual juvenile Chinook salmon (O. tshawytscha) from the Columbia River estuary over a two-year period (2010-2012). We used dynamic factor analysis to determine whether there were common patterns in growth rates within juveniles based on their natal region, capture location habitat type, and whether they were wild or of hatchery origin. We identified up to five large-scale trends in juvenile rates depending on month and year of capture. We also found that hatchery fish had a narrower range of trend loadings for some capture groups, suggesting that hatchery fish do not express the same breadth of growth variability as wild fish. However, we were unable to resolve a relationship between specific growth transitions based on habitat transitions.
|Theme:||Ecosystem approach to improve management of marine resources|
Characterize ecological interactions (e.g. predation, competition, parasitism, disease, etc.) within and among species.
Understand how climate influences ecosystem variability.