Growth and survival of Pacific sardine (Sardinops sagax) in the California Current region

Abstract

We hypothesized that faster growth during the larval and juvenile stages results in higher survival in Pacific sardine (Sardinops sagax) in the California Current region. Growth rate estimated from the width of otolith daily increments was compared among larval, juvenile and pre-recruit S. sagax spawned in 2004 and 2006. Larvae, juveniles and pre-recruits were collected in spring, autumn and the spring of the subsequent year, respectively. Hatch-date distribution of the pre-recruits ranged from April to August with peaks in late spring and summer, corresponding to the seasons of spawning and larval production in the Southern California Bight. The pre-recruits, from eggs hatched in the late spring, were assumed to originate from the larvae and juveniles from eggs hatched in April to June. Fish collected as pre-recruits grew faster than those collected as juveniles during the 3-5 months after hatching. Growth-selective survival for the late spring-hatched cohorts took place during July-November for the early juveniles. These results are consistent with the hypothesis that early juveniles with faster growth rate during summer and autumn had a higher probability of survival to the adult stock in the California Current region.