Open AccessEvolution of age and length at maturation of A laskan salmon under size‐selective harvest
Author(s) -
Kendall Neala W.,
Dieckmann Ulf,
Heino Mikko,
Punt André E.,
Quinn Thomas P.
Publication year - 2014
Publication title -
evolutionary applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.776
H-Index - 68
ISSN - 1752-4571
DOI - 10.1111/eva.12123
Subject(s) - biology , microevolution , intraspecific competition , competition (biology) , productivity , life history theory , selection (genetic algorithm) , ecology , natural selection , adaptation (eye) , life history , zoology , population , demography , macroeconomics , artificial intelligence , neuroscience , sociology , computer science , economics
Spatial and temporal trends and variation in life‐history traits, including age and length at maturation, can be influenced by environmental and anthropogenic processes, including size‐selective exploitation. Spawning adults in many wild A laskan sockeye salmon populations have become shorter at a given age over the past half‐century, but their age composition has not changed. These fish have been exploited by a gillnet fishery since the late 1800s that has tended to remove the larger fish. Using a rare, long‐term dataset, we estimated probabilistic maturation reaction norms ( PMRN s) for males and females in nine populations in two basins and correlated these changes with fishery size selection and intensity to determine whether such selection contributed to microevolutionary changes in maturation length. PMRN midpoints decreased in six of nine populations for both sexes, consistent with the harvest. These results support the hypothesis that environmental changes in the ocean (likely from competition) combined with adaptive microevolution (decreased PMRN s) have produced the observed life‐history patterns. PMRN s did not decrease in all populations, and we documented differences in magnitude and consistency of size selection and exploitation rates among populations. Incorporating evolutionary considerations and tracking further changes in life‐history traits can support continued sustainable exploitation and productivity in these and other exploited natural resources.