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Patterns of density‐dependent growth in juvenile stream‐dwelling salmonids
Author(s) -
Grant J. W. A.,
Imre I.
Publication year - 2005
Publication title -
journal of fish biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.672
H-Index - 115
eISSN - 1095-8649
pISSN - 0022-1112
DOI - 10.1111/j.0022-1112.2005.00916.x
Subject(s) - biology , akaike information criterion , density dependence , population density , juvenile , population , growth rate , linear regression , statistics , growth curve (statistics) , competition (biology) , ecology , regression , zoology , mathematics , demography , sociology , geometry
Literature data for 19 populations from 16 different studies of six species of stream‐dwelling salmonids were analysed to test the hypothesis that density‐dependent growth is stronger at low rather than at high population density. Fifteen of 19 populations showed evidence of a significant decrease in growth rate with increasing density. In 11 of these 15 populations, the pattern of density‐dependent growth was better described by a negative power curve than by a linear regression ( i.e . Akaike Information Criterion, AIC linear − AIC power > 2), whereas only one population was better described by a linear regression than by a negative power curve; three populations were adequately described by both models ( AIC < 2). In 10 of the 11 populations that were best described by a negative power curve, most of the decrease in growth rate occurred at population densities <1 fish m −2 , when space limitation is unlikely. This analysis provides broad support for the hypothesis that density‐dependent growth in stream salmonids occurs primarily at low population densities, probably due to exploitative competition.