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Interactive effects of shelter and conspecific density shape mortality, growth, and condition in juvenile reef fish
Author(s) -
Ford John R.,
Shima Jeffrey S.,
Swearer Stephen E.
Publication year - 2016
Publication title -
ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.144
H-Index - 294
eISSN - 1939-9170
pISSN - 0012-9658
DOI - 10.1002/ecy.1436
Subject(s) - metapopulation , density dependence , ecology , reef , juvenile , intraspecific competition , context (archaeology) , biology , habitat , population density , stocking , competition (biology) , parrotfish , coral reef fish , coral reef , juvenile fish , geography , population , fishery , biological dispersal , demography , paleontology , sociology
How landscape context influences density‐dependent processes is important, as environmental heterogeneity can confound estimates of density dependence in demographic parameters. Here we evaluate 19 populations in a shoaling temperate reef fish ( Trachinops caudimaculatus ) metapopulation within a heterogeneous seascape (Port Phillip Bay, Australia) to show empirically that shelter availability and population density interact to influence juvenile mortality, growth and condition. Although heterogeneity in shelter availability obscured the underlying patterns of density dependence in different ways, the combination of habitat and its interaction with density were two to six times more important than density alone in explaining variation in demographic parameters for juveniles. These findings contradict many small‐scale studies and highlight the need for landscape‐scale observations of how density dependence interacts with resource availability and competition to better understand how demographic parameters influence the dynamics of metapopulations in heterogeneous environments.