Differing importance of salinity stratification and freshwater flow for the recruitment of apex species of estuarine fish

Abstract

Estuarine fish live in a highly dynamic environment where recruitment variability is a key determinant of population trajectory. Environmental requirements for successful recruitment may differ between co-occurring species, and therefore species may be advantaged or disadvantaged under climate change. Recruitment variability in black bream Acanthopagrus butcheri and estuary perch Macquaria colonorum in estuaries along the coast of western Victoria, south-eastern Australia, was determined from the age structure of the populations. Recruitment was found to be episodic in both species, with the populations dominated by a few year classes; however, abundant year classes differed between species...