Reproduction, Ontogeny and Recruitment

This chapter reviews and synthesises knowledge on reproduction and recruitment in estuary-dependent and estuary-associated fishes. Resident and migrating species (anadromous, catadromous and amphidromous) capitalise on estuarine productivity to ensure successful reproduction. The variable estuarine environments are challenging, but many species are adapted to reproduce in and recruit to these rich and productive ecosystems. Modes of reproduction, including utilisation of nursery habitat by early-life stages and behavioural adaptations, are described, as are contributions of adults to recruitment. Scales and patterns of environmental, hydrodynamic and biological processes that control ingress or retention of early-life stages in estuaries are reviewed. Recruitment processes in estuary-associated species are highly dynamic, depend on fish behaviour, are variably dependent on adult abundance and are difficult to predict. Case studies and global examples are presented to highlight the diversity of strategies and factors that ensure reproductive success.