Recruitment Ecology of Freshwater Fish in Rivers of Australia's Wet Tropics Region

Abstract

Hydrologic variation has a profound influence on the life cycles of fishes in tropical rivers. Several studies highlighting the critical links between fish recruitment, river hydrology and other environmental factors exist globally. However, understanding of the influence of abiotic drivers on fish recruitment in Australia’s Wet Tropics rivers is limited. There is potential for humans to further alter the hydrologic regimes and the landscapes of these rivers and therefore, gathering knowledge about fish recruitment dynamics is needed to support the implementation of appropriate management strategies aimed at preserving the diversity within the Wet Tropics freshwater fish community. This thesis investigates relationships between key environmental factors – river hydrology, instream habitat structure and food availability – and fish recruitment among five coastal rivers in the Wet Tropics bioregion of north-eastern Australia, and describes how differences in key flow-regime attributes among the rivers may influence these relationships