ABSTRACT

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Catchments Adjoining the GBR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Suspended Sediments in North Queensland Rivers . . . . . . . . . . . . . . . . . . . . . . . . 41 Dissolved and Particulate Nutrients in North Queensland Rivers. . . . . . . . . . . . . . 42 Nutrient Transformations within Catchments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Nutrients (e.g., C, N, P, trace metals) are the elemental building blocks of all marine ecosystems, including coral reefs. The quantity, form, and availability of nutrients directly affect ecosystem productivity and the quality of the water upon which the health of corals and other reef organisms ultimately depend. While corals can grow in a variety of shallow-water tropical habitats and in waters with a range of suspended sediment loads and nutrient concentrations, well-developed reef ecosystems only occur where the waters are typically characterised by low suspended particulate and dissolved nutrient concentrations. Extensive coral reefs do not typically develop or persist where nutrient and suspended sediment concentrations are acutely or chronically very high.