title: An assessment of residence times of land-sourced contaminants in the Great Barrier Reef lagoon and the implications for management and reef recovery.
abstract: We argue that the residence times of key pollutants exported to the Great Barrier Reef (GBR) are greater in the GBR lagoon than those of the water itself, in contradiction to some previous assumptions. Adverse effects of the pollutant discharge will be greater and longer lasting than previously considered, in turn requiring stronger or more urgent action to remediate land practices. Residence times of fine sediments, nitrogen and phosphorus, pesticides and trace metals are suggested to be from years to decades in the GBR lagoon and highly likely to be greater than the residence time of water, estimated at around 15-365days. The recovery of corals and seagrass in the central region of the GBR following current land-use remediation in the catchment depends on the residence time of these contaminants. Ecohydrological modeling suggests that this recovery may take decades even with adequate levels of improved land management practices.
authors.affiliation: Catchment to Reef Research Group, Australian Centre for Tropical Freshwater Research, James Cook University, Townsville, Queensland 4811, Australia. jon.brodie@jcu.edu.au
authors.forename: Jon
authors.initials: J
authors.lastname: Brodie
authors.forename: Eric
authors.initials: E
authors.lastname: Wolanski
authors.forename: Stephen
authors.initials: S
authors.lastname: Lewis
authors.forename: Zoe
authors.initials: Z
authors.lastname: Bainbridge
mesh_terms: D003247:Conservation of Natural Resources / Q000379:methods*; D057894:Coral Reefs; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000032:analysis; D008670:Metals / Q000032:analysis; D009584:Nitrogen / Q000032:analysis; D010575:Pesticides / Q000032:analysis; D010758:Phosphorus / Q000032:analysis; D058998:Remote Sensing Technology; D018531:Spacecraft; D014873:Water Pollutants / Q000032:analysis*; D014876:Water Pollution / Q000706:statistics & numerical data
chemical_list: D008670:Metals; D010575:Pesticides; D014873:Water Pollutants; D010758:Phosphorus; D009584:Nitrogen