Spatially explicit scenarios for conservation planning in the Great Barrier Reef coastal zone, Australia

The Great Barrier Reef World Heritage Area (GBRWHA) borders the east coast of Northern Australia for almost 2000 km. Parts of this coast have been extensively developed with planned and potential further coastal developments, including for mining, ports, agriculture, urban, industrial and tourism. These developments may threaten the health of the GBRWHA through sediment, nutrient and pollutant run-off and habitat loss. In the context of conservation planning, the future must be taken into consideration to understand which ecosystems, species or ecological processes may be at risk and where. However, future coastal development is difficult to predict as it depends on volatile socio-economic factors. With this in mind, we develop a research project that uses spatially explicit scenario planning to identify plausible futures to 2035 for the GBRWHA coastal zone. Land use change modelling to produce eight scenarios is being done with GIS. The resulting maps of scenarios allow for comprehensive conservation planning

Dispersal of suspended sediments and nutrients in the Great Barrier Reef lagoon during river-discharge events: conclusions from satellite remote sensing and concurrent flood-plume sampling

Intense wet-season rainfall in January 2005 caused rivers in the Mackay–Whitsunday region of Queensland, Australia, to produce large discharges to the Great Barrier Reef (GBR) lagoon. The regional land use is dominated by sugarcane cultivation, beef grazing and urban uses. The high nutrient (nitrogen and phosphorus) fluxes from these land uses via river runoff produced a massive phytoplankton bloom in the GBR lagoon, which, after 9 days, had spread 150 km offshore. The plume and algal bloom surrounded inner-shelf reefs of the GBR such as Brampton Island Reef and its spread was tracked with a variety of satellite sensors including MODIS, SeaWiFS and Landsat over the 9-day period. The ability to be able to access imagery from a large number of satellite sensors allowed almost daily estimates of the extent of plume to be made, despite periods of cloud. Analysis of water samples from the plume revealed elevated (2–50 times higher) concentrations of Chlorophyll a (and hence phytoplankton biomass), up to 50 times higher than in non-flood conditions, nutrients (2–100 times higher) and herbicide residues (10–100 times higher) compared with GBR lagoon waters in non-discharge conditions. The concentration data from the samples and estimated exposure periods from the satellite images allowed estimates of the exposure of GBR marine ecosystems (coral reefs, the pelagic community, seagrass beds and mangrove forests) to the terrestrial contaminants to be made

Herbicides: A new threat to the Great Barrier Reef

The runoff of pesticides (insecticides, herbicides and fungicides) from agricultural lands is a key concern for the health of the iconic Great Barrier Reef, Australia. Relatively low levels of herbicide residues can reduce the productivity of marine plants and corals. However, the risk of these residues to Great Barrier Reef ecosystems has been poorly quantified due to a lack of large-scale datasets. Here we present results of a study tracing pesticide residues from rivers and creeks in three catchment regions to the adjacent marine environment. Several pesticides (mainly herbicides) were detected in both freshwater and coastal marine waters and were attributed to specific land uses in the catchment. Elevated herbicide concentrations were particularly associated with sugar cane cultivation in the adjacent catchment. We demonstrate that herbicides reach the Great Barrier Reef lagoon and may disturb sensitive marine ecosystems already affected by other pressures such as climate change. Herbicide residues have been detected in Great Barrier Reef catchment waterways and river water plumes which may affect marine ecosystems

Catchment-Scale Governance in Northern Australia: A Preliminary Evaluation

Northern Australia covers vast and diverse landscapes comprising largely public and Indigenous tenures. Long-term Aboriginal and pastoral management, isolation and a challenging terrain and climate have shaped a landscape of national, if not international, conservation value. Northern Australia, however, also has a fragile economy, and there is tension amongst Indigenous, economic and conservation interests. Managed poorly, emerging conflicts could damage the real opportunities that each presents, resulting in major land and natural resource-use conflicts or unsustainable development. As healthy governance systems are the key to effective natural resource management (NRM), this paper presents a preliminary exploration of the health of NRM governance across Northern Australia, with a focus on the catchment scale. We analysed three focal catchments; the Fitzroy in the Kimberley region of Western Australia, the Daly in the top end of the Northern Territory and the Gilbert in north-western Queensland. We find that the governance of each catchment has different strengths and weaknesses depending on history and context. Common challenges, however, include shifting national and state/territory policy frameworks, fragmented funding of science and limited consensus building via spatial decision support. From this analysis, we explore potential reforms in catchment governance across this increasingly contested landscape

Integrated cross-realm planning: a decision-makers' perspective

Pursuing development and conservation goals often requires thinking and planning across terrestrial, freshwater and marine realms because many threats and social–ecological processes transcend realm boundaries. Consequently, effective conservation planning must consider the social and ecological links between realms and follow a cross-realm approach to allocate land/water uses and conservation actions to mitigate cross-realm threats and maintain cross-realm ecological processes. Cross-realm planning requires integrating multiple objectives for conservation and development, and assessing the potential co-benefits and trade-offs between them under alternative development scenarios. Despite progress in cross-realm planning theory, few fully-integrated and applied cross-realm plans exist. The gaps between research and implementation are not unique to cross-realm planning, but are accentuated by the complexity of spatial decision-making entailed. Based on a collaborative process including scientists, resource managers and policy-makers, we developed an operational framework for cross realm planning based on up-to-date thinking in conservation science, but offering practical guidance to operationalise real-world planning. Our approach has a strong theoretical basis while addressing the visions and needs of decision-makers. We discuss the foundations and limitations of current approaches in cross-realm planning, describe key requirements to undertake this approach, and present a real-world application of our framework