(2012) identifies that highest concentrations of total suspended solids (TSS) were from mining, horticulture, and Sorafenib dryland cropping with highest median total nitrogen (TN) concentrations from horticulture, cotton and bananas. The transport and potential toxicity of pesticides from agricultural areas is a key concern for the ecosystem health of both freshwater environments and the GBR. Photosystem II inhibiting (PSII) herbicides are used in large quantities on agricultural lands adjoining the GBR and case studies presented in this Special Issue demonstrate the widespread presence

of pesticides, particularly PSII herbicides, in all systems, from the catchment to the GBR lagoon (Smith et al., 2012). The increase in agricultural land-use is one of the main sources of pressure on the GBR and improved land management practices play a key role for the long-term sustainability of the GBR. Webster et al. (2012) report on an agricultural practice change with positive outcomes for the GBR where adjustments in the rate of fertiliser application lead to significant reductions of dissolved inorganic nitrogen in the downstream water systems, with no significant difference in sugarcane yield. Changes in agricultural management to reduce pollutant loads are the focus of another Special Issue arising from the Conference on the Challenges in Environmental Science and Engineering; ‘Catchment to Reef

continuum: Minimising impacts

Selleckchem SP600125 of agriculture’ (Thorburn, 2012). Papers in that Special Issue assess the effectiveness of certain management practices, quantify paddock-scale transport processes, consider the significance of climate change for land practice management, as well as economic and policy aspects of reducing sediment, nitrogen and pesticide exports. One of the conclusions is that substantial (e.g., >20%) load reductions will be very difficult to achieve for most pollutants exported from the GBR catchment, with the exception of dissolved inorganic nitrogen (Thorburn and Wilkinson, 2012) which is very responsive to reduced N fertiliser application Rebamipide in croplands (Webster et al., 2012; Biggs et al., 2012). The best possible quantification of pollutant loads exported from coastal catchments is essential for natural resource management. For example, Reef Plan, a joint initiative by the Australian Government and the Queensland Government, stipulates that a 20% reduction in sediment loads is required by 2020 to halt and reverse the decline of water quality in the inshore GBR lagoon. Accurate reporting of loads allows better informed land management through prioritisation of actions based on the pollutant type. The improved assessment of the true load of materials to the GBR lagoon is also an important contribution to the monitoring and reporting of progress towards Reef Plan and associated load targets (described in Carroll et al., 2012).