Suchergebnisse

AbstractFreshwater ecosystems, such as wetlands, are among the most impacted by agricultural expansion and intensification through extensive drainage and pollution. There is a pressing need to identify ways of managing agricultural landscapes to ensure food and water security without jeopardising biodiversity and other environmental benefits. Here we examine the potential fish biodiversity and landholder financial benefits arising from the integration of constructed lagoons to improve drainage, flow regulation and habitat connectivity within a sugarcane dominated catchment in north Queensland, Australia. A hybrid approach was used, combining the findings of both fish ecological surveys and a financial cost-benefit analysis. We found that the constructed lagoons supported at least 36 native freshwater fishes (over half of all native freshwater fishes in the region), owing to their depth, vegetated margins, moderate water quality and high connectivity to the Tully River. In addition to biodiversity benefits, we estimated that surrounding sugarcane farms would have financially benefited from reduced flooding of cropland and the elevation of low-lying cropland with deposited spoil excavated from lagoon construction. Improved drainage and flow regulation allowed for improvement in sugarcane yield and elevated land increased gross margins from extending the length of the cane production cycle or enabling a switch from cattle grazing to cane production. Restoring or creating wetlands to reduce flooding in flood-prone catchments is a globally applicable model that could improve both agricultural productivity and aquatic biodiversity, while potentially increasing farm income by attracting payments for provision of ecosystem services.

Managers are moving toward implementing large-scale coastal ecosystem restoration projects, however, many fail to achieve desired outcomes. Among the key reasons for this is the lack of integration with a whole-of-catchment approach, the scale of the project (temporal, spatial), the requirement for on-going costs for maintenance, the lack of clear objectives, a focus on threats rather than services/values, funding cycles, engagement or change in stakeholders, and prioritization of project sites. Here we critically assess the outcomes of activities in three coastal wetland complexes positioned along the catchments of the Great Barrier Reef (GBR) lagoon, Australia, that have been subjected to restoration investment over a number of decades. Each floodplain has been modified by intensive agricultural production, heavy industry and mining infrastructure, urban/peri urban expansion, aquaculture development and infrastructure expansion. Most development has occurred in low-lying coastal floodplains, resulting in major hydrological modifications to the landscape. This has left the floodplain wetlands in a degraded and hydrologically modified state, with poor water quality (hypoxic, eutrophication, sedimentation, and persistent turbidity), loss of habitat, and disconnected because of flow hydraulic barriers, excessive aquatic plant growth, or establishment of invasive species. Successful GBR wetland ecosystem restoration and management first requires an understanding of what constitutes "success" and must be underpinned by an understanding of complex cause and effect pathways, with a focus on management of services and values. This approach should recognize that these wetlands are still assets in a modified landscape. Suitable, long term, scientific knowledge is necessary to provide government and private companies with the confidence and comfort that their investment delivers dividend (environmental) returns.

Marine coastal (or "blue") ecosystems provide valuable services to humanity and the environment, but global loss and degradation of blue ecosystems necessitates ecological restoration. However, blue restoration is an emerging field and is still relatively experimental and small-scale. Identification of the key barriers to scaling-up blue restoration will enable targeted problem solving and increase the likelihood of success. Here we describe the environmental, technical, social, economic, and political barriers to restoration of blue ecosystems, including saltmarsh, mangroves, seagrass, shellfish reefs, coral reefs, and kelp forests. We provide managers, practitioners, and decision-makers with solutions to construct barrier-informed blue restoration plans and illustrate these solutions through the use of case studies where barriers were overcome. We offer a way forward to build confidence in blue restoration for society, government, and restoration practitioners at larger and more ambitious scales.