Constructed Wetlands Suitability for Sugarcane Profitability, Freshwater Biodiversity and Ecosystem Services

• Published in: Environmental management (New York) Vol. 71; no. 2; pp. 304 - 320
• Main Authors: Canning, Adam D., Smart, James C. R., Dyke, Joshua, Curwen, Graeme, Hasan, Syezlin, Waltham, Nathan J.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.02.2023; Springer Nature B.V
• Subjects: Agricultural economics; Agricultural expansion; Agricultural land; Agricultural management; Agricultural production; Animals; Aquatic ecosystems; Aquatic Pollution; Artificial wetlands; Atmospheric Protection/Air Quality Control/Air Pollution; Biodiversity; Catchments; Cattle; Conservation of Natural Resources; Cost benefit analysis; Crop yield; Drainage; Earth and Environmental Science; Ecology; Economics; Ecosystem; Ecosystem services; Environment; Environmental Management; Farm income; Farms; Fish; Fishes; Flooding; Forestry Management; Fresh Water; Freshwater ecosystems; Freshwater fish; Lagoons; Nature Conservation; Profitability; Saccharum; Sugarcane; Waste Water Technology; Water depth; Water Management; Water Pollution Control; Water quality; Water security; Wetlands; Fish habitat; Flood reduction; Restoration; Flow regulation; Crop production
• ISSN: 0364-152X; 1432-1009; 1432-1009
• DOI: 10.1007/s00267-022-01734-4

Freshwater 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.