Restoring blue carbon ecosystems unlocks fisheries' potential

Abstract

Globally, blue carbon ecosystems, including salt marsh, mangroves, and seagrasses, and the associated ecosystem services they provide, have declined substantially. In response, ecosystem restoration has recently increased but the scale and urgency of these activities has been limited by the lack of economic drivers. Herein, a multidisciplinary approach is presented that links hydrologic restoration with ecologic outputs to highlight the economic potential for commercial fisheries that could arise from restoring a drained floodplain. Initially, stable isotope models are used to predict the return of Eastern school prawn (approximately 300 kg yr−1 ha−1). Hydrologic models are then applied to determine the area of salt marshes and mangroves (over 2,000 ha) that could be potentially restored via tidal introduction. Together, these results indicate that ecological restoration in this region could contribute an annual benefit of approximately 230 tons of additional Eastern school prawn harvest, which could be valued at $3.1 ± 1.3 million AUD to commercial fisheries. This would represent a growth of nearly 50% from current annual harvest in the state. Given that this assessment excludes other values that would be gained, such as other species of fisheries value, carbon sequestration, biodiversity, and flood control, it represents a conservative financial estimate. Overall, this analysis highlights the scale of fisheries co‐benefits from tidal restoration projects, and how business cases for large‐scale blue carbon ecosystem restoration projects could be developed using multidisciplinary approaches.