Fish and crustaceans provide early indicators of success in wetland restoration

Abstract

Early indicators of restoration success can inform adaptive management strategies and maintain community interest and financial investment. Coastal wetland restoration projects prioritize monitoring the succession of habitat forming communities. However, these communities often expand slowly. In contrast, fish and crustaceans can quickly occupy newly available habitats and therefore, may be early indicators of restoration success. Here, we compared the short‐term responses of fish and crustacean communities and landcover area to restoration actions at a restoring wetland and three reference wetlands in the Maroochy River in eastern Australia. Fish and crustacean communities and landcover area were surveyed every 6 months between Spring 2017 and Spring 2019 (n = 5), with two sampling events conducted before restoration actions commenced in May 2018 and three after. Fish and crustaceans were surveyed using baited underwater video stations and fyke nets. Landcover was remotely sensed using a combination of Worldview‐2 satellite imagery, object‐based image analysis, and random forest classification. Fish and crustaceans make viable indicators for early restoration success, as our findings show the composition, diversity, and abundance of species targeted in fisheries of these communities can resemble assemblages at reference sites within 1 year of restoration actions. The area of tidal inundation significantly increased overtime, but the recovery of mangroves and saltmarsh communities did not. These findings support the notion that coastal wetland restoration can promote immediate recruitment by fish and crustacean communities, thus making these taxa useful indicators for communicating early success of restoration projects.