Measuring fisheries outcomes from coastal wetland restoration: a review and meta‐analysis

Abstract

Coastal wetlands, including saltmarshes, mangrove forests, and seagrass meadows, can support fisheries by providing habitat and exporting food and nutrients to adjacent or distant ecosystems. However, there is insufficient understanding about the extent to which wetland restoration can benefit fishery species. Here, we report qualitative and quantitative reviews of literature to evaluate the approaches used to measure or estimate fisheries outcomes of coastal wetland restoration and test for the effects of restoration on fisheries outcomes. Most studies focused on saltmarshes and mangroves, with fewer studies focussing on seagrasses. We found that effects of wetland restoration on fish populations have mainly been assessed for species that reside in coastal wetlands for at least part of their life cycle, while few studies have tested effects on fish populations via trophic subsidies. Moreover, few studies have directly assessed the effects of restoration on fisheries production. Instead, most studies have measured abundances of individual species at restored sites and compared those to undisturbed and/or disturbed areas. Restored areas contained similar fish densities to undisturbed or disturbed areas; but few studies compared restored areas to both undisturbed and disturbed areas at the same time. Overall, we did not find consistent and robust evidence for fisheries outcomes from wetland restoration projects because (1) there were not many studies, (2) the studies reported substantial variability in outcomes, and (3) the density of fish measured at a restoration site is not an accurate measure of the total fisheries benefit as adult fishes do not always reside in the restored habitat.