Restoring mangrove biodiversity: can restored mangroves support fish assemblages comparable to natural mangroves over time?

Abstract

Despite the recent global increase in mangrove restoration efforts, our understanding of the outcomes and recovery of biodiversity and re-establishing functionality, such as productive fish habitat, is limited due to the lack of long-term monitoring. Here, we used a space-for-time approach to investigate whether restored mangroves attain similar fish communities to natural mangroves of the same age (5–11 years old). Fish in restored and natural mangrove forests along the Guyana coastline, South America, were sampled using trammel nets to collect data and compare the abundance, species richness, and biomass. This study found no notable differences in fish assemblages between restored and natural mangroves of the same ages. Nonmetric multidimensional scaling (NMDS), analysis of similarities (ANOSIM), and similarity percentage analysis (SIMPER) revealed a high overlap in fish species composition between the restored and natural mangrove habitats, age, seasons, and diel cycle. There was no clear trajectory between fish abundance, species richness, biomass, and the age of the restored and natural mangrove habitats, which indciates that fish quickly colonized the restored mangrove habitats. Our study provides evidence of the success of mangrove restoration projects in yielding positive ecological benefits as fish habitat. This information is useful for restoration practitioners when setting goals and timelines for fish habitat recovery after mangrove restoration.