Quantifying fisheries enhancement from coastal vegetated ecosystems

Coastal ecosystems are estimated to support 95% of the world's commercially-important fish, owing largely to their provision of nursery habitat for juveniles; however, systematic databases with such data are scarce. By systematically reviewing the literature across Australia, we quantified fisheries enhancement from three key coastal vegetated habitats: seagrass meadows, mangrove forests, and tidal marshes. From juvenile densities, we modelled adult fish biomass enhancement resulting from these structured habitats and linked fish of economic importance with market values. We found that seagrass displayed higher per hectare abundance, biomass and economic enhancement compared to mangroves and tidal marshes. On average, one hectare of seagrass supported 55,000 more fish annually compared to unvegetated seabed, resulting in an additional biomass of 4000 kg and a value increase of AUD 21,200 annually. Mangroves supported 19,000 more fish, equivalent to 265 kg−1 ha−1 y−1, and tidal marshes provided a modest 1700 more fish, equivalent to 64 kg−1 ha−1 y−1. The most abundant fish across all ecosystems were small, non-commercial species (e.g. gobies and glassfish), but the highest biomass and economic value originated from larger, longer-lived fish that are regularly targeted by fisheries (e.g. breams and mullets). By quantifying enhancement value across Australia, our findings provide further evidence for, the benefit these critical habitats provide in supporting coastal fisheries and human well-being.