You Can't Reach the Lost Valley by Boat: Navigating Bottom‐Up Restoration Pathways

Abstract

We explore bottom‐up restoration pathways on the West Florida Shelf using an Atlantis end‐to‐end biogeochemical food web model. We simulate three ecosystem states, the 1990s, the present day, and a restored future ecosystem. The restored ecosystem is informed by current restoration efforts by the Florida Trustee Implementation Group, responsible for administering restoration projects totaling $680 million. These will restore nearshore habitat, improve water quality and promote user access. We consider four bottom‐up drivers of productivity: seagrass coverage, mangrove presence, wave energy and nutrient inputs. We developed a series of generalised additive models to analyse Florida Wildlife Commission fisheries independent monitoring fish abundance data from inshore sites in Florida. After correcting for confounding environmental variables using statistical models, we describe the relationship between relative abundance and habitat. These relationships were used to parameterize recruitment and feeding effects in Atlantis to reflect the ecology of seagrass‐associated fish. Model results suggest restoration efforts in inshore areas yield a 2%–3% increase in small‐bodied forage fish and support a more robust pelagic food web. Restoration increases demersal fish abundance, and there is a suggestion that mangroves may promote this via a habitat mosaic effect. Cross‐shelf ontogenetic migration offers an express route by which terrigenous production is exported to offshore food webs, but benefits to species of interest are variable. There were increases of 1%–3% for pelagic fish groups and 1%–5% for demersal fish groups.