Ecosystem services of restored oyster reefs in a Chesapeake Bay tributary: Abundance and foraging of estuarine fishes

Abstract

Restoration of oyster reefs in coastal ecosystems may enhance fish and fisheries by providing valuable refuge and foraging habitat, but understanding the effects of restoration requires an improved understanding of fish habitat use and trophic dynamics, coupled with long-term (>5 yr) monitoring of restored habitats. We evaluated the relationship between large (3−5 ha) restored subtidal oyster reefs and mobile estuarine fishes in the Lynnhaven River System (LRS), Virginia, more than 8 yr following reef construction. We compared the (1) diversity, (2) abundance, (3) size, (4) stomach fullness, (5) diet composition, and (6) daily consumption rate of fishes collected from restored oyster reefs with those from an area of unstructured, unrestored bottom, via experimental gill nets. We sampled monthly from April to October 2016 and conducted 24 h sampling in July and September 2016. Community composition was similar between habitats, dominated by spot Leiostomus xanthurus, Atlantic menhaden Brevoortia tyrannus, silver perch Bairdiella chrysoura, and Atlantic croaker Micropogonias undulatus. Abundance in reef habitat was significantly reduced relative to unstructured bottom, but the mean length of fishes collected from reefs was significantly greater than that of unstructured bottom. In addition, the estimated consumption rate of silver perch foraging in reef habitat significantly exceeded that of silver perch foraging in unstructured bottom. Nearly a decade post-restoration, restored reefs in the LRS are used by a similar assemblage as unrestored areas, but the manner of use differs by species and size. Considering a broad range of responses is necessary to evaluate the impacts of oyster restoration on mobile fishes.