A novel richness-weighted relative abundance index of age-0 fishes to identify key habitat features

Session: Restoration and Management of Great Lakes Fishes (3)

Kevin Kapuscinski, Lake Superior State University, [email protected]
Derek Crane, Coastal Carolina University, Dept of Biology/KESH 113, [email protected]
John Hutchens, Coastal Carolina University, [email protected]

Abstract

Prioritizing sites for conservation or setting restoration goals is often difficult due to limited knowledge about relations between habitat characteristics and faunal assemblages.  We used a novel method to value habitat quality for native age-0 fishes based on a richness-weighted relative abundance index.  Habitat features and fishes were sampled in the Niagara River (July-September, 2013-2015), and we used multivariate adaptive regression splines to model the relation between our index and habitat features.  The best habitats for native age-0 fishes contained low water velocities, fine to very fine substrates, and substantial submerged aquatic vegetation extending into the water column; such habitats within 3,500 m of wetlands or tributaries provided additional value.  Managers intending to maximize habitat quality for age-0 native fishes in the Niagara River should (1) conserve and develop habitats with low water velocities (<0.1 m/s) and fine to very fine sediments, which promote growth of submerged aquatic vegetation, (2) prioritize sites with such conditions that are close to wetlands or tributaries, and (3) avoid creating habitats that support abundant floating vegetation, because index values were lower in such areas. Our approach should be applicable to other ecosystems, and have value for ranking sites for conservation and setting restoration goals.