Response of Tidal Creek Fish Communities to Dredging and Coastal Development Pressures in a Shallow-Water Estuary

Abstract

To investigate the effects of dredging and associated development pressures (i.e., shoreline armoring, developed land use) on fish, three sets of paired dredged and undredged tidal creeks were surveyed within Lynnhaven River, Virginia. Fish species diversity, community abundance, biomass, and size structure were compared among creeks and related to watershed, shoreline, and physicochemical characteristics. Mean fish community characteristics (e.g., abundance) were similar among creeks; however, species-specific analysis revealed subtle differences. Species biomass differed between dredged and undredged creeks, though species abundance was similar. Turbidity highly influenced differences in species abundance among creeks, while organic matter, dissolved oxygen, turbidity, and shoreline hardening may be influencing biomass patterns. The most recently dredged creek appeared to provide less suitable nursery habitat for some species than historically dredged creeks, suggesting initial adverse effects with eventual recovery. Protective measures, such as preservation of marshes, dredge depth, and time-of-year restrictions, may be moderating development and dredging pressures.

Generalizing Ecological Effects of Shoreline Armoring Across Soft Sediment Environments

“…In the histogram for each box, the number of significantly positive (green), negative (red), and not significant (NS) (gray) observations is plotted shorelines (Gittman et al 2016a). However, the majority of observations in Box 1a were negative and included decreased species diversity and/or abundance for a wide range of assemblages including microbial communities (Bernhard et al 2012), primary producers (e.g., Sturdevant et al 2002;O'Connor et al 2011), infaunal invertebrates (e.g., Peterson et al 2000;Seitz et al 2006;Bilkovic and Mitchell 2013), nekton and fish (Bilkovic 2011;Boys et al 2012;Peterson 2014, 2015) and waterbirds (Bolduc and Afton 2003). In Box 1b, negative responses to armoring dominated the results with decreases in diversity and abundance reported for mangroves (Anthony and Gratiot 2012; Heatherington and Bishop 2012), salt marsh vegetation (Bozek and Burdick 2005), invertebrates (Seitz et al 2006;Lawless and Seitz 2014;Swamy et al 2002), and nekton and fish (e.g., Balouskus and Targett 2016;Peterson 2014, 2015).…”

Living shorelines achieve functional equivalence to natural fringe marshes across multiple ecological metrics

“…Whereas both riprap and bulkheads are effective at reducing tidally-driven shore erosion, hardened shorelines are unable to naturally adapt to rising seas, are less resilient during storms, and scour the nearshore sediment through wave refraction (Gittman et al, 2014;Smith et al, 2017). Ecological studies have consistently found that shoreline armoring negatively impacts the intertidal and nearshore benthic and nekton communities relative to unmodified sections of shoreline via habitat fragmentation (Peterson & Lowe, 2009), changes in nearshore erosion processes (Bozek & Burdick, 2005), increased depth of nearby waters (Toft et al, 2013), reduced species abundance and diversity (Bilkovic et al, 2006;Bilkovic & Roggero, 2008;Kornis et al, 2017;Seitz et al, 2006) at both local and landscape scales (Isdell et al, 2015), and prevention of landward migration of intertidal habitats (Bilkovic, 2011;Titus et al, 2009). The ecological and social benefits of coastal wetlands (e.g., Mitsch & Gosselink, 2015) typically center around storm surge protection (Spalding et al, 2014;Shephard & Grimes, 1983), water quality enhancement (Bilkovic et al, 2017a;Erwin, 2009;Nelson & Zavaleta, 2012;Zedler & Kercher, 2005), habitat provision (Angelini et al, 2015;Isdell, Bilkovic & Hershner, 2018;Rozas & Minello, 1998), and carbon sequestration (Davis et al, 2015;Mcleod et al, 2011).…”

Effects of dredging operations on the demersal fish fauna of a South American tropical–subtropical transition estuary

“…Research on the effects of habitat fragmentation by deepening of channels and removal of wetland vegetation in Lake Huron (Uzarski et al ., ), damage to commercial fisheries from marine sand mining in Korea (Kim & Grigalunas, ), the response of the fish community to the dredging operations of coastal rivers in the BioBio region in Chile (Ortiz‐Sandoval et al ., ), the response of tidal creek fishes to dredging and coastal development pressures in Lynnhaven River (Chesapeake Bay) (Bilkovic, ), interannual changes in benthic fish populations in the eastern region of the English Channel after sand and gravel mining (Drabble, ), and harbour construction effects on reef fish communities in north‐east Brazil (Freitas et al ., ), are types of indicators reported. Experiments evaluating the risks of prolonged exposure to high concentrations of suspended sediment (SS) in orange‐spotted grouper Epinephelus coioides (Hamilton 1822), an important mariculture species that has a wide distribution in the Indo‐Pacific, showed that damages to gill structure were evident and strongly correlated with SS concentration (Au et al ., ).…”