Effects of coastal development on nearshore estuarine nekton communities

Abstract

Coastal development affects estuarine resources by severing terrestrial-aquatic linkages, reducing shallow water habitats, and degrading ecosystem services, which is predicted to result in measurable declines in nekton community integrity. We assessed the effects of landscape features on nearshore habitats and biological communities, relating subtidal habitat, shoreline condition, upland land use and nearshore fish communities in a Chesapeake Bay tributary, the James River, Virginia. Both upland development and the placement of erosion control structures on the shoreline were associated with reduced fish community integrity, and shoreline alterations were linked with the amount of subtidal structural habitat in the nearshore. Ecological thresholds in nekton community integrity were evident at ≥23% developed land use within 200 and 1000 m buffer increments. Nekton assemblages at sites with low development (< 23%) and natural or riprap shorelines were different from all other combinations of altered conditions (low development with bulkhead, and high development with riprap or bulkhead). Species composition along natural or riprap revetment shorelines with low upland development tended to be diverse and inclusive of tidal marsh species, while highly developed sites or bulkhead shorelines were dominated by a few generalist species. The complex interaction between watershed (both nearshore and inland) and shoreline development presents a unique challenge for coastal planning. Alternate moderating approaches for coastal development may include preservation of riparian buffers, the placement of living shorelines for erosion control where appropriate, and development of targeting tools to identify landscapes near an ecological threshold.

Habitat Quality and Salt-Marsh Species Assemblages along an Anthropogenic Estuarine Landscape

“…It is possible the decreased diversity was in some way associated with the urbanization gradient because studies have found decreased diversity in relation to urbanization elsewhere, albeit at smaller scales (Balouskus and Targett, 2016;Bilkovic and Roggero, 2008). It is also possible the observed differences were unassociated with the large-scale urbanization gradient.…”

“…In this study, urbanization was intentionally used as a broad term to encompass all components of anthropogenic development, and no effort was made to discern effects from a particular component. Further study is necessary and will need to include investigations at the species level and smaller scales, where urbanization impacts are more readily detectable (Bilkovic and Roggero, 2008). For example, investigation of fish community structure in urbanized marsh creeks vs. natural marsh creeks will determine potential impacts from bulk-headed shorelines.…”

“…Several studies have documented effects of urbanization on species composition, abundance, and diversity within fish communities (Able, Manderson, and Studholme, 1998;Bilkovic and Roggero, 2008;Davis, Levin, and Walther, 2002;Hendon, Peterson, and Comyns, 2000;Partyka and Peterson, 2008;Peterson et al, 2000). For instance, Balouskus and Targett (2016) demonstrated fish were more abundant along natural marsh shorelines compared with altered rip-rap shorelines.…”

Linking the Abundance of Estuarine Fish and Crustaceans in Nearshore Waters to Shoreline Hardening and Land Cover

“…Shoreline hardening degrades environments by reducing water and sediment quality, altering communities of benthic infauna, and contributing to loss of emergent wetland and SAV (Peterson & Lowe 2009). However, the effect of shoreline hardening on assemblages of fishes and crustaceans is poorly understood (Seitz et al 2006;Bilkovic & Roggero 2008;Strayer et al 2012). Localized negative effects have been documented for early life stages (Rozas et al 2007) and in areas where hardening alters the subtidal zone (Toft et al 2007), which can affect the abundances of fish species that select for specific substrates (Munsch et al 2015a).…”

Shoreline development and degradation of coastal fish reproduction habitats

“…We estimated that each jetty leads to direct habitat loss along an on average 10-15-m wide stretch of the shoreline through loss of habitat-forming vegetation. This density of constructions thus corresponds to a direct loss of 30-45 % of the habitat along the shoreline and is well above the threshold of construction previously shown to affect fish communities (Bilkovic and Roggero 2008).…”