Effects of Coastal Urbanization on Salt‐Marsh Faunal Assemblages in the Northern Gulf of Mexico

Abstract

Coastal landscapes in the northern Gulf of Mexico, specifically the Mississippi coast, have undergone rapid urbanization that may impact the suitability of salt‐marsh ecosystems for maintaining and regulating estuarine faunal communities. We used a landscape ecology approach to quantify the composition and configuration of salt‐marsh habitats and developed surfaces at multiple spatial scales surrounding three small, first‐order salt‐marsh tidal creeks arrayed along a gradient of urbanization in two river‐dominated estuaries. From May 3 to June 4, 2010, nekton and macroinfauna were collected weekly at all six sites. Due to the greater abundance of grass shrimp Palaemonetes spp., brown shrimp Farfantepenaeus aztecus, blue crab Callinectes sapidus, Gulf Menhaden Brevoortia patronus, and Spot Leiostomus xanthurus, tidal creeks in intact natural (IN) salt‐marsh landscapes supported a nekton assemblage that was significantly different from those in partially urbanized (PU) or completely urbanized (CU) salt‐marsh landscapes. However, PU landscapes still supported an abundant nekton assemblage. In addition, the results illustrated a linkage between life history traits and landscape characteristics. Resident and transient nekton species that have specific habitat requirements are more likely to be impacted in urbanized landscapes than more mobile species that are able to exploit multiple habitats. Patterns were less clear for macroinfaunal assemblages, although they were comparatively less abundant in CU salt‐marsh landscapes than in either IN or PU landscapes. The low abundance or absence of several macroinfaunal taxa in CU landscapes may be viewed as an additional indicator of poor habitat quality for nekton. The observed patterns also suggested that benthic sediments in the CU salt‐marsh landscapes were altered in comparison with IN or PU landscapes. The amount of developed shoreline and various metrics related to salt marsh fragmentation were important drivers of observed patterns in nekton and macroinfaunal assemblages. Received September 14, 2013; accepted January 27, 2014

Effects of shoreline armouring and overwater structures on coastal and estuarine fish: opportunities for habitat improvement

“…Studies in many locations have found that armouring influenced localized fish abundances or the composition of fish communities Peterson et al 2000;Davis, Takacs & Schnabel 2006;Toft et al 2007;Pastor et al 2013;Lowe & Peterson 2014). Some of these studies also found that armoured shorelines supported lower fish community integrity measured by indices such as diversity and richness (Bilkovic & Roggero 2008;Strayer et al 2012;Balouskus & Targett 2016;Torre & Targett 2016), and lower annual stability of fish abundance and community composition .…”

“…; Pastor et al . ; Lowe & Peterson ). Some of these studies also found that armoured shorelines supported lower fish community integrity measured by indices such as diversity and richness (Bilkovic & Roggero ; Strayer et al .…”

Consistent SpatioTemporal Estuarine Habitat Use during Emigration or Immigration of a Western Population of Gulf Sturgeon

“…For example, temporally variable sturgeon movement downriver during fall emigration occurred in drought years in the Pascagoula River compared with fish pulsing quickly from the summer holding area in wet years (Heise et al 2005). This influence of natural variability coupled with the increased urbanization in the coastal zone worldwide (Flowers et al 2009;Peterson and Lowe 2009;Lowe and Peterson 2014) and issues with water withdrawals and climate change (USFWS and Gulf States Marine Fisheries Commission 1995;Flowers et al 2009;USFWS 2009;Mims and Olden 2012;Farrae et al 2014) make it vital that we understand long-term ontogenetic habitat use patterns and how natural riverine variability might influence the initiation of migration of anadromous species. This information will help ensure that we are knowledgeable when promoting any future recovery actions.…”

Impact of Armored Shorelines on Shore-Zone Fish Density in a Mid-Atlantic, USA, Estuary: Modulation by Hypoxia and Temperature

“…Density of estuary-resident and estuary-dependent species (hereafter grouped together as estuarine) can reflect habitat quality (Szedlmayer and Able 1996;Rountree and Able 2007). As estuaries continue to be modified and degraded, additional processes such as competitive release and water quality tolerance (Lowe and Peterson 2014) can also contribute to species presence and density.…”