Impacts of Coastal Land Use and Shoreline Armoring on Estuarine Ecosystems: an Introduction to a Special Issue

Abstract

The nearshore land-water interface is an important ecological zone that faces anthropogenic pressure from development in coastal regions throughout the world. Coastal waters and estuaries like Chesapeake Bay receive and process land discharges loaded with anthropogenic nutrients and other pollutants that cause eutrophication, hypoxia, and other damage to shallow-water ecosystems. In addition, shorelines are increasingly armored with bulkhead (seawall), riprap, and other structures to protect human infrastructure against the threats of sea-level rise, storm surge, and erosion. Armoring can further influence estuarine and nearshore marine ecosystem functions by degrading water quality, spreading invasive species, and destroying ecologically valuable habitat. These detrimental effects on ecosystem function have ramifications for ecologically and economically important flora and fauna. This special issue of Estuaries and Coasts explores the interacting effects of coastal land use and shoreline armoring on estuarine and coastal marine ecosystems. The majority of papers focus on the Chesapeake Bay region, USA, where 50 major tributaries and an extensive watershed (~167,000 km 2), provide an ideal model to examine the impacts of human activities at scales ranging from the local shoreline to the entire watershed. The papers consider the influence of watershed land use and natural versus armored shorelines on ecosystem properties and processes as well as on key natural resources.

Integrating Regional Management Needs into a Mid-Atlantic Shorelines Research Project

“…The overall goal of the shorelines project was to increase knowledge of the combined effects of shoreline hardening, watershed land-use, water clarity, diel hypoxia, and Phragmites invasion of tidal wetlands on habitat quality for submerged aquatic vegetation (SAV) and estuarine fauna (Prosser et al 2017). To address this array of subjects, the project was divided into four working groups with these foci: water quality, wetlands, SAV, and macrofauna (including: benthic invertebrates, gelatinous zooplankton, fish, crustaceans, and waterbirds).…”

“…The research compared a number of sub-estuaries of the Chesapeake Bay and coastal bays along the Mid-Atlantic coast (Prosser et al 2017). Each sub-estuary (an embayment at the mouth of a tributary stream) has its own local watershed.…”

“…Finding one or two county representatives that could articulate needs for the entire Mid-Atlantic region would be a problem, and expanding the size of the MTAG to incorporate representatives from every locality was not feasible. Furthermore, the project would not have been able to produce individualized science products for every locality, as the strongest relationships were uncovered by analyzing data that looked across the whole bay, rather than a single subestuary (Jordan et al 2017, Kornis et al 2017b, Landry and Golden 2017, Prosser 2017. One of the initial recommendations from the MTAG was support for the project's focus on the sub-estuary scale, which was thought to be the most fruitful spatial scale for investigation of multiple stresses in a regional context.…”

Maximum Run-Up and Alongshore Mass Transport Due to Edge Waves

“…Coastal morphological changes have interested many researchers in the fields of coastal engineering and oceanography. Morphological changes, such as beach scarps, directly affect the safety of artificial structures around dunes, while underwater morphological changes affect seabed ecology [1,2], maintenance of navigation channels [3], and the sustainability and resilience of beaches [4][5][6][7].…”

Characterizing Nearshore Fish Assemblages From Intact and Altered Mangrove Shorelines in Biscayne Bay, Florida, United States

“…Coastal developments and canals reduce and divide mangrove habitats, resulting in smaller habitat fragments which support fewer species (MacArthur and Wilson, 1963;Carugati et al, 2018). Seawall construction leads to the deterioration of coastal habitats, which affects the animal communities that rely on nearshore habitats for food sources and shelter (Prosser et al, 2018). Grey coastal structures lack the structural complexity of natural vegetation, thus reducing habitat niches, shelter, and refuge (Bulleri and Chapman, 2010;Loke and Todd, 2016;Schoonees et al, 2019).…”