Assessing shoreline exposure and oyster habitat suitability maximizes potential success for sustainable shoreline protection using restored oyster reefs.
Oyster reefs provide valuable ecosystem services that contribute to coastal resilience. Unfortunately, many reefs have been degraded or removed completely, and there are increased efforts to restore oysters in many coastal areas. In particular, much attention has recently been given to the restoration of shellfish reefs along eroding shorelines to reduce erosion. Such fringing reef approaches, however, often lack empirical data to identify locations where reefs are most effective in reducing marsh erosion, or fully take into account habitat suitability. Using monitoring data from 5 separate fringing reef projects across coastal Louisiana, we quantify shoreline exposure (fetch + wind direction + wind speed) and reef impacts on shoreline retreat. Our results indicate that fringing oyster reefs have a higher impact on shoreline retreat at higher exposure shorelines. At higher exposures, fringing reefs reduced marsh edge erosion an average of 1.0 m y(-1). Using these data, we identify ranges of shoreline exposure values where oyster reefs are most effective at reducing marsh edge erosion and apply this knowledge to a case study within one Louisiana estuary. In Breton Sound estuary, we calculate shoreline exposure at 500 random points and then overlay a habitat suitability index for oysters. This method and the resulting visualization show areas most likely to support sustainable oyster populations as well as significantly reduce shoreline erosion. Our results demonstrate how site selection criteria, which include shoreline exposure and habitat suitability, are critical to ensuring greater positive impacts and longevity of oyster reef restoration projects.
US Geological Survey, Louisiana Cooperative Fish and Wildlife Research Unit, School of Renewable Natural Resources , Baton Rouge, LA , United States.
Megan K
MK
La Peyre
Department of Geosciences, Geospatial Exploration Lab, East Tennessee State University , Johnson City, TN , United States.
Kayla
K
Serra
Department of Geosciences, Geospatial Exploration Lab, East Tennessee State University , Johnson City, TN , United States.
T Andrew
TA
Joyner
Department of Fisheries, Animal and Veterinary Sciences, College of the Environment and Life Sciences, University of Rhode Island , Kingston, RI , United States.
Austin
A
Humphries
Coastal protection; Crassostrea virginica; Ecosystem services; Gulf of Mexico; Living shoreline; Marsh; Natural breakwaters; Wave attenuation