Assessing coastal wetland vulnerability to sea-level rise along the northern Gulf of Mexico coast: Gaps and opportunities for developing a coordinated regional sampling network

PLoS One. 2017 Sep 13;12(9):e0183431. doi: 10.1371/journal.pone.0183431. eCollection 2017.

Abstract

Coastal wetland responses to sea-level rise are greatly influenced by biogeomorphic processes that affect wetland surface elevation. Small changes in elevation relative to sea level can lead to comparatively large changes in ecosystem structure, function, and stability. The surface elevation table-marker horizon (SET-MH) approach is being used globally to quantify the relative contributions of processes affecting wetland elevation change. Historically, SET-MH measurements have been obtained at local scales to address site-specific research questions. However, in the face of accelerated sea-level rise, there is an increasing need for elevation change network data that can be incorporated into regional ecological models and vulnerability assessments. In particular, there is a need for long-term, high-temporal resolution data that are strategically distributed across ecologically-relevant abiotic gradients. Here, we quantify the distribution of SET-MH stations along the northern Gulf of Mexico coast (USA) across political boundaries (states), wetland habitats, and ecologically-relevant abiotic gradients (i.e., gradients in temperature, precipitation, elevation, and relative sea-level rise). Our analyses identify areas with high SET-MH station densities as well as areas with notable gaps. Salt marshes, intermediate elevations, and colder areas with high rainfall have a high number of stations, while salt flat ecosystems, certain elevation zones, the mangrove-marsh ecotone, and hypersaline coastal areas with low rainfall have fewer stations. Due to rapid rates of wetland loss and relative sea-level rise, the state of Louisiana has the most extensive SET-MH station network in the region, and we provide several recent examples where data from Louisiana's network have been used to assess and compare wetland vulnerability to sea-level rise. Our findings represent the first attempt to examine spatial gaps in SET-MH coverage across abiotic gradients. Our analyses can be used to transform a broadly disseminated and unplanned collection of SET-MH stations into a coordinated and strategic regional network. This regional network would provide data for predicting and preparing for the responses of coastal wetlands to accelerated sea-level rise and other aspects of global change.

MeSH terms

  • Alabama
  • Climate Change*
  • Ecosystem*
  • Environmental Monitoring / methods
  • Environmental Monitoring / standards*
  • Florida
  • Gulf of Mexico
  • Information Services / organization & administration
  • Information Services / standards
  • Louisiana
  • Mississippi
  • Research Design / standards
  • Sampling Studies
  • Seawater*
  • Texas
  • Wetlands*

Grants and funding

This inventory was the result of an effort between individuals at the USGS Wetland and Aquatic Research Center and the NOAA Northern Gulf of Mexico Sentinel Site Cooperative, who worked with scientists from other state, federal, and academic organizations to compile this information. The participation of David Oster was supported by the USFWS Directorate Resource Assistant Fellows Program. We thank the Gulf Coastal Plains and Ozarks Landscape Conservation Cooperative for hosting the inventory results on their conservation planning atlas. This research was partially funded by the USGS Ecosystems Mission Area, USGS Climate and Land Use Change R&D Program, and the USGS Greater Everglades Priority Ecosystems Science Program.