A Dire Future for Coastal Wetlands
March 25, 2021
BATON ROUGE — A new study co-authored by Torbjörn Törnqvist of Tulane University, Donald R. Cahoon of US Geological Survey, James Morris of University of South Carolina, and John Day of Louisiana State University suggests a dire future for coastal wetlands around the globe. The study, Coastal Wetland Resilience, Accelerated Sea-Level Rise, and the Importance of Timescale published in AGU Advances addresses conflicting results of recent studies as to whether coastal wetlands can keep up with current and future sea-level rise.
They report that the historic wetland response to sea-level rise preserved in the soil strata shows that threshold rates for coastal wetland submergence or retreat are lower than results from more recent instrumental records [such as tide gauges and satellite data], suggesting that wetland extent will shrink considerably under high rates of sea-level rise. They state that these apparent conflicts can be reconciled by recognizing that many coastal wetlands still lie at an elevation high enough to cope with sea-level rise over the near future because processes like sediment compaction, ponding, and wave erosion require multidecadal or longer timescales to drive wetland loss that is in many cases inevitable in the longer term.
Coastal wetlands provide many benefits including protection from storms along with other ecosystem services to vulnerable coastal communities, including several megacities. But the rapid, climate-driven acceleration of global sea-level rise threatens coastal wetlands worldwide, especially where the tide range is small. The authors conclude the contradictory answers of how coastal wetlands will fare with accelerated sea-level rise can be attributed to the time window under consideration. Their analysis shows that coastal wetlands that can persist during the next few decades are likely to be much less resilient through the remainder of this century and beyond. This finding has important implications for management and restoration planning of coastal wetlands.
Read the full paper at AGU Advances.
Contact Christine Wendling
LSU College of the Coast & Environment
225-578-4984
christinew@lsu.edu
Alison Satake
LSU Media Relations
510-816-8161
asatake@lsu.edu