Rising sea levels spell disaster for US coastal wetlands

Research points to the Gulf Coast as being an especially high-risk region.(CN) — It’s not news to ecologists that climate change will impact the Earth’s oceanic regions just as catastrophically as it does the atmosphere, but accurately quantifying what that looks like is a taller ask.A new study published in the American Geophysical Union science journal Earth’s Future has produced an answer regarding the future of American coastal wetland biomes, and its figures might be frightening for environmentalists, land use planners and Gulf Coast residents.Eighty-four percent of coastal wetlands in the U.S. are gradually being overtaken by rising seas, scientists found. The 14-member team behind the study, headed by Duke University wetland ecologist Justine Neville, believes many of those wetland areas will become entirely submerged if mitigating action isn’t taken.While wetland vegetation thrives in water, and higher sea levels to an extent have increased wetland growth, hydration can turn from beneficial to lethal when in excess of what an organism requires. Humans have suffered from fatal hyperhydration after consuming unhealthy amounts of water, a fate not far off from the slow drowning that could await wetland plant life like cattails and reeds.“All coastal plants have optimum ranges,” said Glenn Guntenspergen, a researcher working for the U.S. Geological Survey in Maryland. “But if they get flooded too much, then the system shuts down. The plants decrease production and eventually die.”The researchers took an expanded approach compared to past wetland studies, which had been mostly limited to localized fieldwork instead of exhaustive nationwide analysis.Guntenspergen called the study “daunting” logistically: Neville’s team traveled by sea and air, lugged heavy equipment across cake-like marshland soil, and collected data from hundreds of sites along the Atlantic, Gulf and Pacific coasts to achieve a more complete picture.While 89% of U.S. coastal wetlands are slowly climbing in elevation due to growing layers of sediment, 73% of those areas are not rising fast enough to avoid future submergence without human intervention, the study found.Atlantic and Pacific coastal biomes are considered less vulnerable than Gulf Coast wetlands, which Neville attributed to the Southern region’s heavy historical shipping traffic and fossil fuel extraction.“It’s not all doom and gloom,” Neville added. Around 70% percent of studied wetlands could be able to grow further inland and avoid this anthropogenically induced death by drowning.However, ecologists and conservationists will need to take action by balancing sediment levels in wetlands when necessary, ridding them of manmade features like dikes, and protecting adjacent inland areas from development to allow the wetlands a path of retreat.Marine ecosystems and the species that call them home face many stark risks from climate change. The continued diminishing of coastal wetlands would be a severe blow to the longevity of endangered species like the Gulf sturgeon and leatherback sea turtle.Subscribe to our free newslettersOur weekly newsletter Closing Arguments offers the latest about ongoing trials, major litigation and rulings in courthouses around the U.S. and the world, while the monthly Under the Lights dishes the legal dirt from Hollywood, sports, Big Tech and the arts.Additional Reads