The race against rising sea levels is on, and America's coastal wetlands are in a losing battle. A recent study reveals a dire situation: 84% of these vital ecosystems are slowly being submerged, while only 16% are rising fast enough to keep pace with the encroaching tides. This alarming trend is particularly evident along the Gulf Coast, where human activities have exacerbated the crisis. However, there's a glimmer of hope: many wetlands could shift inland if space allows, emphasizing the critical need for conservation efforts to preserve these invaluable habitats.
The study, conducted by coastal wetland ecologist Glenn Guntenspergen and his team, analyzed data from nearly 450 monitoring stations across the contiguous US coasts. They found that while 89% of coastal wetlands are gaining elevation through sediment buildup, only 16% are doing so at a rate that can outpace sea level rise. This means that the majority of wetlands are gradually being inundated, and many are on track to transform into open water.
The Gulf Coast wetlands are bearing the brunt of this crisis, largely due to human impact. Shipping canals and oil and gas extraction have altered the Gulf's waterways, reducing the flow of river sediments that sustain wetlands. Additionally, the subsidence of wetlands above due to reduced underground pressure further exacerbates the problem. However, the study also highlights a silver lining: 73% of wetlands in the study still have a chance to expand inland rather than drown in place, provided the land slope isn't too steep and no human structures block the way.
Justine Neville, a wetland ecologist at Duke University and lead author on the study, emphasizes the importance of understanding how wetlands are changing. These ecosystems provide trillions of dollars' worth of services every year, from protecting infrastructure and providing homes for wildlife to dissipating the impact of storm surges. Neville notes that many endangered and endemic species and migratory birds in the US depend on these ecosystems for habitat, making the study's findings all the more crucial.
The study's findings also highlight regional differences in vulnerability. The Atlantic Coast appears less vulnerable, with submergence slow enough at about 75% of monitoring stations to rule out any critical threat. In contrast, the Gulf Coast is the most vulnerable, with submergence occurring at the fastest rate. This disparity can be attributed to higher rates of marine sediment deposition from ocean waves on the Atlantic Coast, as well as the historical impact of human activities on the Gulf Coast.
Despite the dire situation, the study offers a glimmer of hope. By understanding where wetlands are most vulnerable, land managers can focus conservation efforts on the areas that need it most. This includes removing dikes, artificially adding sediment to wetlands, and protecting inland areas for wetlands to migrate to. As Neville states, 'It's not all doom and gloom.' While there is an urgency to address the changing state of wetlands, the study provides valuable insights into where conservation efforts should be directed.
