Reductions in Coastal Salt Marsh Habitat for Wildlife From Sea-Level Rise in the United States

The rate of sea-level rise (SLR) has increased due to climate change, affecting coastal salt marshes. It is uncertain if species can persist with rapid SLR compounded with other effects of climate change and human activity. SLR-induced habitat loss may lead to extirpations and decreased biodiversity. We conducted a literature review of wildlife that use salt marshes and selected 25 species of birds, mammals, and reptiles representing obligate, facultative, and generalist salt marsh users. We developed three regional case studies to quantify the percentage change in species habitat. We used the National Oceanic and Atmospheric Administration Sea Level Rise Viewer and ImageJ to calculate areal habitat changes in Apalachicola Bay, FL; Blackwater National Wildlife Refuge, MD; and Cape Cod Bay, MA. We used available literature to determine land cover types to estimate species-specific habitat changes by 2050 and 2100. The changes in habitat availability varied among species and salt marsh dependence, but by 2100, average losses were projected to range across accretion rates from 56% to 63% for birds, 44% to 53% for mammals, and 65% to 66% loss for reptiles. Mean habitat loss was greater for obligate (70%-77%) than facultative (69%-70%) and generalist (49%-56%) salt marsh users. SLR-induced habitat loss has been examined for individual species, but few multispecies assessments exist. Our results suggest ubiquitous habitat loss by 2100. Protection, restoration, and management of salt marsh habitat are necessary to conserve common and imperiled wildlife species, sustaining the ecosystem services provided by wildlife and salt marshes.