Evaluating the Role of Coastal Wetlands in Mitigating the Impacts of Sea-Level Rise on Marine Biodiversity

Abstract

Mangroves, salt marshes, and seagrass meadows are coastal wetlands that alleviate the ecological effects of sea-level rise (SLR) on the marine biodiversity. The occurrence of rising sea levels, however, at a rate of 3.6 mm yr 3 -1 worldwide over the last 20 years, is a threat to the survival and ecological activity of these environments. This paper assesses the importance of coastal wetlands in mitigating biodiversity loss from accelerating SLR by combining spatial analysis, ecological modeling, and long-term biodiversity data from three representative coastal areas. The study employed a mixed-methods research design, using Digital Elevation Models (DEM), SLR inundation modeling, biodiversity richness indices, and Generalized Linear Models (GLMs) to assess buffering capacity and species-level responses. The findings indicate that wetlands minimize habitat exposure to flooding by 32-47%, increase fish nursery habitat stability by 28%, and retain species richness levels 22 times higher in wetland shorelines than in non-wetland shorelines. Belts of mangroves were statistically linked to reduced shoreline erosion rates (41%; p < 0.01), and the Shannon Diversity Index of nearby marine communities was positively correlated with belt width (0.7). The model results indicate that sea wetland conservation and landward migration space could, in turn, lead to the disappearance of 35 percent of marine nursery habitat by 2050 under high-SLR conditions. The paper concludes that coastal wetlands are essential nature-based defenses against biodiversity loss from SLR and should be featured in coastal adaptation plans. Creation of wetland migration corridors, sediment supply, and incorporation of wetland functionality into marine zoning can all importantly improve the ecosystem's resilience. The findings present statistically supported arguments on the policy makers in need of sustainable, biodiversity-based coastal management guidelines.