Anthropogenic, Direct Pressures on Coastal Wetlands

NEWTON, ALICE; ICELY, JOHN; CRISTINA, SONIA; PERILLO, GERARDO M. E.; TURNER, R. EUGENE; ASHAN, DEWAN; CRAGG, SIMON; LUO, YONGMING; TU, CHEN; LI, YUAN; ZHANG, HAIBO; RAMESH, RAMACHANDRAN; FORBES, DONALD L.; SOLIDORO, COSIMO; BÉJAOUI, BÉCHIR; GAO, SHU; PASTRES, ROBERTO; KELSEY, HEATH; TAILLIE, DYLAN; NHAN, NGUYEN; BRITO, ANA C.; DE LIMA, RICARDO; KUENZER, CLAUDIA

Frontiers in Ecology and Evolution

FRONTIERSIN

Lugar: LAUSANA; Año: 2020 vol. 8

Coastal wetlands, such as saltmarshes and mangroves that fringe transitional waters,deliver important ecosystem services that support human development. Coastalwetlands are complex social-ecological systems that occur at all latitudes, from polarregions to the tropics. This overview covers wetlands in five continents. The wetlandsare of varying size, catchment size, human population and stages of economicdevelopment. Economic sectors and activities in and around the coastal wetlands andtheir catchments exert multiple, direct pressures. These pressures affect the state of thewetland environment, ecology and valuable ecosystem services. All the coastal wetlandswere found to be affected in some ways, irrespective of the conservation status.The main economic sectors were agriculture, animal rearing including aquaculture,fisheries, tourism, urbanization, shipping, industrial development and mining. Specifichuman activities include land reclamation, damming, draining and water extraction,construction of ponds for aquaculture and salt extraction, construction of ports andmarinas, dredging, discharge of effluents from urban and industrial areas and logging,in the case of mangroves, subsistence hunting and oil and gas extraction. The mainpressures were loss of wetland habitat, changes in connectivity affecting hydrology andsedimentology, as well as contamination and pollution. These pressures lead to changesin environmental state, such as erosion, subsidence and hypoxia that threaten thesustainability of the wetlands. There are also changes in the state of the ecology, suchas loss of saltmarsh plants and seagrasses, and mangrove trees, in tropical wetlands.Changes in the structure and function of the wetland ecosystems affect ecosystem services that are often underestimated. The loss of ecosystem services impacts humanwelfare as well as the regulation of climate change by coastal wetlands. Thesecumulative impacts and multi-stressors are further aggravated by indirect pressures,such as sea-level rise.