Are the wetlands on the Pacific coast of South America shrinking? The case of Lima wetlands

Coastal wetlands are threatened by anthropogenic activities that cause changes in the area. The present study evaluated the potential changes in the total areas and the vegetation cover of six coastal wetlands of Lima from 2002 to 2019 using remote sensing and GIS. The results showed an increase in the area of two wetlands: Albufera de Medio Mundo (+ 37.51%) and Laguna El Paraíso (+ 6.40%). On the other hand, the wetlands of Ventanilla (-21.88%), Puerto Viejo (-7.37%), and Santa Rosa (-3.17%) showed a decrease. The average exchange rate of the area (+ 0.14% per year) was higher than the world average change (-1.08% per year). Regarding vegetation cover, three wetlands showed an increase: Albufera de Medio Mundo (+ 51.54%), Laguna El Paraiso (+ 26.03%), and Humedal Santa Rosa (+ 12.36%). On the contrary, a decrease was registered in the wetlands of Puerto Viejo (-1.34%), Ventanilla (-6.62%), and Los Pantanos de Villa (-18.13%). The reductions may be due to anthropogenic activities (agriculture, dumping of construction waste, or livestock) reported in previous studies for these areas. The increases in the coverage and the area may be related to the expected development of ecosystems when they are far from the population while vegetation increases in water bodies may respond to eutrophication processes. We suggest evaluating the evolution of these wetlands independently to avoid losing information about their increase or decrease.