Eten's Coastal Wetland, its geomorphology, water quality and biodiversity

The Eten's wetland is located in the lower part of the Chancay-Lambayeque River basin at the Peruvian coast. This wetland contains salt and fresh marshes, swamps, lagoons and an estuary which is the result of Reque River's morphodynamics. It provides a great source of totora (Schoenoplectus californicus), a native plant that is used for knitting hats which are an ancient cultural expression in Lambayeque. UNESCO recognized this wetland as one of the ecosystems with the greatest biodiversity along the South Pacific Coast, providing a unique habitat for migratory birds, such as the Peruvian Tern (Sternula lorata). This bird has been classified as endangered in 2005, by the International Union for Conservation of Nature (IUCN). When the area of a wetland is reduced, the resting point function is affected leading to loss in biodiversity due to the habitat conditions are not the same. In 2005, Lambayeque's government established an area of 1377 Ha in order to preserve wetland's ecosystem and Eten's archeological value but wet areas were reduced to 200 Ha. This reduction was promoted by agriculture, urbanization and an inadequate urban waste disposal. The scope of the study is to assess the environmental impacts that affect Eten's wetland. Preliminary results of an assessment with remote sensing indicate that: 1) the Reque River's geomorphic activity was reduced by urbanization, thus, the connection between surface water bodies has been lost, leading the drying out of ponds, 2) the conversion of wet areas to agricultural land, and 3) the natural interaction between the Reque River and the Pacific Ocean was modified due to water control upstream, resulting in a dryer wetland during the last years. Furthermore, the aquatic biodiversity of the wetland was assessed through a biomonitoring method in order to study the impact of water contamination. Four benthic macroinvertebrate Families (Hydrophilidae, Baetidae, Planorbidae and Palaemonidae) were found. The quality of the surface water of lakes was classified as bad, according to the Biological Monitoring Working Party Index (BMWP/Col). This was corroborated by a laboratory testing in water quality, that showed a reduction of Dissolved Oxygen in 8%. Therefore, the Eten's wetland presents a unique scenario where anthropogenic effects are diminishing its ecosystem functionality.