Biological Invasion in the coastal zone: environmental threat and management perspectives on the Tramandaí River Hydrographic Basin’s coastal counties.

Abstract

Abstract

Biological invasion is one of the main threats to natural environments. The invasive alien species cause a series of impacts on native species, especially on those endangered - which are one of the main conservation targets of the Plano de Ação Nacional dos Sistemas Lacustres e Lagunares do Sul do Brasil. As a result of the human actions, invasive alien species become more frequent in regions under great demographic pressure, especially in degraded areas, such as those found in the coastal zone of the Tramandaí River Hydrographic Basin, a region within the Action Plan’s territory and selected to be the study area of this report. The aim of this work was to characterize the situation of biological invasion in this part of the basin and identify management and control initiatives by coastal counties, in order to contribute to future conservation actions. We consulted the National Database of Invasive Alien Species and the Conflict Management Plans for Urbanization, Sandy Fields and Dunes submitted to FEPAM/RS, to search for the 12 water basin coastal municipalities’ data. We found records of 30 out of 100 invasive alien species of the state of Rio Grande do Sul, mostly plant species. Only in Tramandaí, one of the most populous counties in the region, 21 different species were identified. The low number of records found in the other municipalities indicates a probable lack of information available in the consulted sources. Of the nine Dune’s Management Plans consulted, five presented indications of the presence of invasive alien species and control action or dunes restoration plans, which implies some knowledge about this environmental problem. However, we observed that a more embracing strategy, reaching portions beyond the dune range, needs to be adopted to contain the invasion process, as well as the effort to increase invasive alien species records. Community awareness and the integration of the society’s different sectors for integrated environmental management of the territory will allow more actions to be taken and the reaching of PAN Lagoas do Sul conservation objectives.