From 2015 to today, the area at the mouth of the Maipo river where the homonymous Naturalistic Oasis is located, has lost 81% of the surface of its body of water.
This is one of the results of a recent study commissioned by the City of Santo Domingo and developed by researchers from different study houses, led by Eduardo Jaramillo, from the Faculty of Sciences of the Austral University of Chile.
For about 16 months, scientists have been sampling the area of the Sanctuary in order to diagnose its current state and learn about the opinions of the local community in relation to this coastal ecosystem.
Subsequently, a management plan was designed for its conservation for the protection of five conservation objects: the coastal sand ecosystem (Marbella beach, coastal sand dune and dune scrub), the coastal birdlife (sedentary and migratory species) , Mioporo forest, the mouth of the estuary (body of water, marshes and intertidal sedimentary plains) and fishing community (Chinchorro fishing equipment).
Based on the information available since 1986, the study reports a decrease in the area of the body of water, given that in 2015 its coverage reached 82 hectares, while in 2018 it was only about 16 hectares, i.e. being 81 % less flooding the area. The downward trend, albeit fluctuating and dependent on the season, has been maintained since 2010. Added to this decrease are the increasingly frequent intrusions of salt water into the mouth during winter storms and the subsidence of the continent due to the seismic cycle.
“All of the above can result in salinization of the water at the estuary and a negative impact on its biotic components, such as plants and aquatic fauna,” says Jaramillo.
The study also reports threats to the shrine. The increase in the frequency of storm surges during the winter produces a significant decrease in the plant and sand cover of the coastal dunes adjacent to the Sanctuary and which form the rear limit of the sandy beach of Marbella.
Jaramillo mentions “these storm surges also affect the beach, as during the winter it enters a period of sand erosion, habitat loss which results in the decline of the sea pigs commonly called (Emerita analoga), which are a fundamental part of the diet of coastal birds – migratory and resident – such as the plover (Calidris alba), the curlew (Numenius phaeopus) and the common pilpilén (Haematopus palliatus), among other species.The Pilpilén is a notable bird of the Sanctuary and its persistence is threatened , as its eggs are eaten by stray dogs and probably by the Norway rat (Rattus norvegicus), an introduced species present in the area,” says Jaramillo.
The eventual expansion of the port of San Antonio is considered by much of the community to be a real threat to the preservation of the sanctuary.
“Among its potential effects, the possible change in the direction of the coastal currents that supply sand to Marbella beach, the loss of what remains of Llolleo beach and the expansion of the port urbanization towards the shores of the lagoons of the same name (considered as part of an ecological network that includes the Sanctuary, the beach of Marbella and the mouth of the Maipo River),” said Jaramillo.
On the other hand, the report details the work with the surrounding communities, identifying 51 key actors, who detailed their concerns, objects of conservation, threats and determined the actions to follow, determining a three-year period to deal with emergencies . .
“In the field and in collaboration with the municipality of Santo Domingo, Fundación Cosmos and other key players, it was decided to carry out more than 50 actions which aim, among other things, to change land use and reduce the extraction of water and dry areas in the riverbed, to implement a plan that reduces the presence of invasive species and to contribute to responsible pet ownership (dogs and cats within the wetland),” said María Ignacia Fuenzalida, director of the Center of continuing education of the UACh and professional in charge of social media studies.
For his part, Diego Urrejola, executive director of the Cosmos Foundation, reiterated that the greatest number of threats and the current situation of the sanctuary respond to human activity.
“It is an urban wetland, it is a sanctuary that is located between two cities and that presents major threats such as port expansion, city sprawl, river pollution, drought, poor agricultural practices and above all the anthropization of that place, including pet ownership. Therefore, the future challenge for us is to take each of these threats to manage the reduction of their impact on the sanctuary; In this sense, the management plan includes each of these threats and provides us with guidance on how to deal with them. The conservation of this place is multidimensional and complex, but has clearly established threats,” Urrejola said.
Referring to the results, Fuenzalida (UACh) underlined that more than lessons “there are challenges for the governance of the sanctuary, where, as the Fundación Cosmos mentioned in the last workshop where the Plan was presented, it must be made inclusive and participatory because the proposed actions must be carried out and this requires a shared effort”.
In this regard, Urrejola appreciated the fact that this tool will allow for better management of the sanctuary.
“For us it will be a super relevant tool to be able to have clear indicators and objectives for 3 and 10 years, which will allow us to concentrate the search for economic and human resources and focus on the actions we need to take”.