An international study led by researcher Pedro Costa of the University of Coimbra (UC) announced today that heavy metals and microplastics are some of the pollutants detected on the Algarve continental shelf.
“Human presence has left a polluting signature in the coastal zone of the Algarve, with a negative impact, for example, in terms of biodiversity”, says Pedro Costa, from the Department of Earth Sciences of the Faculty of Sciences and Technology of the University of Coimbra (FCTUC) in a statement to Lusa news agency.
The “OnOff” project, which involves more than 20 researchers, made it possible to carry out “a chronography of extreme events such as tsunamis and storms, and the effects of human contamination” in this area of Portugal, over the last 12,000 years.
The study “alerts the impacts of human pollution on the continental shelf of the Algarve”, says the FCTUC press office, according to which “heavy metals and organic contaminants were detected along the coastal area of the Algarve, between Sagres and Portimão”, the results of the investigation have been published in the specialist journal Marine Pollution Bulletin.
“The data obtained seem to indicate that in the 1960s there was a peak of pollution, but, curiously, in recent years, this pollution seems to be slowing down slightly, with the exception of the Arade River area where regular discharges are carried out”, reveals Pedro Costa, co-author of the scientific article.
The study reports the presence of “various inorganic and organic pollutants related to human activity, including different heavy metals and even microplastics”.
Due to climate change, “it is expected that we will have more high-energy events, both in precipitation and in storms, which will cause more intense erosive phenomena”.
“In Portugal, there are already a number of areas under pressure, which means that this problem will inevitably worsen. We have always had pollution, but with the changing climate and with the energy levels of these extreme events, phenomena that would be of low intensity could cause serious negative consequences and serious imbalances in coastal systems”, warns the FCTUC researcher.
In addition to the University of Coimbra, “OnOff” includes the University of Lisbon, the University of Algarve, the Hydrographic Institute and the Portuguese Environment Agency, in addition to the University of Aachen (Germany) and the United States Geological Survey.
Titled “Contemporary pollution of surface sediments from the Algarve shelf, Portugal”, the project, started in 2018, “essentially aims to fully reconstruct extreme events, such as tsunamis and storms, and their impacts on the Portuguese coast, based on geological evidence” .
“In other words, it seeks to get information from the seabed to carry out the reconstruction of extreme events, whether tsunamis, storms or floods, as well as more recent phenomena, such as pollution”, explains Pedro Costa.
For this, the scientists carried out “a series of sea campaigns”, with underwater soundings, along the coast of the Algarve, collecting samples of water, sediments and geophysical data between 500 and 30 metres deep.
“This is the innovative aspect of the project, because it shows a different archive that was not normally considered and which allows a detailed reconstruction of the evolution of this region. The information obtained at sea is combined with data obtained on land, in lagoon and estuarine areas of the Algarve”, adds the project leader.
“OnOff” can support “government authorities with useful data in planning, ordering and also in operationalisation”.
The project is financed with funds from the Foundation for Science and Technology (FCT), the European Union and the Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro, Brazil.