Those contesting the development claim the marsh-like land known as the ‘Alagoas Brancas’ is being levelled for the construction of a large supermarket belonging to major national group Sonae.
It would sit directly opposite two other large food stores and within a few kilometres of another two supermarkets.
Critics say the plot is an important ecosystem that is home to many species of birds.
They hope their action is still in time to have some effect within the local council, and query “how many supermarkets does a town of this size need?”
According to the petition, which at the time of going to press had been signed by almost a thousand people, the Alagoas Brancas “are one of the last fresh water wetlands left in the Algarve where many species of birds come to rest and breed every year.”
These are said to include glossy ibis, kingfishers, reed warblers, ducks and other wildfowl as well as small mammals and insect life.
One critic, local resident James Watson, told The Portugal News: “This site is particularly important as it is a fresh water wetland. “Most of the wetland reserves in the Algarve are either salt water or brackish [a mixture of the two].
“Not only is it fresh water, but because of its very low and slow draining nature it stays wet all the year round. This site needs urgent surveying to establish exactly what wildlife is currently being destroyed.”
Mechanical diggers moved in on the site at the end of last week, which observers say has left the birds “clearly in distress.”
“This site is small but so rich and so could be a fantastic nature reserve for the residents and tourists of Lagoa. It could be a wonderful outdoor classroom for the children of the county. This site needs urgent protection now”, Mr Watson argued.
This stance is backed by cultural heritage and environment protection association Almargem, which said while the small wetland is “considered by many people, and apparently also by the Municipality, as simply wasteland with stagnant water,” the fact is that “it is of significant importance.”
“Therefore, Almargem has already asked Lagoa Municipal Council, the General Environmental Inspectorate and SEPNA-GNR [police] to carry out the necessary actions for the immediate suspension of the works in progress, in order to avoid another regrettable environmental crime in the Algarve”, the association revealed.
In response to questions posed by The Portugal News, Lagoa council said the project, which is taking shape on land that falls within the municipal Urbanisation Plan (UP3), underwent “all the necessary technical assessments for the depletion of soils of National Agricultural Reserves and environmental assessments.
“Thus, verifying that the project in question complied with the proper legal framework, there were no reasons to prevent its licensing.”
Lagoa council added a public consultation process was held for 15 days in 2013 after notice was published in the Government Gazette on 28 August 2013.