Thousands of onlookers watched the traditional opening of the Santo André Lagoon to the sea, 2010

More than three thousand onlookers enjoyed the sunny afternoon of Sunday to watch the work of machines that opened a channel through dunes, fulfilling the centuries-old tradition of opening the artificial lake of Santo Andre to the sea. 

The tradition is repeated annually, at the time of the spring equinox, from the seventeenth century, then about the strength of men.

Today the work was undertaken by two 'tracks' (or crawler tractors) and a rotary excavator, an initiative sponsored by the Institute for Nature Conservation and Biodiversity (ICNB).

The Sunday afternoon was enjoyed by thousands of people – tourists, families, and many inhabitants of the region – which have lost the opportunity to witness a repetition of the ritual up close, reaching the beach of Costa de Santo André to have more movement than during the bathing season.

The corridor, this year with about ten feet wide and 50 long, opened the lagoon to the Atlantic Ocean just minutes after 16:00, initiating the renewal of the waters.

In addition to the renewal of the water, the process is repeated annually to allow exit and entry of organic matter in sandy sediments and organisms (fish and invertebrates).

"It is an action not only management of the ecosystem – the coastal lagoons are priority habitats and as such we have an obligation to protect and renew – but also so that fishing continues to exist in the pond," said the head of the Lusa Nature Reserve das Lagoas de Santo André and Sancha, Ana Vidal.

With the highest water levels since 2001, the five rivers flow into the pond where this year hit an area of ??350 hectares, with an average of two meters deep.

"The mass of water will allow the canal to remain open for a long time," he said, predicting an opening of about 60 days, which he considered "very good", because the longer it remains open, the more effective is the renewal waters.

"In 2008 it was open five days and last year they reached a month," he recalled, explaining that although the opening to the sea be made artificially, the dunes were eventually re-form naturally and closed the pond again .

The opening day is chosen taking into account the ideas, like the greatest tidal range (the highest and lowest on the same day), the sea waves and wind.

Lagoa de Santo André receives "an abundant water birds", and, for some species, serves as refuge after the player during the summer, and also presented in the autumn and winter, "large concentrations of birds, mostly from the north and central Europe, "said the ICNB.

Considered the largest lake system of the Alentejo coast, in Santo André Lagoon is classified as a RAMSAR Site – Wetland of International Importance, and its existence by ICNB considered crucial to maintaining the natural values ??and human activities such as fishing.