24 Sep 2018

Vital Argentinan marshlands under threat from dredging, clearing

Valenzuela marsh, which we've identified as in Important Bird & Biodiversity Area (IBA) is being threatened by dredging and forest clearance. We're mobilising support and lobbying for another solution to the floods plaguing the region.

By Daniela Paz

The Valenzuela marsh in Argentina, which is home to a number of globally threatened species, is in danger from dredging works and deforestation.

Located in the Corrientes province, just south of the Paraguayan border, the Valenzuela marsh (estero Valenzuela) forms the mouth of the Riachuelo river. The area is a lush one, marked by stretches of rolling grasslands, verdant jungles, and blue lagoons. The fertile environment nurtures many bird species including the Sharp-tailed Tyrant Culicivora caudacutathe Ochre-breasted Pipit Anthus nattereriand the Chestnut Seedeater Sporophila cinnamomeaall of which are listed as Vulnerable, largely due to extensive habitat loss. Unfortunately, scientists, conservationists and the local community worry that dredging along the Riachuelo river, as well as the clearing of riverside forests is threatening the area. 

Ostensibly, the reason for the dredging and clearing is to stop floods, following heavy rains in the region last year which caused a substantial rise in water levels. However, scientists have warned that the dredging work will simply be a short-term solution, lowering the water levels temporarily. Sediment will soon build up again, meaning that continual and expensive dredging works would be needed to have any lasting effect. Not only will dredging be ineffective, but it could actually increase flooding in the coming years by damaging the mangrove forests in the area, which naturally regulate water levels and purity. This artificial stop-gap solution harms nature’s ability to control flooding in the long term.

The dredging and clearing will also do considerable damage to the environment. The clearing of riverside forests will remove habitats that are vital to the birds and animals in the region, while the dredging will cause substantial pollution within the estuary and river, affecting both water quality, and the fish and crustaceans that reside in the Riachuelo river and Valenzuela marsh.

BirdLife International is trying to raise awareness of what is happening with Valenzuela marsh, while supporting local groups in their quest to find another solution to the flooding of the region. Through Aves Argentinas (BirdLife Partner) we have been supporting members of these groups as they call for a thorough investigation of the decision making process that led to the dredging and clearing, as well as an examination of exactly how much environmental damage these actions will cause. We also join them in lobbying for efforts to find another solution to the flooding in the region; one that will not damage the surrounding ecosystem.