The Parana delta is a complex ecosystem of rivers, streams and islands stretching over 22,590 sq km. Here, a woodworker is enjoying his lunch break in front of a poplar plantation.By Cecilia CaminosThe Parana delta is one of Argentina’s most bountiful ecosystems and an internationally protected wetlands but human encroachment in the form of urban settlements, farming and cattle breeding is jeopardising this vast coastal region and its biodiversity.“The main danger is the spread of activities that have no connection to the region,” said Carmen Penedo, a biologist with the Wetlands Foundation. The Parana delta is very vulnerable, she added.The Parana delta is a Ramsar site (the 1971 Ramsar, Iran, Convention was created to protect the world’s wetlands) and has been declared a biosphere reserve by Argentina.Its ecosystem, comprising rivers, streams and islands stretches over 22,590 sq km. To the north it reaches out over the Paraguay river and to the south along the Parana river until it merges with the River Plate. The delta is also a major water reservoir for South America.The characteristics of the delta differ depending on each particular area of the territory. For example, there is the touristic and more populated area known as the Lower Delta, near Buenos Aires, the Argentinan capital. Then there are the bleak and inhospitable islands covered in scrub and rushes in the provinces of Entre Rios and Santa Fe.The Parana delta is the fifth most important of its kind in the world. The Parana is also one of the few deltas that flows into another freshwater river, not directly into the ocean, and one of the few that continue to grow. It is growing at the rate of about 100m per year and experts say that by 2100 it might reach the coast off Buenos Aires.The Parana delta has ecological functions such as softening the effects of floods and droughts, preventing erosion, protecting the coast and regulating the climate. The delta helps to purify water and provides natural resources. It is a refuge for flora to grow and fauna to feed and reproduce.Penedo said that many of those functions are under threat because farmers and animal breeders are encroaching on the delta islands. “Before cattle raising was done in keeping with the way a wetland works. But now breeders are transferring methods used on the mainland to the islands. They are bringing a lot of animals and they are doing construction works to dry out the wetlands to keep the animals from dying,” she said.Cattle also trample and destroy native vegetation and that contributes to the arrival of other species. The Parana delta islands are shaped like basins or deep bowls, so that their central sections fill up with water. But Penedo said that cattle breeders now want to stop that in order to increase productivity and they are building large dikes that change water flow directions. They build up earth layers on the islands and fill up the central parts that would previously become flooded.With those changes, farmers have been able to introduce soya beans, Argentina’s main crop, to the Delta. Another grave danger threatening the ecosystem is that urbanised areas are springing up on islands and coastal sections.Penedo said the problem with those urban areas is that they are drying out the wetlands because they are changing its geophysical nature of being open to flooding.While building the urbanised areas workers open new streams, change the course of existing ones and close off the natural flow of rivers.Penedo called on authorities to take action to put some order on the way the delta region is being urbanised. The Wetlands Foundation has counted 229 closed-off urban settlements on the Parana Delta.The foundation says that draining, land filling and shifting the course of rivers and streams increases the negative effects of floods and undermines adaptation to climate change. Ninety-per-cent of the urban compounds were built on the alluvial plains of the delta tributary rivers in the mainland section.Several non-government organisations, foundations and environmental groups are carrying out studies and programmes to raise awareness about the need to save the Parana Delta.The government National Parks department manages two reservation areas in the Parana delta. They are the Pre-delta in the province of Entre Rios and the Otamendi Estricta Natural Reserve in the Campana section of Buenos Aires province. These two reserves however only comprise 52,000 hectares of the Delta’s vast territory.The first section of the Delta, the one closest to Buenos Aires, is the most affected by man.Some 9,000 people live in an area of about 220sq km. They live in rustic houses built on piles and with wooden or concrete walls facing the river. Casuarina trees were planted there in the early 20th century to keep river waters from rising over the islands.The area has schools, medical centres and commercial boats ride along the river to provide provisions to inhabitants. Tourist hostels and cabin compounds are mushrooming.Just 20 minutes by boat from the port of Tigre, the main access point to the delta, can be found the first “protected landscape” of this section. It is called “Delta Terra” and measures about 40 hectares.In an interview, Adrian Giacchino, head of the Azara Foundation that oversees Delta Terra, said that reserve plays more of an environmental teaching role even though it does have a conservation programme. “The reason for such a small reserve is that it can receive a number of visitors, with an educational purpose, that 50,000 hectares on the distant edge of Argentina cannot because it is close to the city.”He added that even though the first section has been changed a great deal, it still has all the natural elements of a delta. Giacchino said that for example, on the higher edges of the island, poplars, casuarinas and pine trees replaced native trees such as Pindo palms, willows and ceibas. But in the middle lower part, the island has retained more of the original vegetation.The Delta Terra project also seeks to bring back certain animal species commonly found in other parts of the delta, but which were wiped out in the first section. Those animals include otters, guans, nutrias, capybaras and marsh deer. — DPA