After the first phase of the Besòs renaturalization project with the biodiversity refuge promoted by the Santa Coloma de Gramenet City Council, the experts note that fauna has recolonized the river and the river park two decades after the environmental restoration that has turned it into a great green infrastructure.
One of the privileges of an ecosystem like the lower section of the Besòs is that the river is also a great educational tool. The built biodiversity refuge is an environmental eco-classroom set with a 400-metre mural that makes it possible to identify the species that repopulate the river thanks to the recovery process of the flora and fauna.
"It still has to be a more resilient area", affirmed the mayor of Santa Coloma de Gramenet, Núria Parlon, hopeful with the new impetus that European funds and the Metropolitan Area of Barcelona (AMB) will allow to start the second and third phase, which will replicate the environmental actions of the lower basin, up to the border with Montcada and Reixac. "A very ambitious project", defined Ramon Torra, manager of the AMB, "which has allowed the river to return to its original functions". All of the actions have a budget of seven million euros.
Getting the little blue tern to nest in the Besòs is one of the immediate objectives of the Colomenc council, as are the mallard, the green-necked duck, the mallard and the night martin, which have already colonized the course of the river. The wagtail is a showy, strikingly colored species of the order Coraciformes, which is characterized by maintaining a straight, fast flight and by its sharp and powerful call.
El Besòs is now a great showcase for bird lovers, who enjoy the large number of species in the two artificial lagoons created next to the biodiversity refuge and on the banks of the river, facilities that delight school children "It's a sight to see so many birds flitting about and that you can recognize them thanks to the educational material provided by the City Council," acknowledges Javier Martínez, a retiree who walks the bridge with binoculars and hopes "that observation points will be opened" . Other residents, such as Octavio, regret that incivility can damage "all this beauty" and ask the municipal government to "be more vigilant with the loose dogs that get into the river and chase the birds", a practice prohibited in a nature reserve .
On the banks of the Besòs, numerous groups of schoolchildren are called to participate in the educational days. The young people exultantly comment on having watched a bluefish dive to catch an American red crab – an invasive species –, a catfish or a mountain barbel in the educational lagoon, which is also part of a research project in collaboration with the University of Barcelona.
Amphibians and mammals deserve a separate case, which have also returned to Besòs thanks to the quality of the waters. Thus, the night cameras have already been able to confirm the presence of otters, well hidden among the Asian reeds – an invasive plant species – that populate the banks and which, in view of the scarcity of trees, serve as a refuge for the species of wildlife Special attention is paid to the preservation of eels, a critically endangered species that has begun to frequent the lower section, thanks to interventions for their migration, such as the removal of artificial barriers. The southern frog, which had been considered extinct in Catalan rivers, has also returned to the Besòs.
