Rediscovering Ribeira de Coselhas: A community walk through time and biodiversity
On Saturday, February 22nd at 3 p.m., residents of São Romão and other citizens from Coimbra, gathered for a community walk along the urban stream of Ribeira de Coselhas. The event offered an opportunity to reconnect with the stream’s rich biodiversity and history while reflecting on the significance of this ecosystem and its transformation over time.
Approximately 30 participants—from children to older adults—assembled at a small historic chapel and set off on the walk accompanied by the Freshwater Ecology Lab Team from the University of Coimbra (MARE – ARNET).
The walk began at a downstream location where the team sampled benthic macroinvertebrates and made a quick identification of some groups with the participants. This demonstration highlighted a remarkable diversity of species, and many participants learned that certain aquatic organisms, insects, spend most of their lives underwater before transforming into terrestrial, flying adults. Along the margins, various plant species were also observed, with some participants recognizing those traditionally used for herbal infusions and medicinal purposes.
The event further served as a stage to celebrate local biodiversity and share memories of the stream’s past. Many recalled a time before the construction of Coimbra external ring road, when the area was predominantly farmland with few houses and when people would wash their clothes in the stream and fish. They remember to see eels swimming upstream from Mondego. An important family inhabited the valley since the XII century where they built a small palace and a church that are now in ruins
In the second part of the activity, the group proceeded upstream to where specially designed nets had been set up for the safe capture of birds. A certified expert demonstrated bird ringing (banding) techniques, explained the significance of the data collected, and then released all the birds back into their habitat.
Despite visible changes in the urban stream—such as areas affected by improper reed cutting—native riparian trees, like elderberry and elm, still thrive upstream near more developed zones, suggesting that these natural elements have endured for generations.
Participants expressed great surprise at the rich biodiversity encountered during the walk. Some, who had believed that the stream had lost much of its natural life, remained fascinated until the very end, while older residents recollected about species they remembered seeing more frequently in their youth.
Overall, the event was highly appreciated for fostering mutual learning and strengthening the community’s connection to its natural environment.
Members of the municipality and water agency also participated, as well as journalists of a local newspaper, which published an article in the following day. This led also to further contacts by other citizens which read the news and offered additional historical information about the stream.
Author(s): Sónia R. Q. Serra (PhD), University of Coimbra