As the UN conference for the oceans begins on Monday, June 27 in Lisbon, Portugal, it is the dolphins of Lisbon who embody the hope for the preservation of marine biodiversity. These dolphins of the Tagus river prove by their recent return to the waters of the Portuguese capital, that it is not too late to act.
In recent years, the dolphins, which had been paddling there in flocks for millennia, had ended up leaving, chased away by increasingly intense maritime traffic, the multiplication of cargo passages, gigantic trawlers, their wild degassing, but also the overfishing which has deprived them of food, not to mention the underwater noise pollution which disorients them. All these nuisances ended up getting the better of their presence, until the Covid epidemic arose… and changed the situation.
They remain, as a symbol
Thanks to the confinements and the slowdown in maritime traffic, they have returned. In April 2020, the first photos of bottlenose gray dolphins and common dolphins, black with white sides, began to flourish on social networks. The municipality welcomed it. And since, ultimate curiosity, they have remained. This is what the biologists of the Lisbon aquarium have observed, who explain that before the pandemic, there were only about ten appearances per year and that now, for 2021, we have increased to nearly 200 passages recorded in the estuary of the river, without scientists being able to really say why since the world economy has resumed, bringing with it everything that had made them flee before, maritime traffic, noise, pollution.
Regardless, the dolphins stay. Maybe because they resist better? Because they don’t want to let go of their territory a second time? Perhaps so that the representatives of the 120 countries who will sit at the conference for the ocean see concretely what their decisions can preserve.
In any case, the organizers have made them the emblem of the event, to better convince of the need to limit maritime traffic, to fight against overfishing by eliminating the tens of billions of euros in subsidies which encourage, or to create vast marine protected areas to preserve 30% of the seas and oceans against less than 10% today. The summit is being held in Lisbon until July 1.