A fishing spot
In summer, on the riverbanks below the Palais de Tokyo, fishermen try their luck at catching bleak and roach, two species commonly found in the waters of the Seine in Paris.
Common bleak (Alburnus alburnus) generally move in large shoals. They swim near the surface as they prefer the well-oxygenated water found there. They reproduce between mid-April and July, laying 1,000 to 12,000 eggs among the gravel and stones.
To promote biodiversity in the river, the Ports de Paris (the organization responsible for river activity in Paris) has set up a gravel bed at Pont de l’Alma by the left bank (in the 7th district). This is ideal for the fish, which come to spawn here. The water quality has gradually improved since the near-asphyxiation of the river in the early 1970s with an especially marked improvement during the 2000s. Water treatment plants are more efficient and more numerous, the industrial infrastructure of the city has evolved over the years and industrial waste is partly pre-treated before it reaches the main sewer system.
The average level of oxygenation in the Seine was therefore able to increase by 10%, allowing for the return of many wildlife species. Thirty-five species of fish have been recorded in the Seine in Paris over the last 10 years, compared to just three species recorded in 1970 and five in the late 70s. The Seine is an important national ecological corridor and serves as a circulation route for biodiversity. The river ensures a connection between biodiversity source sites and allows species to move around freely in order to ensure their development.
On the left bank near the Pont de l’Alma, the Paris Sewer Museum (Musée des Egouts de Paris) offers visitors the chance to explore part of the 2 500 km (1550 miles) network of sewers. These carry domestic waste water to treatment plants. The waste water is then treated before being discharged into the Seine.
A cough remedy
A vivid yellow plant which stands 10 to 30 cm (4 to 12 inches) high appears on the riverbank at the end of the winter. Commonly known as coltsfoot (Tussilago farfara), the Latin name tussilago means “cough suppressant”. As early as February, before its leaves appear, the plant produces bright yellow flowers which resemble those of the dandelion. The plant’s nectar and pollen provide a feast for insects early in the season. In earlier times, the leaves were harvested for their properties as a cough suppressant.