A pond that never dries out risks becoming unhealthy, just as a person who never rests can suffer from exhaustion. This is the challenge facing the Dombes region in France, a clay plateau in the Ain department where fish farming has long been a traditional practice. In an effort to simplify their work and ensure better fish harvests, some local fish farmers have stopped using a centuries-old technique called "assec," which involves periodically draining ponds. This process, inherited from the Middle Ages, allows the pond bottom to be exposed to air, helping decompose organic matter that would otherwise build up over time. When ponds are kept full year-round, this natural cycle is disrupted, leading to the gradual depletion of oxygen and nutrients, which can harm aquatic life. The Dombes system relies on a careful balance between fish farming and land cultivation. For several years, ponds are filled with water to raise fish, a period known as "évolage." Then, every three to four years, the water is drained, and the land is used to grow crops for a season. This alternating process helps maintain the health of the ecosystem by preventing the buildup of silt and ensuring the pond remains oxygenated. Traditional practices such as draining, maintaining vegetation around the ponds, and rotating between aquatic and agricultural uses are crucial for sustaining both the fish and the surrounding environment. Without these practices, the water becomes stagnant, and the biodiversity that depends on these ponds declines. Recent studies, including a 2024 thesis and a 2026 study published in the journal Hydrobiologia, have confirmed the importance of assec in maintaining ecological balance. These studies show that the number of fish in a pond can influence the growth of aquatic plants, which in turn support insects, amphibians, and birds. While fish farming and biodiversity conservation can coexist, the balance is delicate and requires careful management. The Dombes region, with its unique mix of water and land, has become a critical stopover for migratory birds. More than 280 bird species, including rare ones like the singing swan and the black duck, rely on this area during their journeys. The region was officially recognized in 2023 as an internationally important wetland under the Ramsar Convention, highlighting its ecological significance. Despite this recognition, the Dombes still faces challenges. Climate change has increased the frequency of droughts, and traditional water management practices are being abandoned in favor of more modern, less sustainable methods. Intensive agriculture and invasive species are also contributing to environmental stress. The decline in fish farming is leading to the loss of habitats and food sources for many species, including birds that depend on the ponds for survival. Local efforts, such as the Dombes Pond Fish Association, are trying to encourage landowners to continue traditional practices that have sustained the region for centuries. However, each pond is privately owned, and the decision to drain or not drain remains in the hands of individual landowners, shaping the future of this unique and ecologically rich landscape.