World Fish Migration Day – 21st April 2018
Events will be held across the world tomorrow to highlight the importance of free-flowing rivers and migratory fish. Hundreds of events are planned as part of World Fish Migration Day, involving groups of people and organisations on a diverse range of river and streams.
Migratory fish populations are threatened in many global rivers and streams. Often this is the result of multiple pressures such as barriers to migration (like weirs and dams), water flow alterations (such as agricultural abstraction) or damage to habitat (such as removal of spawning beds).
Migratory fish lifecycles can occur over very large geographic areas – with breeding, feeding and reproduction all potentially taking place hundreds of miles apart. This means that conservation and restoration actions often need to be coordinated over large areas. For example, for the Atlantic salmon in northern Europe, this includes managing fishing both at sea and in estuaries, alongside mitigating water pollution, conserving spawning grounds, and providing fish passes on weirs and dams.
Migratory fish often provide valuable sources of food and livelihood for local communities. They can also be important parts of large-scale nutrient cycles. For example, migratory Pacific salmon in North America and Canada carry nutrients upriver from the ocean, where they both provide food for predators such as bears, and also fertiliser for riparian ecosystems when their die and their bodies decay.
Pacific salmon migrating upstream. Image: World Fish Migration Day
The main goal of World Fish Migration Day is to improve public understanding of the importance of migratory fish, and to highlight the need for healthy rivers and the communities that depend on them. The events – co-ordinated by the World Fish Migration Foundation – aim to engage citizens around the world to take action on these topics. Through showcasing a global community of people and organisations passionate about conserving and restoring migratory fish populations, the World Fish Migration Day aims to agree lasting commitments from NGOs, governments and industry on safeguarding free-flowing rivers.
Clemens Strehl of the IWW Water Centre in Germany outlines the value of World Fish Migration Day, “I believe it is a great opportunity to raise awareness of this issue. Healthy rivers and fish migration mean increased biodiversity. However, it is a continual challenge to balance the need for rivers to provide services and benefits to humans – energy production and industry, hydropower, drinking water, agriculture, recreation, and so on – whilst at the same time achieving good ecological status. But fishes do not ‘scream’ in this struggle, so the World Fish Migration Day event is a nice opportunity to give them a symbolic voice.”
“There are many great opportunities to restore streams and waterways to encourage fish migration. See the examples from our area – Essen in Germany – where the Emschergenossenschaft took the challenge to restore a stream which had been degraded completely to an open wastewater channel. This former ‘sewer’ is now returning piece by piece to a healthy urban ecosystem. See our European water research DESSIN project and the latest open-access publication from Nadine Gerner and colleagues, which shows the many benefits of river restoration on the Emscher,” Strehl says.
The restored Lippe River in Germany. Image: Benjamin Kupilas | REFORM
“On the River Lippe in Germany, the sighting of one migratory salmon in a previously degraded river triggered enthusiastic reactions in the local area (see here and here for coverage). The Lippe was nominated as ‘River of the year 2018/19’ in Germany, as a result of successful restoration actions. On the Lippe – which crosses a former coal mining and industrial area, much like the Emscher – measures were taken to connect former non-connected stream sections and reactivate floodplain areas. This enabled a local fish species called ‘Quappe’ (Lota lota) to return to the Lippe system. Fishes do not ‘scream’, but they can be ‘happy’ – appropriately the symbol of the World Fish Migration Day is a happy fish!” Strehl says.
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