Now that the black-tailed godwits are enjoying the warmer climes of Portugal, Spain and West Africa for the winter, our focus turns to ensuring their habitat is in tip-top condition for when they return in the spring. Black-tailed godwits need invertebrate rich, well managed wet-grassland habitat.
Creating more habitat for godwits
At the Nene Washes we have been working to restore a 260 hectare block of former arable land, (known locally as March Farmers) into ideal wet-grassland habitat for godwits and other birds. March Farmers is enclosed by earth banks that were originally designed to allow farming to continue when the washes were in flood. However, these banks frequently over top and leak, and the water becomes trapped in the low-lying farm. We have now installed spillways and discharge pipes that allow flood water in and out of March Farmers in a controlled manner, but that still leaves one million cubic metres of water which needs pumping out if we are going to provide the grassland that the godwits need for nesting. The farm’s electric pump broke in 2014 and since then we have been hiring in expensive and inefficient diesel pumps to evacuate the water. We are in the process of installing a new Dutch built fish-friendly pump, capable of pumping 1440 cubic metres per hour.
Good for godwits – and safe for eels
The new pump weighs a whopping 1.5 tonnes and was manufactured in Winterswijk, in The Netherlands. Water control structures can cause big problems for eels – they can get caught up in them as they try to navigate through freshwater systems. The European eel has a fascinating life-cycle. Mature eels congregate to breed in the Sargasso Sea (in the western Atlantic Ocean). Once the larvae reach coastal waters, they transform into small transparent eels known as ‘glass eels’ and move into estuaries to begin their inland journey. When they enter freshwater they become miniature versions of the adults, known as ‘elvers’. They grow into yellow eels and reach sexual maturity after six to 20 years when they become silver eels. They then migrate back downstream to the sea and make the 4,000 mile journey back to the Sargasso Sea to breed. The Nene Washes are known to be an important habitat for eels but they can become trapped in March Farmers and the new eel-friendly pump is a means by which they can leave the farm and get back into the River Nene.
The European Eel is Critically Endangered, with the UK supporting a significant proportion of the global population. So what makes the new pump eel- friendly? The impeller and guide vanes have a special design that creates an optimal water flow, allowing the fish to pass through the pump safely. The edges are rounded and the space between the impeller blades is much wider, which reduces impact risk. This pump allows more than 97% of fish and even 100% of eel to pass through unscathed. It even has a telemetry system that will send a text-message to the site manager notifying them of any faults.
We have also been working with UK Power Networks to underground 650 metres of powerlines that cross March Farmers and create a significant hazard for swans, cranes and ducks. Due to the undergrounding of the cables we will need new, much taller poles to span the River Nene. These will be arriving from Wales and are so long they require their own police escort!
We are looking forward to the new pump being up and running and helping us create even more habitat for godwits in the spring.
We’re very grateful to our partners Aquatic Control Engineering, Stirling Maynard, Natural England, the Environment Agency, UK Power Networks and the Childers Estate. This work has been supported by a £250,000 grant through the Landfill Communities Fund of Waste Recycling Group (WRG) administered by the Environmental Body WREN.