Excavators were once again at work last December at the Haverlahwiese open pit at Salzgitter for European green and Natterjack toad
Creation of a poolfield Newly created pools
At various water bodies in the south-eastern valley floor which are, for the most part, permanently aquiferous, seven new pools were created ranging from nine to 25m² in size and with a maximum depth of 60cm. Furthermore, restoration of two water bodies involved stripping off flat parts of the shore sections while, in order to create a summer habitat, fast-warming open ground was achieved by removing willow bush and stripping the surface of ruderal vegetation.
Preceding the exact determination of the area, sample excavations were carried out with a spade and the conductivity of the water that gathered in the test holes was measured. The high level of salinity in the water bodies is caused by heavy salt leaching from the mining dump located to the north and, although it allows for some amphibian species to deposit their spawn, the eggs and hatchlings are at risk of deformation. All newly created pools exhibit levels of salinity that will enable successful reproduction, not only for the salt tolerant European green and Natterjack toad, but also for more sensitive species like the Crested newt. While the Natterjack toad still shows (or exhibits) a small recent population, the European green toad was last spotted (or observed) in the area in 2004. It was the westernmost occurrence of that species in Lower Saxony at that time, while also constituting the only occurrence in the continental region in this federal state. Since the European green toad is known to stray for several kilometres, for example along abandoned railway systems, a re-population might definitely be possible.
Restored, very shallow water body