Venherstel voor amfibieën gedwarsboomd door Amerikaanse hondsvis

Heathland pool restoration for amphibians hampered by Eastern mudminnow The effects of habitat restoration measures were investigated in six heathland pools in the province of Noord-Brabant, the Netherlands. In 2014 and 2017 the heathland pools were sampled for amphibians in a standardized way. Eight amphibian species are present in the heathland pools, but almost all with a limited population size and low breeding success. The restoration measures show little positive effects on amphibians. Increasing the pH value has been positive for amphibians in two heathland pools, but only the common toad (Bufo bufo) benefits. An important cause is the presence of fish. Nine fish species have been found in the six heathland pools, including sunfish (Lepomis gibbosus). Eastern mudminnow (Umbra pygmaea) was found in high densities in all heathland pools. Fish have a major negative impact on amphibians through predation. The common toad is unaffected by these fish, due to toxins in its skin that deter predators. Aquatic plants and dragonflies do show a more positive recovery after the measures. Effective control methods against exotic fish in heathland pools are urgently needed, to make habitat restoration effective for amphibians as well.