The American bullfrog is an invasive frog species in Europe. A large and voracious predator with no natural enemies in its invasive range, the bullfrog has had a significant impact on other aquatic species. The American bullfrog was imported in the 90s from America into Flanders, mainly for ornamental purposes in ponds. Many of these individuals escaped or were released and established viable population in Flanders. Some tadpoles were also accidentally introduced as part of fish stockings in fishing ponds. The main population in Flanders is situated in the valley of the Grote Nete, where the presence of the bullfrog exerts considerable pressure on our native frog and newt species. This large population increases its range every year, both up- and downstream. Hence the traditional methods for combatting this species of placing fykes and draining ponds are no longer sufficient.
The life 3n-bullfrog project seeks to find a sustainable way for controlling and eventually halting the spread of the American bullfrog in the Flemish populations, particularly in the large population in the Grote Nete valley. The project aims to combine the traditional controlling methods with a new method of releasing sterile triploid (3n) animals. In a 3n frog there are three chromosomal copies in each cell instead of the normal two. After some years of research, scientists of the PXL University have succeeded in breeding sterile triploid frogs.
The project was officially launched in October 2019 and will run until March 2025. You can follow its progress on this website or on facebook or twitter. Life 3n bullfrog is a collaboration between the PXL University, the Research Institute Nature and Forest, the Agency for Nature and Forests of the Flemish Government and Natuurpunt. The project has received funding from the LIFE programme of the European Union (LIFE18 NAT/BE/001016) and from Antwerp province.
The progress can be followed on the (Dutch) website.