27 may 2022

To maximize the chances of survival for the sterile bullfrog larvae, they are transferred to a natural pond after 10 days in the lab. The pond is free of fish and other bullfrogs and surrounded by a grid. In this enclosure they will continue to grow into small sterile frogs. The first larvae of the culture were just released. All they need to do now is graze on the algae present and grow!

22 may 2022

Today is the International Day for Biological Diversity. By eradicating the American bullfrog from our ecosystems, we can give other species more and better opportunities. Curious how we plan on achieving this? Then go out today with a guide in Griesbroek (

18 may 2022

Bullfrog season has started again! The trapping efforts of the social economy companies Natuurwerk vzw and Natuur-en Landschapszorg vzw are gradually reaching cruising speed. Our breeding efforts of sterile frogs in the lab follow suit, some females have already deposited eggs via hormone stimulation, which we now use to produce sterile American bullfrogs.

6 may 2022

May 21 is European Natura2000 Day. This year marks the 30th anniversary of Natura 2000 and the Life program. With the 'Nature's birthday' campaign, various outdoor activities in both Flanders and Wallonia are being organised between 8 and 31 May. All information about the different activities can be found at

Life Bull Frog is also participating. You can go out on Sunday 22 May with a guide in the Griesbroek ( or choose our walk via the digital app Route You

28 april 2022

Thanks to the sunny and warm weather, the vegetation around our breeding ponds had grown considerably and was in need of a serious trimming! As there are currently no young frogs hopping around yet, we were able to mow carefree. In future mowings, we will have to restrict mowing to the inactive period of the frogs and maintain a minimum height of 30 cm, to ensure that we don’t injure young frogs.

24 april 2022

From 19 to 23 April, the International Congress on Invasive Aquatic Exotics (ICAIS) took plawas being held in the Thermae Palace Hotel in Ostend. Naturally, LIFE 3n-Bullfrog was also present with a lecture about our new management insights and the application of the Sterile-Triploid-Method (STM) for the passive control of these unwanted species.

13 april 2022

Thanks to various measurements of the water since the release of our tadpoles, we know that the water quality in our pond is optimal. The water is crystal clear and many aquatic plants and algae are present. These should provide more than enough food for our tadpoles once they wake up from hibernation. And hopefully this won't take long with the rising temperatures.

31 march 2022

After a full week of pumping and cleaning, the ponds are almost ready for this year’s first batch of tadpoles. Now it's just a matter of waiting for the water level to return to normal. Our removal of the water unfortunately created temporary breeding grounds for brown frogs and common toads. Now that the pump is gone and the water levels of those breeding grounds are dropping, we have moved the egg to more permanent bodies of water nearby to ensure their survival.

25 march 2022

This week our contractor started preparing the fenced ponds the will house our sterile frogs. The water will be pumped out, so that we can remove all waste, stones, tree trunks, etc. from the ponds. The brown frogs looked on approvingly from a distance.

24 march 2022

This week we organized a training day for everyone who is responsible for trapping American bullfrogs in Flanders. The program included an approach to active control of the American bullfrog, an overview of currently used materials, planning and a demonstration of the installation of traps for different life stages of the bullfrog. We are ready for a trapping season.

Thank you to all who attended!

March 11, 2022

On February 22, Life 3n-Bullfrog organized a contact day concerning the eradication efforts for bullfrogs. The information day took place in the provincial house of Antwerp. During this contact day, we informed various parties involved such as municipalities, social economy companies, government agencies, Natuurpunt volunteers, etc. about the project, our management strategy including the sterile triploid method and the ongoing trapping efforts. Would you like to know what was said? Are you interested in the project or do you want to review something? The various presentations were recorded and are available on our youtube channel.

February 18, 2022

The American bullfrog is now also advancing in Limburg. They were discovered thanks to the innovative eDNA-techniques used in the LIFE 3n-bullfrog project.

October 13, 2021

Trapping efforts for 2021 are still ongoing. The final trapping efforts are currently taking place in Heist-Op-Den-Berg, among other places, where the Natuurwerk team has caught a few large specimens in the fykes. Rtv came by for a short report:

July 5, 2021

American bullfrogs, where do they come from and how can you recognize them? What is on their diet and why is the species so harmful to our nature? How are we going to eradicate this threat to our nature? You will find out this and much more in the small exhibition that we have set up and which is now ready for viewing in the Grote Netewoud visitor center. The exhibition can be visited all summer, so be sure to take a look if you have a summer walk planned in the area.

Speaking of summer walks, on August 22 our local division of Natuurpunt is organising a guided walk in the area, with the American bullfrog as its main topic. You can combine a visit to our exhibition with a refreshing walk in the nearby Griesbroek, where you will almost certainly encounter some bullfrogs.

July 4, 2021

The first pond has now been cleared of all fish, drained and cleaned. All we have to do now is wait until everything has settled and we can release the first tadpoles in our enclosures.

May 21, 2021

All pond are now properly fenced. Next step is to prepare the actual ponds for releasing sterile tadpoles. We will need to catch and relocate all fish that are present in the ponds, drain them and clean them out.

Today also happens to be the Birthday of Nature, which we celebrate with a walk in the Griesbroek nature area. 

May 3, 2021

Construction works are going as planned, small dykes have been erected around the ponds to help protect against floods and the first pond is now fulle fenced.


March 25, 2021

The last few sunny days have caused an explosion of amphibian activity in our ponds. Sadly there are also American bullfrogs present and reproducing in these ponds. Before we can use the ponds for raising sterile frogs, the fish and amphibian populations need to be removed and relocated.

Left: common frog and common toad spawn - Right; an adult common toad and a bullfrog tadpole

March 22, 2021

Construction works have commenced for our first site with four ponds in Olmen, where we will be rearing sterile tadpoles and juvenile frogs. The trees surrounding the ponds have been cleared. Luckily most of these were exotic species with fairly low ecological value.

Now that the trees have been cleared, the terrain will be leveled and fencing will be installed around the ponds. This fence (with 1 cm mesh size) prevents escaping frogs and at the same time also prevents animals from entering the ponds from outside. This way the sterile animals can grow up peacefully and safely.



December 11, 2020

The Life 3n-bullfrog project has started around a year ago. But how do we plan to eradicate bullfrogs from Flanders and why is this important? Find out in this info video

August 28, 2020

Yesterday the LIFE 3n-bullfrog project was covered by the news. Fykes, frogs and tadpoles were examined with great interest while our project employees gave explanations. Did you miss it? You can view and read the various reports again with the links below:

August 27, 2020

Today we presented our project to the press. You can read the press release here.

August 14, 2020

We now have a informational folder, which you can download here.

June 16, 2020

Follow us on our newly setup social media pages on youtube, facebook and twitter.

May 6, 2020

To be able to catch even the smallest bullfrog tadpoles, we now use fykes with a mesh size of only 5 mm! The leader is also a bit longer to improve catch efficiency.

fuik voor stierkikkerlarven

May 4, 2020

The first bullfrogs of the 2020 season have arrived in the PXL Bio-Research lab. The breeding season can now fully start! Excellent work by Natuurwerk vzw!

April 25, 2020

Our LIFE project can now also be found on Twitter:

April 10, 2020

Have you spotted or heard a bullfrog? Let us know!

It is of the utmost importance to act quickly on new sightings of American bullfrogs. And for that we need your help! Have you seen or heard a bullfrog? Enter your sighting on

December 2019

The LIFE 3n-bullfrog project officially started in October. Fieldwork preparations have started, and so has the development of a project logo.