First assignment of group n° 008


Resources used by the team

Gwenaëlle NICOLAS

Book : Sauvages de ma rue : Guide des plantes sauvages des villes de France - Nathalie Machon, Broché edition (2012)



Book : Guide des plantes invasives - Guillaume Fried, Belin (2012)



Book : La gouvernance des biens communs : Pour une nouvelle approche des ressources naturelles - Ostrom, E., De Boeck edition (2011)


Kristen DURAND

Book : Plantes invasives en France - Serge Muller, Broché edition (2006)



Book : Les plantes envahissantes des corridors fluviaux : traits biologiques, impacts de Ludwigia peploides et L. grandiflora en Loire moyenne et implications pour la gestion, Brigitte Ruaux's Thesis, François Rabelais University of Tours, 2008.



Book : Sustainable Economic Development : Resources, Environment, and Institutions - Balisacan Arsenio ; Chakravorty Ujjayant ; Ravago, Majah-Leah, Elsevier Science edition, (2014)



Book : Recréer la nature : écologie paysage et société au marais d’orx - Baron-Yellès Nacima, Coup d'essai Collection Rue d'ULM edition, (2000)


Fight against the new water predator : the creeping water primerose

How to limit the expansion of the invasive Water Primrose plant in order to protect the biodiversity of freshwater surfaces ?

1. What Problem do you want to solve ?

The environmental problems and the destruction of the biodiversity really provides us with food for thought these days. That’s why it is an absolute necessity for all of us to have a positive impact on the environment.

In France, but also in many other European countries, the creeping Water Primrose is often considered to be one of the most damaging and out of control aquatic plant. Indeed, this perennial plant floats on the water’s surface - it usually grows over shallow water - and has one particular characteristic : it is literally impossible to get rid of it! Of course, the plant can be cut down and the roots can also be dug up, but it is impossible to completely control it because it regrows from seeds and roots always remain.

Furthermore, it has really negative effects and consequences on the biodiversity : these dense floating mats of vegetation alter the aquatic environment by reducing the transfer of oxygen between the water and the air. It deeply degrades the quality of the water and by the same way, all of the wildlife : the creeping Water Primrose makes it impossible for the invertebrates and fishes to move and live easily between all of the dense mats of vegetation, and all of the other aquatic plants don’t have any more space to grow in such an environment.

This way, we would like to find a way to limit and control the expansion of this plant in order to protect the aquatic habitat and its wildlife.

2. Why does this problem exist?

The Water Primrose is principally native of tropical regions of South America. Certain species, which were introduced in decorative purposes in Europe and in North America, acclimatized to it and behave as intrusive plant there. Nowadays, Ludwigia (the Water Primrose) has a big area of distribution, recovering the temperate and hot zones of Europe and North America. It was introduced for the first time in the south of France (in the Lez river near Montpellier) in the nineteenth century for decorative purposes because of the trend (exotic attraction). It colonizes gradually all the lakes and ponds and the banks of several vast geographical areas. Then, a lot of people use it as decorative purposes and sell it, that is why the Ludwigia had fast widespread in France in Europe and in the other places it had been introduced.

Moreover, the Ludwigia has a fast proliferation. Indeed, it develops in shallow water (ponds, streams, swamps). A simple cutting makes possible the fast development of a new seedling, even in an environment which is little comfortable. But the fast development and proliferation of this plant creates a real burden on the aquatic life, fishing and on the biodiversity in general. What is more, the extraction of the Ludwigia must be done in a proper way and people must carry not simply to cut it but to totally remove it from the water. Its extraction and lifting have to be made with precaution and in a appropriate way. On one hand, cutting the stalk is not enough because the roots of this plant are very deep and on the other hand, the cut part creates a cutting and engenders the creation of a new plant.

Furthermore, the heat is unfortunately profitable to its development and the global warming of some regions of the north will have some bad consequences. The Water Primrose is going to spread even more and to be much more invasive than it is today, biodiversity may be in jeopardy. Today this problem in Europe affects overall France but the “invasion” has started in Germany, in the UK and even in Switzerand. Finding an efficient and low-cost solution has become a necessity.

3. What breakthrough are you committed to creating?

As we are working about the Water Primrose issue, we are committed to create a breakthrough that answer to four criteria:

  • 1st  - A worldwide idea that can be use by most of people such as individual people, firms, fishermen, towns, etc.
  • 2nd - A priceless means than the existing solution : less tools’ cost and less workforces.
  • 3rd  - An efficient means that can be use in every kind of situation and environment and that can solve the problem quickly.
  • 4th - A means that respects the ecosystem.

       The Water Primrose is a good-looking flower that has fast reproduction characteristics. Thus, quantity of Water Primrose exists in France and will also soon be in Germany and in England. This flower is a problem for biodiversity, but we may find a way to eradicate it faster and easier than now.

Some solutions already exist such as machines and tools or manual weed. But those solutions generate a lot of costs and they are not simple to use in every kind of environment. We could also think about biological solutions - and not only mechanical ones - which would directly tackle the current issue.

Today Water Primrose is a sustainable plant. It can proliferate itself in an uncomfortable environment. It doesn’t need to be taking care of. That’s why we should think about breakthrough that can be efficient with few efforts. The experts will be able to explain to us the characteristics of the plant in detail and how does it grow. Thus, they will help us study the range of the solutions we could work on.

Potential experts already identified

  • Mrs AYCAGUER Julie is a Project Manager at Natura 2000, an Association for the Development of the Bassin Versant de la Baie de Bourgneuf in Vendée. She is in charge of the Water Primrose issue, mainly in the Bourgneuf bay (Pays de la Loire).


  • Mrs RUAUX Brigitte is a Project Mananer at the Conservatoire d’espaces naturel de la région Centre. She wrote a thesis in 2008 at the University François-Rabelais de Tours entitled “Les plantes envahissantes des corridors fluviaux : traits biologiques, impacts de Ludwigia peploides et L. grandiflora en Loire moyenne et implications pour la gestion”.


  • Mr HUBERT Jean-François is a biologist researcher in the Institut de Génétique et Développement de Rennes and a teacher at the University of Rennes 1. His research are focus on biological molecular interaction. He can help us to evaluate a biological solution to the Water Primerose issue.

Phone number: 02 23 23 61 15 Mail: jean-franç

  • Mr GALLAIS André is an agricultural engineer, professor emeritus in AgroParisTech and scientific consultant in the Association Française des Biotechnologies Végétales. He is specialized in strategies for crop improvement.

Phone: +33(0)1 69 33 23 31

  • CDO Innov is a company specialized in innovative machines for sensitive environments. Its machines help to face invasive plants like the Water Primrose. This company can help us to evaluate a mechanic solution.

Phone: +33(0)2 51 70 87 48

  • Vegenov is a not-for-profit organization based in Britanny, which is a region affected by the Water Primerose issue, and specialized in biotechnology expertise and consulting. For instance, it assists projects which deal with crop protection. Mr BAZINET Christophe is the Vegenov's Consultant in Innovation.

Mail : Phone: +33(0)2 98 29 06 44

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