In France as in other countries, the management of biodiversity has brought about technical schemes and public policy tools that increasingly draw their inspiration from neoliberalism. Moreover, this management has resulted in an order to professionalise given to the naturalist NGOs playing a significant role in biodiversity conservation. Our proposal focuses on the NGOs involved in the production of field data and the way they deal with this demand that has come from the French government. We will first present the elements that compose the notion of professionalisation in the context of data collection (rationalisation, standardisation and commoditisation). This neo-liberal definition has been applied in the name of State modernisation. ...