The Ecological Monitoring Network (NEM) consists of 17 monitoring programmes and 43 monitoring networks. These monitoring networks systematically collect the ecological data needed to calculate trends in the distribution and abundance of flora and fauna. There are monitoring networks for mammals, birds, reptiles, amphibians, fish, butterflies, dragonflies, ‘other insects’, molluscs, marine macrofauna, vascular plants, mosses, lichens, mushrooms and invasive exotics. Data collection is conducted according to monitoring objectives agreed by the participating bodies (Ministry of Agriculture, Fisheries, Food Security and Nature, Rijkswaterstaat, the provincial governments and their BIJ12 agency). There are currently 33 objectives: international reporting obligations (20), information for policymaking and evaluation (9), and national reporting and accountability (4). Each monitoring network serves several objectives.

WOT-NEM is responsible for the general coordination of the monitoring networks. The networks are operated by national species conservation organisations, the Sovon Dutch Centre for Field Ornithology and the provincial governments. The species conservation organisations and Sovon coordinate the volunteers who do the fieldwork. There are about 17,000 volunteers in total.

WOT-NEM supplies the collated data to Statistics Netherlands (CBS). Statistics Netherlands uses the data to calculate trends and supplies these to PBL, for the Nature Outlook and a state-of-the-environment report (Balans van de Leefomgeving) and to the Nature Information Infrastructure expertise area, where the information is used in reports prepared under national and international conventions and EU directives.

WOT-NEM also supplies data to the National Database of Flora and Fauna (as long as the data producer/volunteers have no objections), where they are made widely available.

The performance of WOT-NEM is reported in the publicly available annual report on the monitoring programmes produced by Statistics Netherlands.