Ecological monitoring: my work since 1992. From then onwards I have studied aquatic invertebrates and aquatic vegetation, as they are used as indicators for the ecological quality of Dutch waters systems. The projects involved in these studies mainly relate to the European Water Framework Directive (WFD). Other projects have management of nature reserves as focus. Looking for valuable aquatic ecosystems (‘Water Pearls’) is another of my favourite fields of study. All these projects together involved lots of fieldwork, sampling, identifying aquatic invertebrates, data analysis and reporting. All this enabled me to gain knowledge of the ecology of Dutch water systems and their inhabitants. Encountering all these creatures in those samples it soon struck me so much is still to be discovered. Also many insect groups are still to be keyed properly. With many colleagues, I published papers on faunistics of insects and other invertebrates and engaged in writing identification keys. Adult Trichoptera are my favorite group and our book is near there! Chironomidae, water bugs and little known, tiny sea creatures are others that have my interest.Specialties • Identification of macro-invertebrates of fresh- to brackish waters as well as species of North Sea soft sediments (Polychaeta, Bivalvia and Crustacea).• Special interest for fresh water mites, Chironomidae, Trichoptera and Heteroptera.• Special interest in the ecology of moorland pools and lowland streams.• Reports: I translate information hidden below the water surface into a report which is readable and useful for management of aquatic ecosystems.• Monitoring programmes for water board authorities (WFD). Field work: sampling; consulting local people (interviews); vegetation; looking for valuable aquatic systems (‘Water Pearls’).• Microscopic photography.• Training courses and workshops for identification of macro-invertebrates, lectures and preparation of educational material.