You focus attention on biological diversity, nature conservation and the effects of climate warming in your special issue on biodiversity (19 November 2009). 'Cryptic' biodiversity is also crucial, because it helps natural ecosystems to continue functioning and habitats to bounce back in response to environmental change.

Cryptic biodiversity includes aquatic organisms invisible to the naked eye, dormant species, and other species present in such low numbers that they go undetected. These are not included in conservation surveys.

Work on cryptic biodiversity has started in the United Kingdom with financial support from the Esmée Fairbairn Foundation. The project is a partnership among academics and local and national conservation organizations (Dorset Wildlife Trust and Pond Conservation) to link research with conservation. Our aim is to incorporate small aquatic organisms into biodiversity surveys and develop guidelines for the management of cryptic diversity.

Local biodiversity conservation will eventually cover the full range of aquatic organisms — not just the more obviously appealing ones — that contribute to the functioning of a healthy ecosystem and to water quality.