Conservation challenges for a microscopic world: Documenting desmids

Abstract

Freshwaters are amongst the most threatened habitats in the world. Many waters in the UK have irreversibly changed or disappeared and those that remain are under immense pressure largely due to habitat loss, pollution, recreation, abstraction and the introduction of nonnative species. Climate change is also becoming a major concern for freshwater life. The conservation of biodiversity associated with freshwaters has for obvious reasons focused on the larger animal and plant species, however, microorganisms such as the algae play a fundamental role in these ecosystems and constitute rich assemblages which are also threatened. Desmids are a diverse group of freshwater microalgae which dominate the algal flora of nutrient poor, lentic waters and are particularly diverse in such oligotrophic habitats as moorland pools and shallow lakes. They are ecologically highly sensitive, acting as useful indicators of water quality. The conservation of microscopic organisms poses many difficulties due to taxonomic impediments and lack of knowledge of ecology and distribution. To gain a better understanding of desmid distribution patterns across the UK and Ireland this project has undertaken the digitisation of 50 years worth of biological recording data collated by desmid expert David Williamson. Reliable datasets of species occurrence are essential to biodiversity research and conservation so these data, in conjunction with published literature, will provide a basis for developing a more robust checklist of verified desmid taxa known to occur in the UK and Ireland and provide distribution information for these taxa. Furthermore, this will enable us to review the conservation status of the desmid flora and provide data of practical use in the designation and management of protected freshwater habitats.