Dr Harries' research interests lie within in the field of marine benthic community ecology and conservation. His main specific interests include the ecology and conservation of shallow marine biogenic reefs, the ecological impacts of invasive marine species and the ecology of sea caves. He is also interested in the community ecology of meiofauna (multicellular animals less than 1mm in size), subterranean biology and the ecology of fauna inhabiting aquatic and terrestrial cave environments. Within these subject areas he is interested in aspects such as the interaction of the biological and environmental factors that structure biological communities and the evaluation of the influence of anthropogenic factors (e.g. fishing disturbance or pollution).

Dr Dan Harries began his research career at Heriot-Watt University while conducting postgraduate research on meiofaunal ecology for his PhD. He remained at Heriot-Watt for several years working as a research associate and was engaged on a range of different research projects. These encompassed work on meiofauna, on biogenic reefs and on long term changes in the benthos of the North Sea. Other projects included biological mapping surveys of marine protected areas. During this period he also worked for other organizations, conducting scientific diving surveys on behalf of Imperial College London, Stirling University and Edinburgh Napier University. Before taking up his current post he worked for Scottish Natural Heritage and was responsible for the coordination, management and execution of a series of monitoring surveys of marine protected sites around Scotland.