Our knowledge of the ecology and distribution freshwater/subaerial algae in the British Isles lags far behind that of seaweeds and most other aquatic organisms. One of the few exceptions are a group of macrophytic algae known as the stoneworts or charophytes that are commonly collected along with other aquatic macrophytes. There is sufficient information on this group  for an assessment to be made of their conservation status which resulted in the publication of a Red Data book on the stoneworts of Britain and Ireland (Stewart & Church 1992).   Determining the conservation status of even the better known groups of freshwater algae (e.g. desmids, diatoms) is proving very difficult since reliable site-specific records are scattered rather than in searchable databases. For this reason we would encourage you to upload your records here to enable such a conservation assessment to be undertaken in the future and to follow distributional changes linked to pollution, climate change and other factors.