A beautiful view from the coastal cliffs in Exmoor – but not if you look more closely. The right side of the photograph is dominated by a dense yellow-green canopy extending up and down the cliffs for kilometers in each direction. It looks like a scar, or a cancer. What is it? If you walk…

Can you guess what this is a photograph of? It’s an algal bloom on the surface of a lake, seen from above. The algae are growing so well because of eutrophication due to shallow depths, low flow, and high nutrient inputs. The pattern is beautiful, but the lake itself is a mess. When I say…