Ashes and Pennance
In most places where hydro electric dams are built, and the land flooded. Where soil and vegetation are not removed from the flooded area, the result down stream is a hazardous marked in crease of methylmercury. Essentially poisoning the fish below and everything that eats those fish. This renders them, essentially, no longer viable as a food source and like ashes in an turn the fish and life they sustained are only a memory. The ashes are at once a memory and a penance of the travesty.