The crossword solution for the term 'BIT OF SCUM' is ALGA, which is an acronym for aquatic plant life. Algae are a type of organism that can be found in both freshwater and saltwater environments. They are typically small and can range in color from green to brown. Algae are important for providing oxygen to aquatic ecosystems and are also used as a food source for many species of fish and other aquatic animals.