A film, also called a movie, motion picture, theatrical film, or photoplay, is a series of still images that, when shown on a screen, create the illusion of moving images. (See the glossary of motion picture terms.)
The mass is a matrix from which all traditional behavior toward works of art issues today in a new form. Quantity has been transmuted into quality. The greatly increased mass of participants has produced a change in the mode of participation.
Walter Benjamin, “The work of art in the age of mechanical reproduction,” Illuminations (1968), p. 239.
Like all ecosystems on Earth supporting animal and plant life, aquatic ecosystems need oxygen. However, oxygen availability in these systems is threatened by global warming and excessive input of nutrients such as from agriculture and wastewaters, known as eutrophication.