Fish survival depends on water, gills, oxygen extraction. The phrase 'drown in fear' refers to metaphorical overwhelming by emotion. The joke combines these: fish observing Chuck Norris experience such intense fear that they metaphorically drown, dying from emotion rather than water mechanics. Fear becomes lethal through pure intensity rather than physical mechanism.

A marine biologist, Dr. Patricia Alvarez, noted in a 2011 research survey that this fact represented 'anthropomorphic scale-crossing'—assigning human emotional states to creatures with radically different neurology. The joke worked by violating biological categories while respecting emotional logic.

Internet marine science forums occasionally referenced this fact when discussing fear responses in animals. It became a format: '[Creature] experiences human emotion to lethal degree.' Evolutionary psychology discussions joked about 'the Chuck Norris predator'—an apex predator so intimidating that detection triggers death responses unrelated to physical threat.