Do Dead Fish Float?
Contrary to popular belief, most fish never float after death. Taphonomic research confirms that most sink to the bottom and never resurface. However, many people have seen a dead fish floating in a lake “belly up.” This happens because bacteria in the fish’s gut and swim bladder produce a gas that causes the fish to inflate like a balloon. Experiments reveal that when a fish floats, it cannot float for very long. Many times the belly of the fish will rupture, causing the fish to sink to the bottom. Even on tranquil lake bottoms, as fish decay, their remains are scattered. In many cases the decay process is complete, leaving no traces of bones. All types of fish remains are exceedingly rare in modern lake settings, and searches for bones and scales in lake mud have often turned up empty.4,5 We can conclude that rocks containing fish remains (fossils) are usually made under different conditions from what we normally see operating today. So, why are there so many beautiful fossil fish sp
