Alma 3 records burial for the Nephites, but dumping Lamanite bodies into the Sidon. I argue that the respect of the first mode and disrespect of the second was a distinction Mormon would have understood so clearly that it did not merit explanation.
Because the battle site was upriver from Zarahemla, this method of corpse disposal presents the unsavory picture of a very large number of dead bodies floating past the city. A modern reader would wonder about possible contamination of the city’s major water source; however, modern instances abound of people continuing to use water for drinking and washing from the same source in which they dispose of refuse and even bodies. The Nephites, of course, were not aware of the health risks and may even have rejoiced, seeing the floating corpses as a symbol of this significant victory.