As a kid I remember hearing that the pilgrims at the Plymouth colony used fish as fertilizer.
Growing up on the banks of the Tittabawassee River near Midland, Michigan, any carp that we caught were buried in our garden as fertilizer. Particularly planted at the base of the raspberry bushes, dead carp worked really well ... about the only good use that a carp has.
They would put the fish heads at the base of the corn plants they planted.