Jim Carter writes:
Aside from the smell, I think that it is unethical to use a perfectly good
source of edible protein (fish) in a protein short world to feed plants. The
plants can do just as well using nitrogen fixed by legumes.

Fish emulsion is not edible.

Fish emulsion is made from a type of fish called "menhaden". Interesting
stuff. You can read all about it at http://www.menhaden.org/ . Here is a
snippet from that site:
...
The menhaden is a remarkable citizen of the sea. Inedible to humans because of
its bones, it provides forage for a number of other fish species.

A fish emulsion product manufactured in Australia is Charlie Carp. It is
made from the European Carp--a worsening introduced pest that has been
thriving in our inland streams and fresh water lakes. Carp is so full of
bones as to be inedible. I think some people make fish soup from it, but
not too many. Until the garden fertiliser was marketted, the fish were
just gathered up and buried--a valuable resource wasted.
--
John Savage (news address invalid; keep news replies in newsgroup)