The Bullocks use bags of dried fish bits for fertilizer. They get it somewhere on the coast, at least that was practice while I was there. Dave would have details...
It seemed very benign, like the fish-bits are just waste from a major processing place. Some vegans may not want to participate in that, but it IS waste that wouldn't otherwise be used. ?
I haven't been involved much with the use, but I know that we use Alaska Fish Fertilizer in our compost tea mix. Currently, we're using a liquid product, but we've usually used a powder. I think we had trouble finding it this spring, but I'm not sure.
Dave
Principal - Terra Phoenix Design
http://TerraPhoenixDesign.com