What constituents of fishmeal waste may be pose a waste issue and why?

Question

I know that fishmeal is a process of utilizing fish waste to make fish oil, fishmeal and by-products. I am wondering what constituents of the waste from such activites give rise to waste streams? All help is much appreciated as I am really stuck on this one.

Answer 1

The guts of fish are nutritious food, but the contents of the gut are at best fertilizer. They should be disposed of as such. If they are washed into streams they carry with them not only a lot of plant nutrients that will be slightly harmful, but also pathogens that may be a problem for fish in the waters.

Small amounts of plant nutrients are not a problem. small amounts of infection are a moderate risk. We avoid both problems by using this as fertilizer.