Processing large volume of fish waste

Hi everyone,

I don't know if this is the right place to post this question.

We managed to get access to a large volume of fish waste from a local freshwater fish plant.  Does anyone have experience processing large volumes?  It is all going to waste at the moment.  The owner said that we can have as much as we want.

I see a lot of potential here.  Recycling these waste and converting them to fertilizers or sprays.  I shall appreciate any feedback you may have.  What equipment is needed?  I don't know the best way to dry this stuff.  We don't want bears around.

1) You could also feed the fish waste directly to poultry or fish
2) Add some water kefir microbes to the fish waste then feed it you poultry/fishes
3) You could feed it to black soldier flies, and then feed those to poultry or other fishes.
4) Add the fish waste to some woodchip/hay/etc and then run poultry thru it to farm bugs and make compost quickly.
5) The fish waste plus some woodchip/hay could be used to warmup a greenhouse as it is composted  

Do you have (or have access to) biochar? My experience with fish hydrolysate and emulsion is that they are some of the stinkiest substances around. Anything that smells that nasty is usually good for growing food and also massively beneficial for soil life. We've found that soaking biochar with fish "soup" completely deodorizes it in a day or two, which is a real bonus for the humans involved in the process of getting it where it needs to go.

At the most recent biochar workshop I helped run, our hosts had a bucket of kīna juice (basically shells and scraps from sea urchins) that had been sitting in the sun for about six weeks. This, to date, is the only thing I've been close to that blows away fish hydrolysate as far as stench goes. Needless to say, this became our inoculation candidate. They told me a few days later that the smell was nearly gone.

I had a weather event that killed all of the big tilapia in my pond. I put a bunch at the base of my fruit trees, and I put others in buckets with small holes in the bottom. I placed these near growing areas, and would fill them with water for a slow release watering/fertilizing. You can make you own emulsion or hydrolysate as well, but that’s extra steps and processes. How about composting them in wood chips? I’ve done this with poultry guts and feathers when I worked on a poultry farm.. it smelled awful, but created beautiful soil.

S Bengi wrote:

1) You could also feed the fish waste directly to poultry or fish
2) Add some water kefir microbes to the fish waste then feed it you poultry/fishes
3) You could feed it to black soldier flies, and then feed those to poultry or other fishes.
4) Add the fish waste to some woodchip/hay/etc and then run poultry thru it to farm bugs and make compost quickly.
5) The fish waste plus some woodchip/hay could be used to warmup a greenhouse as it is composted  

Those are awesome suggestions. Thank you.  I never thought of using the fish wastes to harvest the bugs for other uses.

I'm new to all this.  Yesterday, I read processing of fish wastes is a smelly issue.  and it will attract a lot of insects, so using the bugs makes perfect sense.

Do you have suggestions or sources on how to keep the strong odour and bug swarm under control? How to capture the bug and frass?

Edited after:  I just read Phil's suggestion above using biochar for odour control which I'll definitely try.

Phil Stevens wrote:Do you have (or have access to) biochar? My experience with fish hydrolysate and emulsion is that they are some of the stinkiest substances around. Anything that smells that nasty is usually good for growing food and also massively beneficial for soil life. We've found that soaking biochar with fish "soup" completely deodorizes it in a day or two, which is a real bonus for the humans involved in the process of getting it where it needs to go.

At the most recent biochar workshop I helped run, our hosts had a bucket of kīna juice (basically shells and scraps from sea urchins) that had been sitting in the sun for about six weeks. This, to date, is the only thing I've been close to that blows away fish hydrolysate as far as stench goes. Needless to say, this became our inoculation candidate. They told me a few days later that the smell was nearly gone.

Thank you Phil.  I will definitely give biochar a go for odour control.  Was initially thinking sawdust might work.

Ted Abbey wrote:I had a weather event that killed all of the big tilapia in my pond. I put a bunch at the base of my fruit trees, and I put others in buckets with small holes in the bottom. I placed these near growing areas, and would fill them with water for a slow release watering/fertilizing. You can make you own emulsion or hydrolysate as well, but that’s extra steps and processes. How about composting them in wood chips? I’ve done this with poultry guts and feathers when I worked on a poultry farm.. it smelled awful, but created beautiful soil.

Thank you Ted.  Creating some holes in buckets with nitrogen rich scraps in them for watering is a cool idea.  

+1 for biochar.  We put 6 inches of raw charcoal in the bottom of a plastic 55 gallon drum with a few drain holes in the bottom, then around 30-40 gallons of fish waste, then top with around a foot of raw charcoal.  The fish composts with minimal odor 50 ft or so from our deck.

Gray Henon wrote:+1 for biochar.  We put 6 inches of raw charcoal in the bottom of a plastic 55 gallon drum with a few drain holes in the bottom, then around 30-40 gallons of fish waste, then top with around a foot of raw charcoal.  The fish composts with minimal odor 50 ft or so from our deck.

Hi Gray.  I say really?  That's amazing. 30-40 gallons of fish.  That's quite a bit. Please, I'd appreciate if you could tell me more.

Do you put the fish waste into the drum in large chunks?

How long (what's your average temperature?) does it take for the 30-40 gallons of fish waste to break down? Or when is is ready to use? When the odour completely disappears?

Do you collect and use the liquid draining out of the holes of the drum?

Do insects and critters get into the drum?

How would you store the finished compost if you had to keep on processing new fish waste on an ongoing basis?

We had a friend who was in a supervisor position on Dutch Harbor. My wife wanted and adventure and took an office position for a year. She didn't work in the processing facility, but she explained how absolutely nothing went to the waste stream, from the processing. I'm sure even if you were to macerate the waste and bottle it like Alaskan Fish Fertilizer, I buy in a gallon jug you're going to have to jump through some hoops. Just how expensive those hoops would be is the question.

Years ago, an old timer told me if I want to have a great garden just plant some fish.

I never got around to taking his advice.

Robert Ray wrote:We had a friend who was in a supervisor position on Dutch Harbor. My wife wanted and adventure and took an office position for a year. She didn't work in the processing facility, but she explained how absolutely nothing went to the waste stream, from the processing. I'm sure even if you were to macerate the waste and bottle it like Alaskan Fish Fertilizer, I buy in a gallon jug you're going to have to jump through some hoops. Just how expensive those hoops would be is the question.

Yes, you are absolutely right about working through the red tape.