Fish Fertilizer is Damaging the Environment

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Robert Pavlis

I always thought that fish fertilizer was an acceptable product. As a nitrogen source it is very over priced as explained in Fish Fertilizer – Is It Worth Buying? but at least the fertilizer is being made from a resource that is a waste product, namely fish guts (offal) , bones and heads. It seemed like a good use for this waste product.

But a comment left on my other post, by Cynthia E. Olen, June 12, 2016 made me rethink things. Thank you Cynthia.

Did you know that companies are harvesting whole fish to make the fertilizer? I didn’t believe it myself, but is is true.

Catching fish to make fish fertilizer
Catching fish to make fish fertilizer

Raw Materials for Fish Fertilizer

Fish fertilizer is made from two different types of ingredients; either fish waste (guts , bones and heads) or whole fish caught specifically for the purpose.

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A fish called menhaden is not used for human consumption. It is harvested, ground up, processed and some of it eventually is used to make fish fertilizer.

In a documented letter from Alaska Fish Fertilizer (ref 1), a leader in supplying fish fertilizer, they confirm that almost all of their fertilizer is made from whole menhaden fish. Ironically, this company called Alaska Fish Fertilizer gets it fish raw material from the Atlantic and Caribbean Oceans.

Here is a video showing the process of grinding up the fish. You can clearly see whole fish are used.

YouTube video

If the above link does not work, click here:

It is important to point out that not all fish fertilizer is made from whole fish.

Fish Fertilizer is Damaging the Environment

So why is this a concern? After all they are ‘useless’ fish – right? Wrong!

According to Wikipedia (ref 2), “menhaden are an invaluable prey species for many predatory fish, such as striped bass, bluefish, mackerel, flounder, tuna, Drum (fish), and sharks. They are also a very important food source for many birds, including egrets, ospreys, seagulls, northern gannets, pelicans, and herons.” By harvesting the menhaden and turning it into fertilizer companies are removing an important food source for other species. They are damaging the environment!

Wikipedia goes on to say “In 2012 the Atlantic States Marine Fisheries Commission declared that the Atlantic menhaden was depleted due to over fishing.” The current website for ASMFC says “Atlantic menhaden are neither over fished nor experiencing over fishing. ”

Fish Fertilizer is Not a Renewable Resource

The letter from Alaska Fish Fertilizer (ref 1) goes on to say that they use just 20 rail cars per year of the ‘fish solubles’ (one rail car is approximately 20,000 gallons). The company supplying this, Zapata Haynie Corp, can manufacture about 20 rail cars per day.  The rest of their production is used for animal feed and pet food.

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So it would be incorrect to say that the manufacturers of fish fertilizer are responsible for depleted stocks of menhaden, but they are certainly contributing to the problem.

It has become clear for many years that fish stocks in our oceans are dwindling. It is no longer a renewable resource unless fishing stops.

Which Brands Use Whole Fish?

I checked on a number of brands of fish fertilizer and it was never easy to tell which brands use whole fish. They like to use terms like “fresh fish”, as if that is important when you are making fertilizer!

Whole fish are processed into three separate components; fish meal (solid parts), fish oil and fish emulsion. Fish emulsion is what is left after the meal and oil have been removed (ref 3). Wikipedia defines fish emulsion as ” the fluid remains of fish processed for the fish oil and fish meal industrially”.

Based on this definition you might conclude that any fish fertilizer made from ‘fish emulsion’ is made from whole fish. But …. advertisers have a different point of view. I guess the term fish emulsion has become popular and is seen as a ‘good thing’ . I found several manufacturers that promote their product as fish emulsion,  but in small print somewhere on their web site, they say made from fish remains, or fish viscera. The term ’emulsion’ is not a reliable term for determining the source of the fish.

I was not able to find the % of fish fertilizer that comes from whole fish. If you find such a value, let me know in the comments below.

Fish Fertilizer Made From Carp

Some companies are catching invasive species like the carp and using them as a source for making fertilizer. This is a good practice and should be encouraged. If you Google ‘fish fertilizer made from carp’ you will find these companies. I found some in both the USA and Australia.

Is Fish Fertilizer Organic?

I will deal with most of this topic in another post, but for now lets assume that fish fertilizer is organic. Gardening organically is a good thing – it should be environmentally friendly.

If you use fish fertilizer that is made from whole fish – you are not being environmentally friendly, and in my opinion you are not gardening organically. Organic certification organizations disagree – as long as you follow their rules, even if you are damaging to the environment you are gardening organically. I disagree.

Feel free to use fish fertilizer – your plants will like it. But make sure the product is made from fish waste products, or carp and not whole fish.


  1. How a Fish Becomes Fertilizer – letter from Alaska Fish Fertilizer;
  2. Menhaden;
  3. The Principal Method of Processing Fish;
  4. Photo source; Ra Boe


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Robert Pavlis

I have been gardening my whole life and have a science background. Besides writing and speaking about gardening, I own and operate a 6 acre private garden called Aspen Grove Gardens which now has over 3,000 perennials, grasses, shrubs and trees. Yes--I am a plantaholic!

18 thoughts on “Fish Fertilizer is Damaging the Environment”

  1. Misleading. The article should say Fish fertilizer is good to the environment- but not when you harvest fish to be manufactured for pure fertilizer. Most use fish scraps like fish guts, which I do is very beneficial to my garden. Badly written article.

    • Most commercial fish fertilizer is NOT made from fish scraps – but if you have data to show this is wrong – lets see it.

      Most people who use fish fertilizer do NOT make their own.

  2. If you buy Charlie Carp liquid fertiliser from Australia; its made from pest carp taken from our inland rivers. They are a pest and hunt native fish so the more fertiliser you buy the better for our environment.

  3. Well, this is so disappointing! I’m glad I found your page before I opened my Neptune’s Fish fertilizer. Your right to say it’s not truly organic to murder fish just to spray on plants. I was told this product would help me control Japanese Beetles, it’s not worth it. Darn!

  4. Found it. Yes this is exactly what I was referencing in my last comment. The Atlantic States Marine Fisheries Commission increased the allowable harvest of menhaden 6.5% at last year’s annual meeting, and then just voted last week to maintain their current method of evaluating the stock (not scientifically or ecologically based) even though they got thousands of public comments urging them to adopt better standards that evaluate the importance of menhaden in the food chain before making changes to the management plan. Incidentally (or not) Omega Protein was owned by Zapata Corp, founded by George Bush. It is a very powerful company with many powerful ties to politics and obviously last week’s vote, against overwhelming public input, shows that the board can’t even make a sound decision without being influenced by lobbyists. The fleet has almost 40 boats and nearly 30 spotter planes to find the fish. And I was wrong when I wrote Omega Protein is responsible for taking 80% of the allowable commercial harvest…they are responsible for taking 90%.

  5. In Australia, as you said, we have a product made from Carp. This is a pest fish ,incorrectly released, in some of our Rivers. A company has been running for well over 30 years now using whole carp and producing liquid fertiliser. So the product has a beneficial impact on the environment. In fact if they are so successful they will do themselves out of business, but given the way Carp breed thats unlikely.

  6. You are great for sniffing out the self delusions of many people who call themselves organic and rather look down on the rest of us ‘who are not natural’ with a feeling of superiority.
    I have been making snide comments about fishmeal often being damaging to the environment for a long time now – but you put flesh on the story – or perhaps in this case take it away!
    I remember when the great organic vogue over here was calcified seaweed. Manufacturers scraped it off the ocean floor causing untold environmental damage

    • Seaweed is still very popular here. Some is harvested and causing environmental problems, but other sources are quite sustainable. It really depends on how and where it is being harvested. Need to rite about this one day.

  7. Thank you for this article. If my goal (or one of them) as an organic gardener is to minimize my “footprint” on the environment, then i needed to know this.

  8. Thank you for posting this. It has been a concern of mine for many years, which is why I won’t use commercial emulsion anymore. In case your readers are wondering what happens to that portion of industrial fish catches that are for “feed,” well…it doesn’t all go into your Morris’ Friskies. It is also used as a “cheap” protein source for cattle and poultry feed.

    I got onto this bad side of organic gardening when, years ago, I read an article in a magazine about sudden drops in seabird populations and the virtual abandonment of traditional rookeries in the East Atlantic. I can’t recall now which magazine, but it would have had to have been Scientific American, Discover, or Audubon as these were the only ones I read. Similar losses in non-avian species were also noted. No disease or other factor could be identified, and the conclusion, based upon troubles in the fishing industry there, pointed to years of over harvesting food fishes such as anchovies, upon which the seabird population depended for successful reproduction. These fish were being harvested largely for fertilizer at the time, with some of the catch going toward human consumption and animal feed. The fishermen’s troubles started with the depletion of fish stocks, causing ever-diminishing catches and a loss of income—they created their own problem. Menhaden is the current favorite since the depletion of other fishes. Once those stocks start to run dry, the industry will switch to some other “plentiful” fish.

    And you are right in that you can’t tell from the labeling on fish fertilizer products just where the fish comes from. There is no answer to that as long as companies that make fish-based fertilizers remain imprecise in their labeling. This is perhaps why it is better to make your own emulsion—at least you know its provenance.

    An alternative to fish, especially in large garden operations or small farms, is to use “green manure.” This is a practice that is catching on with commercial farmers who have embraced the mantra, “No Bare Ground.” Between crop rotations and during fallow periods, farmers will plant a cover crop to reduce erosion, protect their soil from the sun, conserve moisture, and ultimately replenish the organic component of their soils (much of which will have been removed during harvest). Any fast growing plant can be used as a cover crop, but the preferred ones are legumes, usually annual clovers, because they also replenish nitrogen. Although the nitrogen is sequestered in the roots during the plant’s lifetime, it is released once the plant dies and decomposes. Farmers, of course, can’t sit about waiting for these annuals to die off on their own, so they till them under shortly before they set their next crop. The process is slower than using fish emulsion, and requires more work, but the long term and collateral benefits make it worth the effort.

    Unlike fish emulsion, you are adding benefits every step of the way and really subtracting nothing from the environment. You are protecting your fallow soil, the flowers provide food for bees and other pollinators (which as we all know need all the help they can get right now), you are adding bulk organic material to your soil (a good thing, especially in heavy soils), and, if you are not going to plant for a while and have small livestock, it makes a great pasture. The stuff makes a great lawn substitute, too, if you are thinking of going truly green and getting rid of that swathe of water-sucking food desert, but haven’t yet decided on permanent replacement landscaping. If you are too attached to your lawn to get rid of it entirely, you can inter-seed clover into it to increase moisture retention, discourage other weeds, and increase nitrogen—you mow it right along with the rest of the grass. Clover (or any legume, such as vetch) makes a perfect cover crop for those annoying areas that get left bare for one reason or another. You can find out more on this on some farming websites and websites found using keywords, “clover cover crops” and “no bare ground.”

    Note: The seeds do not have a long shelf life, so don’t buy more than what you will need in the course of a year or two. Store the left overs properly to maintain their shelf life. Annual clover seed is cheap, and in some feed and seed stores you can buy it in bulk.

    Again, thank you for this post. The word needs to get out that just because its organic, doesn’t mean its ecologically responsible.

  9. I used the Alaska brand or one from Alaska last year. Did not make that big of a difference in my tomatoes. Being all the rage with the gardeners I know it is just to cost prohibitive for me. This year I just went back to Good old miracle grow.


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