Can You Compost Shrimp Shells? (And Are They Good For Garden?)

The world’s waters are home to many species of edible creatures. They include lobsters, fish, prawns, crayfish, crabs and of course shrimp. Shrimp is one of the most commonly consumed types of shellfish and is quite nutritious and provides high amounts of certain nutrients, such as iodine, that are not abundant in many other foods. However, some claim that they are unhealthy because of their high cholesterol content.

Shrimp come in shells that are not cooked when the shrimp is being prepared for a dish. The shells have a myriad of uses including making shrimp broth, making a stock that is rich in flavor and of course composting. Yes, shrimp shells can be used in the garden to enrich the soil as well as produce better yields. This article focuses on shrimp shells vis-à-vis the idea of composting.

Are Shrimp Shells Compostable?

Yes, shrimp shells are fully compostable. Shrimp shells can go in compost whether they are raw or cooked. The shells will decompose and be broken down by the microorganisms into organic compost. The compounds in shellfish are beneficial to maintain soil health as well.

When you add shrimp to your compost pile, they provide beneficial microorganisms with rich compounds suitable for their growth. This will help the microorganisms grow and break down the other organic waste in the compost pile.

Also, shrimp shells contain bacteria that help them decompose. They are largely made of chitin, which forms the exoskeleton and contains large amounts of nitrogen. Nitrogen is a primary nutrient that plants need for growth and is a vital part of the composting process. Canadian researchers found that compost containing chitin-digesting bacteria protected potato crops against several fungal diseases.

Some advice against composting shrimp because they produce some odors that invite pests. The good thing is that you can eliminate the odors coming from decomposing shrimp by boiling them for up to 30 minutes, drying and crushing the shells before adding them to the compost.

The first step cooks out residual fats from the shells, minimizing odours while crushing the dried shells to fragments helps speed decomposition by exposing more surface area to beneficial bacteria. You can also choose to compost shrimp shells inside a hot compost where the process will take a couple of weeks to complete.

You can also compost the shells in cold composting, although the process can take months to complete. treat them like other potentially pest-tempting items like fruit and vegetable scraps.

Be sure to add the shrimp shells at the middle of the composting pile and cover them well to conceal the odors, reducing the risks of pests. Also, remember to add the shrimp shells along with other nitrogen-containing ingredients such as fresh grass clippings, and carbon-containing ingredients such as dried leaves.

Can You Compost Shrimp Tails?

Yes, you can. Almost any form of organic material can be broken down, and this includes shrimp tails. Composts made from seafood trash is especially popular in Thailand. The compost made from shrimp heads and tails as well as crab shells is rich in chitin and chitosan.

To compost shrimp heads and tails, green waste and molasses are normally added to the mix. The tails are still part of the shrimp shells and are largely made of chitin. The chitin can benefit your garden as it is a rich source of nitrogen and phosphates, and is particularly high in calcium and magnesium.

The same precautions observed with composting shrimp shells should be applied when composting shrimp tails. Therefore, enclose your compost to avoid scavengers and other pests from having their way with them.

Bury them in the middle of the composting pile to avoid attracting more pests and to conceal odors. This also ensures they decompose quite quickly. Also, clean and crush the shells before adding them to compost for the same reasons as you would the shrimp shells.

Are Shrimp Shells Good For the Garden?

Oh yes! Shrimp shells, like other shellfish, are very useful in compost and subsequently to the garden and plants. The shells contain compounds that feed bacteria and fungi which, in turn, helps the soil to break down.

When used in a potato patch, for instance, the compounds in shrimp shells can destroy hatching eggs of nematodes, which can damage the plants and destroy the crop.

Shrimp shells are made from a chemical in shrimp shells called chitosan. Chitosan is a version of chitin, the second-most abundant organic material on the planet, also found in fungal cells, insect exoskeletons, and butterfly wings.

Chitin can also hamper fungus growth and activate natural defense mechanisms in plants. By making compost from shrimp shells, you are saving organic waste from reaching the landfill and you will also be creating rich, organic material for growing healthy plants.

Adding compost to your vegetable garden, potted plants or flower beds is beneficial in a variety of ways. Shrimp-based compost is rich in calcium which is perfect for promoting fast root growth and plant development.

Calcium is responsible for holding together the cell walls of plants. It is also crucial in activating certain enzymes and sending signals that coordinate certain cellular activities. It is calcium that is key to normal root system development.

Calcium also increases resistance to outside attack and increases the feed value of forage crops to livestock. What is even better is that shrimp shells can be composted either raw or cooked.

Can You Put Shrimp Shells in the Garbage Disposal?

It is advisable not to put shrimp shells in the garbage disposal. As soon as you put shrimp peels and/or tails into the garbage disposal it will form a nice little ball and clog the drain. Nothing will clean that clog and you must take apart your sink. 

Shrimp shells are tough and can potentially bend or break the blades. They can also spin the blades until they wear themselves out, eventually forcing the appliance to clog your pipes, defeating the whole purpose entirely.

Additionally, the shrimp can also become quite smelly, especially if pieces of the shrimp are either stuck on the blades, or the garbage disposal is put out of commission by the shrimp shells themselves. To keep your appliance clean, just avoid dumping the shrimp shells or tails in the garbage disposal. Either compost them, eat them or make something else out of the shells.

Are Shrimp Shells Edible?

Shrimp shells are edible and based on recent scientific research, may also provide additional health benefits, like lowering cholesterol and improving cartilage and joint health. In fact, shrimp shells are sold as prawn or shrimp tails in the sophisticated markets of the world. Although shrimp shells and tails are edible, they are not meant to be eaten.

The majority of the people keep them for flavor and presentation, but not necessarily for them to be eaten. It is much like the cartilage on chicken bones; some people love it, some pick the meat of it and others do not touch it.

A common practice in most restaurants is to leave the tails on the food, a thing done to make the food more attractive. It also adds flavor to the dish, makes the shrimp look larger, is easier for the restaurant as they do not need to remove them, and is a crunchy and tasty addition.

Shrimp shells are not glamorous, particularly appetizing and you can even argue that they are not food, but they are perfectly safe to consume. They are said to be shockingly delicious, with a treasure trove of flavour and texture that naked unshelled shrimp cannot even match.

Shrimp shells are formed of chitin, which is normally indigestible and a bit uncomfortable to try to chew and swallow. However, if they are deep-fried, they are easy to eat, crispy, with a great taste. You can even eat the whole animal, heads and all if prepared this way. If not, just add the shells and bits to the stockpot.

The shells and tails themselves are very chewy and hard but are easier to chew through when the shrimp are very small. They have a lot of flavors but you can remove them if you like. Very large shrimp, such as jumbo and colossal, will have larger and harder shells that are not recommended to be eaten as they can be a choking hazard.

What to Do With Shrimp Shells?

1. Making shrimp stock or broth

You can make your shrimp stock for your next seafood soup or risotto, completely from shrimp shells. If you do not hate shrimp or are allergic, this part is for you. Take your shells from your freezer where you left them after dinner.

Toss them in a pot and cover them with water and bring them to boil. Reduce it to a simmer and let it hang out for a bit. After about five to fifteen minutes, a noticeable amount of shrimpy flavor will have been transferred to the liquid.

Then strain out the shells, after which you can just compost them. You can also add some aromatics like shallots or garlic, a bay leaf, and a few peppercorns. A splash of white wine would also be quite welcome. Once you have the flavors, just how you want them, you can use your shrimp stock as a ramen broth, as the base for risotto, or in a seafood stew.

2. Making plastic packaging and bags

As reported by Design News, researchers at the University of Nottingham, used chitin, the organic compound extracted from shrimp shells, to develop chitosan. Chitosan is a bioplastic material for plastic packaging and bags.

The material is also a biopolymer nanocomposite material that is more environmentally friendly than typical oil-based materials. Natural biopolymer products made from plant materials could offer an eco-friendlier alternative to the non-degradable plastic packaging that has caused environmental and public health problems all over the world.

The researchers promised to continue their work to develop an active polymer film that absorbs oxygen and would be viable and affordable.

3. Adsorption of metal present in surface runoffs

The research analyzed the use of natural shrimp shells and commercial chitin for biosorption of metal ions in surface runoff. It sought to jointly resolve two particularly environmentally sensitive issues in Brazil, waste management from fishing activity and surface runoff quality.

In general, good metal ion removal results of commercial chitin suggest its application as a full-scale biosorbent, for instance as a draining mattress in an infiltration swale. This application may indicate the effective functionality of this compensatory technique.

Unfortunately, the shrimp shell tested had excessive amounts of metal ions of lead, copper and nickel, which resulted in the contamination of the sample, affecting the results of the treatments applied.

Further research on the water quality in shrimp breeding environments was also advised needed, due to the shrimp’s ability to absorb undesirable substances in the water.


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About Rinkesh

A true environmentalist by heart ❤️. Founded Conserve Energy Future with the sole motto of providing helpful information related to our rapidly depleting environment. Unless you strongly believe in Elon Musk‘s idea of making Mars as another habitable planet, do remember that there really is no 'Planet B' in this whole universe.