Environment

Sea cucumbers could clean up fish farms – and then be eaten by humans

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Researchers are looking at introducing sea cucumbers to fish farms, where they could clean up fish waste and be bred for food
Researchers are looking at introducing sea cucumbers to fish farms, where they could clean up fish waste and be bred for food
Sea cucumber, looking distinctly more appetizing in a bowl than it does in the wild (Photo: avlxyz)

Marine net-pen fish farms aren’t popular with environmentalists for a number of reasons, one of the main ones being the amount of fish feces and uneaten food that they release into the surrounding ocean. In the UK, help for that problem may be coming in the form of the sea cucumber. Despite its name, the sea cucumber is an animal, that resembles a big slug and is about the same size as ... well, as a cucumber, or sometimes larger. Given that sea cukes subsist on organic matter that they scavenge from the sea floor, scientists at Newcastle University have proposed that they be introduced to fish farms where they could process waste. After eating all that fish poop, some of the cucumbers could then be served up as gourmet cuisine for humans.

Not only would this initiative theoretically be good for the environment, but it should also help sea cucumbers – perhaps not the ones that get eaten, but sea cucumbers in general. Because they are a rich source of glucosamine and chondroitin, the animals are currently harvested for use in traditional Chinese medicine and cuisine, to the point that worldwide populations of key species are declining. At fish farms, not only would they be used to minimize waste, but they would also be bred for the marketplace.

“We wanted to find a way to clean up waste produced by large-scale aquaculture so that farming activities in the sea have little or no impact on the ocean floor,” said Newcastle’s Dr. Matthew Slater. “By growing sea cucumbers on waste from fish farms we are not only farming a valuable food product and giving the wild sea cucumber populations a chance to recover, we are also developing solutions to fish farming impacts.”

Sea cucumber, looking distinctly more appetizing in a bowl than it does in the wild (Photo: avlxyz)

After having studied them at Newcastle's Dove Marine Laboratory, the research team is now looking towards actually placing them at fish farms around the UK. The team is also leading an aquaculture project in Tanzania, where sea cucumbers are being bred in cages in a lagoon.

Fish farming has also been criticized for introducing antibiotics and anti-algal chemicals into the ocean, allowing escaped non-native fish to disturb the local ecological balance, creating higher levels of toxins in farmed fish flesh, and for putting strain on wild populations of fish caught to feed carnivorous domesticated fish such as salmon.

It’s hard to say if the cukes can help with all of that, but every little bit helps.

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10 comments
Alien
What is the likelihood that infections could be passed via the fish faeces into the sea cucumber population?
Troy Bailey
Considering the lack of some sort of previous relationship in the wild or a symbiosis between them as well as the differences in morphology the chance of them transferring infections, viruses etc would be low. Of concern would be the transfer of vitamins and antibiotics etc. not all of these are broken down in the body .some go through unaffected and this could cause issues.
Luan To
You guys eat Tilapia now which is NOT a natural for U.S. and it cleans our sewer waste and they sell by the 1000s in the US as food.
Adrian Akau
I don\'t know if the proposal will be accepted but I have tasted sea cucumbers (namako) from the ocean (prepared with a little vinegar, salt and other spices) and they are truly delicious. Not any old sea cucumber will do but the variety shown in the picture above really is good. I have never tried the more common black type that shoots out its insides when disturbed.
srmorb
The sea cucumber scavenger characteristic could have additional (or alternate) benefits. Since this creature consumes biowaste of of sea animals they could be appliedas an alternate fuel source in the way manure or algea is seen as. Imagine the harvesting of these cucumbers and apply them for processingmethane, a natural gas, or some other form of synfuel that can be used as a transportation fuel source or for generating electricity. Think of these creatures as an application of a form of aquaphytoremediation.They start out as a means to remove toxic/waste material from fish farms andend up processed into a source of biofuel. People in the western world be hesitant to a having a gourmet sea food dishknowing the creature\'s food source but would easily overlook the thought of thesource of gas the kitchen stove used to fry their shrimp.
Dave Myers
People hardly need convincing to eat seafood, of any sort. This isn\'t a maklet problem. Obviously there are forms of aquaculture, yet to be properly developed, or lost to the ages, that resemble high intensity organic land agriculture. We could do this. Aquaponics, using trout, worms, and plants, are an existing example.
With climate change, the intermingling of ocean species to a different state from what they are now seems inevitable, however, closed tank animal farming is the best solution until we\'ve actually figured these systems out and done the research.
MrGadget
Who eats the sea cucumber\'s poop?
Greg Zeng
Indonesian fishermen are criminalized by the Australian government for doing what they have been doing for thousands of years - eating sea cucumbers around north Australia.

@srmorb: white people are shy of seafood; fish excepted. The first English invaders of Australia nearly died because of their hatred of Australia\'s native seafood. A food supply ship arriving just in time, led to the almost extinction of all the colored people in Australia. As a fifth generation Australian, I had never eaten sea cucumber until I married my Hong Kong wife, 18 years ago.

As many comments agree here, seafood (fish excepted) is generally not seen as food by English-type people.
Denise General
LOL, I know I\'ve eaten sea cucumber without knowing (at some Chinese restaurant or other) and I\'m none the worse for wear, but I could never accept those things as \"tasty seafood\". It goes back to when I was little and I accidentally stepped on a dead one on the beach. It innards just smushed out and it was the grossest thing ever! In fact, I still shudder just thinking of it and I can still almost feel it. Ewwwww! But gimme anything else from the sea and I\'d demolish a whole plate of it!
limbodog
What about not eating the sea cucumbers that are feeding off the fish poop, but instead just feeding them to more fish?