How one urban farmer is making crab farming a reality in Singapore flats

Urban farmer Shannon Lim started building "crab condos" around seven years ago. (Photo: CNA/Marcus Mark Ramos)

SINGAPORE: Imagine preparing a seafood dinner at home – but instead of buying crab from the market, you simply pick one up from your own crab farm, which fits in the corner of your kitchen.

This is the vision that urban farmer Shannon Lim, 37, has for his students. The founder of OnHand Agrarian runs classes where he teaches participants how to build "crab condos" and how to take care of the crabs that live in them.

The crab condo is a set of modified plastic storage drawers – seven "storeys" high – filled with water and fitted with pumps and filters so that crabs can live in them. An ultraviolet steriliser and algae that breaks down organic waste prevent unpleasant smells.

Mr Lim charges S$680 (US$510) for a 10-hour course across two days, and the fee includes the cost of equipment to build the crab condo, use of tools and a ride home after the class. Participants can also bring a guest along if the class is not too full.

Mr Lim started building crab condos around 2016, but it is not his invention. He saw a post on a forum many years ago where crayfish were being reared in plastic drawers, and adapted it to farm crabs.

Shannon Lim shows class participants how to go about building their own crab condos. (Photo: CNA/Marcus Mark Ramos)

A test kit is used to check if the ammonia level of the water is safe for the crabs. (Photo: CNA/Marcus Mark Ramos)

Each crab gets one drawer to call home, where it can grow from a few hundred grams to close to 2kg or even heavier in some cases. Online seafood sellers typically sell live crabs that are between 300g and 1kg.

Mr Lim said he usually buys crabs that have been sitting in a warehouse for too long.

“They get skinny and become water crabs – they’re called that because they’re mostly water and they’re less valuable,” he said.

“Then we just start fattening them up again.”

The crab condo fits one crab per drawer, where it can grow from a few hundred grams to close to 2kg. (Photo: CNA/Marcus Mark Ramos)

CARING FOR CRABS

One of Mr Lim’s students, management consultant Lee Ray Sheng, 24, feeds his crabs once every two or three days.

“Crabs eat absolutely everything, so the easiest way is of course to go to a fish monger and ask them for fish gills,” he said.

An avid kayaker, Mr Lee harvests mussels from floating safety barriers off Singapore’s coast to feed his crabs.

“Normally when I go kayaking, I go with some friends, I just go to (Pulau) Ubin and try to spot animals. But now, going to Ubin has a very different purpose.”

Lee Ray Sheng scraped mussels from safety barriers off Singapore's coast to feed to his crabs. (Photo: Lee Ray Sheng)

Mr Lee said he first learned about vertical crab farming a few years ago when he visited a farm unrelated to OnHand Agrarian. A few months ago, he came across a video on TikTok about Mr Lim’s crab condo classes.

“First thing, I love to eat crab. Second thing, I’d definitely love to grow my crabs and eat them,” he said. “So I signed up for the course … and I built my own crab condominium.”

The crabs that he took home from the class were about the size of his palm, and he estimates that they grew about 50 per cent in two months.

FOOD SECURITY IN SINGAPORE

Mr Lim has taught about 50 students how to build crab condos since before the pandemic and wants to encourage more Singaporeans to be urban farmers. One tip he gives his students is to not name their crabs if they want to eat them, to avoid forming an emotional attachment.

“I’d like to see more Singaporeans growing their own food because we are ridiculously dependent on Malaysia,” he said, referring to how the neighbouring country is a top source of seafood and other foods for Singapore.

Stories that his grandparents told him about World War II also shaped the way he thinks about food security.

“It kind of affected my view of how we should be a bit more prepared for strange things to happen,” he said. Mr Lim rears several types of fish and, on his home-based farm, grows some herbs as well as ducks that he describes as pets that may get eaten.

Shannon Lim also rears a small flock of ducks in his backyard. (Photo: CNA/Marcus Mark Ramos)

Shannon Lim feeding his fish in a tank he made. The tank can be converted into a full-sized table. (Photo: CNA/Marcus Mark Ramos)

Mr Lim also has an aquaponics system made from recycled bottles. He grows mint, stevia and other small plants. (Photo: CNA/Marcus Mark Ramos)

He has taken on projects to help hotels, schools and individuals to set up farming systems.

For those who do not want to farm their own food, Mr Lim does sell seafood and vegetables on a subscription basis. He also occasionally accepts customers who pay him to rear crabs for them.

He is currently taking care of about 200 crabs in Pasir Ris and his home farm in Simei for customers.

CRAB HATCHERY?

But he has a big dream for crab farming in Singapore. He hopes more people will learn how to farm crabs and Singapore eventually has its own crab hatchery.

Crabs cannot mate and reproduce in the condo set-up, so a hatchery can provide farmers with baby crabs to rear.

When asked why the focus on crabs, Mr Lim said many Singaporeans love eating crabs, and that cleaning and preparing a crab is easier than scaling or filleting a fish.

Prawns and cave-dwelling fish can also be farmed in the crab condo – which is what self-declared seafood lover Mr Lee said he plans to do.

Lee Ray Sheng now rears crabs at home after learning the ropes from urban farmer Shannon Lim. (Photo: CNA/Marcus Mark Ramos)

“If I could rear lobsters, I would gladly rear lobsters,” he said. “(Mr Lim) mentioned that that’s a lot harder, the environment needs to be more controlled.”

For now, only crabs are on the menu. When CNA spoke to Mr Lee, he had not cooked any of his crabs except for a single claw.

“I was handling one of the crabs and the crab decided to cut off its own arm … and his pincer just dropped off,” he said. Crabs are able to detach their claws as an escape mechanism when they feel threatened.

“It became an upgrade for my instant noodles,” he said with a laugh. But when the time comes to cook one of his crabs, how will he prepare it?

Without hesitation, he said: “Chilli crab.”

This article was originally published on ChannelNewsAsia. Its inclusion on this website is solely for education purposes.