KOCHI: Prawn dishes are celebrated as delicacies in many regional cuisines. In Kerala, just prawns fried in coconut oil and a bowl of steaming rice can work magic.
On the flipside, every year 8 million to 15 million tonnes of prawn shell waste is generated globally. They either go to landfills or get dumped directly into the sea, disturbing the natural ecosystem.
This data piqued Rhea Thomas. The 27-year-old, who finished her masters in global innovation design from the Royal College of Art and Imperial College in London, decided to chalk out a plan that would find daily life uses for prawn shell waste.
“About 60 per cent of a prawn is discarded as waste. They go either as landfill or as sea waste. This happens majorly because there’s a cost involved in the proper disposal of the waste,” Rhea explains.
“Seafood waste breaks down rapidly, so when dumped in waterways it kills the bacteria and natural elements required for the growth of the ecosystem. This also affects the natural purification of water. In landfills, prawn shells cause methane emissions. The disposal happens daily and it is a threat to the environment. Unfortunately, it’s overlooked.”
As a maiden step, the youngster invented the idea of processing them into plant pots as part of her college programme. For this finding, Rhea won the Arts Foundation Future Award worth 10,000 pounds this year.
Though she grew up in the coastal regions of Kochi and Mangalore, Rhea admits the issue of shell waste never crossed her mind. It was only after she went to Yokohama in Japan, as part of the exchange programme, that she realised the demand for seafood and the possibility of reusing the seafood waste.
“One tends to observe a lot while travelling to new places. Japan is one of the top seafood-consuming countries. While I was there, my diet predominantly consisted of seafood. The supermarkets there are packed with seafood products. That made me think of the waste part,” says Rhea.
A sustainable approach
After delving into the subject, Rhea focused on designing the biomaterial. “Of late, there has been a lot of push for sustainability. I intended to come up with something that has an impact. Since prawn shells is a biomaterial, we aren’t extracting anything out of the earth to make anything new. I am using what’s been thrown out,” says Rhea.
According to her, the project could be executed easily if she could partner with the frozen food manufacturing plants as they extract a lot of shells and stock them because it has to be processed before discarding.
The recycled prawn shell-based plant pots are intended to be utilised for agriculture and horticulture purposes. “The shells are processed into a sheet format, and this is what’s moulded in the shape of a pot. The processed shells are then dried and powdered. Once the organic binders are added, the powder will form into a paste, and this is used to develop the products,” Rhea explains.
Plastic is widely used in agriculture and horticulture, especially while growing seedlings. Rhea’s recycled pots are a solution to this problem. “Seedlings are usually grown in trays and plastic pots in long stretches. Once grown into a sapling, it is taken out of the plastic and planted in the soil. If prawn shell pots are used, the sapling can be planted in the soil along with the pot. Over time, it will degrade and also serve as soil nutrient,” she says.
Further research
Rhea adds that prawn shell waste is versatile and can be used in everyday life as well. “Shells can be used in indoor furnishings, foam packaging, storage bags, etc. Based on the product, the pigments present in the shells can be removed. However, research is required to analyse its longevity, and probable issues posed by allergens,” she says. Rhea expects her findings to garner more attention, and is eager to collaborate with investors who are interested in sustainability projects.