Pearls are one of nature’s most environmentally sustainable gems. This is especially true for saltwater pearls. Pearl oysters purify water and when managed properly, a healthy increase in ocean biodiversity can be observed around pearl farms.
At every pearl farm, pearl harvesting yields three by-products- the shell, the adductor muscle and the body meat of the oyster. The shells have several different uses. Mother-of-Pearl often finds itself set in jewellery and watches or is fashioned into buttons. By contrast, the adductor muscle is a culinary delicacy, enjoyed by many people.
The body meat of the oyster has two distinct uses. Often it is returned to the ocean as fish food. Or it is used as fertilizer on the small agricultural fields and plots, that are an integral part of pearl farms. (this is where farmers grow their own fruits and vegetables.) As fertilizer, while the body meat does provide essential nutrients to the soil, it has two disadvantages. First, it leaves behind an unpleasant fishy odour as the meat decomposes. Second, it releases a lot of water, making it a difficult material to transport. In such cases, pearl body meat in excess of the farmer’s needs then becomes waste material
This is all set to change with the recent introduction of Pearl Compost. First introduced in Mie Prefecture, Shima City, Japan, pearl compost allows the body meat of akoya pearl oysters to be used more effectively while also meeting three UN sustainable development goals.
What is Pearl Compost?
Pearl compost is an environmentally efficient natural fertilizer that is produced using pearl body meat, rice bran and rice husks. Fermented over a period of three to four months, the compost is light in weight and almost odourless. It can be used to grow vegetables, herbs and flowers.
The pearl compost project began in 2019 when some pearl farmers of Mie Prefecture, Shima City, the Pearl Promotion Society of Japan and the Fisheries Agency of Japan collaborated to find an environmentally sustainable use for pearl body meat. After several rounds of trial and error, finally in 2021, a workable prototype of pearl compost was developed. Today, pearl compost is being successfully produced in five separate locations, including Shinmei, Tategami, Katada, Wagu and Koshika, on the Ago Bay.
Pearl Compost and UN’s Sustainable Development Goals
As a project, pearl compost is significant because it meets three important Sustainable Development Goals (SDGs) set out in UN’s 2030 Agenda for Sustainable Development. First, it meets Goal 12 which lays emphasis on ensuring sustainable production and consumption patterns. Next, it also meets Goal 14 which looks into the conservation and sustainable use of oceans, seas and marine resources. Finally, the pearl compost project meets the requirements for Goal 17, which focuses on strengthening the means of implementation and revitalization of the Global Partnership for Sustainable Development.
Pearl compost also meets the ecological sustainability brief by closing the soil nutrient loop at pearl farms. Soil nutrients from land flow into the oceans when rivers empty into the sea. Pearl oysters feed on these nutrients, directly and indirectly. With pearl compost, nutrients from pearl body meat are brought back to the soil, and play an important part in growing vegetables, fruits and flowers. Closing this soil nutrient loop has many long term benefits for agriculture.
Introduction of Pearl Compost at the Japan Jewellery Fair
According to Yuichi Nakamura, CEO of PJ Nakamura and vice chairman and spokesperson of the Mie Prefecture Pearl Promotion Council, pearl compost is now being actively promoted by the Council. In fact, this product was formally introduced to the jewellery industry at the Japan Jewellery Fair last week. Free samples of pearl compost were given away to attendees who visited the Council’s booth at the fair. Mr. Nakamura noted that the overall response to both the product and the project was positive and several Japanese pearl companies have shown interest in financially supporting this initiative.
Next Steps
Mie Prefecture Pearl Promotion Council has set ambitious goals for the expansion of the pearl compost project. Currently, in Shima city alone, there are 24 pearl farmers who have started composting pearl body meat. Additionally, pearl farmers in the Ehime Prefecture and in Kyushu (mainly Nagasaki Prefecture) are also participating in this project. The plan now is to expand the project to pearl farmers in other parts of Japan.
Note: Shima city is important for one more reason- it is the birthplace of pearl cultivation in Japan.
Featured Image: Ise-Shima G-7 Lapel Pins, Provided by the Mie Prefecture Pearl Promotion Council
