【ニュース】廃棄カキ殻を再活用、環境に優しい「ケアシェル」注目

Contents

Vocabulary
Article
Comprehension Questions
Summary
Discussion

Vocabulary

Upcycle – reuse waste materials to create something of higher value.

The company upcycled oyster shells into useful products..

Granules– small grains or tiny pieces of a material.

The shells were crushed into granules for use in clam farms.

Sustainability– actions that protect the environment for the long term.

The project promotes sustainability by reducing waste.

Recognition– public acknowledgement or praise.

Their innovation received national recognition.

Circular economy– an economy where resources are reused continuously.

Upcycling supports a circular economy by reducing waste.

Article

Upcycling Oyster Shells in Japan

In Toba City, Mie Prefecture—one of Japan’s major oyster-producing regions—around 15,000 tons of oyster shells are discarded each year. To address this waste, a local company developed Careshell, an innovative product made by compacting powdered oyster shells into mineral-rich granules. First created about 20 years ago, Careshell is now gaining attention both in Japan and abroad for its potential to support marine ecosystems and promote environmental sustainability.

The idea originated with Megumu Yamaguchi, who wondered whether discarded shells could be returned to the sea in a useful form. By collaborating with university researchers, he developed granules using powdered shells and magnesium hydroxide—a compound naturally found in seawater. These granules were later tested in Manila clam farming, where they helped young clams grow faster and larger by enriching the surrounding environment with minerals.

Careshell’s success earned national recognition, including the Emperor’s Cup in 2013, and has since expanded into new uses such as improving water quality in aquariums. International researchers have also taken notice. At a recent global conference in France, Megumu’s daughter Keiko Yamaguchi presented the company’s work, sparking lively interest and a joint research project between Japan and France.

Unexpectedly, researchers from the University of Tokyo discovered that Careshell absorbs CO₂ instead of releasing it, adding another environmental benefit. This finding inspired local colleges and a ceramic manufacturer to create decorative tiles made from oyster shells—an example of how upcycling can inspire new industries.

Although the company nearly closed due to slow progress, Keiko decided to leave her previous job to support her father. By organizing tours and simplifying complex information for visitors, she helped raise awareness of Careshell’s value. Today, the Yamaguchis hope their work will support coastal communities facing similar challenges and promote a more circular economy.

_{Source: Associated Press News (English)}

Comprehension Questions

Answer the questions following the article in English.

What problem in Toba City led to the creation of Careshell?
How does Careshell help Manila clams grow?
Why did Careshell gain international attention?
What surprising discovery did researchers make about Careshell and CO₂?

Summary

In your own words, attempt to summarise the article in 4 sentences or less.

Discussion

Discuss these topics with your tutor, and support your answers with examples or experience.

How can small, local companies contribute to global sustainability?
What challenges might arise when trying to introduce environmentally friendly products to international markets?
If you were to upcycle a local waste product from your country, what would you create?