Hiroshima is the biggest producer of oysters in Japan, with an oyster-growing history spanning approximately 500 years. Today, it accounts for around two thirds of Japan’s oyster production, or 20,000 tonnes a year.
Hiroshima’s oyster farming and fishing play a particularly unique role in terms of marine environment and demand in the region.
The prefecture’s unique topography, tidal currents (with relatively slow currents compared to other major bays) and water temperatures make it an ideal location, while Hiroshima oysters have long been renowned for their high quality and stakeholders’ efforts to build a thriving oyster industry.
In the past, oyster fishery productivity decreased significantly due to worsened environmental conditions from coastal industrialisation, the tragic environmental influence from the atomic bomb and a redistribution of resources as a result of war. However, since the post-war era the fishery has been improving its methods and technologies, increasing production volume over the years.
In Hiroshima, oysters are grown on ropes and fished on vertical lines that are attached to buoys. Oyster spat is collected from plankton from the environment using scallop shells as spat collectors. Those scallop shells are then arranged along a wire string or rope, and the oysters attached to the scallop shells grow to maturity in one to three years while suspended in water under bamboo rafts.
Now Hiroshima’s oysters are in the spotlight with the launch of a new Fishery Improvement Project (FIP). Participants include five fishing companies conducting oyster raft hanging culture – Kawasaki Suisan Ltd., Aya Suisan Ltd., Amibun Kaisan Ltd., Yoneda Suisan Ltd., and Dairyo Ltd. These are grouped under a parent company, fishing and processing company Kurahashijima Kaisan Co., Ltd.
Also part of the project are the Japan Consumers’ Co-operative Union (JCCU), Japan’s largest consumer cooperative comprised of 29 million members that buys and sells Hiroshima oysters, Japanese seafood consulting firm Seafood Legacy and international NPO Ocean Outcomes (O2).
The FIP’s launch was announced in early February 2020.
After completing the improvement work, participating companies will seek Marine Stewardship Council certification by 2021 so that JCCU can sell Hiroshima oyster products to consumers in Japan using the blue MSC ecolabel.
‘The FIP and its goal of certification was driven by the market demand of the FIP participant JCCU,’ said Shunji Murakami, Vice-President and COO at Seafood Legacy.
‘JCCU has a sustainable seafood procurement policy and reached out to Kurahashijima Kaisan Co., Ltd as a potential partner in the FIP, given their long-standing relationship.Kurahashijima Kaisan was eager to pursue certification through the FIP due to its history and pride of being a key oyster company in Japan. Neighbouring and competing oyster farms recently gained MSC certification as well, and this has likely helped pressure Kurahashijima to pursue certification.’
‘The FIP participants have a lot of pride in their fishery,’ he continued.
‘It’s the oldest oyster fishery in Japan and a key cog sustaining the local economy. This FIP is also being seen as a continuation of post-war efforts to improve farming methods and increase production volume.’
Read more about Hiroshima’s oyster FIP