Ehime's pearl production Why did it fall to second place? June 15 11:46

Many people think of Mie Prefecture, which is famous as the birthplace of pearl farming, when it comes to pearl production, but in reality, Ehime Prefecture has much more production.

With a nationwide market share of 40%, it has maintained its number one position for many years, but was overtaken by Nagasaki Prefecture in terms of production volume last year.

Shock is spreading locally.

What is happening in the calm Ehime sea?

(Matsuyama Broadcasting Station reporter Shunsuke Goto)

Overtaken by Nagasaki

The history of pearl farming in Ehime Prefecture goes back more than 100 years.

In the latter half of the Meiji era, aquaculture began in the sea in the southern part of Ehime prefecture with the cooperation of the people involved in Mie prefecture, which succeeded in aquaculture for the first time in Japan.

Due to its suitability for aquaculture on the ria coast and the active production of pearl oysters used as mother oysters, production increased dramatically in the middle of the Showa period.

Since becoming No. 1 in Japan for the first time in 1974, it has been No. 1 in Japan for 12 consecutive years from 2009 to the end of the year.

In 2020, the national market share will be 42% and the output will be 5.7 billion yen, making it an important industry indispensable to the local economy.

However, according to the preliminary figures of the 2021 fishery statistics released by the Ministry of Agriculture, Forestry and Fisheries, Ehime prefecture weighs 4,300 kilograms (down 36% from the previous year).

On the other hand, Nagasaki Prefecture ranked first, surpassing Ehime Prefecture with 5100 kilograms (down 10% from the previous year).

Mie Prefecture was third with 2000 kilograms.

The people of Uwajima

The local Uwajima citizens were shocked by the unexpected fall to 2nd place.

A woman in her 40s

"I'm very disappointed. Ehime's pearls are wonderful, so I want you to regain the 1st place in production instead of the 2nd place."

A woman in her 70s

"My friends outside the prefecture say that pearls and oranges are the representatives of Uwajima. It's sad to fall to 2nd place."

When I visited the pearl shop in the roadside station "Uwajima Kisaiya Hiroba", which is popular with tourists, the words "Japan's No. 1 pearl producing area" are proudly written next to the pearl products. had.

The store manager lonely said, "I can't use this selling phrase anymore."

Pearl shop manager Matsuhiro

"When asked why customers from outside the prefecture sell pearls in Uwajima, I explained that the production volume is the highest in Japan. It

is very sad that such PR cannot be done .

I feel

, but I think the quality is the best in Japan, so I would like to convey that from now on. "

The cause of the decrease is the mass death of pearl oysters

The cause of the significant reduction in production is the mass death of pearl oyster larvae used for aquaculture.

Pearl farming is carried out by putting the core of the pearl into the body of the pearl oyster.

Then, a film called nacre is formed around the nucleus and finally becomes a pearl.

However, in the Uwa Sea, the pearl oyster larvae have been killed in large numbers for three consecutive years since 2019.

The reason why the juvenile mussels die was a mystery, but a survey by national and prefectural research institutes identified for the first time that it was caused by a new virus called "a new species of the Birnaviridae".

Shellfish infected with this virus have symptoms of atrophy.

This virus can be detected by PCR, and the first possible countermeasure against infection is a vaccine, but it is said that the vaccine does not work for shellfish.

When humans are vaccinated, antibodies are produced in the body and can be expected to prevent the onset, and livestock and farmed fish can take similar measures.

However, bivalves such as pearl oysters do not have the protective function of antigen-antibody reaction, so no effect can be expected.

PCR is a reliable way to confirm virus infection, but it is also effective to shine light from the back of the shell to see through it.

If the shellfish in the shadow is atrophied, it is suspected to be infected.

So what should I do?

As a countermeasure, the change of aquaculture site started this season in Ehime prefecture.

Since it has become clear that the water temperature in the northern part of the Uwa Sea is relatively low and there are few viruses, we are conducting breeding tests to move shellfish to that area.

There is one more thing I found out.

That is, not all shellfish die when infected with the virus.

If you get infected, it is important not to do any damage.

Director Higaki, Ehime Prefectural Fisheries Research Center

"If you work to damage shellfish that are infected with a virus and are weakened, mass death is likely to occur.

If atrophy is observed, the shellfish will be netted. I would like you to refrain from the work of cutting the foot thread (thread-like fiber) to adhere to the virus, raising the net, and changing the net

. It is an attempt to leave more shellfish by letting them do it.

I want to find as many symptomatic things as possible and spread them widely. "

Can this be prevented?

Mass mortality of pearl oyster juveniles, which will continue from 2019, is confirmed to occur from June to July every year.

In May, the gene for the virus in question was detected in juvenile mussels at a farm in Ainan, a town next to Uwajima.

Although mass death of juvenile clams has not been confirmed yet, caution is required from this time when the temperature of seawater rises, and it is important to detect abnormalities at an early stage.

In order to regain the number one production volume in Japan, we must minimize the damage.

Producers are paying close attention to changes in the ocean.

Ehime Prefectural Fisheries Cooperative Association President Hirai "The temperature of seawater is 22 degrees

now

(June), but research data shows that viruses are the most dangerous in the temperature range of 20 to 24 degrees.

I can't let my guard down during this period, so if I think something is wrong, I'd like to be careful when working, such as performing a PCR test.

Although the difficult situation continues, Ehime is producing the number of people involved in production. I think that the power is at the top level in Japan, so I want to stop the mass death of juvenile Akoyagai as much as possible and aim to be the best in Japan. "

After the interview

The most memorable thing about this interview is that the local residents are regretful that the production of pearls has turned to the second place in Japan.

I strongly felt that so many Ehime citizens are proud of the pearl industry.

Although production fell to second place, I heard a strong statement that quality and productivity are the best in Japan.

I would like to continue to support through interviews, hoping that measures against the mass death of pearl oysters will progress and producers will be able to cultivate as usual.

Matsuyama Broadcasting Station Reporter

Shunsuke Goto Joined the station in

2016 The

predecessor was the Minamisoma branch office in Fukushima prefecture

. Aiming for a big catch

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