OSTREID HERPES VIRUS 1, OYSTERS - EUROPE, OCEANIA: EMERGING
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Date: 17 May 2011
Source: Bloomberg News [summarised, edited] <http://www.bloomberg.com/news/2011-05-17/japan-quake-dashes-effort-to-overcome-oyster-herpes-in-france.html>
A deadly virus is stalking France's coastline, killing at least 60 percent of the young oysters there since 2008 [see commentary].
The 11 Mar 2011 natural disasters destroyed the fishing industry in Miyagi prefecture, which produced 80 percent of Japan's oyster seeds in 2009. That is forcing France to abandon plans to import and breed Miyagi's Pacific oyster species, and find another solution for diners seeing fewer, and more costly, options.
The French eat about 108 000 metric tons of the mollusks, typically on the half-shell atop a bed of ice and garnished with a squeeze of lemon or splash of vinegar. Domestic production fell 38 percent last year [2010], driving up wholesale prices 20 percent. Some brasseries in Paris sell the largest oysters for 6.5 euros [USD 9.17] a piece.
France, whose oyster industry was worth about 400 million euros [USD
572 million] in 2010, imported young Miyagi oysters in October 2010 and February 2011 to test their resistance to the virus, a variant of Ostreid herpesvirus 1, or OsHV-1. That required special permission from the European Commission to circumvent 1991 restrictions on importing oysters for breeding.
Test results are expected this month [May 2011], yet "the dramatic events in Japan in March 2011 have altered the chances of success of the Japanese track," Veronique Lopes, a spokeswoman for the French Ministry of Agriculture, said in an e-mail.
The ministry is drawing up a new list of potential importers with "sufficient health guarantees," she said.
Japanese oysters also are less attractive because of the possibility that their beds were contaminated by radiation leaking from a damaged nuclear-power plant on the coast in neighboring Fukushima prefecture, Lopes said.
The virus is not just a blow to France, Europe's biggest producer.
The global industry, worth at least USD 3.3 billion in 2009, has been plagued by OsHV-1 in Ireland, England and Australia.
In Ireland, Europe's 2nd-largest producer, about half of the bays where Pacific oysters are grown have been affected by the virus since 2008. Research has suggested "a very strong association" with imports of oyster seeds from France, said John Joyce, a spokesman for the Irish Marine Institute based in Galway.
The virus starts killing oysters when water temperatures top about 16 C (61 F). It has reappeared along the French coast this year [2011] and mostly affects oysters under one year old, Tristan Renault, director of the genetics and pathology laboratory at the French Research Institute for Exploration of the Sea in La Tremblade, said in a phone interview. Oysters need 3 years to mature, so the past winter was the 1st to show the effect on supply, Maingam said.
Oyster production declined to 80 000 tons from 130 000 tons last year [2010] in France, Maingam said. Wholesale prices are 20 percent higher than a year ago, according to the National Institute of Statistics and Economic Studies in Paris.
The problem may worsen after 2012, when many of the French colonies wiped out by the virus would have been ready for the table. That's also when the Japanese-imported oysters would have been growing.
Miyagi oystermen already have lost this year's [2011] harvesting season, and they won't be able to plant seeds for the breeding season typically beginning in July. Fishing and farming were suspended all along Miyagi's coast because of efforts to locate the 9000 people still missing after the natural disasters.
The Miyagi oysters, whose scientific name is _Crassostrea gigas_, are more resistant to infectious diseases than other species and have a history of being sent abroad to jump start farming or revive crops devastated by illness. It is now the most widely farmed oyster species in the world, Renault said.
Miyagi oysters came to France's rescue in the 1970s after the iridovirus killed most of the oyster population. The oysters also have been transplanted to more than 30 countries, including the USA, China, South Korea, Spain and New Zealand. "_Crassostrea gigas_ has been cultivated all around the world, showing it is capable of adapting to different environments," Renault said.
Oystermen prefer Miyagi's seeds because the oysters also are free of a parasite found elsewhere in Japan, Renault said. Now Japan may have to increase oyster imports to keep prices stable.
[Byline: Makiko Kitamura, Maki Shiraki, Rudy Ruitenberg]
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[For background and additional information, see commentary in 20101223.4520 and France's OIE reporting since April 2010 on Herpesvirus OsHV-1 as an emerging disease (spread along the Atlantic coasts as well as the Mediterranean, including Corsica) at <http://web.oie.int/wahis/public.php?page=event_summary&reportid=9179>.
Ireland reported to the OIE, during 2010, 18 foci of an emerging disease in oysters, suspected as Ostreid herpes virus 1 (OsHV1). See, with interactive map, at <http://web.oie.int/wahis/public.php?page=event_summary&reportid=9577>.
On 3 Dec 2010, the following epidemiological commentary was
submitted:
"Mortalities have been considerable, particularly in seed. Half grown and adult oysters have also suffered mortalities in some areas, though at lower levels. Transmission from site to site as well as through the water is believed to be occurring, but the presence of the virus in all of these areas last year (2010) and the possibility of latency makes it impossible to be sure whether the source is introduction of stock from an infected area or as a result of latent infections in existing populations. Although mortalities now appear to be at an end, re-infection of stocks which will be introduced between now and next summer is anticipated once the temperatures begin to climb again in June. Between 3 Jun and 5 Aug 2010, OsHV1 uVar strain (was) detected in all 14 bays, by using PCR and histopathology."
UK's reports and map, starting July 2010, are available at <http://web.oie.int/wahis/public.php?page=event_summary&reportid=9527>.
Australia's reports and map, since January 2011, are available at <http://web.oie.int/wahis/public.php?page=event_summary&reportid=10136>.
New Zealand's reports since December 2010, including an extensive epidemiological commentary and an interactive map, are available at <http://web.oie.int/wahis/public.php?page=single_report&pop=1&reportid=10013>.
- Mod.AS]
[Oyster farming
<http://www.dhgladwelloysters.co.uk/images/may09/turning.jpg>
<http://www.agmrc.org/media/cms/Oystersars_73E1FC3216FF9.jpg>
French oysters at table
<http://inlinethumb10.webshots.com/43529/2088744590100204599S500x500Q85.jpg>
- Mod.JW]
[see also:
2010
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Herpesvirus, V. splendidus, oysters - France: susp 20101223.4520
2009
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Undiagnosed die-off, oysters - France: RFI 20090801.2697
2008
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Undiagnosed die-off, oysters - France, RFI 20080712.2125] .................................................sb/arn/msp/jwll
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