Transcript DAY 2 1050 shellfish diseases sagb

Ian Laing
Some oyster diseases
List of Diseases
Bower, S.M. and McGladdery, S.E. (2003): Synopsis of Infectious
Diseases and Parasites of Commercially Exploited Shellfish
URL: http://www-sci.pac.dfo-mpo.gc.ca/shelldis/title_e.htm
The Single European Union Market
• Animal health conditions for placing aquaculture animals
on the market ~ EC Directive 91/67, as amended.
Europa
Animal Health and Welfare Web site
Listed diseases - THEN
91/67
95/70
Bonamia ostreae
Haplosploridium nelsoni
Marteilia refringens
Haplosploridium costale
Perkinsus marinus
2003/390
NON-Susceptible species
Bonamia – Pacific oysters,
mussels and clams
Marteilia – Pacific oysters
Perkinsus olseni
Mikrocytos mackini
Mikrocytos roughleyi
Oyster velar virus
Marteilia sydneyi
OIE - International Organisation
for Animal Health
Aquatic Animal Code and Manual
Listed diseases - NOW
2006/88
Susceptible species
Diseases
Flat
oysters
Bonamia ostreae
Yes
Marteilia refringens
Yes
Perkinsus marinus
Cupped
oysters
Yes
Yes
Bonamia exitiosa
Yes
Microcytos mackini
Yes
Mussels
Yes
Aims of the legislation
• Prevent the spread of serious disease
• Allow trade
This means
• Controlling the movement of shellfish
• Import and export checks
Bonamiasis
• Introduced into Europe
in 1979 - Brittany
Bonamia ostreae
is an intracellular
plasmodial
protozoan parasite
(2-5m) that
belongs to the
Haplosporidium
group. It affects
the granular blood
cells (haemocytes)
of flat oysters.
Bonamia ostreae
Web site – www.bonamia.com
Google – 14,000 results
ASFA – 168 papers
Project BOLCI
Shellfish News
Zones in
Great Britain
1993 – 2005
3 infected areas
2006 - Loch
Sunart (E) and
Milford Haven (F)
2007 – West Loch
Tarbert (G)
2008 – North Kent
•EU Health Rules
(91/67/EEC)
•UK programmes approved
(92/528/EEC)
•Approved Zones
(2002/300/EC)
Meanwhile, in Ireland
1993 - 2002
2003 – Achill Sound
and Blacksod Bay
2005 – Lough Foyle
2006 – Lough Swilly
2008 - Strangford
Lough
“Placing on the market” (2006/88 continued)
• Authorisation of Aquaculture Production Businesses
•
includes dispatch and purification centres
• Susceptible and vector species
• Risk-based surveillance
•
for increased mortality
Surveillance for mortality
Fish
Molluscs
Mobile
Visible behaviour
Endoskeleton
Contained
Sedentary
Static
Shell
Open (sea bed)
Marteilia refringens
One species?
Two types?
Marteilia (type M)
in mussels in
Southampton Water
(and elsewhere)
Pacific oysters
“Summer mortality”
• Oyster Herpes Virus
• Vibrio splendidus
• Environmental factors
500 μm
Listed diseases - NEW
2006/88
Diseases
Susceptible species
White Spot Disease All decapod crustaceans
Taura Syndrome
Three tropical shrimp spp
Yellowhead disease
Seven tropical shrimp spp
White spot disease (WSD)
• Global spread via live and frozen
animal movements – 100% mortality in
days – no effective treatment
• Can be transmitted to European
decapods (crayfish, crabs, lobsters)
• Experimental infection of European
lobster via feeding of WSD-infected
prawns
• Causes disease within the European
water temperature range
• Little research into vectors/carrier hosts
White spot disease (WSD)
IS THERE A THREAT IN EUROPE?
• Small crustacean aquaculture industry
• Large and very valuable marine fishery for prawns, lobsters and crabs
• Potential routes of entry of WSD to Europe – larvae or broodstock for
aquaculture, imported fresh and frozen prawns or live potentially carrier
species for consumption
• Significant movement of fresh, frozen and live European crustaceans
within the EU
I hope that was not too complicated
Note: None of these diseases affect humans