Crustacean and Molluscs -production and diseases in Europe

Ed Peeler

Isabelle Arzul

Grant Stentiford

Disease emergence & host switching

Disease spread through trade in live animals

Spill over from farmed to wild populations

Wild populations as disease reservoirs

Disease control in open water farming

Farmed Wild

Managed

Exploited

Wild Farmed

Mo

lluscs •Oysters (Ostrea edulis, Crassostrea gigas)

•Mussels (Mytilis edulis, M. galloprovincialis)

•Scallops (e.g. Pecten maximus)

•Cockles (Cerastoderma edule)

•Clams (e.g. Venerupis decussata)

Cru

sta

ce

a

•Native crayfish

• Non-native crayfish (Signal crayfish )

•Crabs

•Lobsters

•Norway lobster

•Brown shrimp

•Shrimp (P. Japonicus)

Major European Shellfish Spp.

European crustacean consumption

(annual mt)

Crustacean production

- 2011 mt

Shrimp production (2011mt)

European mollusc production

(FAO 2008)

Mollusc production

Crassostrea gigas (Pacific oysters)

France, Ireland, Spain, Portugal

Mytilis edulis (blue mussel)

France, Netherlands, Ireland, UK

M. galloprovincialis (Mediterranean mussel)

Spain, Italy

European aquaculture relies on

non-native species Invasive Non-invasive

at least 80% increase in shellfish,

especially mussel, production by 2020

OIE listed diseases

CRUSTACEAN DISEASES

• Crayfish plague

• White spot disease

• Yellow head disease

• Taura syndrome

• Infectious hypodermal and haematopoietic necrosis

• Infectious myonecrosis

• Necrotising hepatopancreatitis

• White tail disease

MOLLUSCAN DISEASES

• Bonamia exitiosa

• Bonamia ostreae

• Marteilia refringens

• Perkinsus marinus

• Perkinsus olseni

• Microcytos mackini

• Xenohaliotis californiensis

• abalone herpesvirus

• [Oyster herpesvirus µVar]

Diseases listed in EU legislation

White

spot ?

Taura

syndrome

Yellowhead

virus

Bonamia ostreae

Marteilia refringens

Bonamia exitiosa?

Perkinsus marinus

Microcystos mackini?

Diseases listed in EU legislation

Other crustacean diseases of

interest

• Gaffkaemia

(Aerococcus vividans)

• Haematodinium

infections

White spot syndrome virus

No reports of WSSV in the EU since 2001

WSSV

• The EU may be free of WSSV

BUT

• No WSSV approved free areas in the EU

have been established

costs benefits

Establishing WSSV freedom

Crayfish plague

Crayfish plague in Europe

1859

Introduction

from US via

ballast water /

fish / crayfish

1960

Introduction

of signal

crayfish for

farming –

further spread

to UK and

Greece

Oyster production in France

Marteilia refringens

• Not known outside Europe

• May have emerged in flat oysters by

jumping from mussels

• Can cause mortality in mussels but

economic impact unknown

• Small proportion of production in M.

refringens free areas

Bonamia ostrea

• Contributed to the decline in O. edulis

• First identified in Northern France and

Spain in 1979

• Associated with the import of O. edulis

from a hatchery in Californian

• Original host is a North American species

of oyster?

• Small proportion of production in free

areas

Bonamia exitiosa

• Well established in Australia and New

Zealand

• Discovered in Spain in 2009?

• Identified in France and Italy

• Date of introduction unknown

• Route of introduction unknown

• No observed impact on C. gigas

• Eradication not attempted

Oyster herpesvirus new variant • Emergence in France in 2008

• Spread through France and to other European

countries via movement of infected stock

• Subsequently observed in Australia and New

Zealand

• Free areas in Ireland the UK established under

EU legislation

– Recent spread through movement of stock for

human consumption

• Planned listing by the OIE

– Sets precedent for listing a specific strain

Vibrio aestauranius – a new

threat?

• Vibrios are endemic, ubiquitious bacteria

in the marine environment which can

cause mortality in oysters

• In 2012 mortality in adult C. gigas

attributed to V. aestauranius

Disease emergence & host switching

Disease spread through trade in live animals

Spill over from farmed to wild populations

Wild populations as disease reservoirs

Disease control in open water farming

Challenges • Disease emergence

– Underlying processes

– Early detection

• Rapid response to prevent spread

• Spread of disease through international

trade

– Importance of trade in commodity

– Notification of emerging diseases

– Rapid disease listing