Effect of Vibrio tubiashii on West Coast shellfish

CHRIS LANGDONCoastal Oregon Marine Experiment Station,

Hatfield Marine Science Center,

Oregon State University

CLAUDIA HÄSECollege of Veterinary Medicine,

Oregon State University

RALPH ELSTONAquaTechnics Inc., WA

EFFECT OF VIBRIO TUBIASHII ON WEST COAST SHELLFISH

ECONOMIC VALUE OF THE WEST COASTSHELLFISH INDUSTRY

(PACIFIC COAST SHELLFISH GROWERS ASSOC. DATA FOR 2005)

ANNUAL DOCKSIDE VALUE OF ALL SHELLFISH $111 MILLION

ANNUAL DOCKSIDE VALUE OF OYSTER HARVESTS $83 MILLION

WHOLESALE SALES + SERVICES + SUPPLIES $278 MILLION

EMPLOYMENT 3000

PACIFIC COAST OYSTER GROWERS DEPEND ON TWO SOURCES FOR THEIR SEED

1)Wild set from Willapa and Dabob Bays

2)Commercial hatcheries

NO NATURAL SET OF PACIFIC OYSTERS IN WILLAPA BAY, WA, IN LAST 5 YEARS

DATA OF WASHINGTON DEPT. FISHERIES AND WILDLIFE

SOURCES OF OYSTER SEED

TAYLOR HATCHERY

WHISKEY CREEKHATCHERY

IMPACTED PRODUCTION OF PACIFIC OYSTER LARVAEFROM WHISKEY CREEK AND TAYLOR HATCHERIES2007WHISKEY CREEK < 70% NORMAL PRODUCTION

HIGH CONCENTRATIONS OF V. TUBIASHII-LKE BACTERIA IN NETARTS BAY AND VIBRIOSIS EVIDENT IN HATCHERY

LARVAE

SEAWATER TREATMENT SYSTEM (BASED ON MBP’S SYSTEM) WAS INSTALLED IN THE WHISKEY CREEK HATCHERY

IN EARLY 2008 TO EXCLUDE V. TUBIASHII AND ITS EXTACELLULAR TOXINS

FOAMFRACTIONATOR

BIOLOGICALFILTER

UV

IMPACTED PRODUCTION OF PACIFIC OYSTER LARVAEFROM WHISKEY CREEK AND TAYLOR HATCHERIES2007WHISKEY CREEK < 70% NORMAL PRODUCTION

HIGH CONCENTRATIONS OF V. TUBIASHII-LKE BACTERIA IN NETARTS BAY AND VIBRIOSIS EVIDENT IN HATCHERY

LARVAE

2008WHISKEY CREEK <50% NORMAL PRODUCTION.LITTLE SIGN OF VIBRIOSIS. PROLONGED UPWELLING OF LOW pH SEAWATER

TAYLOR PRODUCTION 50% NORMAL PRODUCTION.LOW pH WATER FROM HOOD CANAL

2009WHISKEY CREEK PRODUCTION IMPACTED BY DISCRETE UPWELLING EVENTS. NO VIBRIOSIS EVIDENT IN LARVAE

TAYLOR HATCHERY 20% NORMAL PRODUCTIONV. TUBIASHII-LIKE BACTERIA ASSOCIATED WITH 70% LARVAL MORTALITIES

Vibrio tubiashii• One of the most serious diseases of

shellfish larvae caused by a marine Vibrio species

• Rapid reduction in larval motility and necrotic soft tissue, leading to high mortality rates

• Extracellular toxins – Metalloproteases– Haemolysins– Ciliastatins

• Invasive - leading to tissue necrosis

• Facultative anaerobe

(Tubiash et al., 1965)

INFECTED LARVAE NORMAL LARVAE

CHARACTERIZATION OF METALLOPROTEASE TOXIN OF V. TUBIASHII

ALIGNMENT OF THE SEQUENCE FOR METALLOPROTEASE FROMVIBRIO TUBIASHII WITH THOSE OF OTHER VIBRIO SPECIES

(HASAGAWA ET AL. 2008)

TOXICITY OF V. TUBIASHII METALLOPROTEASE FOR PACIFIC OYSTER LARVAE(HASAGAWA ET AL. 2008)

+ protease

- protease

NEW MOLECULAR TOOLS FOR DETECTION OF V. TUBIASHII

RESEARCH GOALS:

1)DETERMINE THE PATHOGENICITY OF V. TUBIASHII FOR EARLY LIFE STAGES OF THE:

a) Pacific oysterb) Olympia oysterc) Bay mussel

APPROACH:

DETERMINE GROWTH AND SURVIVAL OF LARVAE AND JUVENILES EXPOSED TO CELL SUSPENSIONS AND SUPER-NATENTS OF: - A HIGHLY PATHOGENIC STRAIN OF V. TUBIASHII

- A MUTANT STRAIN WITH DELETED GENE FOR METALLOPROTEASE

RESEARCH GOALS:

1)DETERMINE THE PATHOGENICITY OF V. TUBIASHII FOR EARLY LIFE STAGES

2) EVALUATION OF GROWTH AND SURVIVAL OF PACIFIC OYSTER

LARVAE EXPOSED TO NATURALLY OCCURING V. TUBIASHII INCOMMERCIAL HATCHERIES

APPROACH:

a) monitor culture systems for V. tubiashii during good and poor larval production periods

b) correlate larval performance with water quality and V. tubiashii, using selective media and PCR

RESEARCH GOALS:

1)DETERMINE THE PATHOGENICITY OF V. TUBIASHII FOR EARLY LIFE STAGES OF THE

2) EVALUATION OF GROWTH AND SURVIVAL OF PACIFIC OYSTER

LARVAE EXPOSED TO NATURALLY OCCURING V. TUBIASHII INCOMMERCIAL HATCHERIES

3) APPLY THE RESULTS OF THE STUDY TO IMPROVE MANAGEMENTOF OYSTER POPULATIONS IN HATCHERIES AND IN THEFIELD

a) husbandry practices in commercial hatcheriesb) planting schedules for restoration of Olympia oysters

QUESTIONS?

UPWELLED DEEP WATER CAN BE ACIDIC AND CORROSIVE FOR ARAGONITEVERTICAL SECTION OFF ST. GEORGE, CA. SUMMER 2007

FEELY ET AL. 2008. SCIENCE 320: 1490 - 1492

HYPOXIC WATER ON INNER SHELF OFF OREGON AND WASHINGTON COASTS (DEAD ZONES)

SINCE 2002, LARGE AREAS OF HYPOXIC WATER (<1.4 ml O2. l-1) HAVE BEEN FOUND ON THE INNER SHELF (< 50 M) IN SUMMER

SOURCE: PISCO, OSU