Effect of Vibrio tubiashii on West Coast shellfish
1. CHRIS LANGDON Coastal Oregon Marine Experiment Station, Hatfield Marine Science Center, Oregon State University CLAUDIA HÄSE College of Veterinary Medicine, Oregon State University RALPH ELSTON AquaTechnics Inc., WA EFFECT OF VIBRIO TUBIASHII ON WEST COAST SHELLFISH
2. ECONOMIC VALUE OF THE WEST COAST SHELLFISH 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
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4. NO NATURAL SET OF PACIFIC OYSTERS IN WILLAPA BAY, WA, IN LAST 5 YEARS DATA OF WASHINGTON DEPT. FISHERIES AND WILDLIFE
6. IMPACTED PRODUCTION OF PACIFIC OYSTER LARVAE FROM WHISKEY CREEK AND TAYLOR HATCHERIES 2007 WHISKEY CREEK < 70% NORMAL PRODUCTION HIGH CONCENTRATIONS OF V. TUBIASHII -LKE BACTERIA IN NETARTS BAY AND VIBRIOSIS EVIDENT IN HATCHERY LARVAE
7. 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 FOAM FRACTIONATOR BIOLOGICAL FILTER UV
8. IMPACTED PRODUCTION OF PACIFIC OYSTER LARVAE FROM WHISKEY CREEK AND TAYLOR HATCHERIES 2007 WHISKEY CREEK < 70% NORMAL PRODUCTION HIGH CONCENTRATIONS OF V. TUBIASHII -LKE BACTERIA IN NETARTS BAY AND VIBRIOSIS EVIDENT IN HATCHERY LARVAE 2008 WHISKEY 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 2009 WHISKEY CREEK PRODUCTION IMPACTED BY DISCRETE UPWELLING EVENTS . NO VIBRIOSIS EVIDENT IN LARVAE TAYLOR HATCHERY 20% NORMAL PRODUCTION V. TUBIASHII- LIKE BACTERIA ASSOCIATED WITH 70% LARVAL MORTALITIES
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10. CHARACTERIZATION OF METALLOPROTEASE TOXIN OF V. TUBIASHII ALIGNMENT OF THE SEQUENCE FOR METALLOPROTEASE FROM VIBRIO 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
17. UPWELLED DEEP WATER CAN BE ACIDIC AND CORROSIVE FOR ARAGONITE VERTICAL SECTION OFF ST. GEORGE, CA. SUMMER 2007 FEELY ET AL. 2008. SCIENCE 320: 1490 - 1492
18. HYPOXIC WATER ON INNER SHELF OFF OREGON AND WASHINGTON COASTS (DEAD ZONES) SINCE 2002, LARGE AREAS OF HYPOXIC WATER (<1.4 ml O 2 . l -1 ) HAVE BEEN FOUND ON THE INNER SHELF (< 50 M) IN SUMMER SOURCE: PISCO, OSU
Notas del editor
Thanks for the invitation. I am not the other Chris Langdon! Asked to talk about some of the problems the West coast oyster hatcheries have been facing in the last two years and how they may be associated with upwelling of acidic seawater with high concentrations of dissolved carbon dioxide.
The West coast shellfish industry has harvests worth about $111 million a year with oyster harvests making up about 75% of the total or $83 million. When you include services, wholesale sales and supplies, the industry has an economic impact of a little over ¼ billion and employs about 3000 folks
The loss of adequate supplies of oyster seed from hatcheries has been compounded by the absence of a natural set of wild oysters in Willapa Bay, WA. This bay is the main bay for oyster production on the West coast as is usually an important source of wild seed that is collected by farmers. Sets of wild oysters have been recorded in Willapa Bay since 1942 – i.e. for about 70 years. There have been other periods of 4 to 6 years were sets of wild oysters have been poor……
The to hatcheries that have been having problems are the Whiskey Creek hatchery on the Oregon coast and another hatchery situated on Dabob Bay, Puget Sound. The Whiskey Creek hatchery is important is that it supplies about 75% of the oyster growers with seed (eyed larvae). The growers set the eyed larvae to produce juvenile oysters or spat.
After 2007, some of the hatcheries started to implement seawater systems to treat incoming seawater to kill Vt with UV irradiation and remove its extracellular toxins using foam fractionation and biological filtration. This technology had been found to be effective in the experimental hatchery/nursery based at the Hatfield Marine Science Center, Oregon State University, Newport.
This is a very serious pathogen for shellfish, mainly affecting the larval stage. It kills larvae by a combination of extracellular proteases and invasion of tissues. Interesting, it is a facultative anaerobe and has been found in hatcheries growing in stock solutions of sodium thiosulfate.
Another large-scale change in ocean conditions that might be affecting oyster recruitment and rearing on the Oregon coast is the development of large-scale hypoxic water masses or “Dead Zones” on the inner shelf in summer. The area of the hypoxic water mass varies from year to year but is thought to have increased in this millenium.
Another large-scale change in ocean conditions that might be affecting oyster recruitment and rearing on the Oregon coast is the development of large-scale hypoxic water masses or “Dead Zones” on the inner shelf in summer. The area of the hypoxic water mass varies from year to year but is thought to have increased in this millenium.
Another large-scale change in ocean conditions that might be affecting oyster recruitment and rearing on the Oregon coast is the development of large-scale hypoxic water masses or “Dead Zones” on the inner shelf in summer. The area of the hypoxic water mass varies from year to year but is thought to have increased in this millenium.
Work by Feely and co-workers in 2008 has shed some light on some of the large-scale oceanographic factors that might be affecting oyster larval production in hatcheries and natural sets in Willapa Bay. In this Science paper, the authors noted that in 2007, low pH (7.6 to 7.7) water was upwelled in coastal waters of CA. Furthermore, the low pH water was corrosive for aragonite, one of the forms of calcium carbonate found in molluscan shells, including oysters. A saturation state of less than 1 (shown by the dark line in the bottom figure) for aragonite indicates that it is soluble in seawater of that pH.
Another large-scale change in ocean conditions that might be affecting oyster recruitment and rearing on the Oregon coast is the development of large-scale hypoxic water masses or “Dead Zones” on the inner shelf in summer. The area of the hypoxic water mass varies from year to year but is thought to have increased in this millenium.