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Status Of The Major Oyster Diseases In Virginia 2006-2008 A Summary Of The Annual Oyster Disease Monitoring Program, Ryan B. Carnegie, Eugene M. Burreson Dec 2009

Status Of The Major Oyster Diseases In Virginia 2006-2008 A Summary Of The Annual Oyster Disease Monitoring Program, Ryan B. Carnegie, Eugene M. Burreson

Reports

Fall Survey sampling revealed P. marinus levels to be generally normal to high in Virginia tributaries. By 2007 P. marinus was present on every oyster reef sampled, and by the end of the 2006-2008 period the parasite was probably causing some mortality throughout Virginia waters. Data for H. nelsoni are still incomplete for 2006/7 because of funding limitations, but in 2008 H. nelsoni was observed at 17 of 31 sampled reefs, a marked expansion in distribution since 2003/4. A significant MSX disease outbreak occurred in the Great Wicomico River in 2008, as a mild winter and a long ...


Status Of The Major Oyster Diseases In Virginia 2005 A Summary Of The Annual Monitoring Program, Ryan B. Carnegie, Eugene M. Burreson Jul 2006

Status Of The Major Oyster Diseases In Virginia 2005 A Summary Of The Annual Monitoring Program, Ryan B. Carnegie, Eugene M. Burreson

Reports

More normal riverflows and salinities returned in 2005 after two very wet years. Temperatures were somewhat colder than normal during the winter, and warmer during the summer. The physical environment was generally more favorable for parasite activity, and thus brought a slight increase in prevalence and intensity of the oyster diseases caused by Perkinsus marinus (Dermo) and Haplosporidium nelsoni (MSX). Among quarterly James River Survey sites, maximum annual P. marinus prevalences returned to levels typical of the mid- 1990s, before the years of drought. P. marinus prevalence reached 92% at Wreck Shoal, 56% at Point of Shoal, 68% at Horsehead ...


Status Of The Major Oyster Diseases In Virginia 2004 A Summary Of The Annual Monitoring Program, Ryan B. Carnegie, Eugene M. Burreson Mar 2005

Status Of The Major Oyster Diseases In Virginia 2004 A Summary Of The Annual Monitoring Program, Ryan B. Carnegie, Eugene M. Burreson

Reports

2004 was the second very wet year in a row. While rainfall and streamflows were normal in winter and early spring, and just slightly above average during the summer, the fall of 2004 was nearly as wet as the year before. Salinities were again depressed throughout the lower Bay. Water temperatures were below normal during the winter, but typical otherwise. Low salinities and, in the winter, temperatures brought continued abatement in the oyster diseases caused by Perkinsus marinus (Dermo) and Haplosporidium nelsoni (MSX). Among quarterly James River Survey sites, maximum annual P. marinus prevalences were the lowest they had been ...


Status Of The Major Oyster Diseases In Virginia 2003 A Summary Of The Annual Monitoring Program, Ryan B. Carnegie, Lisa M. Ragone Calvo, Eugene M. Burreson Jun 2004

Status Of The Major Oyster Diseases In Virginia 2003 A Summary Of The Annual Monitoring Program, Ryan B. Carnegie, Lisa M. Ragone Calvo, Eugene M. Burreson

Reports

Low temperatures and salinities brought abatement in the oyster diseases caused by Perkinsus marinus (Dermo) and Haplosporidium nelsoni (MSX) for the first time since 1998. In the James River, P. marinus prevalences were the lowest they had been since 1998. In summer and fall, when P. marinus is normally most prevalent, it was found in a maximum of 72% of oysters at Wreck Shoal and in less than half the oysters at Horsehead Rock and Point of Shoals. Advanced infections were very rare. Haplosporidium nelsoni had disappeared completely from quarterly James River samples by July


Status Of The Major Oyster Diseases In Virginia 2002 A Summary Of The Annual Monitoring Program, Lisa M. Ragone Calvo, Eugene M. Burreson Mar 2003

Status Of The Major Oyster Diseases In Virginia 2002 A Summary Of The Annual Monitoring Program, Lisa M. Ragone Calvo, Eugene M. Burreson

Reports

Samples collected monthly from the upper James River sites from January through May showed a decline in P. marinus prevalence during the 4 winter and spring following a typical annual pattern; however, annual minimums were atypically high, particularly at Point of Shoals and Wreck Shoal (12-44%). Unusually high salinity conditions and warm winter temperatures promoted high overwintering survival of the pathogen and an early onset of the disease in the summer months. Perkinsus marinus prevalence increased to 100% at all four of the upper river stations and record high infection intensities were observed at Deepwater Shoal and Horsehead Rock. It ...


Status Of The Major Oyster Diseases In Virginia 2001 A Summary Of The Annual Monitoring Program, Lisa M. Ragone Calvo, Eugene M. Burreson Feb 2002

Status Of The Major Oyster Diseases In Virginia 2001 A Summary Of The Annual Monitoring Program, Lisa M. Ragone Calvo, Eugene M. Burreson

Reports

Thirty-nine oyster populations were surveyed for disease in fall 2001. Perkinsus marinus was found in all areas sampled and prevalence exceeded 90% at all but 5 sample locations. In the James River P. marinus prevalence ranged from 88-100% at Deepwater Shoal, Horsehead Rock, Point of Shoals, Wreck Shoal, Mulberry Point, Swash, Long Shoal, and Dry Shoal. A lower prevalence was observed down river at Thomas Rock, 72%, and at Nansemond Ridge, 12%. The extremely low prevalence at Nansemond Ridge is likely age and density related; the oyster population was primarily comprised of spat; few small to market oysters were present ...


Status Of The Major Oyster Diseases In Virginia 2000 A Summary Of The Annual Monitoring Program, Lisa M. Ragone Calvo, Eugene M. Burreson May 2001

Status Of The Major Oyster Diseases In Virginia 2000 A Summary Of The Annual Monitoring Program, Lisa M. Ragone Calvo, Eugene M. Burreson

Reports

As a consequence of the relatively warm temperatures, high salinities, and high oyster parasite abundances in the fall of 1999, both P. marinus and H. nelsoni were widely distributed throughout oyster populations in Virginia in 2000. Fortunately, however, we did not see severe epizootics of the diseases as observed in some areas in 1999.


Status Of The Major Oyster Diseases In Virginia 1999 A Summary Of The Annual Monitoring Program, Lisa M. Ragone Calvo, Eugene M. Burreson Feb 2000

Status Of The Major Oyster Diseases In Virginia 1999 A Summary Of The Annual Monitoring Program, Lisa M. Ragone Calvo, Eugene M. Burreson

Reports

As a consequence of the relatively warm temperatures and high salinities severe epizootics of both H. nelsoni and P. marinus occurred in most tributaries in VA. In the upper James River, VA prevalences and intensities of P. marinus were the highest on record. The proportion of advanced infections (moderate and heavy intensity) in October was 60% at Wreck Shoal and 48% at Horsehead Rock suggesting that significant oyster mortalities occurred in these areas. 1 Record high levels of P. marinus were also observed in Virginia's other major tributaries. Of the 39 bay oyster populations surveyed in the fall, P ...


Status Of The Major Oyster Diseases In Virginia 1998 A Summary Of The Annual Monitoring Program, Lisa M. Ragone Calvo, Eugene M. Burreson Mar 1999

Status Of The Major Oyster Diseases In Virginia 1998 A Summary Of The Annual Monitoring Program, Lisa M. Ragone Calvo, Eugene M. Burreson

Reports

No abstract provided.


Status Of The Major Oyster Diseases In Virginia 1997 A Summary Of The Annual Monitoring Program, Lisa M. Ragone Calvo, Eugene M. Burreson Mar 1998

Status Of The Major Oyster Diseases In Virginia 1997 A Summary Of The Annual Monitoring Program, Lisa M. Ragone Calvo, Eugene M. Burreson

Reports

No abstract provided.


Status Of The Major Oyster Diseases In Virginia 1996 A Summary Of The Annual Monitoring Program, Lisa M. Ragone Calvo, Eugene M. Burreson Mar 1997

Status Of The Major Oyster Diseases In Virginia 1996 A Summary Of The Annual Monitoring Program, Lisa M. Ragone Calvo, Eugene M. Burreson

Reports

No abstract provided.


Status Of The Major Oyster Diseases In Virginia 1995 A Summary Of The Annual Monitoring Program, Lisa M. Ragone Calvo, Eugene M. Burreson Jan 1996

Status Of The Major Oyster Diseases In Virginia 1995 A Summary Of The Annual Monitoring Program, Lisa M. Ragone Calvo, Eugene M. Burreson

Reports

No abstract provided.


Status Of The Major Oyster Diseases In Virginia 1994 A Summary Of The Annual Monitoring Program, Lisa M. Ragone Calvo, Eugene M. Burreson Mar 1995

Status Of The Major Oyster Diseases In Virginia 1994 A Summary Of The Annual Monitoring Program, Lisa M. Ragone Calvo, Eugene M. Burreson

Reports

No abstract provided.


Status Of The Major Oyster Diseases In Virginia 1993 A Summary Of The Annual Monitoring Program, Eugene M. Burreson, Lisa M. Ragone Calvo Aug 1994

Status Of The Major Oyster Diseases In Virginia 1993 A Summary Of The Annual Monitoring Program, Eugene M. Burreson, Lisa M. Ragone Calvo

Reports

No abstract provided.


Status Of The Major Oyster Diseases In Virginia 1992 A Summary Of The Annual Monitoring Program, Eugene M. Burreson Mar 1993

Status Of The Major Oyster Diseases In Virginia 1992 A Summary Of The Annual Monitoring Program, Eugene M. Burreson

Reports

No abstract provided.


Status Of The Major Oyster Diseases In Virginia 1991 A Summary Of The Annual Monitoring Program, Eugene M. Burreson Feb 1992

Status Of The Major Oyster Diseases In Virginia 1991 A Summary Of The Annual Monitoring Program, Eugene M. Burreson

Reports

No abstract provided.


Status Of The Major Oyster Diseases In Virginia 1990 A Summary Of The Annual Monitoring Program, Eugene M. Burreson Feb 1991

Status Of The Major Oyster Diseases In Virginia 1990 A Summary Of The Annual Monitoring Program, Eugene M. Burreson

Reports

No abstract provided.


Status Of The Major Oyster Diseases In Virginia 1989 A Summary Of The Annual Monitoring Program, Eugene M. Burreson Feb 1990

Status Of The Major Oyster Diseases In Virginia 1989 A Summary Of The Annual Monitoring Program, Eugene M. Burreson

Reports

No abstract provided.


Prevalence Of The Major Oyster Diseases In Virginia Waters 1988 A Summary Of The Annual Monitoring Program., Eugene M. Burreson Feb 1989

Prevalence Of The Major Oyster Diseases In Virginia Waters 1988 A Summary Of The Annual Monitoring Program., Eugene M. Burreson

Reports

No abstract provided.