ML082880420

River Drainage Yoy Smallmouth Bass Disease Investigations 2005 and 2007

ML082880420
Person / Time
Site:	Susquehanna
Issue date:	10/14/2008
From:	- No Known Affiliation
To:	Office of Nuclear Reactor Regulation
References
Download: ML082880420 (19)

Text

Susquehanna River Drainage YOY Smallmouth Bass Disease Investigations 2005 and 2007

July 2005 Fish Specimen Collection Sites Juniata River Mifflintown access Narrows Granville

External Lesions F

Fungii Motile aeromonads Pseudomonads Flavobacteria

Parasites on the Skin Schyphidia S h hidi Glossatella Trichodina

Kid Kidney Tissue Ti A Assay Flavobacterium columnare isolated

Granville Site Random R d electrofishing l t fi hi sample Fifty YOY SMB 56% - skin lesions 26% - severe skin lesions Granville 2% - gill ill columnaris l i 50% - systemic F.

columnare infection

Viral Assay Results Largemouth Bass virus detected in SMB from the Juniata River Narrows First detection of LMBv in fish from PA waters Tunkhannock Sayres Lake Later in 2005 LMBv was detected in SMB from the Narrows Susquehanna River and LMB from Sayres Lake LMBv was not detected in SMB from the Delaware andd Allegheny All h Rivers Ri

External Lesions 2005 2007

2007 Sample S l SitSites Susquehanna River Danville Shady Nook Montgomery Juniata River Granville

Pathogens Detected Fungi Internal and External parasites it Columnaris Gills Skin Kidney Motile aeromonads Largemouth bass virus

Granville Site 2005 2007 Random Sample: Yes Yes Number of YOY SMB: 50 18 Skin Lesions: 56% 67%

Severe Skin Lesions: 26% 33%

Gill Columnaris: 2% 7%

Systemic F. columnare 50% 7%

infection:

Wh Do Why D Fish Fi h Di Diseases O Occur?  ?

Susceptible Predisposing Host Environment Virulent Pathogen DISEASE

Columnaris Bacterial infection caused by Flavobacterium columnare A common soil and water bacteria All freshwater fish species are susceptible Above 56o F can cause significant mortality An opportunistic pathogen The disease is associated with damage to the skin ki or gills, ill nutritional t iti l deficiencies, d fi i i spawning stress and environmental stressors

Predisposing Environmental Factors Above 56 oF significant columnaris epizootics can occur The optimum growth temperatures for F.

columnare are 82 to 86 oF July 20 - August 5, 2005 pre- and post-dawn water temperatures were l 81 oF approximately i

Predisposing Environmental Factors For warmwater fish species, growth is inhibited at dissolved oxygen levels of 1 to 5 mg/l July 20 to August 5, 2005 pre- and post-dawn dissolved oxygen levels varied f

from 3.1 3 1 tto 6 6.3 3 mg/l

/l

Largemouth Bass Virus and the Juniata River Smallmouth Bass Mortality No documented cases of the virus causing mortality in species other than largemouth bass LMBv causes mortality only in adult largemouth bass Carrier infections in guppies, smallmouth and spotted bass, white and black crappie, Suwanee bass, bluegill and redbreasted sunfish LMBv does not cause external lesions In 2005, the LMBv titers in adult largemouth bass from Sayre Lake were as much as 100,000 x higher The 2007 preliminary histology assay data indicate that the observed tissue changes do not resemble those associated with LMBV

Additi l LMBV Sampling Additional S li in i 2007 Sampling Viral Assay Site Completed Results Allegheny River - Tionesta Sept 10 Pending Lower Allegheny River Pending N.A.

Delaware River - Matamoras Sept 5 Pending Delaware River - Kitnersville Aug 29 Pending Susquehanna River - Laceyville Aug 29 Pending

Susquehanna River Drainage YOY Smallmouth Bass 2005 & 2007 Disease Investigation Summary Low level internal and external parasite infestations Low level fungal and LMBv infections E i Environmental t l Conditions C diti high water temperatures low dissolved oxygen low water flows other stress factors External and systemic columnaris