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 YOY Smallmouth Bass Disease Investigations 2005 and 2007 2005 and 2007

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

External Lesions External Lesions F

i Fungi Motile Motile aeromonads Pseudomonads Flavobacteria

Parasites on the Skin Parasites on the Skin S h hidi Schyphidia Glossatella Trichodina Trichodina

Kid Ti A

Kidney Tissue Assay Flavobacterium columnare isolated

Granville Site R

d l

t fi hi Random electrofishing sample Fifty YOY SMB Fifty YOY SMB 56% - skin lesions 26% - severe skin lesions 2%

ill l

i Granville 2% - gill columnaris 50% - systemic F.

columnare infection columnare infection

Viral Assay Results

Largemouth Bass virus detected in SMB from the detected in SMB from the Juniata River Narrows

First detection of LMBv in

First detection of LMBv in fish from PA waters

Later in 2005 LMBv was Sayres Lake Tunkhannock

Later in 2005 LMBv was detected in SMB from the Susquehanna River and LMB from Sayres Lake Narrows

LMBv was not detected in SMB from the Delaware d All h

Ri and Allegheny Rivers

External Lesions 2005 2007 2005 2007

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

Pathogens Detected Pathogens Detected

Fungi

Internal and External it parasites

Columnaris Gills Gills Skin Kidney

Motile aeromonads

Largemouth bass virus

Granville Site 2005 2007 Random Sample:

Yes Yes Number of YOY SMB:

50 18 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 D Fi h Di O

?

Why Do Fish Diseases Occur?

Susceptible Predisposing Susceptible Host Predisposing Environment Virulent Pathogen Pathogen DISEASE

Columnaris 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 ki ill t iti l d fi i i

skin or gills, nutritional deficiencies, spawning stress and environmental stressors

Predisposing Environmental 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 i

l 81 F approximately 81 oF

Predisposing Environmental 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

3 1 t 6 3

/l from 3.1 to 6.3 mg/l

Largemouth Bass Virus and the Juniata River 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 S li i 2007 Additional LMBV Sampling in 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 Delaware River - Kitnersville Aug 29 Pending Susquehanna River - Laceyville Aug 29 Pending

Susquehanna River Drainage YOY Smallmouth Bass YOY Smallmouth Bass 2005 & 2007 Disease Investigation Summary Disease Investigation Summary

Low level internal and external parasite infestations infestations

Low level fungal and LMBv infections E

i t l C diti

Environmental Conditions high water temperatures low dissolved oxygen low water flows other stress factors

External and systemic columnaris