Transcript FACTORS INFLUENCING INTRODUCTION OF MYXOBOLUS …

DEVELOPMENT OF A MODEL
FOR ASSESSING WHIRLING
DISEASE RISK
What is a Risk Analysis?
• Risk analysis is a tool intended to provide
decision makers with an objective, repeatable
and documented assessment of the risks posed
by a particular course of action.
• Risk analysis is intended to answer;
• What can go wrong?—the hazard identification,
• How likely is it to go wrong and what would be
the consequences of its going wrong?—the risk
assessment, and
• What can be done to reduce either the likelihood
or the consequences of its going wrong?—risk
management.
Risk Analysis
• Hazard identification
– Myxobolus cerebralis
• Risk assessment
• Release assessment
• Exposure assessment
• Consequence assessment
• Risk estimation
Release Assessment
FACTORS AFFECTING
PARASITE INTRODUCTION
+/System 1
(source)
System 2
Overt
disease
pathways for parasite introduction and dispersal
viability of parasite during introduction
Exposure Assessment
FACTORS AFFECTING
PARASITE
ESTABLISHMENT
+/System 1
(source)
System 2
Overt
Disease
Encounters between parasites and hosts
Infection of worm host
Proliferation of infectious stages
Consequence Assessment
FACTORS AFFECTING
DISEASE MANIFESTATION IN
FISH
+/System 1
(source)
System 2
Overt
disease
pathways that are conducive to the development
of the parasite and whirling disease in the fish
Fry
Juveniles
Adults
Species
Boaters,
anglers
Recreational
Activities
Stream
enhancement
Restoration
Activities
Infected fish
products
Commercial Activities
Fish Transfer
Source
Introduction
Natural Dispersal
Free myxospores,
triactinomyxons
Avian
Wild fish
Worms
Species susceptibility
Biotic Community
Population density
Fish
Introduction
frequency
Introduction
size
Spatial/Temporal
Overlap
Establishment &
Proliferation
Habitat
use
Organisms
life histories
Worms
Temperature
Environment
Population density
Substrate
Flow
System Modification
Strain susceptibility
Species susceptibility
Size
Age
Fish
Virulence
Pathogen
Disease
Dose
Environment
Temperature
Goals of Risk Assessment
Workgroup
• To complete the risk assessment exercise begun
at the 2003 WDS
• Develop examples of how a risk assessment
exercise can be used
• Publish a manuscript on a RA model for
whirling disease in Fisheries
• Make model accessible by providing to
National Partnership for further dissemination