6. Likelihood of Introducing Nonindigenous Organisms
79
making process. Risk communication can assume a variety of forms such as
consultation with stakeholders during preparation of risk assessments, public
hearings on proposed actions, and publication of risk assessments. This concept of
risk analysis and the associated definitions conform with most international agreements concerning trade in agricultural commodities and the primary literature in
the field of risk analysis. In this chapter, we focus on the assessment component of
risk analysis.
Plant Pest Risk Assessments for Nonindigenous Organisms
Risk assessments focus on three basic questions: what can go wrong, how bad
would it be, and what is the likelihood that it will happen? Each of these questions
is discussed in the following sections. Risk assessments are science-based evaluations; however, they are not original scientific research. Risk assessments form a
link between scientific data and decision makers and express risk in terms appropriate for decision making. Risk assessments are conducted to support decisions
that must be made regarding agricultural trade, the quarantine status of various
organisms intercepted at U.S. borders, and domestic regulation of agricultural
commodities. Assessments are considered necessary but not sufficient on their
own to provide the basis for regulatory decisions. The process for pathway
(commodity-based) plant pest risk assessments (USDA 1995a) has nine steps. It
starts by documenting the purpose and scope of the assessment, identifying any
previous risk assessments or decisions regarding the entry status of the commodity, and describing the current status of commodity importations. The biological portion of the assessment starts by considering the “weediness potential” of
the commodity. The focus of these biological assessments is on the three key
issues in any risk assessment, summarized by the three following questions.
What Can Go Wrong?
Frequently, we state this question as “What is the bad event?” This phase of a risk
assessment typically is referred to as hazard identification. The answer to the
question determines the endpoint of the risk assessment. The bad event for most of
our assessments is the introduction or spread of a nonindigenous plant pest.
Introduction means the entry and establishment of an organism (Hopper 1995;
FAO 1996) in a new area. Entry and establishment are distinct phenomena and
should be considered separately. Although entry of nonindigenous organisms is
frequently considered undesirable, entry does not necessarily imply establishment. It is probably safe to assert that many more nonindigenous organisms enter
an area than ever become established. Establishment can be defined as growing
and reproducing successfully in a given area (Lincoln et al. 1982).
The hazard identification phase of the assessment typically involves identifying
the species of nonindigenous plant pests that may be moved with the commodity.
The process of determining which pests are quarantine pests follows inter-
79
making process. Risk communication can assume a variety of forms such as
consultation with stakeholders during preparation of risk assessments, public
hearings on proposed actions, and publication of risk assessments. This concept of
risk analysis and the associated definitions conform with most international agreements concerning trade in agricultural commodities and the primary literature in
the field of risk analysis. In this chapter, we focus on the assessment component of
risk analysis.
Plant Pest Risk Assessments for Nonindigenous Organisms
Risk assessments focus on three basic questions: what can go wrong, how bad
would it be, and what is the likelihood that it will happen? Each of these questions
is discussed in the following sections. Risk assessments are science-based evaluations; however, they are not original scientific research. Risk assessments form a
link between scientific data and decision makers and express risk in terms appropriate for decision making. Risk assessments are conducted to support decisions
that must be made regarding agricultural trade, the quarantine status of various
organisms intercepted at U.S. borders, and domestic regulation of agricultural
commodities. Assessments are considered necessary but not sufficient on their
own to provide the basis for regulatory decisions. The process for pathway
(commodity-based) plant pest risk assessments (USDA 1995a) has nine steps. It
starts by documenting the purpose and scope of the assessment, identifying any
previous risk assessments or decisions regarding the entry status of the commodity, and describing the current status of commodity importations. The biological portion of the assessment starts by considering the “weediness potential” of
the commodity. The focus of these biological assessments is on the three key
issues in any risk assessment, summarized by the three following questions.
What Can Go Wrong?
Frequently, we state this question as “What is the bad event?” This phase of a risk
assessment typically is referred to as hazard identification. The answer to the
question determines the endpoint of the risk assessment. The bad event for most of
our assessments is the introduction or spread of a nonindigenous plant pest.
Introduction means the entry and establishment of an organism (Hopper 1995;
FAO 1996) in a new area. Entry and establishment are distinct phenomena and
should be considered separately. Although entry of nonindigenous organisms is
frequently considered undesirable, entry does not necessarily imply establishment. It is probably safe to assert that many more nonindigenous organisms enter
an area than ever become established. Establishment can be defined as growing
and reproducing successfully in a given area (Lincoln et al. 1982).
The hazard identification phase of the assessment typically involves identifying
the species of nonindigenous plant pests that may be moved with the commodity.
The process of determining which pests are quarantine pests follows inter-