Problem formulation and scoping
A multi-step process centered around expert stakeholder input was
designed for the risk ranking exercise (Table 1). As first step, an
initial cluster of stakeholder-experts with expertise in fish health and
aquatic invasive species prevention were identified from the Minnesota
Department of Natural Resources (MNDNR) to provide input throughout the
process and to ensure study outcomes aligned with the state management
objectives.
Best practices indicate that clarifying the objective, question, or
endpoint of interest is critical for the accuracy and applicability of a
risk assessment (Jakob-Hoff et al., 2014). Therefore, the second step of
the risk ranking exercise was to define the primary question of the
analysis, which was formulated as: “What pathogens are most likely to
present a risk to the health of wild fish via release of infected
baitfish?” Although there is some evidence that potential human and
wildlife pathogens (Mahon et al. 2018; Picco et al. 2010) may be present
in live baitfish, the scope of this study was limited to pathogens of
fish. After the definition of the project question, an initial list of
pathogens to be assessed was obtained from existing qualitative
evaluations (Boersen et al. 2017; Gunderson 2018) and lists of important
(regulatory) fish pathogens curated by the OIE (Aquatic Animal Health
Code, OIE) and Minnesota law (MN Statute 17.4982). Inclusion/exclusion
criteria were developed based on host susceptibility for the initial
hosts, live baitfish that could be legally used in Minnesota as listed
in the 2018 fishing regulations handbook (accessible at
https://files.dnr.state.mn.us/rlp/regulations/fishing/fishing_regs.pdf),
and the recipient population (described as “fish of concern”), which
included game fish, fish listed as threatened or endangered by the
Minnesota Endangered Species Statute (MN Statute 84.0895), or fish
receiving management attention from MNDNR (Figure 1).