Table A1.

Consolidated Criteria for Reporting Qualitative Studies (COREQ) Checklist

Domain 1: Research team and reflexivity
Personal Characteristics
Researcher name, credentials, gender, Native affiliation, occupation, and experience and training	Interviewers
	Hugh B. Roland, PhD
	Identifies male
	No Native affiliation
	Postdoctoral Fellow
	Environmental sociologist with training in qualitative research methods and experience in community‐based participatory research
	Jacob Kohlhoff, BS
	Identifies male
	No Native affiliation
	Environmental Education Coordinator
	Trained in relevant qualitative research techniques by Hugh Roland
	Sneha Hoysala, MPH
	Identifies female
	No Native affiliation
	Master of Public Health student during research activities
	Trained in relevant qualitative research techniques by Hugh Roland
	Non‐Interviewers
	Kari Lanphier, MS
	Identifies female
	Kānaka
	Environmental Program Manager
	Expertise in harmful algal blooms, shellfish toxin analysis, community program management, and shellfish toxin risk communication
	Esther G. Kennedy
	Identifies female
	No Native affiliation
	Environmental Specialist and SEATOR Project Manager
	Expertise in harmful algal blooms and community program support
	Christopher Whitehead
	Identifies male
	No Native affiliation
	Environmental Program Manager
	Expertise in harmful algal blooms, shellfish biology, community program development, and project design
	Matthew O. Gribble, PhD
	Identifies male
	No Native affiliation
	Associate Professor
	Environmental epidemiologist with experience in community‐based participatory research
	John Harley, PhD
	Identifies male
	No Native affiliation
	Assistant Research Professor
	Environmental toxicologist with experience in harmful algal bloom modeling and toxin dynamics in shellfish
Relationship with Participants
Relationship established	Several members of the research team have professional relationships with participants and were familiar to participants. This familiarity was unavoidable in this small professional community and necessary to identify prospective key informants
Participant knowledge of the interviewer	Participants were informed of the research rationale when invited to participate and prior to the start of interviews
Interviewer characteristics	As several members of the author team are affiliated with STA or SEATOR, the research team is interested in the direct policy relevance of this research
Domain 2: Study design
Theoretical framework
Methodological orientation and Theory	Thematic analysis was used to analyze qualitative data
Participant selection
Sampling	Purposive sampling was used by SEATOR affiliated members of the research team to identify prospective key informants. Prospective participants were environmental managers responsible for tribes' toxin testing and others with shellfish toxin expertise invited to attend the Southeast Environmental Conference hosted by the Central Council of the Tlingit and Haida Indian Tribes of Southeast Alaska and STA from 29 August 2022 to 2 September 2022. 40 prospective participants were identified, including all environmental managers responsible for shellfish toxin testing at subsistence sites in Southeast Alaska
Method of approach	Participants were invited to participate via email
Sample size	27 participants were interviewed in the study
Non‐participation	13 participants either chose not to participate or could not participate because of scheduling conflicts
Setting
Setting of data collection	In‐person interviews were conducted in a private or semi‐private setting in the same building as the Southeast Environmental Conference. Interviews with participants unable to attend the conference were conducted via Zoom
Presence of non‐participants	No one was present during interviews besides participant and interviewer
Description of sample	The sample consisted of environmental managers responsible for tribes' shellfish toxin testing and others with shellfish toxin expertise invited to attend the Southeast Environmental Conference hosted by the Central Council of the Tlingit and Haida Indian Tribes of Southeast Alaska and STA from 29 August 2022 to 2 September 2022
Data collection
Interview guide	Interviewers used a semi‐structured interview format, where questions were asked from an interview protocol, with follow‐up questions. Questions were organized into several sections: background demographic information, perceptions of the importance of shellfish toxin testing and education, the state of shellfish toxin testing, and barriers and facilitators to toxin testing. The protocol was pilot tested with STA staff and SEATOR members not included in the research team and not invited to participate in interviews
Repeat interviews	No repeat interviews were carried out
Audio/visual recording	Interviews were audio recorded
Field notes	Interviewers made field notes during and after interviews to note relevant contexts and identify emerging themes.
Duration	Interviews lasted from 30 min to 1 hr.
Data saturation	Data saturation considerations did not determine the end of interview conduct. Interviews were conducted with all available identified prospective participants. Following data collection, interviewers agreed that data saturation had been met
Transcripts returned	Transcripts were not returned to participants
Domain 3: Analysis and findings
Data analysis
Number of data coders	The three interviewers coded data. Each interview was coded by a minimum of two coders
Description of the coding tree	Parent codes included shellfish harvesting practices, reasons why people harvest, reasons why people don't harvest, PSP risk perception, toxin exposures, PSP in the community, toxin testing, strengths of toxin testing programs, challenges to toxin testing programs, community engagement, partnerships, and program suggestions
Derivation of themes	Themes were derived from the data
Software	Data analysis was conducted using Dedoose software
Participant checking	Participants did not review findings. SEATOR and STA affiliated members of the research team were involved in data analysis and provided feedback on findings
Reporting
Quotations presented	Participant quotations are used frequently to illustrate themes and findings. Each quotation is identified with a participant number
Data and findings consistent	Participant quotations illustrate consistency between data and findings
Clarity of major themes	Results and discussion are organized by major themes
Clarity of minor themes	Heterogeneity in the data and minor themes are noted where appropriate