Harmful Algal Blooms

Publication Date: 2023

Abstract

Since the mid-1980s, the Tenmile Lakes region on the south-central Oregon coast has been affected by harmful algal blooms with toxin-producing cyanobacteria. These hazard events are known as cyanoHABs, and they have compelled the Oregon Health Authority to issue advisories on multiple occasions that discourage residents from using the lake for recreation or household drinking water for periods spanning weeks to months. With one-quarter of the Tenmile population reliant on lake water for household use and the local economy highly dependent on lake-based recreational tourism, cyanoHABs cause significant health concerns and economic harm in this rural community. With this project we aim to achieve four objectives: (1) determine how residents perceive their health risk from cyanoHABs and how they view the public health response; (2) assess the risk of exposure from lake water and tap water for residents living along the lake; (3) characterize local reliance on the lake and routes of exposure to cyanotoxins, and (4) work with community members to improve cyanoHAB monitoring, guidance, and response. Our multimethod research project employs community-based research design and data collection, citizen science training, longitudinal water sampling and testing for cyanotoxins, and surveys and focus groups with community members. The preliminary results from our water quality testing suggest that cyanotoxin levels exceed state and federal guidelines for potable use, and risk may vary with location along the lake. Our community-based methods have also revealed that community members feel high levels of distrust for federal, state, and local public health agencies because these agencies have had conflicting messaging, lack of transparency, and little community engagement about hazardous blooms. Our results have several implications for public health including highlighting the importance of investing in strong public and environmental health systems and programs in rural communities impacted by cyanoHABs in order to understand the local natural and cultural resource context, as well as emphasizing the value of building strong local partnerships and employing citizen science and community-based research to foster transparency and trust.

Introduction

Harmful algal blooms have been increasing in severity, duration, and intensity across the globe and North America in recent decades. These naturally occurring hazard events are exacerbated by human settlements, farming, and other activities, rendering surface waters hazardous for human and animal consumption and recreational use for weeks to months at a time. The blooms can also devastate local economies and impair human and animal health. Toxic blooms can be formed by several naturally occurring microscopic organisms that proliferate and respond to nutrient loading, light, and temperature conditions. Not all of these organisms produce toxins, but some do, and their production of toxins can vary considerably over the course of hours and days. Freshwater cyanobacterial harmful algal blooms (cyanoHABs) are particularly insidious since they impact recreational waters and can also pose a threat to municipal drinking water sources, private wells, or other private household water sources. They can produce a number of different toxins that last for weeks to months in the water, even after the cyanobacteria producing them have died.

Public health agencies are responsible for providing guidance, monitoring, and surveillance of freshwater cyanoHABs; but, due to limited resources, most of their cyanoHAB efforts are focused on densely populated metropolitan areas or popular recreational sites in the United States. Recently, Toledo, Ohio, and Salem, Oregon, experienced toxic blooms that affected their municipal water sources for weeks to months at a time, forcing the governors of each respective state to send the National Guard to distribute bottled water to affected households. While the risk communication and distribution of information by public health authorities was far from perfect in both cases, the effort and resources that went into addressing these urban cyanoHAB events contrasts sharply with what occurs in rural communities where access to public health guidance, monitoring, and communication is extremely limited.

We focus on one such rural community, Tenmile Lakes, Oregon, which includes the town Lakeside and surrounding rural areas, along the state’s south-central coast. CyanoHAB hazard events at Tenmile result from high counts of toxin producing cyanobacteria, including Microcystis Aeruginosa, Aphanizomenon flos-aquae, and Dolichospermum plantctonicum (formerly Anabaena planctonica) (Hall et al., 2019¹; Oregon Department of Environmental Quality [ODEQ], 2007²). Tenmile Lakes serve as the primary source of household drinking water for approximately 25% of the local population; these typically residents install and manage their own intake and treatment systems to pull water from the lake.

The Oregon Health Authority (OHA) and Oregon Department of Environmental Quality (ODEQ) share the legislative mandate for responsibility and oversight for protecting the public from the health effects of cyanoHABs. OHA can issue recreational and drinking water advisories and also instructs any monitoring related to cyanoHABs response. ODEQ conducts sampling and analysis of drinking water and freshwater recreational sites as requested by OHA (Oregon Health Authority [OHA], 2022a³, 2022b⁴). In addition, ODEQ identifies waterbody impairments because of HABs and helps to develop management solutions (ODEQ, 2007). OHA’s drinking water rule provides resources to monitor and support municipal and public water systems in cyanoHAB events but does not extend to private water sources. The general guidance for households with private water sources counsels residents to ensure adequate treatment or seek another source during cyanoHABs (OHA, 2022a). The situation at Tenmile Lakes is likely representative of many rural communities facing similar hazard events impacting freshwater sources; indeed, 20% of Oregon households are estimated to be on private sources of water (Schimpf & Cude, 2020⁵).

In addition, while the ODEQ monitors cell counts and cyanotoxins at Tenmile Lakes in select locations for the purposes of recreational monitoring and for developing management solutions, funding for these efforts is insecure due to state budget constraints. Given the spatial and temporal variability of both cyanobacterial cells and toxins, a household on a different location along an arm of the lake from monitoring sites could face a substantially different risk, even from recreational use near their house. As such, OHA guidance states:

A water body with no recreational health advisory is not an indication that a bloom is not present. You are your own best advocate when ensuring your safety, and that of your family and pets. Be aware and "when in doubt, stay out." (OHA, 2022b, Disclaimer for table of advisories)

Our community-centered project examines how harmful algal bloom hazard events have impacted the health and wellbeing of residents in one rural community. We have four research objectives: (1) determine how residents perceive their health risk from cyanoHABs and how they view the public health response; (2) assess risk of exposure from lake water and tap water for residents living along the lake; (3) characterize local reliance on the lake and routes of exposure to cyanotoxins, and (4) work with community members to improve cyanoHAB monitoring, guidance, and response.

Our research design employs a community-based participatory research (CBPR) model, citizen science, and mixed research methods. This combined approach has enabled us to begin to longitudinally monitor lake and tap water, to document how vulnerable rural populations experience the impacts of cyanoHABs, and to generate community-based ideas for improving risk communication and sustainable intervention strategies to mitigate cyanoHAB impacts at Tenmile Lakes and more broadly in rural communities across the United States. Our long-term goal is for this project to be a catalyst in reducing the health burdens imposed on vulnerable rural populations during cyanoHAB disaster events. To our knowledge, CBPR methods have not been used before to study cyanoHAB hazards in a rural U.S. context.

Literature Review

Public Health Risk From Cyanotoxins

Freshwater cyanoHABs are an emergent public health threat globally, as climate change contributes to their increasing frequency, duration, severity, and unpredictability (Burford et al., 2020⁶; Griffith & Gobler, 2020⁷; Huisman et al., 2018⁸). CyanoHABs produce acute and chronic toxicants of immense concern for human and animal populations and threaten food and water security (Codd et al., 2020⁹; de la Cruz et al.¹⁰, 2020; Lad et al., 2022¹¹). Cyanotoxins vary in structure, environmental persistence, and target manifold systems including the hepatobiliary, integument, nervous, renal, cardiovascular, digestive, and immune systems (Lad et al., 2022; Merel et al., 2013¹²). The primary routes of exposure are ingestion of drinking water from a bloom-laden source, contaminated shellfish and seafood, crops irrigated with bloom-laden water, and water ingestion and skin contact during recreational activities. In addition to gastrointestinal, respiratory, and skin irritation by bloom components, increasing evidence also points to toxin absorption through skin and inhalation through aerosolization during recreational activities (Codd et al., 2020; Lad et al., 2022; Nielsen & Jiang, 2020¹³).

The most commonly identified group of cyanotoxins in freshwater, microcystins (MCs), acutely target the liver and have a peptide ring structure that makes them difficult to breakdown and remove from water. Cylindrospermopsin (CYN) is another potential liver toxin that is predominantly released outside the cells of cyanobacteria as dissolved toxins. Yet both MCs and CYN can be held inside healthy cells of cyanobacteria. When blooms begin to “die off, there can be an additional release of dissolved toxins into the water (Codd et al., 2020; de la Cruz et al., 2020; Lad et al., 2022; Merel et al., 2013). Both MCs and CYN have been shown to have chronic health impacts, especially relevant since they can also both persist in surface waters for weeks to months due to their stable structures. Anatoxin-a and saxitoxins are alkaloids produced in some blooms that can be potent nerve toxins resulting in paralysis or death (Christensen & Khan, 2020; Testai et al., 2016¹⁴). Although they generally do not remain in water as long as the more stable MCs and CYN, there is also increasing evidence that chronic exposure leads to adverse health outcomes (Christensen & Khan, 2020¹⁵; Testai et al., 2016). Cyanobacterial blooms also have other bioactive metabolites that are unregulated and largely unmonitored by public health agencies. At Tenmile, MCs have been the most commonly found toxin; however, CYN and anatoxin have also been detected, albeit at trace amounts (Hall et al., 2019; ODEQ, 2007).

Cyanobacterial Hazardous Algal Bloom Public Health Guidelines and Advisories

The U.S. Environmental Protection Agency (EPA) and United Nations World Health Organization (WHO) have issued provisional guidelines for cyanotoxin levels in potable water and freshwater used for recreation. The guidelines remain provisional and not regulated as these are natural toxins although anthropogenic activities and nutrient loading augment their production. Various states have adopted comparable or more stringent guidelines (World Health Organization [WHO], 2020a¹⁶, 2020b¹⁷, 2020c¹⁸, 2020d¹⁹, 2022²⁰; U.S. Environmental Protection Agency [EPA], 2015a²¹, 2015b²²; OHA, 2021). Table 1 provides an overview of these provisional guidelines for the four toxins mentioned above.

Table 1. Public Health Guidance for Cyanotoxin Levels in Potable and Recreational Waters

When these cyanoHABs occur in public potable water sources or water used for fishing, or recreation, particularly in more urban and densely populated areas, public health agencies typically issue health advisories and alerts that ask the public to avoid recreational activities on the water and to seek an alternate source of potable water (Chorus & Bartram, 1999²³; Farrer et al., 2015²⁴; Ibelings et al., 2015²⁵; EPA, 2015a, 2015b). However, communication of these advisories and risks do not equally reach all communities nor all individuals and can have a compounding economic burden on communities reliant on surface waters for local economy, fishing, and potable water (Hamilton et al., 2014²⁶; King, 2021²⁷; Kouakou & Poder, 2019²⁸; Kourantidou et al., 2022²⁹; Liu & Klaiber, 2023³⁰). In other scenarios, an alternate source of water, food, or livelihood may simply not be available (Mchau et al., 2019³¹; Roegner et al., 2020³²; Roegner et al., 2014³³).

Difficulty of Removal of Cyanotoxins From Drinking Water Supplies

Globally, cyanoHABs impact sources of freshwater that supply municipal water systems. They also affect an unknown number of households that pull water for domestic use directly from surface waters, with little to no treatment (de la Cruz et al., 2020; Ibelings et al., 2015; Roegner et al., 2014). Even in U.S. municipalities with substantial resources for water treatment, removing cyanoHAB physical bloom material and their toxins is very difficult. Potable water sources can be compromised for periods lasting days to month. The blooms can clog filters, cyanobacterial cells can die and release more toxins in the treatment process, and bloom material can affect water pH and turbidity; as a result of these complications, chemicals or other physical materials designed to treat the water become far less effective (Codd et al., 2020; de la Cruz et al., 2020; Farrer et al., 2015; Roegner et al., 2014). Typically, a multi-step process is needed to ensure that water is safe for consumption; the three major steps needed for treatment include: (1) adequate removal of cells, (2) oxidation to facilitate break down, and (3) physical removal with activated carbon. However, each step in this process can be time consuming, highly site specific, and costly as activated carbon and other filters have to be replaced. In other types of potable water contamination emergencies, public health officials often advise the public to boil water prior to consumption. Boiling water to prevent cyanotoxin exposure, however, is not effective and can be dangerous. Boiling water actually concentrates cyanotoxins as the water evaporates and puts anyone who consumes that water at higher risk for cyanotoxin health effects. In fact, during cyanoHABs, it is important to educate the public about the dangers of boiling water.

Social Vulnerability During Harmful Algal Bloom Crises in the United States

As mentioned above, Toledo, Ohio, and Salem, Oregon—two U.S. cities with populations of over 500,000 residents—were impacted by cyanoHAB hazard events in 2014 and 2018, respectively. The blooms made municipal drinking water dangerous for human or animal consumption. and the EPA issued health advisories stating that cyanotoxins levels were dangerously high for young children, pregnant women, pets, and other vulnerable populations. These groups were advised to utilize an alternate source of water, without clear guidance or emergency messaging. Both cities eventually ran out of bottled water supplies, leaving citizens to fend for themselves (Bratton et al.³⁴, 2016; Miles, 2020³⁵; Radnovich, 2018³⁶).

In both cases, public health messaging simply did not reach vulnerable populations. A 2020 Oregon Water Futures Project Report, for example, chronicled how public health communication has failed to protect vulnerable populations—including migrant farmworkers, rural populations and tribal members—during the Salem disaster and others hazardous algal bloom events, (Reyes-Santos et al., 2021³⁷). Similar critiques on reach, scope, and timeliness of public health messaging during the Toledo crisis emerged when the incident and response was reviewed (Bratton et al., 2016).

Rural areas at risk for cyanoHABs rarely have their waters monitored for evidence of blooms, except by remote sensing or citizen reporting, despite increasing evidence of domestic animals, wildlife, and humans being exposed and intoxicated across the United States (Hilborn & Beasley, 2015³⁸; Roberts et al., 2020³⁹). The OHA and ODEQ acknowledge that they do not have the capacity to monitor all surface waters used for private household consumption or recreational sites in the state and cautions individuals to take their own precautions (OHA, 2022b). OHA, however, also recognizes that the 20% of the state’s population that relies on privately sourced water are very vulnerable to potential breakthrough or accumulation of cyanotoxins (Schimpf & Cude, 2020). In addition, public water infrastructure in rural Oregon is dilapidated and private well owners often lack the means to ensure consistent water access and quality (Reyes-Santos et al., 2021; Schimpf & Cude, 2020).

Natural Hazards and Rural Communities

Rural areas across the United States tend to have less resources for natural hazard preparedness, response, recovery, and mitigation (Federal Emergency Management Agency [FEMA], 2020⁴⁰). In the case of cyanoHAB hazards, public health guidance developed for urban contexts may be less applicable, involve conflicting guidance in appropriate treatment or precautionary measures, and be less accessible (Afifi et al., 2022⁴¹; FEMA, 2020; Hallegatte, et al., 2020⁴²). These gaps are exacerbated by lack of hazard monitoring which is needed to identify risks in a timely manner, the small number of public health officials assigned to rural areas due to low population density, and the general lack of public health infrastructure and resources in rural areas (FEMA, 2020; Friedman et al., 2023 ⁴³; Shi et al., 2021⁴⁴). Absent efforts to strengthen rural climate adaptation and community resilience, the risks posed by natural hazards to rural communities will grow.

Rural populations also tend to have a higher level of distrust of local, state, and federal public health authorities than urban populations (Lister & Joudrey, 2022⁴⁵). During hazard events, conflicting, confusing, and absent messaging or guidance can compound this distrust. Moreover, state and federal officials are often unfamiliar with rural communities and lack relationships with people “on-the ground” that are needed to contextualize hazard events. In the case of cyanoHABs, public health officials must have regular communication with community members to be able to understand the variability of blooms and the unique context of each community and watershed.

Public health officials must start building trust with rural communities prior to hazard events by listening to community needs, providing credible data and reliably identifying the gaps in knowledge and uncertainties, and acknowledging the need for an iterative process in partnership with the community to truly find long-term solutions (FEMA, 2020). As the next section describes, community-based participatory approaches to water research provide an opportunity to build trust between researchers and the community and can also help to facilitate a bottom-up approach to alert systems, empower rural citizens, democratize the process of local knowledge generation, and yield smart long-term decision-making (Roque et al., 2022⁴⁶; Yasmin et al., 2023⁴⁷).

Community-Based Participatory Research and Citizen Science

CBPR has the potential to improve the rigor, relevance, and reach of environmental hazard research through the inclusion of local communities in the planning, prevention, response, mitigation, and repair from natural hazard events (Horowitz et al., 2009⁴⁸; Rohlman et al., 2022⁴⁹). CBPR can take a wide range of forms and take place at various stages of the research process from design to data collection to analysis and dissemination of results, and has to be carefully navigated to avoid reinforcing existing power dynamics and societal inequities (Horowitz et al., 2009; Kondo et al., 2019⁵⁰; Rohlman et al., 2022; Wallerstein & Duran, 2010⁵¹). Ultimately, CBPR has the potential to empower vulnerable groups and define or identify sustainable interventions (Balazs & Morello-Frosch, 2013 ⁵²; Ruszczyk et al., 2020⁵³), particularly if the process employs mixed methods, is iterative, and incorporates new modalities and technologies for data aggregation, as well as new modes of communicating and depicting outcomes of findings easily accessible to the lay public (DeRouen & Smith, 2021⁵⁴; Kim & Reed, 2021⁵⁵; Moezzi & Peek, 2021⁵⁶; Roque et al., 2022).

Citizen science is also a community-based approach that involves community members directly in data collection and generation during the course of the research. It adds a dimension in which community members are trained to collect scientific data and educated on the topic, and has the potential to improve their understanding of hazard events, like cyanoHABs, as well disseminate important public health information organically (Gharaibeh et al., 2021⁵⁷; Roegner et al., 2017⁵⁸; Rohlman et al., 2022; Roque et al., 2022). Citizen science can also facilitate trust and confidence in data when community members see how the data is being collected and analyzed in real time.

Research Questions

We developed this project to understand the impacts of freshwater cyanoHAB hazard events on rural and vulnerable communities at Tenmile Lakes. We posed four research questions:

1. How do Tenmile Lakes residents perceive the risk posed to their health and wellbeing by cyanoHABs? What views do they have about how public health agencies monitor lake water for cyanotoxins and respond to bloom events?
2. What is the risk of exposure to cyanotoxins to individuals who use the lake for recreation water and to Tenmile households who draw lake water for domestic use and consumption?
3. To what degree do the local population and seasonal visitors rely on Tenmile Lakes for household consumption or recreational use, and what are the potential routes of cyanotoxin exposure to lake users?
4. What do Tenmile Lakes residents recommend that public health agencies do to improve their cyanoHAB monitoring, guidance, and response in the area?

Research Design

Overview

Embracing CBPR principles, we dedicated ourselves to an iterative research design process. Based on initial conversations in the fall of 2022 with our research partner, the Tenmile Lakes Basin Partnership (TLBP) who we describe in more detail below, we designed a multimethod research project that involved the following activities: (a) community-based research design and data collection methods, (b) longitudinal water sampling and testing for cyanotoxins, (c) citizen science trainings, and (d) surveys and focus groups with community members. Figure 1 displays our multiple research activities and timeline. As Figure 1 shows, we used community-based methods to get feedback on our research design from community members, trained citizen scientists, and worked with citizen scientists to collect initial water samples during the low-risk period for cyanoHABs between December 2022 and May 2023. The right side of Figure 1 shows how we scheduled surveys, focus groups, and ongoing water sampling and testing with citizen scientists to coincide with seasonal tourism and the high-risk period for cyanoHABs during late spring and summer 2023. As we explain in more detail below, community members provided substantial input into developing this timeline.

Figure 1. Research Activities and Timeline

Study Site

Since the mid -1980s, the Tenmile Lakes—which consist of North Tenmile Lake, South Tenmile and Tenmile Lake located on the south-central Oregon coast, near Lakeside, OR—has experienced cyanoHABs with high counts of toxin-producing cyanobacteria (Hall et al., 2019; ODEQ, 2007), and has been placed permanently on the ODEQ 303 (d) list of impaired water sources, as required by the Federal Clean Water Act. Lakeside is the main population center in the Tenmile Basin, with approximately 1,800 residents. The basin is classified as rural by the Oregon Office of Rural Health (n.d.)⁵⁹, and by the U.S. Census. Despite the fact that these cyanoHABs render the water unsafe for humans and animals for increasingly longer periods of time, Tenmile Lakes serve as the primary source of drinking water for domestic use for lakeshore residents, who make up approximately 25% of the local population, per the city manager and other city officials.

Residents have varied backgrounds and knowledge about the region, the impact of cyanoHABs, and the use of natural resources. The area has undergone a lot of recent change with tourism slowly replacing the main logging, fishing, and agricultural industries. As a result, there is a mixture of self-described “old-timers” that have been in the area through the changes and newcomers seeking to escape the crowds. In addition, although it does not fall within tribal lands, the Tenmile Lakes basin is an important area for Native peoples of the Coos, Siuslaw, and Umpqua Tribes. The basin is considered to have a high occurrence of cultural resources. In addition to members of the Confederated Tribes of Coos, Lower Umpqua and Siuslaw Indians (CTCLUSI), Coquille tribal members also consider the basin to have high cultural value.

Research Partner: Tenmile Lakes Basin Partnership

TLBP has been leading the effort to reduce the quantity and severity of cyanoHABs at Tenmile Lakes, as well as improving other aspects of water quality and protecting native fisheries. TLBP is a community-based nonprofit, involving industry, local citizens, natural resource agencies, Native American tribes, and conservation groups to protect, encourage and enhance the use of natural resource principles that promote ecosystem health and diversity.

Data Collection Activities

Initial Water Sampling and Testing for Cyanotoxins

On September 22, 2022, during the initial stages of planning for the grant and project, water was collected during visible blooms to establish an initial assessment of risk from the lake during the peak of bloom season. Surface grabs in 250 mL sampling bottles were taken from a boat at historical monitoring sites and areas of high use for recreation or contact. These included near North Lake Resort Beach (NR), North Lake Center (NC), Coleman Arm (CA), Devore Site (DS), the Yacht Club (YC), South Lake Boat Ramp (SL), Templeton Arm (TA), and Coleman Arm (CA). Samples were kept on ice and frozen until sent overnight on ice to the Miller Lab at University of Wisconsin-Milwaukee. Samples were then extracted for cyanotoxins and analyzed using mass spectrometry, using similar procedures from previous investigations by the lead author (i.e., Roegner et al., 2020; Roegner et al., 2019⁶⁰). Samples were analyzed for MCs, CYN, and anatoxins, as well as range of additional bioactive metabolites found in blooms with unknown health consequences, including anabaenopeptins, cyanopeptolins, and microginins.

Research Design Meetings with Community Members

We met with stakeholders and community members in December 2022 to inform them about our research project and receive feedback on our methods. The meetings were organized by TLBP and not recorded with less than ten individuals present for each discussion; the objective of the meetings was to discuss the aims of the research and review the preliminary survey questionnaire and focus group guides that we had developed. Participants in the meetings later related to us that they had also shared the questionnaire and guide with neighbors. During the meetings, we listened actively to feedback and suggestions and emphasized that this project was meant to empower community participants to protect their own health. As such, we asked community members to describe what they felt would be the most useful way to address the health risks, environmental and economic impacts, and other challenges caused by blooms. Community members expressed during the meeting that the most pressing needs to address were the following: (a) unclear information about the risk that cyanotoxins pose to residents and tourists throughout the year, even in the absence of visible blooms and cell counts; (b) lack of knowledge about the effectiveness of the treatment systems that households were currently using to make their water safe for domestic consumption; and (c) whether OHA recommendations, as implemented locally, were effectively reducing household risk from cyanotoxin exposure through drinking water.

During the meetings, we reached a consensus with community members that our research design should be revised to prioritize testing of household tap and lake water for cyanotoxins over time. Community members also expressed wanting to be involved with water quality monitoring and testing, so our new design included citizen scientist training with two groups of lakeside residents. Based on feedback, we decided to recruit citizen scientists from households using a range of different treatment types and whose residences were distributed across the lake. This diversity in sampling would provide invaluable information and provide better overall insight of risk from the lake. In addition, community members also gave input on the survey questionnaire and the focus group guide. Their recommendations included modifying questions in ways that would enhance trust. We followed up with revisions and further feedback with a handful of meeting participants over email in the subsequent months.

Citizen Science Training and Household Tap and Lake Water Testing

The citizen science training was designed to examine household risk at two points in time: (1) pre-treatment at the actual lake water source, and (2) post-treatment at the household tap. Our objectives in the citizen science training and participation were to: (a) engender trust and transparency through a shared passion and curiosity for scientific inquiry, (b) provide critical data to improve public health guidance locally and within rural communities, and (c) provide knowledgeable conduits for information to organically seep back into the community. We aimed to recruit up to twenty households to participate in the citizen science training and longitudinal water sampling and testing program. The first citizen training session was conducted in March 2023 and a second session for seasonal residents was scheduled for June 2023, after this paper was submitted for publication.

We recruited participants for the citizen science training through TLBP and Tenmile Lakes Association websites, emails, and word of mouth. To date, eleven lakeside households agreed to participate in the training and to test both their source and tap water for trace levels of cyanotoxins bi-weekly during the peak of the bloom season and monthly during absence of visible blooms. The first training was held on March 21, 2023, at TLBP headquarters and eight household representatives attended. During the training, we distributed sampling supplies, provided a general overview of the project, and trained participants in sample collection procedures, labeling, storage, and note keeping. (See Appendix A for a full description of the citizen science training components). We also recorded a demonstration video for household participants that could not attend the training or for training other households that express interests. Additional supplies were also left for these groups. During the trainings, we also provided an opportunity for participants to ask questions about blooms and their toxins and encouraged active discussion on the blooms, the lake, and their community and gave participants our contact information for follow-up questions and consultations. A number of participants reached out by email for information about how, when, and where to sample, or further refinements.

Figure 2 shows the distribution of the eight citizen scientist households around various sites on the lake, initially enrolled in March 2023. We included one participating household that uses well water adjacent to the lake; this household will sample both lake water and well water to evaluate the potential breakthrough of cyanotoxins into the well. During the training, we recorded details about the water treatment systems that each participating household uses to treat the water they draw from the lake. That information is provided in Appendix B. Since the initial training and writing of this report, three other households have been recruited.

Figure 2. Map of Household Citizen Science Participants at North and South Tenmile Lakes and Initial Water Sampling Sites From September 2022

We will recruit seasonal residents to participate in the June 2023 citizen scientist training. Summer residents may have different knowledge, access to resources, and strategies for bloom intervention than full-year residents. In addition, recruiting seasonal residents will enhance communication and dissemination of study information to different populations.

We trained the citizen scientists to collect monthly samples until blooms appear; thereafter, they will collect samples be every two weeks, until the visible cells are gone; then, return to monthly collection through March 2024. Citizen scientists are collecting samples in 250 mL bottles, prepped with acetic acid, and in conical tubes. Samples will be kept frozen until delivered to TLBP headquarters and then sent monthly overnight to the Miller Lab at University of Wisconsin-Milwaukee. Extracted samples will be analyzed to quantify cyanotoxins at Tenmile Lakes using similar procedures from previous investigations by the lead author (i.e., Roegner et al., 2020; Roegner et al., 2019). Samples will be analyzed for MCs, CYN, and anatoxins, as well as range of additional bioactive metabolites found in blooms with unknown health consequences, including anabaenopeptins, cyanopeptolins, and microginins.

Surveys

Survey Design and Measures. Surveys were designed to identify how residents may be exposed to cyanotoxins, known in the literature as potential “routes of exposure.” The survey also provides data which will allow us to assess the risks that cyanoHABs pose for long-time community residents, seasonal visitors, and the community at large, as well as impacts of cyanoHABS on the local economy, environment, and culture. Participants will be asked questions about household source water use and any treatment, irrigation for gardens, fishing and recreational activities on the lake, household pet engagement with the lake, potential costs of treatments, noted changes in the lake, awareness of notices and public health information related to cyanoHABs at Lakeside, and impacts on local economy. We will also obtain some demographic information and household data. During the initial community meetings, we were asked to shorten surveys substantially and conduct them in-person and on paper. We followed these suggestions and designed the survey to take less than ten minutes to fill out on a physical paper copy.

Survey Sampling and Distribution. Survey distribution, collection, and data analysis will take place between June and August 2023. We aim to distribute 300 surveys to a combination of visitors, seasonal residents, and full-time residents. We will recruit participants using targeted recruitment and outreach and snowball methods, targeting community events, organizations, and locations where blooms occur and impact tourism or business. We also will target vulnerable groups, such as migrant workers or tribal members, using our contacts with research partners. Inclusion criteria for survey include the following: (a) resident of the watershed for at least one month during the year; (b) reliant on the watershed for household water, fishing, work, or recreation, and (c) 18 years of age or older. Exclusion criteria will be through travelers and children under age 18. Surveys will be anonymized and kept secure.

Data Analysis Aims and Procedures. Data will be analyzed utilizing open-source R studio for descriptive statistics, as well as regression analysis exploring potential relationships between household or demographic data, risk from CyanoHABs, perceptions of lake and risk from CyanoHABs, and economic impact. We will examine potential differences between lake “old timers” and newer and more transient populations in order to better target differing populations with public health outreach and information.

Focus Groups

Focus Group Design and Measures. Focus group discussions will delve into concerns and questions faced by communities, regarding lake water use and recreation, community member health and safety, and economic impacts with respect to cyanoHABs disasters, as well as other environmental concerns that might enhance, compound, or mitigate cyanoHABs. In March 2023, we piloted informal focus groups with citizen scientist participants following their training and made some adjustments to the planned focus groups based on their feedback. We have modified the focus group guides to reflect focal areas around ecological, societal, and individual vulnerabilities, and also modified the timeline to include seasonal populations of residents and coincide with the occurrence of the cyanoHAB hazard events.

Focus Group Preparation, Recruitment and Facilitation. We will utilize surveys to recruit focus groups participants from targeted populations. Two to three moderated focus groups will take place between July 2023 through October 2023. Each focus group will have 8-10 participants. They will last approximately one hour in duration with a facilitator assisted by notetakers and be voice recorded. The results from this iterative process will be shared back with public health officials, as well as community groups and members in late summer 2023. We also will work with community groups in the region to identify the potential need for individual or smaller group discussions for historically underrepresented voices that may not be as willing to speak up in a larger group setting. As such, we may opt for smaller focus groups or individual tailored interviews, modified from the focus group guide.

Consent and Confidentiality. Consent and enrollment for survey participation will be obtained per University of Oregon IRB Approval Exemption Category II for Study #00000767. Focus group participants will be identified with an anonymous unique identifier that will be decided upon at the beginning of the interview by choice and consensus. Recorded demographic data will be linked to the anonymous identifier and not the individual’s identity. Note takers will also observe and record non-auditory responses or reactions and link to the anonymous identifier.

Data Analysis Aims and Procedures. Demographic data about participants in focus groups will be obtained (age, gender, ethnicity, years living at the lake, size of household) and will be compiled to characterize overall participation characteristics. NVivo Software will be employed to transcribe, incorporate, analyze, and integrate the recordings, notes taken, and demographic data captured in focus groups. The software will also be used as a way to manage and analyze documents with public health guidance, messaging, and other public health tools or materials about hazardous blooms.

Ethical Considerations and Researcher Positionality

The University of Oregon Institutional Review Board (IRB) found this project (STUDY00000767) exempt on March 9, 2023. We have embraced the CPBR model to foster trust and directly address needs and gaps identified as most pressing for the community at hand. In particular, we recognized the potential distrust of outsiders from academic institutions from a more liberal-leaning, and urban area of Oregon, in a rural region with a largely libertarian ethic. On the ground, we emphasized the importance of local feedback and input to make the project successful and the results meaningful. In addition, we have taken care that out citizen science study only involves existing treatment practices and additional steps and precautions to minimize health risks for participants (e.g., providing them with gloves for sampling or suggesting a post-tap water additional filtration step if utilizing lake water for drinking).

Preliminary Findings

Our collaborative, transdisciplinary research project is on-going and data collection has not been completed. Some emergent themes from our data collection so far, however, provide preliminary findings on perceptions of both blooms and the public health response. In addition, cyanotoxin results from samples collected at the outset of this project in September 2022 show that cyanotoxin levels exceed guidelines and suggest risk for households may be greater than previously anticipated and may vary spatially.

Community Member Views of Public Health Practices and Officials

The piloting of survey and focus group questions revealed profound distrust of public health entities or government oversight with substantial reticence about collection of data about water sources or demographics that could be reported to federal, state, and local agencies. Longer-term distrust had built up during the COVID-19 pandemic with the politicization of public health messaging. There was substantial reticence and concern about asking questions about water sources, demographics, and health that would be communicated and reported back to the federal government, with particular references to the Centers for Disease Control and Prevention, as well as to some state and county agencies. There was also concern about researchers revealing private use of lake water for domestic use to state government agencies and the potential fines or additional permitting requirements that may ensue. Furthermore, none of the participants reported having engaged with public health officials on the ground with respect to blooms. The only information they received about blooms was limited to posted advisories. Community members said public health officials rarely shared water sample results or explained any risks detected during testing, further decreasing trust and confidence in the public health system.

Since a characteristic public health risk assessment approach resulted in distrust, we inverted the question and asked community members what would be most beneficial for their community to better understand health risks posed by the blooms, acknowledging that they had their own “on-the-ground” knowledge. The unanimous response was “knowing which treatment types work” as guidance from the OHA, available online and elsewhere, was deemed “confusing,” “often contradictory,” and “don’t seem to work effectively.” One community member proposed testing the lake water as drawn from the lake and then after household treatment to evaluate efficacy of removal of contaminants. Others concurred, indicating that knowing about potential treatment options and variable risk at different sites around the lake would be most useful for protecting their health and that of their families.

With the pivot in approach and methods as discussed, community members relaxed, readily asked questions about their health risks, and exhibited genuine curiosity about these natural phenomena, the toxins they produce, and the scientific design process used to answer critical questions for their community. While much of the project remains, these interactions suggest the power of both CBPR and citizen science to remove barriers of distrust through a shared passion for science and understanding.

Community Member Views of the Lake and Risks of Harmful Algal Blooms

Informal discussions with project participants about lake water quality focused initially on the impact on individual households, then spread out to include the changes in the local environment and local culture over time. Diving deeper into treatment options during both community meetings and the training sessions, participants asked a lot of questions about available guidance, the types of treatment that have or have not been effective and why, about maintenance, and about their overall risk from blooms at Tenmile. Participants were in consensus about their concern and uncertainty about how much the blooms were impacting local health. In addition, participants expressed substantial concerns about private water systems and lack of guidance. They discussed the economic burden, with costs exceeding $350 to set up and the ongoing cost of filter replacement. They also expressed concern about how to clean or backwash the systems to ensure they are not breaking up cells to release more toxins. Project participants also asked how they might know if their health was being chronically impacted, and really did not know where to turn for additional information on this question. We acknowledged the complicated and site-specific nature of blooms and plethora of unknowns, thus wanting to partner directly with the community and citizen scientists to understand risks.

In terms of impacts locally, community members noted changes in recreation and tourism in the area due to declining lake water quality. This decline includes the appearance of blooms, but also periods of drought and flooding, as well as the growing proliferation and nuisance of lily pads that make lake navigation by boat more difficult. There has been increased awareness of hazardous algal blooms and their impacts on the lake, mainly due to the efforts of TLBP and its outreach, but the participants worried about the lack of posting of signs for seasonal residents or visitors that might not know to check the local webpage and Facebook page for updates.

The residents also discussed how the community has changed significantly over the last five years or so, and that there are approximately 55 residences along Coleman Arm, with 75% of those households new to the area, so they may be less aware of health risks posed to the area. The residents reported that this area often appears to have the worst blooms on the lake, but it also depends upon the time of day and direction of the winds. In addition, many newly purchased homes are being rented out through services like Airbnb so there is concern for new visitors that might not take proper precautions to protect themselves or their animals from the blooms. The participants thought that the best way to reach people would be through the Facebook page, through physical postings, and through the local free monthly newsletter. Residents also discussed that outreach through Father’s Day weekend events, as well as at a late August “state of the lake” event, would be beneficial. Table 2 lists several notable themes that emerged from our discussions and representative quotes from study participants.

Table 2. Emerging Themes and Representative Quotes From Pilot Surveys and Discussions With Study Participants

In our interviews and discussion with residents, we heard frequently about the centrality of the lake to the local economy and way of life. A local business owner described the relationship between the community and the lake as such: “Talking about the condition of the lake is like talking about the weather,” indicating that the lake’s status is on everyone’s mind and is the uniting thread of the community. She reported that the blooms have a noticeable impact on how many bookings are made by visitors to stay at lodgings or other residences and the number of cancellations are frequent topics of concern. She explained that everyone has a vested interest in making sure that the lake stays healthy and vibrant for years to come. The city manager echoed this sentiment, and also described a willingness for individuals to pitch in and get outreach done for the lake, albeit with some resistance to government oversight and restrictions. She described a long history of the area going through several eras of incorporation and dissolution in the face of changing economic times and population movements. The city manager also described a heavy reliance on the lake for tourism as the main economic driver in the region and the need and desire to protect Lakeside and Tenmile Lakes from overdevelopment or overutilization.

Cyanotoxins in Lake Water

Table 3 shows the results of water quality testing of the September 2022 samples. The results indicate that Tenmile Lakes have levels of cyanotoxins (i.e., MCs) that exceed OHA, EPA, and WHO guidelines (OHA, 2021; EPA 2015a, 2015b; WHO, 2022). This suggests that Tenmile Lakes residents may be regularly exposed to cyanotoxins, depending upon their use of lake water and the efficacy of their water treatment systems. Results also indicated that other types of cyanobacterial metabolites were present in Tenmile Lakes at levels beyond those detected previously. Four out of seven samples tested positive for MCs, exceeding the OHA and EPA (0.3 µg/L for vulnerable groups) and WHO (1.0 µg /L for lifetime exposure) guidelines for potable water.

Table 3. Results of Testing for Cyanotoxins Levels at Stratified Lake Sites Sampled in September 2022

Table 3 shows a number of structural variants of the families of cyanotoxins detected (microcystins, anabaenopeptins, and cyanopeptolins) designated by their chemical structure, including the more commonly detected MCLA and dmLR, and the less common congeners, MCLY, MCLF, MCWR, and MCHilRq. In total, over 240 congeners or structural variants of microcystins have been identified across the globe. This high number of variants makes detection and removal more difficult, as they can have variable chemical properties, as well as variable toxicity. In addition, all seven samples tested positive for anabaenopeptins, and two for cyanopeptolins, other classes of cyanobacterial metabolites that have bioactive properties (Janssen, 2019⁶¹; Beversdorf et al., 2018⁶²). Anabaenopeptins have similar mechanisms to MC toxicity and have demonstrated neurotoxicity, and cyanopeptolins have demonstrated potential neurodevelopment impacts in the zebrafish (Zhang & Zhao, 2018⁶³). There is currently no guidance for either class of peptides, and there is a lot of uncertainty about the health implications of chronic exposure to multiple classes of cyanobacterial metabolites and toxins.

The samples were taken from locations that were spatially distributed across the lakes; thus, there may be regions of the lakes that have higher risk than other regions. The data provided by the longitudinal sampling across household lake sources will provide a greater context for spatial and temporal variability of the Tenmile blooms. The September 2022 samples are currently being analyzed for cylindrospermopsins and anatoxins that have been previously detected at trace levels in the region (Hall et al., 2019; ODEQ, 2007). Our results concur with previous studies showing that MCs are likely the most persistent threat in this potable water source (Hall et al., 2019; DEQ, 2007). It will be important, however, to continue to monitor for other cyanotoxins as bloom dynamics change throughout the course of the season. Interestingly, the more common variants of microcystins (i.e., LR and RR) were not detected in these samples, while more atypical structural variants were, in contrast to previous work in the region. This is important because the commercially available enzyme linked Immunoassays (ELISAs) for MCs generally have greater sensitivity and specificity for the more common congeners (MCLR and RR), and thus may underrepresent the true value of total MCs if used by monitoring agencies in lieu of the gold standard yet less accessible high-performance liquid chromatography mass spectrometry (HPLC-MS).

Conclusions

Public Health Implications

Two focal areas of public health importance have thus far emerged from our project: First, our water samples and testing indicate that Tenmile Lakes residents and visitors need to be educated about potential risk and ways to reduce that risk of exposure. Second, monitoring of potential adverse short term and chronic health effects from blooms should be a cooperative effort of local doctors, veterinarians, and public health officials. Third, our community-based methods have revealed community members distrust public health agencies and messaging with respect to cyanoHABs. This is due in part to the public health authorities lacking “boots on the ground” in the rural community that are needed to actively engage with residents, understand their contexts and concerns, and gain their trust. The lack of public health infrastructure and funding needed to monitor and test rural potable and recreational water sources impacted by blooms is leading to a situation in which the risk posed by cyanotoxins to rural communities may be underrepresented or undetected. Moreover, when cyanoHAB hazard events emerge, public health authorities appear to be poorly communicating the risk to residents and providing unclear guidance. As a result, distrust between the local population and public health officials abounds.

The implication of these findings is that more should be invested in public health systems and programs that help rural communities affected by cyanoHABs to critically evaluate blooms within their local natural and cultural resource context. Our preliminary findings and engagement with TLBP suggest that any new public health efforts should develop strong local partnerships and also employ citizen science and community-based projects that foster transparency and trust. Furthermore, our findings point to the need for improved guidance for households using private water treatment systems and improved public health messaging for tourists, seasonal visitors, and newcomers to the area. Community cultural and economic contexts as well as the cyanoHAB hazard conditions, may vary considerably across rural communities, yet by identifying a trusted local partner and centering community needs through CBPR and citizen science, a “grassroots” effort can be laid for improving public health preparedness, response, recovery, and mitigation of these hazard events.

Finally, an additional theme that is emerging from our findings is the need for community members to be self-reliant and seek out information about cyanoHABs on their own due to the public health system’s resource constraints and other shortcomings in regard to cyanotoxins. Currently, state and local public health authorities have limited ability in rural areas to monitor cyanoHABs and provide information about household health risks and mitigation measures.

Limitations

As described above, our study is evaluating private water treatment system options using a citizen scientist approach. The results from this analysis will not be generalizable because we are examining the efficacy of individual treatments systems at different sites with variable water quality, which means that we will neither have replicates of each individual system nor capture true efficiency of removal of cyanotoxins in an optimized system. Instead, we will be able to assess the effectiveness of removal under real world conditions. Moreover, by having repeated samples over time, we will have a general sense of how well each individual system is working to remove cyanotoxins within a household and across a range of water quality conditions and risks of exposure. Without controlled study replicates of each system type and given the limitations of knowing all the intricacies of these “do-it-yourself” household treatment systems, we will not be able to recommend a specific system or approach. Rather, we will be able to provide examples of system types that have been effective for households in this context. The data will also inform us about how existing public health guidance and recommendations actually work on the ground. Lastly, by engaging with a number of different households over time, we will gain insight into the geographic spread of overall lake water risk to the community at large prior to any treatment.

A second limitation is inherent to our decision to center our project on citizen science water quality monitoring. This decision risked prioritizing the needs and concerns of potentially more educated and well-resourced members of the community, while overlooking the needs of marginalized groups. Yet, there is a paucity of publicly available demographic data about households along the lake and about access to lake water, knowledge about cyanoHABs, and treatment options among different demographic groups. By employing a mixed-method approach and diverse recruitment strategies, we aim to include research participants from diverse demographic backgrounds, including groups with potentially less access to economic resources, education, infrastructure, health information, and social support to prepare, respond, recover, and mitigate impacts from these hazard events.

Finally, the Tenmile Lakes region relies heavily on tourism and thus may not be representative of other rural regions or small towns impacted by these hazards. For example, other regions in Oregon may rely more heavily on agriculture or timber and thus may have unique concerns and vulnerable groups to consider. However, some of the lessons learned through this project, such as how to improve outreach, education, and public health prevention to permanent, seasonal, and transient populations in before, during, and after cyanoHABs will be applicable.

Future Research Directions

In the methods section above, we outlined the future directions of this project through March 2024, including the planned longitudinal monitoring, surveys, and focus group discussions. We also hope to seek additional funding to build upon the citizen science and CBPR aspects to address the health and economic impacts of blooms through more sustained intervention approaches.

Acknowledgments. We would especially like to thank Tenmile Lakes Basin Partnership and the community members that have been so integral to the feedback and improvement of this project.

References