This study’s results suggest that some cottage and waterfront homeowners believe algal blooms are a problem and many are aware of the increasing frequency of algal blooms in recent years. However, in this study, many respondents did not consider algal blooms to be a large problem. Generally, people recognize blooms when they occur in their lakes. However, even in regions where blooms occur, people who live near lakes that have not yet been obviously affected are less concerned (Do et al., 2021). A potential reason for this could be related to property values. Waterfront properties are typically more valuable compared to those on adjacent land due to easy access to swimming, boating, and fishing. Poor water quality is known to affect both enjoyment and property values of waterfront property (Hjerppe et al., 2016; Nicholls & Crompton, 2018). Therefore, perceptions of algal blooms are modified by the risks of loss of value of their properties. In this study, property owners may have chosen to understate their worries regarding algal blooms due to their concern for their property values.
In addition to characterizing concern for algal blooms, this study also aimed to explore health risks associated with algal blooms and living near bodies of water. Compared to the average PCS-12 and MCS-12 scores in the general United States population (score of 50), the sample in this study had worse physical health, but slightly better mental health (Ware et al., 1998). Reasons for poorer physical health could include the high mean and median age of this sample, which is 60.22 and 61, respectively. Additionally, living near bodies of water and coastal regions has been shown to improve mental health outcomes, especially in elderly individuals (Chen & Yuan, 2020; Garrett et al., 2019; Gascon et al., 2017). This may have resulted in a slightly higher average mental health score in this population. At the time of the study, no significant association between health and concern for algal blooms was found. However, data from Canada and elsewhere demonstrate that living near water has an important beneficial effect on health from non-accidental causes (Crouse et al., 2018). It is possible that the negative physical and mental health impacts caused by concern for algal blooms are negated by the beneficial health effects granted by living near a body of water.
A key finding of this study was that a large sample of this population demonstrated concern for their pet(s) health. This concern is well-founded as studies have suggested that animal illness and death related to algal blooms are closely linked to human health risks (Hilborn & Beasley, 2015). Interestingly, in this study, mental health scores were notably lower in those who indicated concern for their pets’ health as a result of algal blooms. Studies on algal blooms and mental health are not nearly as common as those focused on physical health symptoms as a result of exposure to HABs (Grattan et al., 2016; Trevino-Garrison et al., 2015). The few studies which have looked at mental health primarily explore the impacts as they relate to advisories or closures resulting from high levels of cyanobacteria in water supplies or fisheries (McCarty et al., 2016; Ritzman et al., 2018). This study’s results may demonstrate a need to explore mental health impacts preceding algal bloom events, in individuals living in areas that are at high-risk of being affected by algal blooms. Additional education surrounding protective actions and identification of algal blooms should also be considered to help mitigate concern and potentially improve the mental health of cottage/waterfront homeowners.
Respondents in this study were also asked about the causes of algal blooms. There was substantial heterogeneity across these responses. At least 10% of the participants identified 5 of the 6 listed options as the most important contributor to algae blooms. Our study participants were drawn from several lakes across the province, and this may contribute to some of these observed differences. Despite this, perceptions of the causes of algal blooms tended to fall into two categories, those supported by evidence and a number lacking known scientific foundation. The ‘most important causes’ consistent with evidence listed, included municipal wastewater plants, farming, and lawn care as well as climate change. Some, but not all, respondents recognized the contribution of climate change on their frequency. Nutrient overload coupled with warming temperatures have driven the increase of freshwater algal blooms across Canada. Sediment cores taken across Canada and the northeast USA have reported algal toxins in cores dated pre-European settlement (Ewing et al., 2020; Pilon et al., 2019; Zastepa et al., 2017). Nutrients and temperature drive these changes. In the early days, nutrients from farming played the major role but as waterfront property was developed in rural areas, septic tanks became major driver of blooms in inland lakes (Celikkol et al., 2021; Mrdjen et al., 2018). Climate change has brought warmer summer temperatures which accelerates bloom growth. In areas where lakes freeze (as in New Brunswick) warmer temperatures have resulted in earlier ice-out dates thus lengthening the season (Ewing et al., 2020; Patterson & Swindles, 2015; Walsh and Patterson, 2022).
Respondents also identified lawn care as a large contributor to algal blooms. This is a contributing cause which has been the target of some lake preservation efforts. In fact, some jurisdictions in Canada encourage or require shoreline naturalization to limit nutrient flux into the lake or river from fertilizer as well as wild animal waste (Foulon et al., 2019). Despite their importance as precipitating causes of freshwater algal blooms, only a few respondents identified old or not to code septic tanks. Several people listed logging as a contributing factor. Recent studies of the impact of forestry on the watersheds indicated that in well managed forestry operations in New Brunswick, nutrient flux into the adjacent watershed had little effect on the biota in the streams (Erdozain et al., 2018, 2021). One person suggested that the use of glyphosate as a contributing factor. This speculation was the subject of an opinion paper suggesting that glyphosate use on farms contributed to phosphate loading (Hébert et al., 2018). However, a careful analysis of phosphate loading in agricultural areas by the US Geological Survey dismissed this as a relevant factor (Stackpoole et al., 2019).
Overall, responses from the survey suggest that public policy and lake associations should prioritize lake conservation efforts and develop better policies to address algal blooms. In Canada, strategies used to ameliorate the effect of blooms have included regulation, incentives and outreach, engagement, and education. Thus far, this approach has only been partially successful (Foulon et al., 2019). As was the case here, a survey of lakefront property owners in New York State as to the causes of algal blooms reported factors supported by scientific evidence and opinions of a subset of the lay public (Armstrong et al., 2022). The authors reported that the differences in causal attributions resulted in “widespread intracommunity disagreement” which hampered management efforts. This demonstrated the need for meaningful public engagement in water management addressing causal beliefs within the community regardless of the science. Armstrong et al. (2022) suggested the need for the development of more appropriate educational materials on the impact of blooms and how to limit their occurrence as well as on community engagement. In addition to educational materials, respondents in this survey indicated a desire for more policies regarding septic systems and waterfront development. Work done in Quebec revealed that most but not all waterfront property owners are willing to pay for the improvements necessary to ameliorate problems with algal blooms (Schinck et al., 2020). This suggests that engagement of waterfront property owners is a key step in developing policies, initiatives, and activities that can effectively address and/or limit the negative impacts of HABs.