Public awareness and visual water quality thresholds at a bloom-prone urban lake (Utah Lake, Utah, USA)

Smith JW. 2026. Public awareness and visual water quality thresholds at a bloom-prone urban lake (Utah Lake, Utah, USA). Lake Reserv Manage. XXX–XXX.Most recreationists at Utah Lake do not make decisions about when and how to recreate based on chlorophyll a (chl-a) concentrations, highlighting the need for more visible and targeted public communication about water quality. This study evaluated the extent to which recreationists and nearby residents were aware of water quality issues at Utah Lake and whether specific aesthetic thresholds—particularly related to chl-a and turbidity—influenced perceptions of recreational suitability. Two surveys were conducted in 2022. An intercept survey of 290 active recreationists was administered at various access points around the lake, and a mail survey was distributed to a stratified random sample of 541 households in Utah and Salt Lake Counties. Respondents evaluated images representing different levels of chl-a and turbidity and rated the water’s suitability for swimming, boating, fishing, fish consumption, and near-water activities. The analysis suggests turbidity, not chl-a, may be a more noticeable visual cue shaping perceptions of recreation suitability; however, neither appears to provide a consistent optical proxy for water quality. Additionally, despite recent harmful algal blooms, 35.2% of those in the on-site sample and 48.8% of those in the resident sample reported no awareness of water quality issues at the lake. Together, these findings suggest resource managers should not assume the public understands or recognizes water quality hazards without direct or more targeted communication. Resource managers should consider deploying a broader array of communication tools, including digital alerts, more signage at trailheads and parking areas, and public outreach to support safe, informed recreation and enhance water quality management.