When to Visually Monitor

When resources are scarce or FHABs are widespread, visual monitoring can be a cost-effective way of evaluating the extent of FHABs, informing the public, and expanding knowledge of the issue. It is also a valuable screening tool for determining additional monitoring methodologies when a bloom is expanding or changing. Visual monitoring cannot measure the presence or amount of cyanotoxins, but visual confirmation of a FHAB triggers the recommendations to post caution level advisory. In addition, visual indicators can be used to determine where to target sampling. Recent updates to the California voluntary guidance for responding to FHABs in recreational waters indicate new thresholds for percent cover of cyanobacteria specific to benthic/toxic algal mats that trigger cautionary and toxic mat alert signage. 

Who can Visually Monitor?

Anyone with curiosity and the ability to safely access a site can participate. All it takes is familiarizing yourself with your local waterbodies and understanding some of the common signs of a FHAB. As a water manager, you can perform recurring visual inspections and document waterbody conditions with photos and/or a field datasheet. As a citizen scientist, visual monitoring can occur while recreating in or near your favorite waterbody. You can review the full standard operating procedure and/or the 2-page, field cheat sheet (see below) that explains steps to monitor benthic FHABs/toxic algal mats, including visual assessments. 

Steps to Visual Monitoring

1. Learn to identify a FHAB using the link below.

2. Choose sites to monitor on regular basis.

3. If a potential FHAB is visually identified, report the information through the FHAB Report Form. Include photos when possible. If identifying and reporting benthic HABs, please refer to this field sheet and include the percentage of spatial coverage.

4. If you are unsure if you are seeing a FHAB include photos with your submission for Regional Waterboard Staff to help assess.