This week a tragic story about dogs dying from exposure to toxic algal blooms grabbed national attention. Dozens of media outlets published pieces including the NY Times, Fox, and even Snopes. For general information about blooms, I recommend reading the LA Times article “Everything you need to know about algal blooms.” For a deeper dive into the most common freshwater toxin, microcystin, and how states around the country are addressing the issue, check out this EWG report. If you’re most concerned about your four-legged friends, read Sea Grant’s dog-specific information sheet.

There are many different types of algal blooms, not all of which are blue-green or harmful. However, because the presence of toxins can only be determined through testing, it is best to avoid contact with all algal blooms. Harmful algal blooms (HABs) are rare in the Catawba chain but are becoming more common, particularly in the southern lakes. This year, there has not been a documented HAB in NC (NC DEQ Algal Bloom Map). While SC’s historical bloom data is not available, there is currently a swim advisory for the Fairfield County portion of Lake Wateree due to a type of bloom which can cause skin irritation.

Blooms are primarily monitored by NC DEQ and SC DHEC. While both agencies have staff dedicated to the issue, HABs can appear and move quickly. If you suspect a bloom, report it to NCSC, or to CRF. The conditions which create algal blooms are not completely understood and the science actively progressing. If you’d like to help collect data, check out the Phytoplankton Monitoring Network or the Lake Wateree WaterWatch. Satellite imagery is also starting to be used to survey Lake James, Norman, Wylie, Fishing Creek, and Wateree through the new EPA CyAN program.

HABs in the Catawba-Wateree basin are generally fueled by excess nutrients. We’re working to limit the sources through public education (don’t over-fertilize), sewer overflow reporting, and our campaign to require the permitting of dry litter poultry operations.