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7/22/2024
Wt Staff
 HAPPENING NOW
Monday, July 22 2024
HAB toxin has tested above the safe limit in Ohio, what's happening in CA?
July 22, 2024 updated 6 pm PDT
A surprising test result has been returned for algal toxin "microcystins" near a Lake Erie beach, prompting the posting of a Recreational Health Advisory over the weekend. Ohio Department of Natural Resources routinely tests recreational water for bacteria. Testing for HAB toxin microcystins is done only where visual observation of the HAB is made. Satellite HAB monitoring is available for the west basin of Lake Erie, this media has been tracking the Lake Erie HAB since spring 2023. The surprise this season, this HAB has not been around long, and has not reached the extreme high concentrations often indicative of high toxin levels. This weekend's health advisory was made for a relatively moderate concentration HAB producing toxin five times the safe limit for recreational water, one hundred and thirty-three times the EPA safe limit for drinking water.
The federal HAB satellite monitoring program of the National Centers for Coastal Ocean Science (NCCOS) has eyes on a dozen high profile water bodies in the USA, including Lake Erie west basin, New York's Lake Champlain and a nice wide angle capture of Lake Pontchartrain southeast Louisiana water bodies. A new image is uploaded for the monitoring projects almost every day. WT HAB Tracker team has been observing and reporting on the appearance of HABs from this imaging, interpreting the bloom position and extent, matching with the color scale to estimate the concentration, reliable where the wind conditions are not too high and where cloud cover does not obscure the view.
No such imaging is available for California, though the state Water Boards have exceptional HAB reporting established for many years. Weekly updates from the freshwater HAB monitoring program in California provide us basic information to convey to the public, repeating and reinforcing public safety messaging. To date this year, we have reported the HAB advisories for San Antonio Lake, Discovery Bay, Clear Lake, Pyramid Lake, Santee Lakes and Heritage Park Pond and others.
What do we know of HAB toxins testing in California? A media announcement for South Lake Tahoe confirmed the presence of a HAB neurotoxin in a pond near Nevada Beach last week. Nevada State officials are recommending the pond, which is not connected to South Lake Tahoe, be completely fenced off to keep people and pets away. Toxin tests results are as yet unknown for the water bodies posted with HAB advisories in California. WTCAL is following this up with the state Water Boards and Department of Health, more to follow.
Guidelines for safe recreational water environments published by the World Health Organization, Geneva 2003 includes a chapter on freshwater cyanobacteria and their associated toxins, highlighting the risk and threat to public safety. The Guidelines reference studies published around the world. Here are some of the reasons we concern ourselves with HABs and public safety around recreational water, these factors being all the more compelling concerning drinking water sources:
HAB toxins bio-accumulate
"Fitzgeorge et al. (1994) demonstrated that microcystin toxicity is cumulative: a single oral dose resulted in no increase in liver weight (a measure of liver
damage), whereas the same dose applied daily over seven days caused an increase in liver weight of 84% and thus had the same effect as a single oral dose 16 times as
large." p.141
Liver injury is likely to go unnoticed until it is severe
- liver injury results in externally noticeable symptoms only when it is severe
- acute dose–response curves for microcystins are steep, meaning little acute damage may occur until levels close to severe acute toxicity are reached.
As a result of the lack of apparent symptoms at moderate exposure, exposure is likely to be continued by people uninformed of the risk (e.g., for consecutive days of a holiday or a hot spell), which will increase the risk of cumulative (irreversible) liver damage.
Historic Cases of HAB poisoning
1931: USA: Drinking Water Contamination with widespread illness
"A massive Microcystis bloom in the Ohio and Potomac rivers caused illness of 5000–8000 people whose drinking-water was taken from these rivers. Drinking-water treatment by precipitation, filtration and chlorination was not sufficient to remove the toxins (Tisdale, 1931)".p 141
1959: Canada: Beachgoers ignored the warnings
"In spite of a kill of livestock and warnings against recreational use, people still swam in a lake infested with cyanobacteria. Thirteen persons became ill (headaches, nausea, muscular pains, painful diarrhoea). In the excreta of one patient—a medical doctor who had accidentally ingested water—numerous cells of Microcystis spp. and some trichomes of Anabaena circinalis could be identified (Dillenberg & Dehnel, 1960)".p 141
WT HAB Tracker from state sources and where available, the satellite monitoring program of the NOAA National Centers for Coastal Ocean Science
California: The weekly HAB postings report from California Water Boards dated July 19 contain one HAB DANGER alert and three WARNING level postings on the list. The DANGER advisory is posted on San Antonio Lake in Monterey County. Water bodies with HAB WARNINGS include the south end of Pyramid Lake near the dam, Santee Lake #7 near the campground and a pond in Heritage Park, San Diego County. Both DANGER and WARNING signage carry the caption "Toxins from the algae in this water can harm humans and kill animals". Caution alerts have been issued for 23 locations, and algal mat awareness alerts for another six sites, visual observations are reported for three more sites. Danger and Warning postings are marked with bluegreen tags on the map, caution advisories are being updated on the report. For the latest report, click here.
Ohio: The latest image of Lake Erie west basin was captured July 21 at moderate wind speed 5.4 mph, partially cloud obscured, showing the expansive extent of the west basin HAB that originated in North Maumee Bay in June. Water samples collected from Maumee Bay State Park by Ohio Dept of Natural Resources and published by the Department of Health show algal toxin at 40ug/L, a level five times above the US EPA safe limit for recreational water guideline. The Algal Toxin advisory was posted on Friday, July 19. Interesting to note, the concentration of this HAB has not exceeded 500 thousand cells per 100 ml, nowhere near the 3 million cells per 100 ml that accumulated along this shoreline for weeks in July 2023, found 85 times over the safe level by August 4th. The latest HAB findings are being updated, more to follow. The last Ohio HAB report is available here.
New York
The latest upload of Lake Champlain was captured Sunday July 21. This image shows a considerable accleration of the concentration of Baie Missisquoi HABs hot spots over the previous image taken twenty-four hours prior. The hot spots have grown larger, now seen extending from the north shore in Canada into the center of the bay at concentration up to 4 million cells per 100 ml. Bear in mind that the Lake Erie toxin levels have been found above safe limits where the concentration has been no higher than 500 thousand cells per 100 ml. The toxin results for this HAB will be found with Vermont Agency of Natural Resources, more to follow.
From the NYS HABs reporting center, seventy-six HABs are confirmed active for interior freshwater lakes Monday morning, down from eighty-three HABs Sunday. Two new HAB reports were confirmed Sunday for Ellicott Creek, a number of reports made prior to July 8 have been archived. See bluegreen tags on the map to the right, the full list of water bodies impacted is found here.
Louisiana: The latest upload from the NCCOS was caught July 21 at surface wind speed 3.2 mph. This image is mostly cloud obscured with Lake Verret Lake Palourde and the Avoca area showing high concentration HABs. See the latest HAB report for Louisiana here.
Georgia: Jekyll Island's beaches have tested clear for bacteria in the latest update from Coastal Health Region. Two permanent advisories remain, even though these beaches have returned results below the threshhold in the last quarterly test, July 1. No new information has been found on the presence of HABs in Georgia. Georgia Environmental Protection Division takes reports on suspicious algal blooms, so far in 2024 there have been no such reports logged. The Georgia Healthy Beaches program of Coastal Public Health tests beaches for bacteria, posting permanent and temporary advisories to warn the public. The latest Georgia beach advisories are available here.
See the North American drainage basin map here, scroll all the way down to see how surface water moves across the continent into the Pacific, Atlantic, Gulf of Mexico and Arctic Oceans. WT Media Group tells the story of water in three countries, Canada, USA and Mexico. See the drinking water advisories, hazardous spills, floods, drought and harmful algal blooms plotted on the maps, as the water flows. Check out the CrimeBox for historic prosecutions under the Clean Water Act, the Safe Drinking Water Act box for details on public drinking water facilities, interviews with the scientists and tech developers on the leading edge of clean water technology here.
As many drinking water facilities are supplied from surface water reservoirs, the streamflow situation is pertinent to both drinking water supply and quality. High flows can stir up sediment and cause turbidity in the reservoirs, requiring additional treatments to render the water potable. Low flow volume is linked to warmer temperatures in the reservoir and can be an issue for water quality where HABs are present. WT tracks streamflow trends with an eye to the impacts on drinking water supply and quality in each of the state's watersheds. Check the watershed layer on the map to see the direction of flow and streamflows that may be impacting drinking water today.
USGS Provisional Data Statement
Data are provisional and subject to revision until they have been thoroughly reviewed and received final approval. Current condition data relayed by satellite or other telemetry are automatically screened to not display improbable values until they can be verified.
Provisional data may be inaccurate due to instrument malfunctions or physical changes at the measurement site. Subsequent review based on field inspections and measurements may result in significant revisions to the data.
Data users are cautioned to consider carefully the provisional nature of the information before using it for decisions that concern personal or public safety or the conduct of business that involves substantial monetary or operational consequences. Information concerning the accuracy and appropriate uses of these data or concerning other hydrologic data may be obtained from the USGS.
Harmful Algal Blooms: WT follows the movement and growth of harmful algal blooms (HABs) as provided by the satellite monitoring program of the NCCOS for New York's Lake Champlain, Ohio's Lake Erie and Louisiana's Lake Pontchartrain and surrounding area. Interpretation of satellite images is best in clear conditions at wind speed less than 4 mph, where the appearance and extent of HABs is reliably matched to a color scale for concentration. HABs are known to produce algal toxins of concern for raw drinking water sources and recreational water bodies. Plan beach access to avoid HABs and consider carrying a rapid test kit to detect the toxin microcystins.
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