By Lanny Brannock and Melissa Miracle
Department for Environmental Protection
The phone rang in the office of the Kentucky Department for Environmental Protection. Louisville Sports Commission executive director, Karl Schmitt, was calling with an urgent question, “Will the Ohio River be safe to use for the swim portion of the IronMan Triathlon?”
The answer from the Kentucky Division of Water (KDOW) director, Peter Goodmann, was not reassuring, “We don’t know.”
The year was 2015. For more than 100 miles, the Ohio River was covered in a green scum that hung suspended like green-colored cobwebs in the water columns. The culprit: Harmful Algal Blooms, commonly known as HABS. And the swim portion of the race was in danger of being cancelled.
Luckily, the water cleared after a rain, and the race went on as scheduled. But it was another lesson to the staff of the KDOW about dealing with HABS.
Since 2013, the KDOW has begun monitoring for and using different scientific methods to determine how dangerous HABS might be to a waterway. It has been a challenge for the division to understand what causes HABS, and how to measure the relative dangers of the toxins in the water.
In 2016, in response to a growing number of HABS in the waterways that Kentuckians enjoy for recreation, The KDOW created a tool to better inform the public about water that might be contaminated with HABS, a tool that came in handy late last year.
What Are HABS?
Harmful Algal Blooms are an overgrowth of naturally-occurring bacteria called cyanobacteria, also known as blue-green algae. Sunny, warm days combined with excess phosphorus and nitrogen in slow flowing or stagnant waters create an environment for these bacteria to rapidly increase and to form what is known as an algal bloom.
Depending on the level of exposure to human and aquatic life, these algal blooms can have serious health consequences, ranging from a mild illness to death. The exposure route could be oral, dermal or as an inhalant. The HAB also could be ingested through contaminated shellfish and dietary supplements.
Fortunately, to date the KDOW has received no reported cases of either illness or death due to HABs. “All the tools, information and testing is more for public safety and awareness,” said Goodmann. “The more aware we can make the public of the safety issues caused by HABs, the better.”
Monitoring and testing for HABS has been an evolving process. In 2014, there were more than a dozen warnings issued when testing was done via counting cells under a microscope. By 2015, there were fewer warnings, but the testing method had vastly improved to give a more accurate view of the level of harmfulness of a bloom. The more bacteria present, the more toxic the bloom.
The HABs that threatened the 2015 IronMan Triathlon were common bacteria, easily visible in the water. But not all HABS look or behave the same way. Not all green scum on a water body is dangerous and not all algal blooms are considered harmful.
And blooms that are considered harmful can be harmful to differing degrees of severity. So how can you make sure you are protected from, and knowledgeable about, harmful blooms in the waters you recreate in?
Part of the KDOW’s mission is to monitor algal blooms and report information to the public when an algal bloom is deemed harmful. This has sometimes proven to be difficult because of the amount of navigable and recreational-use water in Kentucky and the limited resources within the agency.
But the Division, in collaboration with several other agencies, has released several tools to help keep the public informed about HABs.
The KDOW, in 2016, established the HAB Work Group, as a proactive collaboration to develop effective responses and tools to deal with HABs that affect Kentucky’s waters. This work group is made up of a members of state and federal agencies that include the departments of Public Health, Fish & Wildlife, Natural Resources, Parks and the U.S. Army Corps of Engineers.
The group concluded that a dynamic, interactive map of any known HABs would be an essential tool for the public. So The KDOW and the information technology section of the Kentucky Division of Environmental Program Support began developing a responsive, mobile application called the HAB Viewer.
The HAB Viewer was released to the public in time for the first HAB advisory of the 2016 season. This viewer shows, at a glance, the status of any HAB Advisories for public recreation across the state.
The HAB Viewer uses orange symbols to indicate public health watches or if algal toxins are present at levels that may impact sensitive populations. When red symbols appear on the map, they indicate algal toxins exist at unsafe levels so that swimming, wading and activities that create spray are not recommended. Users can click on map symbols to get more detailed information about specific advisories in Kentucky.
“No one knows yet what exactly causes HABs,” said Goodman. “What we can do at this point is make sure we have the tools in place for people to inform themselves of the dangers that may be at hand. Keeping the public safe and our waterways clean is our top priority.”
In addition to the viewer, the HAB Work Group also developed a new sign to post at entrances to recreational waters that have experienced HABs in the past. These signs explain what HABs are, what they look like, what to be aware of and how to get the most current status of the water. They also include the website address and a Quick Response bar code that links users to the HAB Map Viewer so that anyone with a smart phone can find out if that body of water has an active HAB.
A Different Kind of HAB
Of the advisories issued so far, all have been for elevated levels of microcystin, or toxins produced by cyanobacteria upon cell death or lysis, except for Boltz Lake in Dry Ridge, Kentucky. Boltz Lake has been found to contain elevated levels of the toxin cylindrospermopsin. Either toxin can persist in lakes even after cyanobacterial blooms are no longer visible.
Many environmental factors such as pH, temperature, presence of light, salinity, and presence of certain bacteria can influence the rate of toxin degradation, or the lessening of a toxin. Cylindrospermopsin, for instance, is relatively stable at temperatures between 4°C and 50°C with highest degradation rates occurring in warm waters and slower degradation rates occurring in cool waters.
This is evident in Boltz Lake as toxin samples have continued to contain elevated levels of cylindrospermopsin even after the visible bloom was gone. In fact, cold temperatures have had little effect on toxin concentrations.
Because of the many factors that influence toxin degradation rates, it is very difficult to identify how long a cyanobacterial bloom will persist, or even if one will form.
Boltz Lake was tested in January and will be tested once again in February due to positive tests for elevated levels of toxins in both months. At this time, it still continues to be a public safety hazard.
For more information on HABs, please resource the KDOW’s page at http://water.ky.gov/waterquality/pages/HABS.aspx.