The PARE Program

OUR TOOL FOR TRACKING AND ADDRESSING 
HARMFUL ALGAE BLOOMS (HABS)

UNDERSTANDING HABS

Over the past decade we have learned more about the serious health implications associated with intense cyanobacteria (bluegreen algae) blooms. Even though cyanobacteria are not truly algae, these blooms have come to be labeled Harmful Algae Blooms (HABs). Cyanobacteria have a number of evolved advantages relative to “good phytoplankton.” For example, many cyanobacteria are capable of fixing and assimilating atmospheric nitrogen, thus providing them with an unlimited source of a key growth-limiting nutrient. Most are also biologically adept at up-taking and utilizing organic phosphorus, another growth-limiting nutrient. Certain cyanobacteria can also regulate their position in the water column, thereby enabling them to capitalize on changing environmental conditions. Many also are adept at effectively photosynthesizing under low light conditions. Finally, they are selectively rejected as a food source by filter feeders and zooplankton. These “life history” strategies enable cyanobacteria to rapidly out-compete phytoplankton and exploit their environment leading to a bloom.

It has been repeatedly documented that, under the correct set of conditions, HABs may generate very high concentrations of cyanotoxins. These toxins are used by cyanobacteria to achieve dominance in a lake, pond or river. Swimming is waters with even low concentrations of cyanotoxin may cause skin rashes (even for dogs and livestock), ear/throat infections and gastrointestinal distress. At high concentrations cyanotoxins can impact the health of humans, pets, and livestock, and drinking water contaminated by very high cyanotoxin concentrations can actually be lethal. Recently, increased attention is being given to possible links between cyanotoxins and neurodegenerative diseases, including Parkinson’s, ALS and Alzheimer’s.

The cyanobacteria of greatest concern include Microcystis, Planktothrix, Anabaena, Aphanizomenon, Oscillatoria, Lyngbya, and Gloeotrichia. Different types of cyanotoxins are produced by these different cyanobacteria. The cyanotoxins receiving the most attention are Microcystin-LR and Cylindrospermopsin, but Anatoxin–a, Anatoxin-a(S), and Saxitoxins are also very problematic.

Regulatory agencies are still struggling to define what constitutes a “problem” and how to deal with HABs. For a number of years the World Health Organization (WHO) has used a provisional drinking water standard of 1 µg/L microcystin in drinking water. The US Environmental Protection Agency (USEPA) recently issued cyanotoxin guidance for drinking water of 0.7 µg/L and 1.2 µg/L respectively for children and adults (as based on age and body weight). Adding to the confusion, the majority of the States are still developing guidance and/or regulations concerning cyanotoxins in both drinking water and recreational waterbodies. As such, it is difficult to define when a bloom constitutes a problem and, more importantly, what action to implement to protect the health and welfare of the public, pets and livestock.

Cyanotoxins may be released into environment by both living and dead cyanobacteria. However, the greatest concentrations occur as the cyanobacteria die and the cells break down, something that is exacerbated by the standard response to a bloom - that is treating it with copper sulfate. Thus “killing off” a bloom can actually make matters worse by quickly releasing large amounts of cyanotoxins into the water column. Once released into the environment, cyanotoxins are extremely stable and decompose slowly.

SOME COMMON MISCONCEPTIONS ABOUT HABS

There are a variety of common misconceptions about HABs, including: they occur only in the summer when water temperatures are elevated; they are unique to nutrient rich (hypereutrophic) systems; they are driven solely by elevated phosphorus concentrations; and they are most likely to occur under stable (stratified) water column conditions. The most potentially harmful misconception is that HABs can be cured by treating them with copper sulfate; however, as noted above, copper sulfate treatments can actually make things worse.

The above “typical conditions” don’t always lead to a HAB and blooms with elevated cyanotoxin levels may occur even in nutrient-limited waters or under environmental circumstances that deviate from the “norm.” To further complicate matters, not all cyanobacteria are associated with HABs, cyanotoxin producers may not always produce cyanotoxins, and the taste and odor compounds often associated with HABs may be generated by non-HAB algae species. As such, the only definitive way to understand if a waterbody suffers from, or is in danger of suffering from, a HAB is to collect the proper data. This includes:

To date, cyanotoxin testing has been expensive and the data turn-around slow.

A STRATEGY FOR TRACKING AND MANAGING HABS

To help understand and monitor HABs, Princeton Hydro recently launched a multi-prong strategy called PARE™ (Predict, Analyze, React, and Educate). Princeton Hydro’s PARE™ program focuses on the importance of thoroughly understanding site conditions, properly tailoring action programs and sustaining management efforts that go far beyond simply treating a bloom. As noted above, the PARE™ program consists of four key, interrelated elements:

Predict

Ideally, to successfully predict HABs, it is paramount to measure the amounts of phosphorus, nitrogen, and chlorophyll in the water column, track dissolved oxygen and water temperature profiles, and identify the types and densities of cyanobacteria and phytoplankton. Overall, in order to effectively predict the onset, magnitude and duration of a HAB, it is necessary to have good data foundation.

Analyze

With an adequate database it becomes possible to develop algorithms that account for all of the chemical, hydrologic and physical variables that may lead to HABs, including seasonal differences in weather and precipitation. In some cases it may also be possible to utilize remote sensing technology to track bloom development.

With a suitable database it becomes possible to develop HAB thresholds based on:

As part of PARE™ we also now have the ability to quickly and effectively measure the concentration of Microcystin in the water column using a combination of rapid response field test kits and accurate, quick turn-around laboratory analyses. The Microcystin data can then be compared to established USEPA or, when available, state guidance concentrations for cyanotoxins in drinking water and recreational water.

React

The data that are generated from the Predict and Analyze elements of the PARE™ program enables us to know when a bloom is about to occur or has developed, and quantify the severity of the bloom. The many variables that may lead to HABs interact in a complex manner in lake and pond ecosystem. Manipulating the ecosystem to prevent or treat HABs requires extensive expertise. Some of the interactions that must be taken into consideration include:

Through the correct understanding of these interactions it becomes possible to properly React by designing and implementing various pre-emptive controls and corrective measures such as:

On a larger, long-term scale, the React element of the PARE™ program encompasses watershed management programs targeting nutrient load reductions that can actually reduce bloom frequency/intensity.

Although the React element recognizes the role of algaecides as a potential part of the solution, it does not condone repeated extensive treatments with copper sulfate. As noted above, relying solely on substantial copper sulfate treatments most often only triggers worse conditions and leads to spiraling, repetitive blooms.

Education and Outreach

Besides informing the public about health concerns related to cyanobacteria and HABs, it is important that stakeholders are also informed about measures that they can implement to help prevent blooms. This includes “on-lot” nutrient controls such as septic management, limited application of lawn fertilizers, creation of shoreline buffers and waterfowl control. It is also necessary for stakeholders to understand the lifecycle of HABs, that ongoing monitoring and management help address HABs before they peak, and that, while seeming to be the “magic bullet,” copper sulfate is not the priority management tool.

IMPLEMENTING PARE™

Begin PARE™ early. Start sampling the above-noted key water quality parameters and bloom indicators in April. This information can then be used to create a comprehensive database used to make timely management decisions. Microcystin sampling can be focused on beach areas or around water intakes. Begin with simple, rapid response, in-field testing and, if necessary, use the laboratory analyses to confirm or further quantify a bloom. If there is early evidence of a bloom, implement the proper measures needed to control the bloom. While these measures are being implemented, continue to collect and analyze data to confirm water quality improvements and ensure users that conditions are safe. After achieving specific water quality and HAB control goals, continue to implement the measures needed to track conditions and prevent/react to future blooms.

For more information about how PARE™ can help manage HABs, call Stephen Souza at 908-237-5660 
or email us here and take a look at our blog post about managing lakes and ponds without the use of pesticides.