Harmful Algal Blooms

Watershed Action Plans- A conscience effort for combating Harmful Algal Blooms

Image from: savelakeerie.com
Summer time is in full swing and summer algae season (not to be confused with allergy season) is well underway.  It is not unusual to see a layer of algae on the surface of our region’s lakes, ponds, and streams and some algae is good.  However, in recent years harmful types of algae have become more prevalent and toxic to our nation’s surface waters.  Last year, the City of Toledo, issued a “do not drink” advisory for nearly half a million residents who relied on treated water from Lake Erie.  The advisory was a result of a harmful algal bloom (HAB) containing high levels of microcystis, a cyanobacteria.  

Wikepedia identifies microcystis as fresh water cyanobacteria that produces two types of toxins: neurotoxins and peptide hepatotoxins (i.e. microcystin) affecting the nervous system and liver of both humans and animals.  Grand Lake St. Marys is another example of fresh water tainted by harmful algae blooms.  Grand Lake St. Marys is an inland lake in western Ohio that has been a hotspot for local recreation. Unfortunately since June 2009, the lake has also become a hotspot for HAB resulting in a loss for local residents and businesses. The harmful algae events increase due to the phosphorus in the runoff of manure and fertilizers from the watershed’s land users.  Without delving too much further into the technical, scientific background of HABs, a question for our region to ask and strongly consider is, could this happen to us? The answer is yes, if the perfect storm is created.

What is the perfect storm for HABs?
 Although Ohio EPA survey data suggests our drinking water sources are not and have not been in danger of an HAB threat, there are two factors that can influence a regional occurrence: warm temperatures and nutrient loading.  

Harmful algae events are seasonal and form mostly during the summer months, when temperatures are warm.  The higher temperatures create a competitive atmosphere as harmful algal growth, such as the harmful microcystin, overpowers the non-harmful algae.  

Nutrients such as Nitrogen and Phosphorus are two of the most common non-point source pollutants that accelerate the growth of algae. Both nutrients are byproducts of agricultural and residential fertilizer (chemicals , manure) runoff and failing septic systems.  Excess nutrients serve as catalysts for algae as they grow at a rapid pace as algae eat the nutrients.  As the harmful algae continue to grow and die off, harmful toxins are released.  These toxins have an adverse affect on a human’s and animal’s nervous system and liver.

What role does a Watershed Action Plan have?
The American Water Works Association, in their white paper on Algal Toxin Treatment, states “a watershed protection program can help reduce the nutrient load on the watershed area.  An effective watershed management program will help identify specific environmental characteristics of the watershed and actions necessary to reduce or eliminate potential contaminants.” In other words, endorse and implement your local watershed action plan.

The Yellow Creek and Upper Grand River have endorsed watershed action plans. Both watersheds house surface drinking water sources that are susceptible to nutrient enrichment due to their urbanized and/or agricultural landscapes.  The watershed action plans identify sources of nutrients as fertilizers (urban and agricultural), manure, and failing septic systems.  All three sources are manageable and can be contained onsite through several different measures, for example: 

                Using fertilizers sparingly and/or according to manufacturer directions;
                Manure storage and/or land application away from surface waters;
                Establishment of vegetated stream buffers to absorb nutrients prior to entering surface waters;

These and more measures can be found within the plans as well as coordinating agencies that can help identify funding sources to implement the measures. The watershed action plans are insurance measures that communities should consider implementing.