Algal Blooms May Take Hit From Cooler Weather, Farm Methods
Algal blooms are once again causing problems for lakes and streams in Ohio this summer. But farmers are combating the situation, and so far, they’re getting some help from the weather.
When rain falls on farm fields that have been treated with fertilizers containing nitrogen and phosphorus, whatever chemicals haven't soaked deep enough into the soil, or made their way into the crops, can end up in nearby streams and lakes. That runoff is feeding nutrients to harmful algal blooms.
Farmers have been aware of this potentially devastating effect for some time, and, according to Larry Antosch, Senior Director on Environmental Policy with the Ohio Farm Bureau, many of them using the "Four Rs system of Nutrient Management" to combat the situation. He says, "The four R's stand for the right place, right amount, right time and the right form."
According to Antosch, the right place means knowing what farmlands have the potential to facilitate runoff into nearby waterways. The right amount refers to using only what's needed for the expected crop yield, and the right form is about what types of fertilizers are being used - organic materials, bio-solids, or commercial fertilizers.
What may have been tough for farmers this planting season is getting the timing right. It's been a wet season across the state and that's likely contributed to more farm runoff. But Antosch believes the extra rainfall, along with cooler temperatures this season, could actually help stop the inhibit the growth of harmful algal blooms.
The policy director says, "Lake temperatures are probably not warming up as much as they have in past years. We also have been getting a lot of rainfall, so plenty of water coming in and flushing, flowing through the lakes, and so we're not getting that stagnant water, warm water, calm water."
According to the National Oceanic and Atmospheric Administration (NOAA), temperatures have been fluctuating widely this Spring and Summer – short periods of above average temperatures mixed with longer cooler periods. This has actually put Ohio at about average temperatures from April through July. So far in August, we’re running about 4 degrees below normal tempertures.
And NOAA’s predictions for the amount of algal blooms in Lake Erie this August are still significant - 300 sq miles – Larger than 2012, but about a fifth of the size it was in 2011, And nowhere near the conditions Ohio faced in 2010, when some 20 inland lakes posted advisories warning visitors about coming into contact with toxic algae.
Algal Bloom conditions will vary across that state – in late May, Grand Lake St. Mary’s issued an advisory for one stretch beach, but just how bad conditions will get will be determined by weather conditions in late August and September - as Ohio moves into the dog days of summer.