By Matt Reese
Last year I hopped on the boat and made the trek to the fantastic Stone Laboratory on Lake Erie for the announcement about the predictions regarding the 2018 algal bloom.
The boat ride was quite pleasant, the presentations at the event were very sciencey and impressive, the folks doing the research being presented were extremely intelligent — and the forecast was totally wrong.
In July of 2018, the National Oceanic Atmospheric Administration (NOAA) and its research partners predicted western Lake Erie would experience a harmful algal bloom (HAB) of cyanobacteria of a 6 on the severity index, with a range between 5 and 7.5. In late fall, NOAA reported back that the actual harmful algal blooms in Lake Erie for 2018 had a severity index of 3.6, indicating a relatively mild bloom far short of the predicted severity.
Now, I don’t know what the total budget is for this forecasting system, but I would guess it is not a small price tag over the years of developing models, conducting extensive research, paying numerous staff members and researchers at various agencies and entities, and hauling curious farm reporters to the island on boats. There is even satellite technology involved. NOAA continues to expand the use of data from the European Union’s Copernicus Sentinel-3 satellite, which has instruments that measure coastal water color and have proven useful for detecting and tracking algal blooms.
There is surely some value for area officials and water treatment facilities and the general public in having an accurate, reliable forecast of the bloom for the year, but I’m not really sure what the specifics of those benefits are either. What does seem to be clear, though, is some really smart people have put substantive effort, time and financial resources into developing an educated guess about an algae bloom a month or two in the future, and it is still just plain wrong (at least some of the time, but maybe mostly right part of the time).
With that in mind, NOAA predicted the 2019 bloom will measure 7.5 on the severity index, but it could possibly range between 6 and 9. An index above 5 indicates blooms having greater impact. The severity index is based on bloom’s biomass — the amount of algae — over a sustained period. The largest blooms occurred in 2011, with a severity index of 10, and 2015, at 10.5.
“Communities along Lake Erie rely upon clean, healthy water to support their community’s well-being and economic livelihoods,” said Nicole LeBoeuf, acting director of NOAA’s National Ocean Service. “This forecast provides timely and trusted science-based information to water managers and public health officials so they can better anticipate blooms, mitigate impacts and reduce future outbreaks.”
But can it be trusted? And, even if the size of the bloom is exactly what is predicted, the bloom’s size isn’t necessarily an indication of how toxic it is and how area communities should respond. The toxins in a large bloom may not be as concentrated as in smaller blooms and each algal bloom is unique in terms of size, toxicity, and ultimately its impact to local communities.
The timing of the algal bloom is also tricky to anticipate. This year, the lake temperature has remained relatively cool due to the abundant rainfall in the region, so the bloom was not expected to start until late July when the water temperatures hit the 65 to 70 degrees F mark. In 2018, exceptionally warm weather at the beginning of June caused an early start. Calm winds in July, especially in western Lake Erie, tend to allow the algal toxins to concentrate, making blooms more harmful. The bloom typically peaks in the western basin of Lake Erie in September and most of the rest of the lake will not really be affected.
The formulation of the prediction includes a very wide range of factors that contribute to the potential bloom each year. Some of these factors involve what has already happened (spring weather and rainfall) and predictions of what may happen (wind and summer temperatures).
With the release of the 2019 prediction in July, I also wonder how the horrific planting season will factor into the bloom. Many acres in the watershed were not only left unplanted, but also did not receive fertilizer applications said to be a significant contributing factor to the bloom. Fields that were not planted but had fertilizer applied stand to lose a fair amount of nutrients this year as well. Also, it will be interesting to see how the high water levels in Lake Erie will play out in terms of the algal bloom in 2019.
“This spring brought regular, heavy rainfall to the Maumee River watershed which would normally carry a lot of nutrients into the lake,” said Richard Stumpf, Ph.D., NOAA’s National Centers for Coastal Ocean Science’s lead scientist for the seasonal Lake Erie bloom forecast. “However, due to the amount of rain this year, farmers were unable to plant their fields which reduced the nutrient concentration. That combined with higher than normal lake levels, presents an opportunity to test the accuracy of our models.”
This year marks the five-year anniversary of the notorious harmful algal bloom that led to the “do not drink” advisory for more than 400,000 people in the greater Toledo area. Even before the news broke five years ago, Ohio agriculture had set the wheels in motion to address the problems of water quality and nutrient loss from farm fields. Much has been learned since then, yet there are still many unknowns in this confounding issue. The Lake Erie algal bloom is clearly difficult to predict, challenging to understand and maybe impossible to definitively solve. Here’s hoping that this very challenging 2019 yields some much-needed algal bloom insights from the fallow fields of northwest Ohio and the many efforts of those trying to make a difference for Lake Erie and Ohio’s water quality.