SALEM, Ohio — This year’s algal bloom on Lake Erie will likely be smaller than last year, but still worse than the mild bloom of 2016, according to researchers who provided the annual forecast during a news conference July 12.
Scientists expect this year’s bloom to measure a 6 on the severity index, with 10 being the most severe. The most severe bloom was in 2015, which measured 10.5, and in 2011, with a bloom of 10.
This year’s bloom, which is still a few weeks away from prime season, could range between 5 and 7.5, according to researchers with the National Oceanic Atmospheric Administration, and Ohio State University’s Stone Lab, which made the announcement.
They point out, however, that the size of the bloom is not necessarily an indication of how toxic it will become. The toxins in a large bloom may not be as concentrated as in a smaller bloom, and NOAA is continuing to work on a way to better predict toxicity.
Lake Erie continues to be in the spotlight because of ongoing water quality issues, which are caused by runoff from farmers’ fields, municipal waste and residential lawn chemicals. Phosphorus entering the lake is one of the biggest contributors to the growth of algae, which can lead to the growth of toxins produced by the algae, known as microcystins.
In recent years, visible blooms have not appeared until late July or early August. The algae typically start growing when water temperature reach 65-70 degrees, usually in mid-June.
This year, the western basin of the lake warmed almost two weeks earlier than usual, according to NOAA, reaching 70 degrees the last week of May, and leading to the appearance of a small bloom.
But the early warm-up does not necessarily indicate a more severe bloom is in store, according to Richard Stumpf, NOAA oceanographer.
“This early start does not change the forecast severity, because the bloom is determined by the amount of phosphorus that goes into the water,” said Stumpf. “Close attention to the weekly bulletins will be important through July and August to find the best places to enjoy the lake.”
NOAA issues Harmful Algal Bloom bulletins twice a week during the bloom season, which provide lake users a three- to five-day forecast.
Safe to enjoy
Researchers said much of the lake will be safe to enjoy most of the time, but lake users should check the bulletins to be sure.
“You can have a good time on Lake Erie,” Stumpf said. “I can’t emphasize that enough.”
The lake and its water quality have become a contentious issue for farmers, tourists and the millions of citizens who rely on it for drinking water.
A day before the algae forecast, Ohio Gov. John Kasich signed an executive order to declare eight northwestern Ohio watersheds in distress, and to require nutrient management plans. Farm groups fired back that they are already working on nutrient management, and much more.
The farm groups have also argued that more time is needed to figure out how the nutrients are entering the lake, and the best farming practices for preventing runoff.
Laura Johnson, director of the National Center for Water Quality Research at Heidelberg University, said the things in the executive order could help, but she said more time is needed.
Johnson said farmers are headed in the right direction, as they implement new practices to control the movement of phosphorus, but some of the practices will take several years, as many as 15, before results will be seen.
“Has there been enough time to tell — I would truly argue that is not the case,” Johnson said. “To think that after a couple years of implementation. … I would argue that we just haven’t had enough time and that people just need to be patient.”
She said it makes sense for farmers in distressed watersheds to be testing their soils, and reducing their phosphorus inputs. But how soon that produces results will depend on the levels in the soil to begin with — and how much is leaving the field.
“That process, depending on the soil test levels, can take a very long time or a not very long time,” she said.
About the forecast
The Lake Erie forecast is part of a NOAA ecological forecasting initiative that aims to deliver accurate, timely and reliable ecological forecasts directly to coastal resource managers and the public.
This year, NOAA will increase use of the Sentinel-3a satellite data, which first became available last year. The satellite measures coastal water color, which shows the location of HABs, as part of the European Union’s Copernicus program, which just launched the sister satellite, Sentinel-3b, that will start providing imagery by next summer.
The Sentinel-3 series can see features 10 times smaller than has been seen in the HABs forecasts for the last several years. Sentinel-3 provides more detail to improve the forecasts used by the water treatment plants and public safety managers.