Forecast: Algal bloom this year will be big, but won't set record for size

SANDUSKY — Look for a big green harmful algal bloom to spread out over western Lake Erie this summer.Lake Erie's harmful algal bloom this summer will be a big one, bigger than the relatively small bloom in 2016, scientists predict.But they say it won't be as large as the record HAB recorded in 2015, or as big as the second-largest one in 2011.The scientists, speaking at an annual forecast event held at Stone Laboratory on Gibraltar Island near Put-in-Bay, said the bloom is forecast to measure 7.5 on the severity index for how large it will be, compared to 10.5 in 2015 and 10.0 in 2011.The possible range for this year's bloom is 6.5 to 9.5, so the scientists appear pretty confident that the bloom this year won't set a record.Richard Stumpf, an algal bloom expert from the National Oceanic and Atmospheric Administration, said that the size of the bloom and the toxicity of the bloom are too different measurements. Scientists don't have a way to forecast the bloom's toxicity, although they are working on that, he said.Harmful algal blooms, aside from producing a blue-green goo that covers the surface of the lake, can produce toxins that have to be removed during the water purification process.Stumpf noted that the bloom will be concentrated in the western basin, and that much of the lake should be fine. Even the effect on the western basin will depend upon winds, he said.Laura Johnson, a Heidelberg University professor at the school's National Center for Water Quality Research, said the amount of phosphorus placed in the lake to feed harmful algal blooms seems to track closely with the amount of rain and with severe storm events.She said concentrations of phosphorus in the water haven't changed very much.Scientists understand what needs to be done by farmers to reduce the phosphorus runoff feeding harmful algal blooms, she said.That includes good practices for using fertilizer, including putting the right amount on at the right time, planting cover crops, and managing water that drains from the fields. But the data shows that not enough of that is being done yet, she said.Although Thursday's event focused on the harmful algal bloom forecast for this summer, experts also were brought in to discuss related topics. Here is some of what they said:• A new study suggests that it is safe to eat yellow perch and walleyes caught in the lake during harmful algal blooms, said Stuart Ludsin, a scientist at The Ohio State University's Aquatic Ecology Laboratory who is the lead author of the study.Walleyes apparently aren't getting the toxins in their flesh (their livers do a good job of filtering the toxins out), while yellow perch get only small concentrations.Eating fish during harmful algal blooms is particularly safe if people follow the Ohio EPA's guidelines for fish consumption: No more than one walleye meal and two yellow perch meals per week, he said.Ludsin remarked that boiling and cooking has no effect on the amount of microcystin toxin found in fish.• Another new study shows that naturally occurring Lake Erie bacteria can be used to reduce the amount of microcystin toxin when water is being treated in municipal filter plants, supplementing other methods, said Jason Huntley of the University of Toledo's Health Science Campus.The bacteria that gobble up the toxin don't make people sick, he said.• People planning to visit Lake Erie during the harmful algal bloom season should call ahead to make sure their beach or fishing plans won't be affected, said Melinda Huntley, executive director of the Ohio Travel Association.Make that phone call shortly before your trip, she said. Conditions change rapidly, so a phone call two or three weeks in advance may not be very useful.Reach reporter Tom Jackson at jackson@sanduskyregister.com and follow him on Twitter @jacksontom.A slide presented at Thursday's algal bloom forecast at Stone Laboratory shows the projected size of this year's algal bloom and the size of past blooms.