Warming drives spread of toxic algae in US, researchers say
By TOM JAMES
Saturday, June 23
SALEM, Ore. (AP) — The words blasted to cellphones around Oregon’s capital city were ominous: “Civil emergency, prepare for action.”
Within half an hour, a second official alert clarified the subject wasn’t impending violence but toxins from an algae bloom, detected in Salem’s water supply.
Across the U.S., reservoirs that supply drinking water and lakes used for recreation are experiencing similar events with growing frequency. The trend represents another impact of global warming and raises looming questions about the effects on human health, researchers say.
“When water bodies warm up earlier and stay warmer longer … you increase the number of incidents,” said Wayne Carmichael, a retired Wright State University professor specializing in the organisms. “That’s just logical, and it’s being borne out.”
Technically called cyanobacteria, the ancient class of organisms that create the blooms are present nearly everywhere water is found but thrive in warm, still bodies like lakes and ponds. They also create a unique class of toxins, the impact of which on humans is only partly understood.
Long linked to animal deaths, high doses of the toxins in humans can cause liver damage and attack the nervous system. In the largest outbreaks, hundreds have been sickened by blooms in reservoirs and lakes, and officials in some areas now routinely close water bodies used for recreation and post warnings when blooms occur.
But less is known about exposure at lower doses, especially over the long term.
Small studies have linked exposure to liver cancer — one toxin is classified as a carcinogen, and others have pointed to potential links to neurodegenerative disease. But definitively proving those links would require larger studies, said Carmichael, who helped the World Health Organization set the first safe exposure standards for the toxins.
“It’s absolutely certain in my mind that warming temperatures are going to end up causing more of these algal blooms,” said Steven Chapra, an environmental engineering professor at Tufts University.
Chapra led a team including scientists from the Massachusetts Institute of Technology and the U.S. Environmental Protection Agency in one of the most comprehensive studies of the interplay between global warming and the blooms, published in 2017.
Because they prefer warm water, higher summer temperatures and more frequent heat waves help the organisms. More frequent droughts also cause reservoirs to be shallower in summer, causing them to warm faster.
And more intense rainstorms, also conclusively linked to climate change, can wash more nutrients into lakes and reservoirs, especially from farms where nitrogen and phosphorous-rich fertilizers are used, Chapra said.
In Utah, a 2016 algae bloom in a recreational-use lake sickened more than 100. When the story made national headlines, other states reached out.
“We started getting calls from other health departments all over the country saying, ‘Hey, we’re dealing with an algal bloom in a lake that has never ever had one before,’” said Aislynn Tolman-Hill, Utah County Health Department spokeswoman.
Officials only recently started carefully logging the blooms, but they seem to be becoming more intense, said Ben Holcomb, a biologist for Utah’s environmental agency. “They’re starting earlier, they’re lasting longer, and their peaks seem to be getting bigger,” Holcomb said. “I don’t think any state is isolated.”
In Lake Erie, a major bloom in 2014 caused authorities to warn against drinking tap water in Toledo, Ohio, for more than two days, cutting off the main water source for more than 400,000 people.
Now blooms happen every year in Utah and Ohio. Officials in both states say they’ve largely been able to stop them from toxifying drinking water. But the blooms can still sicken people and pets that go in the water, and often hit recreation businesses that depend on lake access.
Other blooms, including flare-ups affecting drinking water, have been logged in recent years in New York, Florida and California.
In Oregon, officials lifted Salem’s drinking water advisory after several days, but then had to re-issue the warning. The water supply serves a population of just over 150,000 in the city, along with residents outside city limits.
Officials also warned that dozens of other water supplies could be vulnerable, and indeed, when workers from the city of Cottage Grove inspected another reservoir, they found a bloom, according to a report by Oregon Public Broadcasting.
Testing for the blooms isn’t required by either federal or state law, officials noted.
Researchers say that needs to change because blooms are likely to become more common, including in states where low temperatures previously provided a buffer against them.
“These things like you’re seeing in Lake Erie and in Oregon are kind of like the canary in the coal mine,” said Chapra, the Tufts researcher.
“It’s going to get worse, and it’s going to get worse in a big way.”
Thank you for an amazing 2017 season! We can’t wait to see you again when we re-open April 1, 2018.
— Olentangy Indian Caverns
About the caverns
Formed millions of years ago by the tremendous force of an underground river cutting through solid limestone rock, the Olentangy Indian Caverns today offer an exciting excursion into ancient Indian lore with a maze of beautiful winding passages and spacious underground rooms. There is evidence that the Wyandotte Indians used these caverns as a haven from the weather and from their enemies, the Delaware Indians. One of the large rooms “Council Chamber” is believed to have been used by the Wyandottes for tribal ceremonies. This room contains a large rock table referred to as Council Table. The first white man believed to have entered the caverns was J. M. Adams, a member of a westbound wagon train that camped nearby in 1821. During the night one of his oxen broke loose and wandered off. In the morning the ox was found dead at the bottom of the entrance to the ancient Indian cavern. After exploring the entrance, Adams carved his name and date on the wall. The carving still remains but is hard to see due to being partially covered by Flowstone.
Various artifacts found in the caverns indicate that the Indian Council Room was used by Wyandotte Indians for making arrows and other stone implements until as late as 1810. These items were found when the caverns were opened and some are on display in the Museum. This remarkable geological wonder is now accessible to everyone from the Museum atop the entrance. Concrete stairways descend 55 feet to the maze of natural passages and rooms occupying three different levels. The second level contains Indian Lover’s Bench, Battleship Rock and The Crystal Room. Fat Man’s Misery is a passage leading to Cathedral Hall and Bell Tower room which is 105 feet below the earth’s surface. Beyond are passages and rooms still unexplored. A fourth level where an underground river is flowing to the Olentangy River has been partially explored but not opened to the public. It is known that the river has formed a lake but its size has not been determined. Many miles of passages have never been explored.