In recent summers, blooms of toxic algae have formed a mucky blanket on some Ohio lakes, killing fish and making swimming unsafe. But for several days in August 2014, these so-called blue-green algae, known technically as cyanobacteria, made national news by crippling the public water supply serving the Toledo area.
Strong winds blew the harmful algae blooms (called HABs for short) against Lake Erie鈥檚 shore, surrounding the region鈥檚 water intake system. And neurotoxins (in this case, microcystins) released by the organisms entered the intakes in high enough amounts to sound an alarm.
Don鈥檛 drink鈥攐r even cook with鈥攖he water from your faucet, authorities warned nearly half a million nearby residents in Ohio and Michigan. Ingesting the tainted water could cause vomiting, diarrhea, skin irritation and even liver damage in humans and animals. Boiling the water only made it more toxic. As people scrambled to buy bottled water, which quickly sold out in stores for miles around, the National Guard was called in to deliver extra supplies.
Could something similar happen this summer?
It鈥檚 not time to hit the panic button, says Joseph D. Ortiz, Ph.D., a geology professor at 麻豆视频鈥檚 College of Arts and Sciences who specializes in aquatic biology and oceanography. Ortiz and his colleagues are among a group of researchers who have been developing methods to better predict future harmful algae blooms.
鈥淢aybe something good has come out of the problem in Toledo last summer,鈥 says Ortiz, whose research has taken on a new sense of urgency. 鈥淲e鈥檝e been galvanized to improve the situation.鈥
With funds and support from the Ohio Sea Grant, the Ohio Board of Regents and NASA, Ortiz is honing methods for spotting a harmful algae bloom, preferably before it gets too large or too close to shore. The goals include minimizing harm to fish, keeping beaches open to swimmers, and alerting communities with water intakes nearby so they can take steps to defend their water supply (such as closing the intakes and stepping up the rate at which they鈥檙e treating the water). Ortiz has been examining crucial questions such as: What types of organisms are in the water? How extensive are they? Where are they and in which direction are they moving?
To advance the understanding of how algae blooms* develop and thrive, Ortiz is putting a space-age spin on long-standing research methods. Traditionally, scientists have plodded along by boat, collecting samples for analysis a single spot at a time. 鈥淢y focus is on trying to identify these organisms in a rapid and remote way,鈥 Ortiz says.
He is developing a remote sensing technology that relies on pictures taken with an instrument aboard NASA鈥檚 International Space Station called a hyperspectral imager. The high-resolution pictures鈥攄ecoded with the help of elaborate computer programs that Ortiz鈥檚 group is continually refining鈥攁llow Ortiz to identify plant pigments by the distinctive way each absorbs and reflects light. This 鈥減igment fingerprint鈥 makes it possible to classify organisms and determine which ones are harmful, and which ones are benign or even beneficial to the ecosystem.
Among Ortiz's 麻豆视频 partners in this mission is microbial ecologist Xiaozhen (Jen) Mou, Ph.D., an associate professor of biological sciences who studies cyanobacterial blooms at the gene level. Says Mou, whose research has helped ensure the accuracy of Ortiz鈥檚 method of converting space data to identify HABs in the water, 鈥淭ogether our findings will help establish a more comprehensive view of the ecology and biology of HABs.鈥
This summer Ortiz is also joining forces with additional experts from 麻豆视频 and three other universities on a HAB study in Sandusky Bay. As part of a $2 million Lake Erie water quality program requested by Ohio Governor John Kasich and created by the Ohio Board of Regents, the 麻豆视频 group is helping develop an early warning system for water filtration plants.
Ortiz鈥檚 specialized knowledge of remote sensing is key to the project, according to George Bullerjahn, Ph.D., a professor of biological sciences at Bowling Green State University and the study鈥檚 principal investigator. While Bullerjahn鈥檚 team measures chlorophyll, toxins and nutrients the conventional way, from the ground, Ortiz will contribute the hyperspectral imager鈥檚 cosmic perspective. Says Bullerjahn: 鈥淛oe鈥檚 angle is 鈥楬ow can we map the movement of this bloom from space so we can tell water treatment plants in advance when to take appropriate measures to treat the water?鈥欌
Ortiz鈥攚ho grew up on the East Coast, got his doctorate in oceanography from Oregon State University and has taught at 麻豆视频 since 2001鈥攈as conducted much of his research on Lake Erie, which he has adopted as his 鈥減ersonal mini ocean.鈥 As he points out, the Great Lakes are important sources of fresh water, accounting for about 20 percent of the world鈥檚 supply. Lake Erie is the smallest of the Great Lakes, and it鈥檚 also surrounded by more agriculture and human activity than the others, which contributes to the harmful algae blooms, Ortiz says.
But HABs are by no means limited to Lake Erie, the Great Lakes or the state of Ohio. They have turned up in bodies of water around the globe, including Europe and China.
鈥淎t a recent conference I attended, they were talking about Lake Taihu in China, which has blooms so intense that scientists estimate they need to cut the nutrient influx by about 90 percent to turn off the bloom conditions,鈥 Ortiz says. 鈥淭hat鈥檚 twice as bad as what we鈥檙e looking at.鈥
Communities are taking steps to prevent nutrients such as phosphorus and nitrogen, common in many fertilizers, from getting into lakes, ponds and rivers where they are known to nourish the algae blooms. 鈥淔or example, the Ohio legislature recently passed a bill to outlaw the spreading of fertilizer or manure during the winter, before the spring thaw, which will help decrease farm runoff,鈥 Ortiz says. 鈥淔armers are learning better practices, which helps them, too, because they want to fertilize their fields, not the lake.鈥
This summer鈥檚 Sandusky Bay project will help Ortiz put into practice his previous research. 鈥淲e鈥檝e developed the basics of the methodology,鈥 he says. 鈥淣ow it鈥檚 time to start rolling it out.鈥 Ortiz enjoys the complex science, but says the tangible promise of preserving local water supplies鈥攁nd ultimately contributing to water safety improvements the world over鈥攚ill be his best reward.
*What Creates an algae bloom?
Algae blooms aren鈥檛 a new phenomenon鈥攖hese ancient organisms have been around for 3.8 billion years, says Ortiz. Although not all algae blooms are harmful, scientists still don鈥檛 know why some produce high levels of toxins. 鈥淐yanobacteria are particularly toxic to multicellular life, yet there was no multicellular life when they first evolved,鈥 notes Ortiz. He says the organisms are proliferating now due to an influx of nitrogen and phosphorus being pumped into rivers and lakes鈥攁nd the blooms may become even more prevalent as the climate warms.
鈥淚n the 1950s and 鈥60s, we introduced high levels of nitrogen by dumping raw sewage into Lake Erie, saying 鈥楧ilution is the solution to pollution,鈥欌 Ortiz says. 鈥淭hat didn鈥檛 work so well.鈥 Algae blooms, fish kills and industrial waste contaminated the lake and nearby rivers.
Over the next two decades, the United States spent $8 billion to improve wastewater treatment, and states and communities passed laws to reduce the levels of minerals that nourish the algae. The measures were successful in restoring the health of Lake Erie by the 鈥90s, but recently the blooms have returned, largely as a result of agricultural runoff.
鈥淪ometimes when you fix one problem, you create another,鈥 Ortiz says. 鈥淚n trying to fix soil erosion, farmers were urged to go with low-till or no-till agricultural practices. But because they changed the way in which they applied the fertilizer, it would sit on the surface and be more apt to run off. That鈥檚 a big reason we鈥檙e having these gigantic blooms now.鈥