Underwater robots deployed and on patrol in Lake Erie

What may appear to some as a torpedo drifting through the water is actually a device that may help scientists detect potential health hazards. Robots have been deployed in the fourth-largest of the Great Lakes and they are diving underwater to hunt down harmful algae blooms (HABs). On their underwater missions, the robots gather data that could help save lives and refine forecasts for harmful algae blooms in Lake Erie, as well as other bodies of water like the Gulf of Mexico.

Algae are simple photosynthetic organisms that live in the sea and freshwater. HABs occur when they grow out of control while producing toxic or harmful effects on people, fish, shellfish, marine mammals, and birds. HABs can have an array of negative impacts on ecosystems and humans, according to the National Ocean Service (NOS).

Just a few weeks ago, a toxic algae bloom was blamed in the deaths of three dogs that were playing at a local pond near midtown Wilmington, North Carolina.

AccuWeather National Weather Reporter Jonathan Petramala traveled to Toledo, Ohio, to investigate how these underwater robots patrol Lake Erie and how they help researchers better understand a harmful algae bloom that plagues the lake on an annual basis.

While the robot may appear to resemble a weapon of war, it is actually a Tethys class long-range autonomous vehicle. There are currently two of these roaming the lake near Toledo, mapping and measuring the toxicity of the algae bloom there.

Petramala visited the lake this week and took a firsthand look at how these robots work and talked with the scientists who deploy them.

Underwater robots are on patrol in Lake Erie helping researchers better understand a harmful algae bloom that plagues the lake on an annual basis. AccuWeather's Jonathan Petramala takes us under the sea to see what they are getting. (AccuWeather/ Jonathan Petramala)

Each robot is capable of working completely autonomously for up to three weeks at a time and they travel distances of nearly 1,000 miles before they need to be recharged.

"It has the ability to be out there in the field acquiring data over the entire period of a bloom, for example, so what we call from bloom to bust," Ben Raanan, an associate engineer with the Monterey Bay Aquarium Research Institute in Moss Landing, California, told Petramala.

The work these robots do is dangerous to be sure. The algae in Lake Erie can make humans ill and be lethal for animals. But the dangerous conditions in Lake Erie are no match for the robots. They are battle-tested, as evidenced by a story Ranaan told about one of the underwater droids tangling with shark.

"What you’re seeing here are the markings of the teeth," Raanan said, pointing to a series of chips in one of the robot's exterior paint. He explained that the vehicle was attacked by a great white shark while on patrol in Monterey Bay. "It had the whole vehicle in its mouth."

Despite the shark attack, the vehicle completed its three-week mission.

In addition to being able to venture into a dangerous environment, the robots will help scientists overcome some of the other challenges that exist with current algae detection methods. Current technology, such as satellites, have inherent limits in forecasting this bloom. Satellite images on a cloudy day can provide incomplete data, Steve Ruberg, a scientist for the National Oceanic and Atmospheric Administration (NOAA) and the Great Lakes Environmental Research Laboratory, said to Petramala. Even thin and whispy clouds can render a satellite basically useless.

Not only do the toxic blooms impact swimming and fishing activities, but they also have an impact on local drinking water.

Cities like Toledo draw drinking water from Lake Erie. While daily testing and treatment helps ensure the water is safe, the constant data stream that these robots can deliver could help make forecasting more accurate.

"Having that information, water intake managers and other managers in the region are using that to make decisions about how to treat their water, which they’re doing successfully, but having that information really helps them do their job better," Ruberg said.

In August 2014, Toledo city officials issued a “Do Not Drink" advisory for residents served by Toledo Water. The advisory was issued after chemical tests confirmed the presence of unsafe levels of the algal toxin Microcystin in the plant's drinking water, EcoWatch reported.

The advisory spanned across three counties in Ohio and one in Michigan. More than 400,000 people in the Toledo area were left without drinking water.

While these vehicles will not destroy these harmful algae blooms, they are already helping researchers better understand them.