War on invasive carp turning to robotic boats

ST. PAUL

Common carp have beset North America for more than a century -- turning once-clear lakes, wetlands and rivers into muddy waters.

Now, biologists and computer scientists at the University of Minnesota and two other universities are teaming up with robots to go after the invasive, non-native fish.

Researchers at the U, Johns Hopkins University and Central State University in Ohio have been awarded $2.2 million from the National Science Foundation to develop robotic boats and program them to track radio-tagged carp as part of a new approach to controlling their numbers.

"It's a little bit of science fiction, but it makes sense," said Peter Sorensen, a fish biology professor in the U's College of Food, Agricultural and Natural Resource Sciences.

The team is led by Volkan Isler, computer science and engineering associate professor in the university's College of Science and Engineering and resident fellow of the Institute on the Environment.

Carp, Sorensen said, are social creatures that, as adults, bunch up in schools, or shoals. But tracking them using conventional boats is expensive and often difficult.

Using the grant money, they'll devise robotic boats capable of studying movement patterns and identifying large gatherings, enabling the fish to be netted and removed more easily.

The project is an extension of work Isler began several years ago with Sorensen. They used funding from the U's Institute on the Environment and the Environmental and Natural

Resources Trust Fund to build and test a prototype robotic boat.

Now, though, the team plans to take things to another level, with multiple robotic boats working together. Isler eventually plans to install solar panels on them so they can be self-powered.

Common carp were brought here from Europe more than a century ago and have since spread throughout the country. With their bottom-feeding behavior, adult carp uproot aquatic plants, stir up pollutants and increase turbidity, ruining habitat for waterfowl and aquatic creatures.

They're as abundant as they are in part because they're not prized for food as they are in other cultures. Oftentimes, lakes are poisoned or drained to get rid of them -- usually with limited success.

Sorensen got interested in controlling common carp about five years ago when he took a trip to Australia, where the fish have overrun many water bodies.

"They take very seriously a problem that we largely neglect here," said Sorensen, noting Australians were placing radio tags in carp and releasing them to seek out large shoals. "I thought: 'We're smart, too. We can do some of this stuff.' "

Using state lottery proceeds, they tried a similar approach here, leading to removal efforts at several state lakes.

Then Isler proposed adding robotics to the mix. "In 'The Land of 10,000 Lakes,' lakes were particularly appealing to me," Isler said.

He said plenty of challenges await researchers, who must figure out ways to coordinate and refine the search capabilities.

With other invasive fish -- Asian silver and bighead carp -- closing in on Minnesota, researchers eventually might be able to use the approach to cut into their numbers, according to Sorensen.

"Ideally, I could send a silver carp out there to find the rest of them for me," he said. "One would lead to another and we would get them. It's the kind of thing that I think we have to be thinking about with invasive fish.

"Frankly, these fish are much better at finding each other than we are at finding them."

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