Across Japan, a new approach to dealing with alien animal species that threaten the native ecosystem is taking hold: Eat them.

Authorities hope eating such dishes as catfish burgers and crawfish soup -- both species have been designated as harmful by the government -- will also raise public awareness of environmental problems.

In Namegata, Ibaraki Prefecture, the local chamber of commerce and industry in 2009 began selling namepakkun -- burgers made with catfish meat.

The catfish patty also contains pieces of lotus root, one of the city's specialty products, which gives the burgers a crispy texture.

Namegata locals catch young channel catfish -- a designated harmful alien species native to North America -- in Lake Kasumigaura and farm them.

For about 30 years, the catfish has been shipped to other prefectures as a foodstuff. Currently, Ibaraki Prefecture ships out about 100 tons a year. Most of it is shipped to areas in Saitama and Gifu prefectures, where there is a tradition of eating catfish -- in Hida, Gifu Prefecture, catfish is called kawafugu (river puffer fish) and is served as sashimi and in hot pot dishes.

However, catfish has not been traditionally consumed in Namegata.

Keiko Hirano of the chamber's development division said, "We hope that eating the fish will make local people think about the future of Lake Kasumigaura."

In October, the chamber introduced funny catfish characters as mascots -- sibling duo Niko-chan and Ototo Namezo -- to promote the local industry.

Catfish farmers have proposed new ways to serve catfish, such as extremely thin sashimi, fried or grilled with sweet soy sauce.

In Hokkaido, similar efforts are under way, but there the focus is controlling the population of signal crayfish -- uchida-zarigani in Japanese -- which cause harm by eating marutanishi shellfish and spherical moss.

An adult signal crayfish is more than 15 centimeters long, larger than an average American crayfish. Though signal crayfish is designated as a harmful species that should be eliminated, it is popular for its delicate flesh.

A fishery co-op in Lake Akan in Kushiro sells crispy chips made with signal crayfish meat. The co-op said the spicy chips are very popular.

Fishermen belonging to the co-op have been catching signal crayfish for 17 years, selling them mainly to French restaurants in Tokyo and its suburbs as well as the Keihanshin area. In French cuisine, crayfish -- or ecrevisse -- is a delicacy.

The co-op also sells canned crayfish soup.

Elsewhere in the nation, efforts are under way to stimulate people's appetite for dishes made with bullfrog, among other potentially delicious pests.

However, how to store and transport the innovative foodstuffs, as well as the expense involved in their production, pose problems.

Professor Akio Maita of Kyoto Saga University of Arts, who also serves as director of the Japan Ecotourism Society, said, "These local groups should be helped to continue their efforts, so they don't just fizzle out.

"For example, local governments should help increase awareness of the new foods. And systems should be established to make sure people can benefit economically from their efforts," he said.