Japan Bugged by Invasion of Foreign Fauna

As the waves lap gently and a stork sweeps its long, white wings over the shore, Akihiko Kubo reaches over the side of the boat and pulls up a net filled with black bass and bluegill from the cold, dark waters.

“It looks so peaceful and beautiful above the waterline,” says Kubo, a director of Shiga prefecture’s Fisheries Cooperative Assn. “But it’s a raging battle down below.”

Aggressive foreigners of the scaly, furry and slimy persuasion are invading Japan, with pastoral Lake Biwa a front line in the battle to stem the spread of alien species. Originally introduced by sports fishermen, the voracious American fish are rapidly outeating and outbreeding their Japanese counterparts.

Kubo heads a program that hires unemployed salarymen to go fishing five days a week in a bid to wipe out the invaders. The 36-mile-long freshwater lake, Japan’s largest, is revered in the nation’s history, literature, kabuki theater and film and is said to be among the oldest lakes in the world.

The fish fight going on here, and a similar one taking place in the moats of Tokyo’s Imperial Palace, is grabbing national attention. But they’re only the most prominent of several battles underway as imported goats, mongooses, dandelions, beetles, raccoons and a host of other flora and fauna threaten to wreak havoc on Japan’s environment.

While countries all over the world struggle against aggressive invasive species, Japan is among the more vulnerable, environmentalists say, given its delicate island ecosystem. As a result, many indigenous plants and animals find themselves ill-prepared for the fierce competition from invaders entering aboard cargo ships and airliners as pets or stowaways.

The struggle parallels the threat some Japanese are feeling in other areas, including the economy, society, crime and sports. “If you look at the Taiwan squirrel, it’s like a foreign home-run hitter coming in and causing a bunch of short-ball local hitters to lose their jobs,” said Ichii Ishiyama, an Environmental Ministry official.

In some cases, foreign animals and plants were brought in to fix another perceived environmental problem. The Javanese mongoose was introduced into Okinawa about 1910 to control rats and the venomous habu snake. The only “environmental impact study” involved releasing a mongoose and a habu in an enclosed room.

The mongoose dutifully attacked and killed the snake, so mongooses were brought in. Once released into the wilds, however, they all but ignored snakes in favor of other far easier native prey. Today tens of thousands of the creatures thrive -- along with untold numbers of snakes and rats -- as two perceived problems have turned into three.

Sometimes, sport has provided the catalyst. Black bass were brought in from California in 1925 by a Japanese angler who enjoyed the fight they provided at the end of a fishing line. Bluegills followed, reportedly a 1960 gift to Japan’s crown prince from the mayor of Chicago. Both species are crowding out original settlers such as crucian carp, baby shrimp and eels.

In other cases, fashion has provided the impetus. The nutria, a rodent with webbed feet, spread rapidly throughout western Japan after it was brought in during the 1930s for the use of its pelts in making military uniforms.

Abandoned pets are another big problem. A television cartoon in the late 1970s starring a raccoon prompted thousands of Japanese to acquire their very own masked scavengers, before people tired of the critters and unleashed them into the wild. Now the Hokkaido prefecture government is battling to limit crop damage.

“We’re catching about 900 raccoons a year,” said Masashi Asano, a manager at Hokkaido’s Environment and Lifestyle Department. “They love fried bread coated with sugar nestled in dog food and caramel corn.”

Other troublesome wayward pets turning up in forests, parks and sewers include snapping turtles, piranhas, alligators and ferrets. Foreign beetles are also a worry, smuggled inside suitcases for the $2,000 or more collectors pay for rare varieties, according to Japan’s Bug Monthly magazine.

In some cases, foreign species threaten to love their domestic counterparts out of existence, such as Taiwanese monkeys that breed with Japanese monkeys, which are on the protected species list.

Often it’s not clear how or why aggressive foreign animals and plants got here. The goats ravaging the Bonin Islands are variously attributed to early settlers from Hawaii, whalers and even Commodore Matthew Perry, the American who forced open Japan’s trading ports in the 1850s, said Toshimitsu Doi, an environmental official with the national government.

For decades, Japan showed little concern for its environmental invaders. However, the 1992 Earth Summit in Rio de Janeiro put the issue on the radar, leading to policies that went into effect last year. They call for the extermination of species deemed a threat to the ecosystem or humans, farmers in particular.

Today there are officially 200 animal invaders, 246 insects and 1,553 plants. And while surveys find 73% of Japanese favoring extermination programs and around 90% supporting import restrictions, there’s no clear list of extermination candidates. Turf wars within the government hamper efforts to address the problem, said Hidenori Kusakari of the environmental group World Wildlife Fund Japan.

In the moat surrounding the Imperial Palace, long a symbol of Japan, researchers are attempting to cleanse the waters of black bass and bluegill with a $450,000, five-year project. Like so many other efforts, however, they’ve been frustrated by the wily foreigners. Some experts say the only solution may be to drain the moat -- hardly a model approach for Biwa or other inland bodies of water.

Extermination programs have seen their share of critics from animal-rights groups and anglers. Fishermen have launched a counteroffensive against efforts at Biwa and other prime fishing spots, questioning government data, methods and rationale.

“Sure I want the indigenous fish to come back, but I also want other fish including black bass to coexist,” said Kyoji Terada, chairman of the Shiga Fishing Boat Assn. and owner of 48 rental boats. “They blame everything on the black bass.... They’re going to destroy our livelihood.”

Anglers first spotted bluegills in Lake Biwa in the mid-1960s and black bass in 1974, with the extermination program launched in 1984. The prefectural program Kubo oversees has 43 people netting fish eight hours a day, rain or shine, in addition to dozens of commercial fishermen paid by the weight of their catch.

Out on the boat, Kubo sighs as he recalls boyhood fishing trips taken almost as soon as he could walk. He shirked his homework for the sport, majored in tuna at fishery college and built his career around fish.

“If I could meet whoever introduced black bass into this lake, I’d give them a piece of my mind and tell them what an idiot they were,” he said. “It used to be the indigenous fish practically jumped into your net. Now you have to try to catch one. I just hope my grandchildren can see the water thick with them again someday.”

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Takashi Yokota in The Times’ Tokyo Bureau contributed to this report.