Nov 4, 2008

Foreign crayfish attract ire, gourmands

Some foreign aquatic species are threatening the country's ecology while simultaneously pleasing its palate.

The signal crayfish, which lives in Lake Akan, Hokkaido, has begun attracting the attention of chefs as a prized dish.

Originally from North America, it was released into Lake Mashu in Hokkaido in 1930.

The crayfish, which can grow to 10-15 centimeters long, overbred and drove away native species such as the Nihon zarigani, or Japanese crayfish.

The signal crayfish also poses a serious threat to the carassius carp in Lake Harutori in Kushiro, Hokkaido, which is designated as a natural monument by the central government.

The crayfish has spread to the Tohoku region and has been designated as an alien species that threatens the ecosystem under the 2005 Invasive Alien Species Law.

Currently, 96 species of plants and animals, including raccoons, black bass and red-back spiders, are designated as invasive alien species under the law. Importing, breeding and transporting these creatures and plants is banned, and corporate violators can be fined up to 100 million yen.

Overseas, however, the signal crayfish is known as the lake lobster, a prized ingredient well known by professional cooks.

"I was surprised with the tender and chewy texture [of the crayfish]," said Kiyomi Mikuni, owner and chef of Hotel de Mikuni, a French restaurant in Yotsuya, Tokyo.

Since his encounter with the signal crayfish about a decade ago, he has been serving it in various dishes in his restaurant, putting it in salads and making sauces with its shells.

Akihiro Ozaki, owner of Jose, a wine bar in Sapporo, also raved about the taste of the crayfish. He said its fine meat and rich brains are good with white wine.

I tried signal crayfish and found it to have stronger flavor and a richer texture than ordinary lobster. It has the potential to be a gourmet ingredient.

However, the crayfish is prohibited from being transported while alive by a law that protects the domestic ecology from invasive alien species. The law also requires permission to ship the crayfish for cooking purposes.

The Akanko fishermen's association in Hokkaido deals solely with domestic shipments of the crayfish. Each year it ships three to four tons of the animal. The association is allowed to handle the crayfish because it had the right to harvest the animal before the law was enacted in June 2005. The association began its business by selling crayfish that had become tangled in fishing nets and would have otherwise been thrown away.

However, the association now receives many orders from top restaurants nationwide. The crayfish now can fetch as much as 1,500 yen per kilogram.

The association is not the only group catching the crayfish. Municipalities and nonprofit organizations in Hokkaido are catching the animal to maintain ecological balance. Although these groups caught about 19,000 crayfish (about a ton) in the last fiscal year, they were unable to sell them because they do not have fishing rights.

Entrepreneurs also have tried to sell black bass. According to the Shiga Prefectural federation of fisheries associations--whose fishing areas include black bass infested Lake Biwa--they could not spread black bass sales because people thought the fish tasted strange.

A federation staffer said good flavor is not enough to generate business.

"If we promote the extermination of alien species, production will eventually drop. Because we cannot breed [restricted foreign species], it's difficult to create a stable supply," said Fukui University Associate Prof. Hideto Hoshina, who once tried to sell a fish product made from an alien species.

It can be problematic if alien species increase rapidly, but complete extermination is undesirable for food lovers.

Isn't there a good way to manage edible alien species?

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