An international coalition of Japanese and American-based manga publishers have joined together to combat what they call the “rampant and growing problem” of scanlations, the practice of posting scanned and translated editions of Japanese comics online without permission of the copyright holders. The group is threatening legal action against 30 scanlation sites.

The effort brings together the 36 member Japanese Digital Comic Association—which includes such major Japanese houses as Kodansha, Shogakukan and Shueisha—as well as manga publisher Square Enix, the Tuttle-Mori Agency and U.S.-based manga publishers Vertical Inc, Viz Media, Tokyopop and Yen Press, the manga/graphic novel imprint of the Hachette Book Group.

A spokesperson for the coalition said the effort shows that Japanese publishers—who license the majority of manga sold in the U.S.—are taking an aggressive interest in combating manga piracy outside of Japan as well as inside the country. The group charges that the former fan-driven practice of scanlating—begun in the 1970s, fans later began to scan, translate and post manga online at a time when it was difficult to find manga outside of Japan—has been transformed by “scanlation aggregators,” heavily trafficked, for-profit Web sites that host thousands of pirated manga editions and offer them for free to readers.

According to a spokesperson, these sites are among the most heavily trafficked sites on the web attracting millions of visits each month while earning advertising revenues and even soliciting donations and sometimes charging for memberships. The group also charges that pirated manga is now beginning to turn up on smartphones and other wireless devices through the use of apps developed “solely to link to and republish the content of scanlations sites.”

A spokesperson said that “we are left with no other alternative but to take aggressive action. It is our sincere hope that offending sites will take it upon themselves to immediately cease their activities. Where this is not the case, however, we will seek injunctive relief and statutory damages.” The group is also aggressively reporting violations to the “federal authorities, including the anti-piracy units of the Justice Department, local law enforcement agencies and FBI.” While the group has yet to file any lawsuits and has declined to name specific scanlators, sites such as MangaFox and OneManga have long been identified as major scanlation aggregators.

After several years of booming manga sales in the U.S. that drove the popularity of comics and graphic novels in the traditional book market, sales of manga in the U.S. have declined more than 30% from a high of $210 million in 2007 to $140 million in sales in 2009, according to pop culture news site Many manga publishers and retailers who used to believe that scanlations actually attracted new readers, now blame the sales decline on the rise of giant for-profit scanlation sites that have allowed a new generation of fans to grow up reading manga for free online.

“Go back 2 years and track these sites and you’ll find an inverse relationship between the rise of traffic on these scanlation sites and the decline in U.S. manga sales,” said Kurt Hassler, publishing director of Yen Press and a former graphic novel and manga buyer for Borders Books and Music. Hassler points out that early fan-driven scanlation sites were aimed at making manga available overseas at a time when English translations of manga were rare. Indeed these fan scanlators would remove their online translations when the books were licensed for the English-language market.

That’s no longer the case, said Hassler. “These sites are run as businesses and include direct scans of licensed English-language manga editions. Some even include our copyright notices. We don’t want to have to do this but publishers are now focused on this problem.”