While it remains unclear on what grounds Stewart is being detained, this wouldn't be the first time Japanese officials interfered with people capturing footage from Taiji's infamous cove. Last year, a Sea Shepherd volunteer was arrested while attempting to film dolphins being transferred into holding tanks.
Prior to the work of documentarians exposing the annual dolphin slaughter in Taiji, it was largely unknown outside of Japan. Coverage by Stewart and others has been instrumental in bringing the dolphin hunt to international attention.
ACTION GUIDE: Taiji Dolphin Slaughter
Dolphin roundups and slaughter -- brought powerfully to the public's imagination by the Oscar-winning documentary "The Cove" -- happen every year in Japan. You can sign our petition to end the brutal hunt here. You can also visit Sea Shepherd's site to learn more about the problem -- the organization has many ways you can help, from volunteering to simply spreading the word on Facebook and Twitter. Sea Shepherd also encourages concerned citizens to call and write to the authorities in Taiji as well as the Japanese Embassy in your country, the U.S. Embassy to Japan, U.S. and Japanese Ambassadors to the UN and the U.S. Senate members of the Committee on Foreign Relations, among others -- all of their contact information is on this page. Another group involved in the issue is Earth Island Institute's Save Japan Dolphins.