The reversal dashes hopes of protecting at least one shark breed, after nations voted earlier this week to reject protections on hammerheads, among other species.

The victory is another in a long string of successes for Japan. Beyond blocking shark protections, the country successfully defeated proposed bans on bluefin tuna and protections on several species of coral.

"Japan clearly mobilized massive efforts to keep fisheries out of CITES," said Mark W. Roberts, senior counsel and policy adviser for the watchdog group Environmental Investigation Agency.

Canada voted with Japan at the CITES meeting.