The demonstration came weeks after the small Japanese town -- thrust into the global spotlight in the Oscar-winning 2009 documentary "The Cove" -- kicked off this season's controversial dolphin and whaling hunt.
Online video footage showed participants marching through the port with a banner which read: "Let's protect Japanese food culture from Western hypocritical values. Japanese should not give in to Sea Shepherd."
"They are environmental terrorists," one of the demonstrators told the rally through a loudspeaker as many of the protesters waved Japanese flags.
There was no clash as no environmentalists showed up during the rally.
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In the annual hunt, people from the southwestern town corral hundreds of dolphins into a secluded bay and butcher them, turning the water crimson red.
The scene was featured in "The Cove" documentary, drawing unwanted attention to the little coastal community.
Environmental campaigners visit the town every year during the gruesome event and authorities have boosted their presence to prevent any clashes between locals and activists.
Some of the dolphins are sold to aquariums.