Female Boston terrier Ikura gathers plastic bottles at the beach. She has collected more than 3,000 bottles in the last five years at Irino beach in Kuroshio, Kochi Prefecture. (Video footage by Masatoshi Kasahara)

KUROSHIO, Kochi Prefecture--A dog has collected more than 3,000 plastic bottles that washed up on a beach here in the past five years, lending a large paw toward solving an increasing global concern--plastic trash in the ocean.

Female Boston terrier Ikura, 8, patrols a 1-kilometer stretch of Irino beach every morning and late afternoon, while surfers are out catching the white waves.

The popular spot for surfing fans that is dotted with pine trees is a government-designated scenic beauty site.

Ikura’s owner, Nobuyuki Niiya, 59, runs a surf shop in front of the beach. A friend gave him Ikura eight years ago.

Ikura tends to want something to chew on when she's out for walk. Niiya initially gave her a small shovel, but he's found she prefers fetching plastic bottles that he flings across the beach.

Ikura picked up the habit of retrieving plastic bottles that washed ashore five years ago. She chews them with a strong sound and brings them to a waste-collection place on the beach.

She collects at least one bottle every time Niiya takes her for a walk.

“About a third of the plastic bottles in the recycling bin are ones Ikura picked up,” Niiya said with a smile.

Plastic trash in the ocean has been attracting increased attention as a social issue since it was discovered in the bodies of sea turtles and whales.

"For surfers like us who want to save our beautiful oceans and who work to clean up the beach each day, Ikura is our idol," said Niiya, who is also the president of a surfing association in the prefecture.