A Japanese ex-dolphin hunter has disputed government claims that the annual slaughter of dolphins in the Taiji Cove is traditional, centuries-old cultural practice, arguing that the hunting method was first used as recently as 1969.

Izumi Ishii told the Japan Times that his mentors in Futo, Shizuoka Prefecture, taught Taiji fishermen how to conduct dolphin drives in 1969 for the first time.

He said early attempts to capture the dolphins involved methods to amplify underwater sounds, causing the animals to panic - the method used now.

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Current Taiji hunting methods involve fishermen on boats surrounding pods of migrating dolphins, lowering metal poles into the sea and banging them to frighten the animals and disrupt their sonar. They are then herded into a nearby cove.

Once the dolphins are herded into the narrow cove, the fishermen attack them with knives, before dragging them to a harbour-side warehouse for slaughter. The best-looking dolphins are separated and sold to aquariums.

In January, Japan’s top government spokesman Yoshihide Suga, defended the controversial cull in the town of Taiji as “lawful”, following international criticism.

Shape Created with Sketch. Annual dolphin hunt in Taiji, Japan Show all 15 left Created with Sketch. right Created with Sketch. Shape Created with Sketch. Annual dolphin hunt in Taiji, Japan 1/15 The annual dolphin hunt in Taiji, Japan A bottlenose dolphin was seen floating on back before slaughter 2/15 The annual dolphin hunt in Taiji, Japan Fishermen hiding their culture and tradition 3/15 The annual dolphin hunt in Taiji, Japan Remaining pod swims just a few feet from the slaughter of their family 4/15 The annual dolphin hunt in Taiji, Japan Dolphin drive out to sea 5/15 The annual dolphin hunt in Taiji, Japan Lathered in blood, fishermen receive more transfers of dolphin carcasses 6/15 The annual dolphin hunt in Taiji, Japan Fishermen enter the cove just after sunrise 7/15 The annual dolphin hunt in Taiji, Japan A juvenile Bottlenose barely surfaces during drive out. The chances of survival are slim after 5 tormenting days in the cove 8/15 The annual dolphin hunt in Taiji, Japan Cove Guardians Jac and Ian document the slaughter 9/15 The annual dolphin hunt in Taiji, Japan SSCS Cove Guardian Leader Melissa Sehgal interviews for CNN 10/15 The annual dolphin hunt in Taiji, Japan Fishermen in wetsuits hunt dolphins at a cove in Taiji, western Japan; U.S. ambassador to Japan Caroline Kennedy has expressed deep concern over the traditional dolphin hunt. Local fisherman corral dolphins in a secluded bay before killing many for meat Adrian Mylne/Reuters 11/15 The annual dolphin hunt in Taiji, Japan The selection process of dolphins, during the annual dolphin hunt in Taiji. With 250 dolphins, this was the largest round-up in years 12/15 The annual dolphin hunt in Taiji, Japan The agitated dolphins in the cove during the selection process. According to Sea Shepherd, Japanese fisherman rounded up more than 250 dolphins, including babies and juveniles 13/15 The annual dolphin hunt in Taiji, Japan Japanese fisherman are shown in the cove. Taiji town claims the hunt is an important ritual dating back centuries 14/15 The annual dolphin hunt in Taiji, Japan A rare albino calf swims close to his/her mother as the pod was herded into the cove. Dolphins captured in the cove are either sold into captivity, or slaughtered and sold for consumption, despite pleas from animal conservationists around the world against the event Sea Shepherd/EPA 15/15 The annual dolphin hunt in Taiji, Japan The process of selecting dolphins during the annual cull, which the mayor of the town defends 'on scientific grounds' 1/15 The annual dolphin hunt in Taiji, Japan A bottlenose dolphin was seen floating on back before slaughter 2/15 The annual dolphin hunt in Taiji, Japan Fishermen hiding their culture and tradition 3/15 The annual dolphin hunt in Taiji, Japan Remaining pod swims just a few feet from the slaughter of their family 4/15 The annual dolphin hunt in Taiji, Japan Dolphin drive out to sea 5/15 The annual dolphin hunt in Taiji, Japan Lathered in blood, fishermen receive more transfers of dolphin carcasses 6/15 The annual dolphin hunt in Taiji, Japan Fishermen enter the cove just after sunrise 7/15 The annual dolphin hunt in Taiji, Japan A juvenile Bottlenose barely surfaces during drive out. The chances of survival are slim after 5 tormenting days in the cove 8/15 The annual dolphin hunt in Taiji, Japan Cove Guardians Jac and Ian document the slaughter 9/15 The annual dolphin hunt in Taiji, Japan SSCS Cove Guardian Leader Melissa Sehgal interviews for CNN 10/15 The annual dolphin hunt in Taiji, Japan Fishermen in wetsuits hunt dolphins at a cove in Taiji, western Japan; U.S. ambassador to Japan Caroline Kennedy has expressed deep concern over the traditional dolphin hunt. Local fisherman corral dolphins in a secluded bay before killing many for meat Adrian Mylne/Reuters 11/15 The annual dolphin hunt in Taiji, Japan The selection process of dolphins, during the annual dolphin hunt in Taiji. With 250 dolphins, this was the largest round-up in years 12/15 The annual dolphin hunt in Taiji, Japan The agitated dolphins in the cove during the selection process. According to Sea Shepherd, Japanese fisherman rounded up more than 250 dolphins, including babies and juveniles 13/15 The annual dolphin hunt in Taiji, Japan Japanese fisherman are shown in the cove. Taiji town claims the hunt is an important ritual dating back centuries 14/15 The annual dolphin hunt in Taiji, Japan A rare albino calf swims close to his/her mother as the pod was herded into the cove. Dolphins captured in the cove are either sold into captivity, or slaughtered and sold for consumption, despite pleas from animal conservationists around the world against the event Sea Shepherd/EPA 15/15 The annual dolphin hunt in Taiji, Japan The process of selecting dolphins during the annual cull, which the mayor of the town defends 'on scientific grounds'

Local fishermen defend the hunt as a centuries old local custom, but conservationists consider the hunt slaughter.

Ishii has now teamed up with dolphin activist Ric O’Barry in a joint presentation to a group of Japanese and foreign residents at Temple University’s Azuma Hall in Tokyo.

He told The Times he believed dolphins to be highly intelligent and peaceful animals and became sympathetic towards their plight after hunting them for decades.

Ishii is also fronting a petition to end the hunt, which he will submit to the government’s Fisheries Agency.

Taiji was exposed to worldwide scrutiny four years ago in the Oscar-winning documentary The Cove, which examined Japan’s infamous dolphin hunting culture and the controversial dolphin hunt that takes place in the town between September and April annually. The film won the Academy Award for Best Documentary the following year.

The hunt was condemned by activists and celebrities earlier this year, when figures such as Sean Penn and Gwyneth Paltrow urged US President Barack Obama not to sign an international trade agreement with Japan until the country bans the slaughter of dolphins.