Japan will resume commercial whaling for the first time in three decades immediately after it leaves the body responsible for protecting global whale populations.

Media reports said a fleet would leave for the country’s coastal waters on 1 July, a day after its official exit from the International Whaling Commission (IWC), whose ban on commercial whaling went into effect in 1986.

A ship owned by a fisheries association in Taiji – known for its annual slaughter of dolphins – will join four vessels from other whaling towns and hunt minke whales off the north-east coast, Kyodo news agency said, quoting association sources.

The decision to openly hunt whales for profit comes weeks after Japan announced its withdrawal from the IWC following years of friction between Tokyo and pro-conservation IWC members such as Australia and New Zealand.

The decision drew widespread condemnation, with the Australian government saying it was “extremely disappointed”.

Some observers, however, have pointed out that the coastal expeditions will be much smaller than previous research hunts and would save hundreds of whales that Japan once caught in more distant waters.

Japan used a clause in the moratorium to hunt a certain number of whales in the Antarctic in the name of scientific research, but grew frustrated over its repeated failure to reform the IWC to raise the prospects of a return to commercial whaling.

It had argued that the ban was intended as a temporary measure and accused a “dysfunctional” IWC of abandoning its original purpose – managing the sustainable use of global whale stocks.

The country’s coastal fleet will hunt minke whales off northern Japan for about a week, with the vessel from Taiji then sailing south to conduct a solo hunt of Baird’s beaked whales and other smaller species off Chiba prefecture, near Tokyo, until late August, Kyodo said. All five vessels will regroup to hunt off the northernmost island of Hokkaido through to October, it added.

The fisheries agency has yet to announce how many whales the fleet plans to kill.

Japanese officials claim that populations of certain types of whale – such as the minke – have recovered sufficiently to allow the resumption of “sustainable” hunting.

But some in the industry have questioned whether hunting whales in coastal waters will be commercially viable. Byproduct from Japan’s expeditions to the Antarctic is sold on the domestic market, but the appetite for whale meat has declined dramatically since the postwar years, when it was an important source of protein.

Japanese consumers ate 200,000 tons of whale meat a year in the 1960s, but consumption has plummeted to about 5,000 tons in recent years, according to government data.

Japan will join Iceland and Norway in openly defying the ban on commercial whale hunting.