TOKYO >> The Fisheries Agency plans to introduce a new vessel that will replace the aging Nisshin Maru, the 8,145-ton mother ship of the Japanese research whaling fleet in the Antarctic and Pacific oceans.

The introduction is intended to make clear Japan’s plans to continue whaling, a move likely to draw fire from antiwhaling countries, such as the United States, Australia and countries in Europe.

“Even though the ship has been painted over, rust that can’t be hidden stands out. It is old, aged nearly 100 in human years,” a person familiar with the research whaling program said of the 30-year-old Nisshin Maru. The vessel was headed for the Antarctic Ocean with 102 people aboard, departing from Innoshima island, Hiroshima Prefecture, last November.

The Nisshin Maru was built in 1987 as a trawler, a type of ship that pulls a massive net. It was remodeled into a whaling mother ship in 1991. Whales caught by small research vessels can be pulled onto the deck of the 426-foot mother ship to be butchered. Up to 1,200 tons of whale meat can be kept in a freezer under the deck.

The mother ship’s engine and main parts of its body are still original material after 30 years. In the wake of fires in 1998 and 2007, the ship resumed operation on both occasions after the interior was repaired.

“We are concerned that if the engine breaks down, the ship won’t operate as there are no replacement parts for it,” a person involved in the whaling program said.

The introduction of a new mother ship is also aimed at countering the Sea Shepherd Conservation Society, which has repeatedly obstructed Japanese whaling activities in the Antarctic Ocean.

According to the Tokyo-based Institute of Cetacean Research, a sabotage vessel approached a Japanese whaling ship and directed laser beams at the ship’s crew in February 2011. A Japanese whaling ship was also rammed by a sabotage vessel in February 2013.

Takeharu Bando, chief of the research whaling team that left for the Antarctic Ocean on the Nisshin Maru, said, “We need a strong and fast ship that can withstand sabotage activities.”

The plan has sparked protests from environmental conservation groups.

“Many countries distrust Japan, which continues to kill whales in the name of research using massive subsidies,” said Nanami Kurasawa, secretary general of the civic group Iruka and Kujira (Dolphin and Whale) Action Network. “The renewal of the mother ship would attract heavy criticism.”