TOKYO — Japan resumed commercial whale hunting on Monday after a hiatus of more than 30 years, defying calls from conservation groups to protect animals once hunted to the brink of extinction.

Now whalers, who have long depended on government subsidies for their survival, face the much tougher challenge of defying basic economic reality: The market for their product is declining while labor costs across the nation are on the rise.

Japanese production of whale meat peaked in 1962, and the taste is generally preferred by an older generation. The government also hopes to start reducing the $46 million in annual subsidies it pays to whale hunters within three years. The value of previous catches, obtained under the auspices of scientific research in the Antarctic, totaled only about a half to a third of that.

“Will whaling succeed commercially?” said Masayuki Komatsu, a former government official who oversaw Japan’s international negotiations on the subject and now works at a think tank in Tokyo. “No way.”