Mr. Loftsson likes to say that whale blood runs in his veins.

He and his sister together are the largest shareholders in Hvalur, the whaling business once run by their father. (Hvalur, pronounced KVA-lur, is the Icelandic word for whale.)

They spent many of their childhood summers at the company’s whaling station. Mr. Loftsson watched as whales were brought to shore and carved up by hand. At age 13, he got a job helping out on a boat, washing dishes and scrubbing floors.

“It was fun,” he said of his early days on the boat.

Later, he worked as a deckhand . In 1974, when Mr. Loftsson was 31, his father died and he became head of the company.

Today, Iceland and Norway are the only countries that allow commercial whaling. Japanese hunters operate under a research permit issued by their own government, and aboriginal subsistence hunting takes place in a handful of countries that includes the United States, Canada, Russia and Greenland .

Globally, fin whales are listed as endangered by the International Union for Conservation of Nature , and commercial hunting of the species was halted in Iceland for 20 years, though some whales were taken under scientific permits.

In 2006, the government allowed hunting to resume. (The next year, an assessment by the I.U.C.N. found that populations in the North Atlantic were not threatened. A 2015 survey estimated there were 40,000 fin whales in the central North Atlantic.)

The country has come under steady international pressure to end whaling. In 2013, President Barack Obama called for an end to the hunt. The following year, the European Union led an international protest against Iceland’s whaling.