Russian officials said on November 10 that they had released the last of dozens of beluga whales whose captivity alongside killer whales in a "whale jail" in the Far East prompted an international outcry and Kremlin intervention.
Images of some of the 97 belugas and orcas in the Srednyaya Bay pens shocked the Russian and international publics and drew complaints from as far afield as Hollywood actor and environmental advocate Leonardo DiCaprio.
A Russian federal research institute said the last 31 beluga whales -- the mostly white cetacean native to the Arctic and sub-Arctic and known for its canary-like "song" -- were freed into the wild in the Bay of Assumption off the southern coast of southern Primorsky Krai, on the Sea of Japan on November 10.
"This was the final release," Interfax quoted the press service of the Pacific branch of the Russian Federal Research Institute for Fisheries and Oceanography as saying. "No animals remain in the whale jail."
Experts and animal-rights groups had debated the best approach to freeing the whales since President Vladimir Putin and other officials intervened earlier this year to order the releases.
Some of the animals had spent years in cramped pens since being separated from their families or pods in the wild.
The animals were released in batches, but concerns about their well-being continue among cetacean specialists.
The last of the releases reportedly followed a weeklong, 1,800-kilometer journey from Srednyaya Bay some four months after the first animals were freed.
Russia has allowed a brisk trade in killer whales and belugas caught in the wild, fetching millions of dollars for Russians eager to sell the highly intelligent creatures to Russian and Chinese entities to feed a growing oceanarium industry.
The deaths of several trainers in incidents with killer whales in captivity -- none has ever attacked a human in the wild -- and the related 2013 documentary film Blackfish dealt severe blows to organizers of marine parks in the United States and around the world that house the hulking black-and-white whales, many of them captured in the wild.
Such parks take in billions of dollars in revenues to allow closer interaction with such marine mammals, which are accustomed to close familial bonds and swimming hundreds of kilometers a day in the wild.
