Whales targeted by Japan on the brink of extinction
ONE of three species Japan has targeted in resuming commercial whaling on Monday is threatened with extinction, and sub-populations of the other two are severely depleted as well, according to experts.
After pulling out of the International Whaling Commission (IWC) at the end of last year, Japan announced it would allow 227 of the giant sea mammals to be harpooned within its territorial waters – extending 200 nautical miles (370km) from its coast – before the end of December.
The commission’s 1986 moratorium on whaling forbids a ll whaling, though a trio of countries, including Japan, flouted the ban through loopholes while remaining within the IWC.
Japan’s new self-arrogated quota – which could be renewed or changed next year – includes 150 Bryde’s, 52 minke and 25 sei whales.
One of these species, the sei, is listed as “endangered” on the International Union of the Conservation of Nature’s Red List, which has assessed the conservation status of some 100,000 animals and plants.
The sei – at 20m (645 feet), the biggest of whales after the blue and the fin – was the main target of Japan’s ostensibly “scientific” whaling from the early 2000s until 2017.
‘Severely depleted’
The Red List classifies Bryde’s and minke whales “of least concern,” meaning they are not currently threatened with extinction.
But these assessments obscure a more nuanced rea lit y that could spell trouble for sub-groups of t he species as well, according to Justin Cooke, a longstanding member of the IWC’s scientific committee and a member of the IUCN’s Cetacean Group.
“There are two types of minke whale exploited off the coast of Japan,” he said.
“The one found in coastal waters – in the Sea of Japan, the East China Sea and the Yellow Sea – is quite severely depleted due to a long history of catches by Japan and South Korea.”
Besides those targeted by whalers, others die after getting caught up in netting set for fish, he explained.
Known as the “J stock”, the coast-hugging minke (Balaenoptera acutorostrata) are highly unusual among baleen, or filter-feeding, whales because they breed during the summer rather than the winter.
Surveys by Japanese and South Korean fisheries agencies have estimated their numbers at about 1,500, Cooke said in an interview.
The more plentiful “O stock” minke – which breed in summer and number about 25,000 – are found further north in the Sea of Okhotsk, in Russian waters.
Whale watching
As wit h ot her t y pes of whales, including orca, sub-populations of the same species can develop highly distinct behav iour patterns, which has led some biologists to describe t hese dif ferences as “cultura l”.
There are t wo known sub-species of t he larger Br yde’s whales – a lso filter feeders – that grow up to 17m (55 feet) in leng t h.
Japan stopped hunting Bryde’s in 1987, but re-authorised yearly catches in international waters of 50 individuals starting in 2000, again for supposedly “scientific” research.
The North Pacific population – found mostly in the middle range of Japan’s exclusive economic zone – was recently estimated at just over 26,000 by t he IWC’s scientific committee.
The ot her sub-species is found in Japan’s southern waters and supports a loca l whale-watching industr y. Also known as Eden’s whale, they number just under 170, according to a 20-year old stockta ke, Cooke said.
For the endangered sei whale, experts disagree on how to characterise its population.
“Japanese scientists insist t hat t here is only one [population] in the whole North Pacific,” said Cooke. “But they have only collected data from t he offshore area.”
A competing hypothesis is that the region is home to five distinct populations, including one along the western coast that will now be hunted for its meat.
The latest estimate for this sub-group is about 400, Cook said.