World's oceans once teemed with whales

American Association: Scientists have seriously underestimated numbers that lived before industrial-scale hunting began

The oceans once teemed with many more now endangered marine mammals than previously thought, new genetic studies of whales suggest.

Whalemeat samples bought from a Japanese sushi market and analysed by scientists indicate that experts have seriously underestimated the size of the populations that roamed the seas before industrial-scale hunting began more than a century ago. The numbers of some species may have been 10 times greater than previously calculated.

The findings refute suggestions by whaling nations such as Japan that a resumption of hunting is justified by the increase of many whale populations beyond their natural size, the researchers said this weekend.

The latest information, reported to the annual meeting of the American Association for the Advancement of Science in Washington DC, is crucial to discussions within the International Whaling Commission (IWC) where some experts are suggesting that hunting minke whales could be resumed because the recent rise in their numbers is unprecedented and is hampering recovery of other whales.

Steve Palumbi, a marine biologist at Stanford University in California, found that the genetic diversity of whales is so large that it can only mean that past population sizes were much bigger than anyone had estimated.

"Genetic variation is related to long-term population size," Dr Palumbi said. "The International Whaling Commission estimates that past population sizes of humpback whales numbered no more than 115,000 before whaling."

His analysis of humpback whale DNA, however, led him to estimate that the past population size of breeding females alone must have been between 125,000 and 250,000 individuals.

"Mature breeding females make up about one sixth to one eighth of a whale population, so these numbers suggest a global humpback whale population size [in the past] of about 750,000 to 2 million animals," he said.

Dr Palumbi also discovered that the Antarctic population of minke whales is now the longest surviving whale population on earth, and was also one of the largest - many times larger than previous estimates for the IWC.

Genetic variation is created by mutations accumulating over many generations. The bigger the population became historically, and the longer it has existed, the bigger the diversity of the DNA within an existing whale population.

"Best estimates suggest past abundance was about 10 times higher than thought for humpback and fin whales, and was about three times higher for minke whales," Dr Palumbi said.

The study also attempted to find out when the dramatic decline in whale numbers occurred. Dr Palumbi said that it was relatively recent - thousands rather than millions of years ago, and probably later than the last Ice Age about 10,000 years ago.

The decline affected many species worldwide. "We know of one factor that accounts for these patterns - historic whaling," Dr Palumbi said.

"Whales have shown remarkable resilience to cataclysmic events, until the last one, which is us.

"Ice ages, sea level change and even loss of local food sources did not interrupt their lives."

Separate research presented to the conference showed that whales sing to one another over hundreds of miles and use their songs to navigate across oceans.

Underwater microphones developed to monitor Soviet submarines have detected cohorts of humpback whales travelling thousands of miles as a group, singing to each other as they go, said Christopher Clark of Cornell University in Ithaca, New York.

"Whales will aim directly at a seamount that is 300 miles away, then once they reach it, change course and head to a new feature," Dr Clark said. "It is as if they are slaloming from one geographic feature to the next. They must have acoustic memories analogous to our visual memories."

CETACEAN FACTS

* The tongue of a mature blue whale has the same mass as an elephant

* Scientists reckon there are up to two million whales surviving

* Antarctic minkes are the world's oldest surviving whale species

* Japanese recipe books include whale kebabs and whale with noodles

* A moratorium on commercial whaling was introduced by the International Whaling Commission (IWC) in 1986. Japan is threatening to withdraw in 2006

Start your day with The Independent, sign up for daily news emails
News
news
Arts and Entertainment
British author Helen Macdonald, pictured with Costa book of the year, 'H is for Hawk'
booksPanel hail Helen Macdonald's 'brilliantly written, muscular prose' in memoir of a grief-stricken daughter who became obsessed with training a goshawk
Sport
footballLive blog: Follow the action from the Capital One Cup semi-final
Life and Style
food + drink
PROMOTED VIDEO
ebooks
ebooksA year of political gossip, levity and intrigue from the sharpest pen in Westminster
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Recruitment Genius: Digital Account Manager - OTE £40,000

£25000 - £40000 per annum: Recruitment Genius: This web-based lead generation ...

Tradewind Recruitment: Intervention Teacher Required To Start ASAP.

£125 - £150 per day + Negotiable: Tradewind Recruitment: A 'wonderful primary ...

Tradewind Recruitment: Maths Teacher

£90 - £140 per day: Tradewind Recruitment: Our client is an 11-16 mixed commun...

Recruitment Genius: PHP / Drupal / SaaS Developer

£32000 - £36000 per annum: Recruitment Genius: A rapidly developing company in...

Day In a Page

Greece elections: In times like these, the EU has far more dangerous adversaries than Syriza

Greece elections

In times like these, the EU has far more dangerous adversaries than Syriza, says Patrick Cockburn
Holocaust Memorial Day: Nazi victims remembered as spectre of prejudice reappears

Holocaust Memorial Day

Nazi victims remembered as spectre of prejudice reappears over Europe
Homeless Veterans appeal: Homeless in Wales can find inspiration from Daniel’s story

Homeless Veterans appeal

Homeless in Wales can find inspiration from Daniel’s story
Front National family feud? Marine Le Pen and her relatives clash over French far-right party's response to Paris terror attacks

Front National family feud?

Marine Le Pen and her relatives clash over French far-right party's response to Paris terror attacks
Woman who was sent to three Nazi death camps describes how she escaped the gas chamber

Auschwitz liberation 70th anniversary

Woman sent to three Nazi death camps describes surviving gas chamber
DSK, Dodo the Pimp, and the Carlton Hotel

The inside track on France's trial of the year

Dominique Strauss-Kahn, Dodo the Pimp, and the Carlton Hotel:
As provocative now as they ever were

Sarah Kane season

Why her plays are as provocative now as when they were written
Murder of Japanese hostage has grim echoes of a killing in Iraq 11 years ago

Murder of Japanese hostage has grim echoes of another killing

Japanese mood was against what was seen as irresponsible trips to a vicious war zone
Syria crisis: Celebrities call on David Cameron to take more refugees as one young mother tells of torture by Assad regime

Celebrities call on David Cameron to take more Syrian refugees

One young mother tells of torture by Assad regime
The enemy within: People who hear voices in their heads are being encouraged to talk back – with promising results

The enemy within

People who hear voices in their heads are being encouraged to talk back
'In Auschwitz you got used to anything'

'In Auschwitz you got used to anything'

Survivors of the Nazi concentration camp remember its horror, 70 years on
Autumn/winter menswear 2015: The uniforms that make up modern life come to the fore

Autumn/winter menswear 2015

The uniforms that make up modern life come to the fore
'I'm gay, and plan to fight military homophobia'

'I'm gay, and plan to fight military homophobia'

Army general planning to come out
Iraq invasion 2003: The bloody warnings six wise men gave to Tony Blair as he prepared to launch poorly planned campaign

What the six wise men told Tony Blair

Months before the invasion of Iraq in 2003, experts sought to warn the PM about his plans. Here, four of them recall that day
25 years of The Independent on Sunday: The stories, the writers and the changes over the last quarter of a century

25 years of The Independent on Sunday

The stories, the writers and the changes over the last quarter of a century