White orcas: beautiful anomalies or a worrying trend?

White ‘albino’ orcas have historically been one of the rarest sights in our oceans, but an increase in the number of sightings has worried some scientists about the whole species’ future.

Black and white
A white orca fin amongst fellow killer whales in the North Pacific

The bold black and white markings of killer whales are one of the most distinctive sights in the natural world. Therefore the existence of completely white or ‘albino’ orcas is something that is not only extremely rare but fascinating and eerily beautiful. However the elusive creatures, previously confined to the stories of fishermen and science fiction, are now becoming a much more common sight in our oceans. But is this something we should be marvelling at or alarmed by? Some scientists believe that the increasing abundance of white orcas is actually a result of increased inbreeding, potentially as a result of human influences. If so these ‘beautiful anomalies’ could just be the start of a worrying trend.

White whales

Historically white whales have been a sight so rare in our oceans that for a long time it was hard to tell if they really existed or were just a myth found in the pages of stories such as Moby Dick. But in 1970 the world was given definitive proof of the phenomenon when a white orca named Chimo was put on display in a Seaworld in Canada. Chimo was caught accidentally in an attempt to find a suitable mate for the park’s resident killer whale Haida. But she became a star in her own right as people travelled from all over to catch a glimpse of the white whale. Although ‘one of a kind’ Chimo was by no means the first albino orca, or even whale, to have ever existed. The occurrence of the discolouration is just so rare that until they were caught or photographed using modern technology there was no way of proving their existence. Albinism in whales is now something that has been documented in multiple species, such as the famous humpback Migaloo. However it is in killer whales that the number of sightings has increased in recent decades leading scientists to speculate as to the reasons why.

Chimo
Chimo on display to the world alongside her mate Haida in 1970

Becoming more common

In 2010 whale researchers in the western North Pacific stumbled across a white orca near Russia. He was the first observed in the area for decades and was affectionately named Iceberg. The team from UK based Whale and Dolphin Conservation (WDC) then began studying Iceberg and his fellow killer whales who are permanent residents in the area. To their surprise in the following six years they found between five to eight other white orcas in the same region. Speaking in 2016 head of WDC Erich Hoyte told New Scientist that “what we are seeing is strange, it’s a very high rate of occurrence” following up by saying “all the other areas where orcas are studied intensively have zero or one or two historically”. The researchers were stumped as to why this population were producing so many albinos compared to the rest of the world. But they were worried that it may be due to high levels of inbreeding, like with other forms of albinism in other animals. Since then white killer whales have also been spotted in British Columbia in Canada and Califronia in the US, both this year, suggesting that it may actually be increasing in other parts of the world too.

Iceberg
Iceberg discovered in 2010 is a white orca despite appearing slightly more grey in colour than Chimo and other albinos

Should we be concerned?

The increasing occurrence of white orcas may seem perfectly innocent, or even a dream come true if you enjoy whale watching. However some researchers are worried about the possible reasons behind the increase. It is important to note that because no genetic testing has been carried out on any white orcas, no one is 100% sure what causes the albinism. But researchers including those like Erich Hoyte at WDC are worried inbreeding is the likely cause behind the condition. This is troubling because it can cause serious health problems in killer whales. For example Chemo the infamous white orca from the 70’s only lived to around three or four years old before she died, although captivity is also likely to have been a contributing factor. It can also reduce a population’s ability to adapt to environmental change, of which there is quite a bit in today’s oceans, due to a reduced gene pool. It may also be a sign that due to human actions the populations and ranges of killer whales may be being reduced.

Juvenile white
A juvenile white orca is spotted by drone in California earlier this year

However before we hit the panic button there are other possible explanations as well. One is that it is just a perfectly innocent genetic mutation that is increasing through the gene pool by chance. It may even be that populations are increasing and so there is a higher chance of finding white orcas, although there is little evidence to back this up. Even if it is a result of inbreeding some researchers suggest this might not be as bad as first feared. For example Iceberg the first white orca spotted by WDC is now believed to be around 25 years old, suggesting he has had a perfectly healthy life. Past research from a team from University of Bern in Switzerland has also shown that some killer whales form ‘culturally diverse groups’ that become genetically isolated from one another. If this is the case in the North Pacific it may also mean inbreeding may have nothing to do with human impacts at all.

So is there really any reason to be concerned? The answer much like these killer whales is not very black and white. If inbreeding is the cause behind the increase in albinism then there is reason to worry but there are also reasons not to get carried away. As a result more research, including genetic sampling and further long-term observations, is needed to tell for sure.

 

 


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