This story mirrors what is going on with cancer among humans.  They say that they don't know what is causing the cancer, it may be toxins, it may be viruses, it may be genetic or it may be a combination of all three.  No doubt it is likely a combination, but look at the obvious clues to what the real culprits are:  industrial pollutants.  In other words, toxins.  The same as it is for people.  Sure, genetics can play a role and no doubt viruses can end up causing conditions that lead to cancer in their aftermath - but where were the genetics and viruses back when cancer was rare in both man and animals?

As the article noted, "18 percent of dead beluga whales stranded in Canada’s St. Lawrence River had intestinal tumors or other cancers that were linked to industrial pollutants".  It also noted that From the late 1940s until the early 1970s, DDTs and PCBs were dumped in the Southern California Bight.

But then the article went on to talk about a virus and possible genetic causes.  Such is the spin and misdirection we see in cancer research today and it is not an accident that toxins are not being aggressively pursued as the primary cause of cancer, along with diet and lifestyle causes.  There is really very little money incentive to investigate diet and lifestyle causes and there are billions of dollars at stake if toxins are placed firmly in the bullseye.  Hiding and diverting attention from toxins was the reason that the third leading source of carcinogen pollutants in the United States created Breast Cancer Awareness Month in the first place.

See:  Breast Cancer Deception - Hiding the Truth Beneath a Sea of Pink

It's the toxins, not genetics or viruses!

Viruses have been around practically as long as life itself has. Is it likely that it has taken viruses thousands, if not millions, of years to suddenly mutate and spread to the point of being the primary cause of cancer?  Not likely.

What has not been around for thousands or even hundreds of years are the 100,000 plus chemical compounds that industrialized society has put in our environment or the heavy metal pollution spewed into our environment.  In other words, toxins.  It is toxins that suppress the natural immune system that is the first line of defense against cancer and illness, and it is a healthy immune system that is the best defense against viruses.  It is also toxins that are mutagenic substances which cause the genetic changes that lead to cancer and other illness and the susceptibility to viruses.

So, while it may be true that genetics and viruses are leading to increased incidences of cancer, to focus on them is akin to being unable to see the forest for the trees.  If not for toxins and, at least in the incidence of humans, poor diet and lifestyle, genetic and viral causes would be greatly increased.

What about that longevity argument?

Besides genetic causes and viruses, we are often told that the primary reason for the increased incidence of cancer in humans is increased longevity.  Of course one cannot make that argument for sea lions and whales, since their average lifespans is probably less due to toxins, hunting and habitat disturbance.  Nevertheless, it certainly it is true that a hundred or more years ago, lifespan was considerably less than today. Primary among the causes of the shorter lifespans  were poor sanitation and nutrition and lack of access to primary medical care.  However, poor nutrition and sanitation should have led to more cancer incidence among both young and old, not less.  Regardless of longevity figures, cancer was was quite rare at the turn of last century among all age groups - no more than a couple of people out of a hundred would be expected to get cancer in their lifetime.  Today, 1 in every 2 men and 1 in every 3 women are expected to get cancer.  That is a rate that is far too great to explain away by longevity.  In addition, the increased incidence of childhood cancers and cancer among younger ages in general cannot be attributed to longevity.

A huge and often overlooked contributor to an overall low average lifespan was vastly higher infant and child mortality rates.  Child birth and childhood were both difficult propositions in earlier times, and the high incidence of infant and child deaths made a very big difference in the average lifespan figures.  However, once a child reached adulthood, life expectancy was actually fairly close to what it is today and it was not at all uncommon to see many elder people among the population of any given community.  Certainly the number of older citizens should have resulted in a much higher cancer rate than merely a couple of people out of every 100.

Conclusion:
 
Viruses and genetics ay be leading to increased incidence of cancer; however it is toxins that lie at the root cause of cancer and which are the cause of genetics and viruses playing a bigger role.  To avoid being susceptible to cancer due to virus or genetic changes, as well as avoid cancer from virtually all causes, one must endeavor to eliminate and avoid toxins and incorporate a proper diet and lifestyle.