Beluga whales making their home in Arctic waters have been found to be infected with a parasite normally found in domestic cats. Researchers from the University of British Columbia have found the Toxoplasma parasite in over 10 percent of the whales living off of Canada’s shores in the Beaufort Sea. It is believed that the whales have become infected with the dangerous parasite through water and fish contaminated by the feces of domestic cats that have been washed into the sea.
The parasite properly known as Toxoplasma gondii is known to cause the disease Toxoplasmosis, known commonly as “kitty litter disease” that is particularly dangerous to pregnant mammals, increasing the risk of congenital abnormalities and miscarriage. It is also strongly associated with infectious blindness and causes problems for those with compromised immune systems. The infected whales observed by researchers did not appear to be sick. It is unknown whether this is because the parasite, which can often be harmless or associated with only mild symptoms, did not adversely affect the whales, of it could be because those that did become ill were quickly the victims of scavengers seeking easy prey.
Natives of the Arctic area near where the infected whales were identified and who rely on the animals as a food source have been warned to be especially diligent about food safety and preparation, particularly if pregnant women are among those who will be consuming the meat.
The Toxoplasma parasite was first found in the Arctic beluga whales in small numbers in 2009, but its presence appears to be rapidly increasing. Scientists who study the animals cannot be absolutely sure why, but believe that there are two likely factors to account for the rapid rise. The first factor is simply an increase in the number of domestic cats in the area. In recent years Inuit natives have included an increasing number of the animals as pets in their communities.
The other factor is related to climate change. Scientists say that while the parasite has long been relatively common among marine mammals outside of the Arctic, with 40 to 60 percent being infected with Toxoplasma, this is the first time that it has been seen in significant numbers in the polar region. They theorize that the rising water temperatures due to climate change, known as “the big thaw,” allows the parasite to better survive in the harsh environment. In fact, exposure to extreme temperatures is known to be one of the few ways to kill the hearty contaminant. The warmer temperatures may allow for the introduction of many pathogens previously unknown to the Arctic region and have potentially devastating effects on marine life there. They say that a loss of ice also means a loss of “a major eco-barrier for pathogens.”
Lead scientists on the project, Michael Grigg and Stephen Raverty of the University of British Columbia’s Marine Mammal Research Unit, presented their findings about the identification of the domestic cat parasite in the Arctic beluga whales at the 2014 Annual Meeting of the American Association for the Advancement of Science.
By Michele Wessel