“Mysterious Cancer” Killing Sea Lions Along US West Coast — Animals Dying at “Alarming Rates”
Sea lions are contracting and dying from cancer, at alarming rates in their uro/genital tracts, most often among the females. “We are concerned that it is such a high incidence. It’s 19 or so percent in this particular population of California sea lions which is very unusual for any mammal,” says Dr. Padraig Duignan, Chief Pathologist at the Marine Mammal Center… “So, usually when you see a severe disease outbreak like this, in wildlife, there’s some big underlying problem,” adds Dr. Cara Field, a rehabilitation veterinarian… “Certainly understanding why they get it and what the contributing factors are and ‘do these contributing factors represent a risk to us?’ is critically important for us in understanding what other risks there may be for us as well as other animals,” says Dr. Field.
A report from Aug 29, 2016:
California Academy of Sciences (bioGraphic): Scientists Investigate a Mysterious Cancer Plaguing California Sea Lions… The disease starts in the reproductive organs… By the time they die, tumors have sometimes infiltrated their backbones and turned vertebrae to “mush,” [Tenaya Norris, a scientist at The Marine Mammal Center] says. She describes examining one dead animal whose spine she could simply slice through. More than a quarter of the adult California sea lions that die at the Marine Mammal Center suffer from cancer, says director of veterinary science Shawn Johnson. That’s one of the highest cancer rates seen in any wild animal… There’s been a surge of sick animals, especially California sea lions… “Off the California coast, the ecosystem is really under stress,” says Johnson. That stress is hitting California sea lions particularly hard… Over the past three years, Johnson says, 80 to 90 percent of all California sea lion pups have died… And whether or not the disease is becoming more common or simply holding steady, Johnson says he knows one thing for certain: “It’s not declining.” The disease rates researchers are seeing among sea lions are far from normal, and they want to know why. “Wild populations shouldn’t have cancers like this,” Johnson says… Tumors first form in the cervix or penis, then spread, often metastasizing to the lymph nodes and spine… Inside a stricken animal, “there’s just masses of yellow, cancerous tissue,” says Frances Gulland, senior scientist at the Marine Mammal Center… [C]ancer-stricken sea lions have more pollutants in their blubber… “That’s really important for the human health perspective as well,” Gulland says. “These are contaminants the sea lions are acquiring from their prey. And the fish they eat are the same fish that we eat”…