Daily Science Dose

While I was watching NOVA last night, which was called “Ocean Animal Emergency” and truly saddening, I was struck by a small seal pup that had facial tumors growing out of its mouth. The tumors were found to be inoperable, and the poor, little Harbor seal had to be euthanized.

The moment I saw the seal’s tumors I was reminded of another creature that has become afflicted with grotesque facial tumors, the Tasmanian Devil.

Are the facial tumors afflicting the harbor seal on NOVA and Tasmanian Devil related? Could there be something more to this? What is it that is causing these odd, devastating growths? In January 2008, reports came out detailing that Tasmanian Devils have elevated levels of chemicals used as flame retardants in their blood stream. Could these chemicals be causing this kind of growth? Or are the chemicals just enabling this kind of cancer, making some animals more susceptible to disease?

The science is still out on the Tasmanian Devil, but as more than 60% of the wild population has died in the last decade since this facial cancer was first discovered, there may not be much time for scientists to figure it out.

The facial growth I saw on the harbor seal did not look quite as gruesome as that which I have seen in pictures of tasmanian devils. The harbor seal’s tumors looked more like big “toes” sticking out of its mouth. The seal didn’t look bothered by them, so it is unsure if the tumors were causing pain of any kind. I have to wonder if there is some correlation between the toxins we keep dumping in the ocean and this poor seal’s face.

NOVA explained that the seal and sea lions that are euthanized at the Marine Mammal Center are given a post-mortum examination, and blood and tissue samples are collected. I have to wonder what the MMC will find, if anything. Of course, it may simply be a birth defect, and I am worrying over nothing. But as seals are higher up on the food chain and consume other marine creatures, they could be the front line when it comes to realizing the effects of the many, many substances we allow to flow into our waters.

The MMC and other marine researchers are finding that another toxin, domoic acid, is killing sea lions and the numbers are only increasing. The domoic acid is a toxin released by the Pseudo-nitzschia algae, an algae that needs sunlight and nutrient-rich water, which are usually not the same water. However, with increasing amounts of nutrients in the form of fertilizers running into our near-shore waters, like Southern California where many sea lions are dying, algae blooms are becoming common in the spring and early summer.

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