 Who doesn't love seals? Those adorable marine creatures playing with beach balls, wriggling in the ice, or just generally blubbering about. But could kissing a seal kill you? Researchers have traced methylmercury, a particularly toxic form of mercury found in some California coastal waters, to elephant seal fur. In humans, mercury poisoning causes nervous system disorders, kidney damage, even death. So are your dreams of a real life recreation of this kiss sunk? Well, for starters, that's a sea lion, and this study's about elephant seals. But suppose you really wanted to kiss a seal. What are the risks? Methylmercury can be transferred from skin to skin contact, or if you're into it, seal kissing. But chronic toxic concentrations occur in humans at about 10 micrograms per gram. Studies find these seals carrying 3.1 to 4.5 micrograms per gram dry weight in their molted fur. But basically, because an individual seal doesn't have toxic levels of methylmercury in their skin, there's no way that making out with one could kill you. So go ahead, kiss all the seals you want. Well, maybe not. They're still pretty dangerous. And you're not off the hook yet. For over two decades, scientists have puzzled over these annual mercury spikes along the California coastline. Now that they've traced the mercury to the elephant seal, there are a lot more questions. And let us be clear, these elephant seals have a lot of mercury in their fur, and it's leaching out. During their molting season, toxicity in the surrounding water jumps to 17 times normal levels. So how are these seals getting so hyped up on mercury? Major sources of mercury pollution in the US include coal-fired power plants, boilers, steel production, cement plants, and incinerators. A lot of mercury is pumped in the air and falls in the ocean as deposits in rain or snow. And then you've got the point sources like industrial and mining waste that straight up dump mercury into the ocean. Once the mercury gets into the ocean, tiny microbes convert it into methylmercury, a neurotoxin easily absorbed by animals when they chow down on those microbes. As it moves up the food chain, the methylmercury accumulates in increasingly large quantities and then proceeds to just stick around, because mercury doesn't break down easily. This is why you see all those warnings for pregnant women on tuna fish cans. Out in the open seas, mercury accumulates in a lot of fish that humans and seals like to eat. Now this study has shown us a mechanism for bringing that neurotoxin back to shore from the open ocean, potentially introducing more ecosystems and species to a dangerous chemical. We don't know what kind of effect that much mercury will have on these seals or how much this mercury leaching will be infiltrating human food sources, but knowing about the mercury in seal fur, that it's in such high concentrations and affecting ecosystems is worrisome to say the least. So kissing a seal won't kill you, but it's probably worth us doing something about all that mercury. And the best way to reduce that mercury in the environment toxifying our seals? Cutting emissions.