New Scientist: The world’s most successful bug hits dolphins

How does a parasite found in kitty litter get into whales and dolphins? By hitching a ride down the sewage pipe and into anchovy guts, say researchers.

Gloeta Massie and Michael Black of California Polytechnic State University say this could explain why one of the most prevalent parasites in humans is now popping up in marine mammals. They presented their findings at the annual meeting of the American Microbiology Society on Monday.

"Toxoplasma gondii is the most successful protozoan pathogen on the planet," says Michael Grigg of the US National Institutes of Health. The US Centers for Disease Control and Prevention estimate that nearly one in four people aged 12 or older in the US have been infected with the parasite.

This is another great example how little we often about the consequences about our actions. Nature is a complex system and even small & stupid acts can have serious consequences.

A lot of science is "wasted" by finding out these often destructive connections and their consequences.