Right now, Washington state is fighting off an invasion! The culprit? Goldfish. Yup, you heard right. Thousands of goldfish have infested the West Medical Lake and are crowding out the native fish population. How did this happen? The Department of Fish and Wildlife thinks that a few irresponsible pet owners are to blame. And while the goldfish may have cost the owners a few dollars, this mess is going to cost the state an estimated $150,000 to try to remove these feral fish. But this isn't the only place this is happening. Goldfish are invading lakes and streams worldwide, and it's all our fault.