In 2022, Jack Brand, an environmental toxicologist, loaded a bunch of Swedish fish with cocaine. He wasn’t trying to bring a Halloween hoax to life; he wanted to see how salmon in the wild reacted to pollution from the illegal drug. In recent years, there has been an alarming rise in the number of waterways polluted with cocaine, prompting scientists to wonder how fish might be handling their highs. As it turns out, fish indeed get wired when on cocaine. In a study published Monday in the journal Current Biology, Brand and his colleagues show that coked-up salmon swim faster and travel farther than their sober counterparts. This study prompts additional questions about the effects that human drug habits may be having on salmon and other freshwater fish. It wasn’t easy for Brand, a researcher with the Swedish University of Agricultural Sciences, to get permission from local governing bodies to dose fish with the drug. “It was a fairly tedious and laborious process,” Brand said of all the paperwork.…