Scientists hope weed-laced feed can help farmed fish chill out

Now, researchers in Lebanon think live fish could actually benefit from absorbing a little THC. In a recent study published in Aquaculture Research, scientists at the American University in Beirut hypothesized that if farmed tilapia ate marijuana-laced fish feed, they would relax and eat more than their stressed-out and overcrowded, conventionally-fed counterparts. If it works to help cancer patients maintain their weight, the logic goes, why shouldn’t it help farmed fish get fat, and chill out?

In intensive aquaculture operations, fish don’t have a whole lot of room to swim around. That can lead to all kinds of problems—lowered water quality, increased spread of disease, and stressful “intraspecific interactions,” the underwater equivalent of getting yelled at for pushing all the elevator buttons or standing on the wrong side of the escalator.

But what if the fish just didn’t care about all the jostling and unnecessary competition that results from a crowded environment? They might get sick less often and grow a little faster. That’s what Dr. Imad Saoud and his team were testing when they added industrial hemp and cannabis oil to fish feed for the eight-week experiment. (The paper’s description of the “experimental diet preparation” reads a lot like something you could try at home: They made the fish-friendly edibles using a dough mixer and a meat grinder.)

In reality, the weed-laced fish feed didn’t produce any of the desired results. The fish that ate the hemp and cannabis oil feeds actually grew more slowly than the control group, coming out shorter and skinnier at the end of the experimental period. They also exhibited faster metabolic rates than their sober cousins, meaning the marijuana didn’t reduce stress as the researchers had expected. There was no evidence that the adulterated feed made the experimental groups more resistant to disease, either.

The researchers write that the contradictory findings may have resulted from an “antagonistic interaction” between Cannabidiol and Tetrahydrocannabinol (THC), both of which were present in the hemp oil and the cannabis oil. That means the two compounds somehow combined in a way that gave the fish the “munchies” but didn’t make them gain weight.

It doesn’t look like farmed fish will be getting permastoned any time in the near future. And as for any recommendation from the scientists who conducted the study? “We do not believe fish should be given reefer.”