Farmed tilapia. (Photo: Stock File)
Can cannabis oil boost tilapia development?
Tuesday, October 24, 2017, 02:40 (GMT + 9)
A team of scientists from the American University of Beirut fed Nile tilapia fish pellets laced with cannabis oil to test whether the drug could make the fish reduce stress and grow faster.
These researchers noted that tilapia is farmed intensively, and in a bid to maximize the amount of product fish farmers can bring to market, some fish pens have become incredibly congested. Living in such close quarters can lead to all kinds of challenges for the fish, including reduced water quality, more incidences of disease, and increasing intraspecific interactions, which leads to stress.
As part of the trial, three diets were made to contain either soy oil, industrial hemp oil or cannabis oil and offered to tilapia for 8 weeks. At termination, survival, growth, feed conversion and blood parameters were assessed.
In this way, they observed that the cannabis extract increases tilapia metabolism and thus, the feed conversion.
On the other hand, cannabis had no effect on blood cell counts, total plasma protein, haematocrit or lysozyme activity.
The results thus obtained suggest that cannabis does not improve immune response of tilapia or body composition but does reduce growth rate by increasing metabolic rate.
Therefore, the Lebanese scientists found that the pot pellets did not quite have the mood-altering effect they had hoped for.
The trial showed that fish fed THC (the main psycoactive cannabis ingredient)-laden edibles did not seem to be surviving any better than fish fed a control diet, which the researchers took to mean that the drugs were not helping the fish deal with the stress of pen life.
Nevertheless, it is possible that the fish simply built up a tolerance after receiving the same amount of THC every day for two straight weeks.
As for growth, the researchers found that feeding fish pot oil does give their metabolism a boost. Farmers could give the fish pot and then feed them more food, but doing so would cut into profit margins, so aquatic scientists Patrick Saoud, lead author of the study, says it is unlikely that any fish farmers will be investing in the drug anytime soon.
As for the prospects of commercially available pot-reared fish, Saoud and his coauthors’ conclusion is a real downer: “Until further research yields different results, we do not believe fish should be given reefer.”
The study results were published in the journal Aquaculture Research.