(Image via bbc.com)
Volunteer Writer: Emma Bowser
Email: ebowser@umassd.edu
Some people like to crack jokes about wild animals consuming cocaine, especially with the release of Cocaine Bear, a 2023 horror film, and Cocaine Bear: The True Story, a TV documentary explaining a real-world event. However, wild animals testing positive for cocaine are quickly becoming a reality.
Being exposed to drugs made by humans is not a new phenomenon for wild animals. People have been manufacturing drugs for a very long time, and sometimes accidents happen.
In July 2024, an article was published by the Instituto Oswaldo Cruz documenting the discovery of cocaine in sharks that the institute off the coast of Rio de Janeiro had captured.
The Instituto Oswaldo Cruz runs a laboratory for environmental health assessment in the area, focusing on “analyzing the presence of viruses and bacteria in sewage to identify and measure the possible silent circulation of disease-causing microorganisms.”
The laboratory also tests for exposure to harmful substances such as lead, mercury, and arsenic.
They have been responsible for multiple environmental health alerts. One of the most notable resulted from a series of studies that enabled scientists to identify the exact cause of metal contamination in samples taken from the fish of Rio de Janeiro.
The collections for the cocaine study were gathered between September 2021 and August 2023, in Rio de Janeiro’s west zone, more specifically, Recreio dos Bandeirantes.
Prior to this study, there was already documentation of mussels and a few other aquatic organisms being contaminated by cocaine. However, this study is the first to document the presence of cocaine in samples obtained from sharks.
Brazil is one of the top global consumers of cocaine, and researchers believe that the main reason why cocaine is entering the marine environment is that the substance is being disposed of in the sewage system and the residue is then released into the ocean.
“Following this finding in the national territory, our research group decided to investigate whether the animals that our laboratory had collected for studies involving other contaminants were also contaminated by cocaine. The result is impressive. We found the substance in all 13 sharks analyzed and in only one of them, benzoylecgonine, which is the main metabolite of the drug, was not detected.”
After obtaining authorization from the Biodiversity Authorization and Information System and National Genetic Heritage Management System the researchers continued looking into the issue.
They used the Advanced Laboratory Section of Santa Catarina to analyze the samples they had collected. Rodrigo Barcellos Hoff, an employee of the laboratory, lead this stage of the study.
Every sample of muscle and liver tissue that was used tested positive for cocaine, and benzoylecgonine was found in 12 samples of muscle tissue and two samples of liver tissue.
The amount of cocaine found in the samples of muscle tissue was higher than the amount found in the samples of liver tissue, which is surprising because it signals an accumulation issue due to the fact that the liver is a metabolizing organ in sharks.
This may mean that the sharks were exposed to cocaine in a variety of ways.
When the data from this study was compared to the data from similar studies, the researchers discovered that the average amount of cocaine in the sharks’ tissue samples was higher than the amount found in samples from other living organisms.
The researchers plan to continue studying the cocaine contamination around Rio de Janeiro by taking more samples of water and various living organisms to gather more data. Since the sharks used in this study are non-migratory, it is possible that this contamination is limited to the coastal Rio de Janeiro area.
