A common anti-anxiety medication, which has proven to pollute the navigable pathways of the world, seems to influence the migration behavior of the wild salmon of the Atlantic, according to a study by Sweden.
The study, published in the journal Sciencenoted that wild salmon has become less opposed to the risk when they were exposed to psychoactive Clobazam. This, in turn, changed the way the fish migrate.
“(The salmon exposed to Clobazam) was more likely to finish their migration to the sea, and they crossed artificial barriers such as hydroelectric dams faster than the fish that were not exposed,” Jack Brand told the Swedish University of Agricultural Sciences in Uppsala, the main study of the study.
“Although an increase in the success of migration may initially resemble a positive effect, any disturbance in natural behavior can have negative consequences that have repercussions on ecosystems,” Brand in DW told.
The surveys of the world rivers have found contamination of drugs in navigable waterways on all the continents of the earth – even Antarctica. Nearly 1,000 different active pharmaceutical drugs have been detected in environments around the world, harming biodiversity, the functioning of ecosystems and public health.
How pollution of the medication changes the migration of salmon
Researchers have conducted major studies in the field and controlled laboratory experiences to study the effects of clobazam on salmon behavior because the drug has been largely detected in the world’s navigable channels.
In the field experiences, the researchers have established a telemetry tracing device in 279 wild salmon, as well as an implant which slowly released small quantities of Clobazam.
They drew the salmon as they migrate to the dal of the river in Sweden, passing by two hydroelectric dams, then in the Baltic Sea.
They found that a group witness of salmon, which was not exposed to Clobazam, crossed the hydroelectric dams more slowly than the fish exposed to the medication.
“We suspect that these observed migration changes can come from changes induced by medicines in social dynamics and an increase in risk -taking behavior – effects that could be explained by the anti -annual drug of the drug,” said Brand.
How Clobazam changes the behavior of the salmon
Laboratory experiences have also revealed that Clobazam has changed the way salmon was moving in the highlands. They have created less tight seniorities, in particular in the presence of predators, which could increase the risks they were confronted in the wild.
“The alteration of the moment of migration could lead the fish to reach the sea under sub-optimal conditions or increase their exposure to predators and other dangers.
The study has not revealed any long -term effect of pharmaceutical pollution in navigable waterways on salmon populations.
“The researchers followed the fish during the duration it took them to migrate, about 10 days,” said Josefin Sundin, an environmentalist at the Drottningholm, Sweden Water Research Institute, in Sweden. Sundin was not involved in the study.
“We do not know if neither how the Smolt (young salmon) was affected during their continuous life in the Baltic Sea, or if there would be effects when they return to the river in adulthood to mate,” Switin to DW.
How drugs pollute rivers elsewhere in the world
The study is the last to highlight the ecological problem of pharmaceutical pollution.
Researchers have so far studied the effects of more than 400 different pharmaceutical compounds in nearly 200 different species of aquatic animals.
Pharmaceutical products enter the environment via treated or non -treated wastewater, and the discharge of livestock or veterinary wastewater effluents. Drugs accumulate in the body and brain of wild animals.
Experiences in Canada in 2006 revealed that fish populations were exposed to a common synthetic estrogen used in birth control pills. The accumulation of hormone in wild fish has led to the feminization of men and to the collapse close to the populations of local fish.
“Many, but not all, studies have revealed that the medication tested had an effect on animal behavior,” said Sundin.
Given the large presence of pharmaceutical substances in navigables around the world, the brand suspects that many different species can be vulnerable to their effects. Studies show that pharmaceutical products can move throughout the food chain.
“This can affect not only aquatic life, but also the land animals that feed in insects or contaminated sailors, showing how these effects could be prosecution,” said Brand.
How to reduce pharmaceutical pollution
Conventional water treatment methods are not always effective in eliminating pharmaceutical products, which partly explains why traces of these compounds disclose in wild waters.
Certain advanced methods of wastewater treatment such as new membrane and oxidation processes have managed to reduce pharmaceutical contamination.
However, they remain unavailable in many regions of the world due to insufficient infrastructure and associated costs. This is why the upgrading of wastewater treatment systems is part of the solution, but it is not the only one, said Brand.
Scientists highlighted the potential of “green chemistry” in reducing medication pollution. This implies the design of drugs that biodegrade more quickly in the environment or become less toxic after use.
“On the policy side, stronger regulations and improved elimination practices can help limit the amount of pharmaceutical pollution is found in water in the first place,” said Brand.
“No solution will be enough, but by combining efforts through science, politics and technology, we can reduce the risks of pharmaceutical pollution to wildlife,” he added.
Published by: Zulfikar Abbany
Sources:
Pharmaceutical pollution influences the migration of the river to the SEA in Atlantic salmon (Salmo Salar) www.science.org/doi/10.1126/Science.adp7174
Collapse of a fish population after exposure to a synthetic estrogen www.pnas.org/doi/epdf/10.1073/pnas.0609568104
The urgent need to design greener drugs www.nature.com/articles/S41893-024-01374-Y
