Crayfish Exposed To Antidepressants Are More Adventurous | Smart News
When human drugs enter waterways, they can affect aquatic animals. In a new study published this week in the open access journal Ecosphere, crayfish exposed to low levels of the antidepressant citalopram, also known as Celexa, changed their behavior and became more daring and adventurous.
Little swimmers spent more time looking for food and less time hiding in shelters, which could leave crayfish susceptible to predators. Over time, their vulnerability could have cascading ecological effects on their natural environments, reports Douglas Main for National Geographic.
Citalopram is a selective serotonin reuptake inhibitor (SSRI) antidepressant, which is the most commonly prescribed type of antidepressant. The drug increases the levels of a mood-balancing neurotransmitter called serotonin in the brain, for example National Geographic. Serotonin is present in many animals, including crayfish, reports Clare Wilson for New Scientist.
Trace amounts of pharmaceuticals end up in water systems from human waste or improper disposal, such as flushing drugs down the toilet, reports Tara Yarlagadda for Reverse.
Treated wastewater still contains traces of drug compounds because the facilities are not fully equipped to filter and remove them. Thus, contaminated water returns to streams, Reverse reports. Although only small amounts end up in streams, these small amounts are enough to influence neurochemistry in the tiny brains of aquatic life.
âWhen you flush the toilet, that small amount of pharmaceuticals will end up everywhere the rest of your wastewater goes,â said study co-author AJ Reisinger, a soil quality scientist and of Urban Water at the University of Florida. Reverse.
To see how crayfish reacted when exposed to antidepressants in a natural setting, Reisinger and his team placed the crustaceans in water tanks that mimicked a usual stream environment. Each tank contained a plexiglass shelter under which the crayfish could hide.
For two weeks, the team infused the reservoirs with 0.5 micrograms of citalopram per liter of water. The researchers placed chemical clues for the food on one side of the tank, while the other side smelled like their crayfish buddies, Reverse reports. From there, the scientists observed the crayfish and calculated how long it took them to come out of their shelter. A control group did not receive the antidepressant.
Compared to the control group, shellfish exposed to low levels of antidepressant were twice as likely to come out of their shelters and explore their surroundings, Natalie Grover reports for the Guardian. The drug-exposed group also spent 400% more time in the part of the reservoir with chemical food cues, reports National Geographic.
No predators were introduced during the experiment, but in the wild, crayfish’s daring new ways can make them easy targets for raccoons, foxes, or other predators, for example National Geographic.
The microbial components of the ecosystem also changed when traces of antidepressants were added to the water, reports the Guardian. Algae and other organic compounds thrived in tanks filled with pharmaceuticals. Researchers suspect that because the crayfish ate more, they produced more waste, which fed the algae. It is also possible that their increased accelerated motions move the sediment at the bottom of reservoirs, which could affect ecosystems in the long term, for example. National Geographic. The research team is working to explore this topic in future experiments.
Rinsed medications may not cause death in animals swimming in them, but they have the potential to alter normal behaviors. One way to help remove substances that get into waterways is to properly dispose of medications.