The intertidal can be a pretty rough place to call home. You have to deal with what seems like a whole web of trophic levels trying to eat you, the constant headache of that damn sun drying you out, and let’s not even get started on the whole wave action problem. Needless to say, for most inhabitants, it can be a downward stressful spiral straight into depression.
Luckily for these seafaring sufferers, more and more antidepressant medications are making it to the intertidal these days! From fluoxetine (Prozac) and fluvoxamine (Luvox) to venlafaxine (Effexor) and citalopram (Celexa), active pharmaceutical ingredients (APIs) are creating an over-the-counter, wastewater cocktail rendering a whole slew of note-worthy side effects you might not exactly find on the label.
Most recently, scientists from Gettysburg College and the University of Flordia, discovered that when exposed to varying doses of these popularly prescribed medications, certain marine snails just couldn’t get a grip. Literally.
Depending on the species and the concentration of exposure, antidepressants would cause snails to suffer from “foot detachment” and be unable to hold onto their petri dishes. (I think we should take this moment to be thankful that the “foot detachment” side effect has yet to be witnessed in human trials.)
Though they don’t yet know why different snail groups are more sensitive than others, scientists can give us insight into the physiological mechanism behind how antidepressants are causing such snail side effects.
The connection is serotonin. For humans, antidepressants work as selective serotonin reuptake inhibitors. Essentially, that’s a big, fancy way of saying they help your brain in regulating your happiness hormones. In snails however, serotonin works a bit differently and more along the lines of locomotion and movement. Thus, when these systems are disrupted, detachment can ensue.
Now most snails will flat out tell you…for the reasons stated above…detachment just won’t do. Unless someone decided to use that new NeverWet stuff and make a snail slip and slide (which my labmate and I may or may not have seriously thought about), nothing good will come from loosing foot power in the intertidal. If the waves don’t take you away, the birds will.
Currently, environmental concentrations of antidepressant waste and other pharmaceuticals are not necessarily at foot detaching levels (though they can accumulate to them). Studies such as these are important however, in that they give us a look at how sub-lethal chemical concentration are disrupting critter behaviors and offer a foreboding warning as to the influences of human run-off in the marine environment.
P.P. Fong and N. Molnar. 2013. Antidepressants cause foot detachment from substrate in five species of marine snail. Marine Environmental Research. 84: 24-30.