Are the Drugs we Take Affecting the Fish That we Eat?

By Jennifer Huizen, E&E reporter
8/9/2014 10:03:47 AM

Among the less obvious effects of climate change are the psychological impacts. In 2005, Australian philosopher Glenn Albrecht coined the term "solastalgia" to describe the increased anxiety experienced by those affected by severe drought and large-scale coal mining in regions of New South Wales.

He found that humans suffer from an intense sense of powerlessness over the changes taking place to their environment, and with future climatic changes predicted to be drastic, anxiety will likely grow.

Since then, many others have looked into the consequences that climate change has on mental health and have found a similar trend. In a study conducted by the Mailman School of Public Heath at Columbia University, researchers found children who had lived through Hurricane Katrina to be four times more likely to suffer from depression and anxiety, and in India, farmers affected by agricultural losses have been linked to higher rates of suicide.

While it would be lovely to think that this new and ever-mounting feeling of anxiousness is limited to humans, in 2013, researchers at the Scripps Institute of Oceanography at the University of California, San Diego, found that juvenile rockfish responded to rising acidity with alarming behavior, showing signs of stress even after being returned to normal pH conditions for a week. On top of this, rises in temperature are known stressors to most forms of life.

So what can we do to help relieve anxiety in both humans and our counterparts in the wild? In humans, we've increased reliance on anti-anxiety medications, and according to a study released today, maybe, so have fish.

Jonatan Klaminder, a postdoctoral research fellow at Umeå University, decided that if humans are increasing our pharmaceutical consumption, the levels of these drugs in our water system must also be increasing.

As our population grows and urban centers become more crowded, the levels of these drugs in effluent wastewater will only grow, but this is not new thinking. Medications intended for human use have been found not only in Sweden's waterways, but in many regions of the world, including the United States.

While this may be common knowledge, what Klaminder found was that no one had determined how this increase was truly conveyed to fish.

Rockfish recruits on the top of Cordell Bank National Marine Sanctuary, taken on the first visit ever by NOAA divers (2010). (Credit: Greg McFall/NOAA)

How perch chill out

"If you want to measure how pharmaceuticals are affecting fish, you need to measure both their positive and negative potential," said Klaminder. "Fish share human receptors, so it is natural that they should respond much as we do, but in the current system, there isn't really a way to measure what these positive effects may be."

That's because conventional risk assessments on aquatic environments are focused on toxicity, but pharmaceuticals don't really fall into this category properly. Pharmaceuticals are designed to enhance health, so risk assessment studies, finding no evidence of increased mortality associated with them, deemed their impact on aquatic environments to be minimal, or not worthy of extensive research.

Yet Klaminder took issue with this approach. He felt that by only focusing on the possible negative effects of pharmaceuticals, we may be masking their other potential effects. Today, his work, published in Environmental Research Letters, found fish not only are consuming and maintaining these chemicals but may actually respond to them precisely as humans do, by chilling out.

Klaminder exposed two subsets of Eurasian perch, fry prior to hatching and 2-year-old mature fish, to Oxazepam, an anti-anxiety drug, and found that in both cases, the drug decreased mortality rates. Populations showed higher feeding rates, higher activity and increased boldness. By reducing anxiety, the perch strayed farther from the school, and as a result, were better scavengers.

"If you're a small fish, you are constantly anxious," said Klaminder, "just waiting for a bigger fish around the corner to eat you. It is very normal for perch especially to be rather inactive, laying in wait for food to come to them, but these bolder fish found more food sources by exploration and taking risks."

While these may sound like advantages, Klaminder is cautious in calling these positive effects. Perch behave the way they do for a reason, gaining protection in numbers, so changing their behavioral normalities may expose fish to increased risk, causing higher mortality rates. But whether or not these effects turn out to be helpful or detrimental is really not the question researchers were trying to answer, nor is it the take-home message, Klaminder said.

"We are not interested so much in the impact of this particular drug so much as the flaws in the system it shows," said Klaminder.

Hoping to prove he's wrong

Gerald Ankley, a toxicologist with U.S. EPA, doesn't fully agree that there is a flaw to be fixed. Having studied a variety of chemicals in aquatic systems for many years, including some pharmaceuticals, Ankley said research has not been driven toward studies like Klaminder's for good reason.

"As toxicologists, we do struggle to explain the cases where contamination actually leads to increased health, when they do better than their control counterparts," said Ankley, "but we're a community looking at toxicity, and ultimately, when it comes down to it, we're looking for negative effects."

Ankley feels that while studies like Klaminder's present interesting inroads, much more proof is needed to label these effects as consequential.

"I think it's a little overstated to claim these findings warrant changing the system, but what would be interesting is to determine whether this effect is reproducible," said Ankley, "not just in the wild but also in other species."

Klaminder and his team hope to do just that, focusing future efforts on extending findings to more species and under more realistic environmental conditions than those found in the lab, but Klaminder added that what he truly desires from his work is something not many scientists would be hoping for.

"It may sound strange for a scientist to say this," he said, "but I actually hope what we found is wrong, and that these effects are not being lived out in the wild already, because if they are, it means we've been looking at this the wrong way and don't really have a clue how many pharmaceuticals are affecting aquatic environments."

Reprinted from ClimateWire with permission from Environment & Energy Publishing, LLC. 202-628-6500.

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