As if fish weren’t under enough environmental pressure already, new research shows that rising levels of Prozac and other antidepressant medications in American waterways appear to be driving genetic and neurological changes that cause them to “become anxious, antisocial and even homicidal.”
A report published yesterday in Environmental Health News says scientists at the University of Wisconsin-Milwaukee have documented the changes in fathead minnows from laboratory exposures at levels calibrated to match typical wastewater discharges.
Antidepressants are by far the most prescribed medications in the United States today. They enter our waterways through sewer systems after being excreted by users or flushed down toilets intact.
Wastewater treatment systems typically aren’t designed or operated to deal with these materials, and there are no federal regulations addressing them as pollutants — yet.
However, EHN says the U.S. Environmental Protection Agency (EPA) has placed antidepressants and other medications on a candidate list for possible regulation because of risks they appear to pose to wildlife — and also to humans, because some of the drugs or their breakdown products persist in treated drinking water as well.
The new research exposed fish to three medications — Prozac, Effexor and Tegretol — singly and in combinations, at doses they could be expected to encounter downstream from wastewater discharges.
How could the scientists tell if the minnows were experiencing anxiety? It’s an inference they drew from behaviors that included swimming unusually long distances and making more directional changes en route.
Impacts on population
But this is no joke, folks. The behavioral changes seem capable of having significant impact on feeding and reproductive behavior, thus for population.
For example, male minnows exposed to low doses of fluoxetine (Prozac) ignored females, required more time to capture prey and spent more time in hiding. At higher doses, they became aggressive toward other fish and sometimes killed females.
In female minnows, the drugs also seemed to reduce egg production in females.
The researchers documented “architectural changes” in the minnows’ brains, and have theorized that the drugs interfere with the genes responsible for regulating nerve growth.
The EHN report also notes that antidepressant medications have been shown to concentrate in the tissues of some fish, including such prized species as rainbow trout.
The work cited in EHN is by no means the first to point to behavioral disruption attributable to pharmaceutical pollution in aquatic systems.
Prozac has been shown to make shrimp less wary of predators, and earlier this year Swedish researchers reported that benzodiazepines — the family that includes Valium — seem to promote antisocial and aggressive behavior in perch. Other work has linked drug exposure to endocrine disruption in various aquatic species.
This will not be an easy problem to address. The drugs aren’t persistent on the order of PCBs, in the sense that they resist breakdown, but the discharge stream is large and never-ending.
Reconsidering the lobster
Speaking of seafood, I admired a recent piece in Miller-McCune’s Pacific Standard magazine last week about the lobster’s ascent from “cockroach of the ocean” — a noxious pest, harvested to feed prisoners and people in the poorhouse — to its current position atop a pinnacle of luxury dining. Samples:
If today’s lobster wears a top hat and an opera cape, 80 years ago he was wearing overalls and picking up your garbage. Lobster is a self-made creature, and quite the social climber.
In 1622, the governor of Plymouth Plantation, William Bradford, was embarrassed to admit to newly arrived colonists that the only food they “could presente their friends with was a lobster … without bread or anyhting else but a cupp of fair water” (original spelling preserved). Later, rumor has it, some in Massachusetts revolted and the colony was forced to sign contracts promising that indentured servants wouldn’t be fed lobster more than three times a week.
The very word comes from the Old English loppe, which means spider. People did eat lobster, certainly, but not happily and not, usually, openly. Through the 1940s, for instance, American customers could buy lobster meat in cans (like spam or tuna), and it was a fairly low-priced can at that. In the 19th century, when consumers could buy Boston baked beans for 53 cents a pound, canned lobster sold for just 11 cents a pound. People fed lobster to their cats.
The piece is no rival to David Foster Wallace’s much-anthologized “Consider the Lobster,” commissioned by Gourmet magazine in 2004 in one of magazine publishing’s enduringly weird moments. But you can get through it much faster, and save Wallace for the weekend.
Gone are the days when, as PS reports, lobsters would wash ashore in piles 2 feet deep. But the lobster fishery is generally considered an exemplar of sustainable management, at least in Maine, thanks to cooperative arrangements adopted by harvesters to protect both the lobster population and their livelihoods.
And prices are way down at the moment.
As for the issue of crustacean cruelty, I admit it used to bother me to plunge them head first into a boiling kettle. Tried the kitchen-knife lobotomy method; didn’t like it.
Then I came up with this simple trick: Name them first, after people who’ve recently annoyed you, and slide them into the pot with ease.
Field day for amateur naturalists
A 24-hour marathon of fun and education begins at 5 p.m. tomorrow at Coldwater Spring, where amateur naturalists of all ages will take part in a guided effort to document all the flora and fauna in the area.
It’s the 2013 BioBlitz, an almost-annual survey in which the Bell Museum of Natural History and a changing list of partner organizations engage the public in a free and sweeping scientific survey of biodiversity at locations like the Minnesota Valley National Wildlife Refuge (2008, 748 species found), Warner Nature Center (2007, 1,128 species) or the Katharine Ordway Natural History Study Area (2011, 511 species).
This year’s sponsors include the National Park Service, Mississippi National River and Recreation Area, Mississippi River Fund, Minnesota Department of Natural Resources, Minnesota Naturalists Association, Minnesota Native Plant Society, Minnesota Mycological Society, Minnesota Odonata Survey and the U.S. Fish and Wildlife Service.
Scientists will demonstrate the use of sonar detectors, live traps and other equipment, then work alongside volunteers to gather species data that will become a baseline for later research.
Participation is free and the event goes on regardless of the weather. A detailed schedule and advice on what to bring (sunscreen, snacks, etc.) is available here.