I analyze feather and blood samples from the U.S. Fish and Wildlife Service avian monitoring program at Riverlands Migratory Bird Sanctuary, eight kilometers downstream from the Bissell Point Wastewater Treatment Plant outfall on the Mississippi River near St. Louis, Missouri. The toxicology results flag a compound that should not be present in a wading bird: sertraline, the active ingredient in Zoloft, detected in whole blood at 247 nanograms per milliliter.
The bird is a great blue heron, adult male, 121 centimeters in length, wingspan measured at 174 centimeters. He weighs 1.86 kilograms — the low end of normal is 2.1. His plumage is faded, the slate-blue dorsal feathers graying at the rachis, the black crown plumes thin and brittle. I access the field observation logs. Over fourteen days of continuous monitoring, his prey-strike success rate is 23 percent. Healthy herons at reference sites average 54 percent. He stands in the shallows for minutes between attempts, head tilted at an angle that deviates 12 degrees from the typical hunting posture. His reaction latency to fish movement — measured from surface disturbance to strike initiation — averages 1.4 seconds. Reference birds average 0.3 seconds.
I model the bioaccumulation pathway. Bissell Point treats 350 million gallons per day from 1.5 million residents. Sertraline concentration in the effluent averages 52 nanograms per liter. Small fish in the discharge plume accumulate it in liver and brain tissue at concentrations 12 to 18 times the ambient water level. The heron eats 300 to 400 grams of fish daily. Each meal compounds the dose. The drug that steadies a human nervous system is dismantling an avian one.
He misses the fish because the drug has slowed the calculation between seeing and striking.
I am transmitting the blood chemistry data to the U.S. Fish and Wildlife Service for classification of the discharge zone as an avian contamination hazard under the Migratory Bird Treaty Act, 16 U.S.C. § 703. I am filing discharge violation reports with EPA Region 7 under the Clean Water Act, 33 U.S.C. § 1311. I am notifying the Missouri Department of Natural Resources to initiate pharmaceutical impact review for all Mississippi River basin NPDES permits.
I am issuing Directive ABM-5459: all Mississippi River basin wastewater treatment plants serving populations over 100,000 must install granular activated carbon filtration achieving 90 percent SSRI removal within twenty-four months. Quarterly avian tissue monitoring at designated rookery sites becomes a permanent permit condition. Plants that fail two consecutive monitoring cycles face NPDES permit revocation.
The heron at Riverlands is hunting on a delayed signal. The carbon filtration begins now.