The Pacific Tide: Pharmaceutical Pollution Along the Coast of California
Updated: Aug 14
California’s Pacific coast is one of the most biodiverse and abundant ecosystems worldwide, teaming with almost 2,000 species of microorganisms, plants, fish, marine mammals, turtles, invertebrates, and seabirds, supported by a Mediterranean climate. Its famous off-shore, underwater, and coastal rock formations date back to the Cretaceous period and help subsidize this special bionetwork making the state’s ocean waters and sea life sacred and unique. Unfortunately, California’s precious coastal ecosystem also faces massive threats in the vein of climate change/global warming, the devastation of kelp forests, ocean acidification, algal blooms, and habitat destruction; sounding the alarm for the time-sensitive need for human intervention, conservation management, and awareness.
The Pacific Tide series highlights monthly oceanic events occurring on the California coast and/or portraits of important species who call the Pacific coastline waters home emphasizing the importance of conserving this critical ecosystem.
In this month’s installment of The Pacific Tide, we introduce one of the fastest-growing, non-traditional forms of water contamination: pharmaceutical pollution. We follow the journey of how pharmaceuticals enter the waterways/ocean and potentially cause great harm to marine animals and oceanic ecosystems. We also explore the recent data from the Pacific Marine Mammal Center in Los Angeles finding that 92.6% of California Sea Lions tested with noticeable NSAID levels in their livers during post-mortem autopsies.
Discover with us as we expose California’s water treatment plants that have regularly failed to filter pharmaceuticals due to a lack of technological upgrades and have reportedly inadequately released reclaimed water; directly contributing to the pharmaceutical pollution problem impacting oceanic ecosystems.
Down the Drain
Think for a moment about your daily routine from the moment you first wake: you might go to the bathroom and take your daily prescription medication or supplemental vitamins. Maybe, you woke with a pounding headache and reach for a bottle of pain reliever. Oops! You accidentally dropped a few pills down the drain of the bathroom sink. Thinking nothing of it, you wash your face with facial cleanser and hop into the shower to use your favorite shower gel and shampoo/conditioner you swear makes your hair shine. It isn’t even 9:00 AM and already you have released contaminants down the sink. Why should you worry, though, when you remember that sewage is filtered by water waste treatment plants before disposal into oceans? You shrug your shoulders and continue with your day that, ultimately, includes dozens of medicines, beauty products, and chemicals flowing down the drain.
In June 2026, Dr. Alissa Demming, the Vice President of Conservation Medicine and Science at Los Angeles (Laguna Beach)’s Pacific Marine Mammal Center, along with Veterinary Intern Dr. Sydney Zotto; revealed a shocking revelation that almost 93% (92.6%) of California Sea Lions were detected with NSAIDs (non-steroidal anti-inflammatory drugs) in their livers during post-mortem toxicology analyses. Pinnipeds (seals and sea lions) are a primary species in California serving as a biomarker for any deviations disquieting the California marine ecosystems especially due to their rookeries being shoreside. Between the years of 2019 and 2021, the Pacific Marine Mammal Center worked in collaboration with the Southern California Water Research Project to collect and study data from sea lions; focusing on any evidence of immunosuppressive or harmful chemicals that might be found in the organs of these pinnipeds. As a principal species in California’s oceanic ecosystem; the bioaccumulation within these marine animals is a window exposing any food chain cataclysms or agitations within California’s Pacific coastal waters.
During this study, post-mortem autopsy liver tissue samples were collected from 27 sea lions in Orange County, California. Scientists used chromatography and spectrometry methodologies to detect any visible levels of NSAIDs, hormones, a mood stabilizer, and a beta blocker commonly used by humans for preventative health and over-the-counter medical treatment that may have contaminated California’s waterways through urban runoff. The study sampled both adult and subadult pinnipeds to evaluate their exposure time potentially impacting the results with almost none having prior rehabilitation medication administered or very little traces.
Results from the Pacific Marine Mammal Center’s study found that 92.6% of the samples (25/27 sea lions) tested with detectable levels of NSAIDs (ibuprofen) while 22.2% of the samples (6/27 sea lions) showed observable Naproxen (example: over-the-counter medication, Aleve). Three out of the 27 sea lions (11.1%) highlighted Diclofenac (example: arthritis topical gel, Voltaren). A more detailed histopathology was performed on the affected liver and kidney tissues of 19/27 pinnipeds finding altered liver states in 13 cases, including liver hepatocellular carcinoma (cancer) in one sample and hepatocellular atrophy in four pinniped samples which can result in the reduction of liver tissue restricting blood flow. Interstitial nephritis, commonly an allergic reaction to NSAIDs which results in swollen and inflamed kidneys, was prevalent in 14/27 cases. 70% of the samples found elevated levels of ALT and ALP within the kidney tissues indicating inflammation. In order to diagnose whether these were indeed a consequence of NSAID exposure; biologists studied the blood cells of impacted cases finding that none of the sea lions had pre-existing correlated issues.
What is the origin of this NSAID epidemic within California’s pinnipeds? Surely, these sea dogs aren’t waddling into their local CVS to grab Tylenol for their aches and pains. The answer: ‘pharmaceutical pollution’. Go back to your morning routine: remember the pills you accidentally dropped down the sink? All the beauty products and ointments you washed off your hands? This discarded, contaminated water runoff travels to a wastewater plant where it is filtered and released back into the waterways, and in California: straight into the sparkling blue waters of the Pacific Ocean. While this may not sound alarming; California’s water treatment plants do not have the technological functionality to filter chemicals comprising household medicines and health products. When the reclaimed water is released into the ocean; these chemicals ascend the food chain from kelp and algae to bivalves (the group of mollusks comprising mussels, clams, oysters, and scallops) up to the pinnipeds like the ones in the Pacific Marine Mammal Center’s study causing damage and destruction along the way.
The Pacific Ocean is a Pharmacy?
Pharmaceutical pollution is one of the fastest-growing, non-traditional water contamination concerns in California with potentially devastating effects on the ocean and its inhabitants. Everything from over-the-counter medications to beauty products enters California’s waterways and the Pacific in two primary ways: (1) The failure to filter these substances by wastewater treatment plants and (2) Human sewage effluent such as flushing medication down toilets or sinks, unmetabolized human excrement containing these complex compounds infiltrating the waterways, washing hands after using ointments, etc. Although lesser in scope, prescription drugs can also eventually enter the ocean from agricultural runoff by means of animal feces containing medication and improper disposal of medications into landfills which leach into the waterways. This poses a major existential threat to marine ecosystems when moving through the food chains ultimately resulting in disruptions in marine animal behavior, reducing reproduction, liver and kidney damage, cellular oxidative stress and cytotoxic death, genotoxic DNA mutations, and damaging food web resilience.
NSAIDs, which are the most commonly found oceanic pharmaceutical pollutant due to their inexpensive cost and easy access, are especially toxic as it is manufactured to be extremely stable and active at low doses making them virtually immune to most environmental chemical decompositions such as hydrolysis (water breakdown), microbial degradation (bacterial or fungal cessation), and photolysis (molecular breakdown via light). While these chemical compounds therapeutically benefit humans and improve health; they directly create toxicosis and harmful bioactivity in vulnerable aquatic animal species. Biologists have even disturbingly found evidence of endocrine disruptors in the ocean causing physiological changes in fish as drastic as gender fluidity with male fish developing female characteristics. Antibiotics, which are designed to kill problematic microbes and actively alter living organisms; do exactly that in the ‘Mighty Blue’ killing ocean grasses, algal communities, and bottom feeders. Mitochondrial dysfunction has also been observed paralyzing the locomotion of sea animals and endangering their survival. Ketoprofen, an NSAID used to treat arthritis entering the oceans through unmetabolized particles in human excrement; is particularly problematic as it avoids waste filtration systems and refuses to decompose at anything faster than a snail’s pace. Over sustained time, pharmaceutical pollution can result in the death of species varietals and eventually kill biodiversity.
The immune systems of oceanic ecosystem participants are also at risk with NSAIDs causing the most damage. Long-term exposure to NSAID chemicals has created a carnival fun house in marine animal immune systems, notably fish and mollusks, resulting in abnormal responses or even creating immunosuppression making the oceanic species defenseless to infection. These NSAIDs have even acted as Dr. Frankenstein on fish organs altering their physical and chemical makeup. Fish, mollusks, and other invertebrates can experience stunted growth and negative hormonal fluctuations; preventing reproduction and risking species population numbers.
Both coastal and remote communities contribute to pharmaceutical pollution via municipal effluent discharge with additional factors such as climate, the existence of hospitals/medical facilities/senior homes and seasons (the heightened use of medications in winter months due to influenza) adding to the chaos. The warmer atmospheric conditions of California raise the temperature of the water being processed inside treatment plants which results in the alteration of the chemical compound chains and pH levels of pharmaceutical drugs effectively making the metabolite stronger than the original parent solution. Once this supercharged, drugged water enters the Pacific; it is absorbed by sediment, accumulates in small organisms/algae and begins its toxic journey throughout the food chain without any discrimination.
California’s Pharmacy Pollution Check List
California’s coastal waters are a hotbed of pharmaceutical pollution. A recent study performed by the University of California, Riverside in conjunction with San Diego’s Scripps Institution of Oceanography found that 250 man-made chemicals were detected in the ocean with pharmaceuticals (particularly birth control, pain relievers, heart medications, and antidepressants) leading the helm in concentration. “Everything that goes down your drain—when you shower, wash your face, or use the bathroom—enters the sewer system, and it has to go somewhere,” Lihini Aluwihare, a Professor of Marine Chemistry at Scripps Institute, clarified.
In a six-year study of California’s sewage effluent, five pharmaceutical drugs were consistently detected in enough sizable concentrations to be considered a point of concern by the U.S. Environmental Protection Agency (EPA) with all found to be a threat to marine species: Carbamazepine (mood stabilizers), Acetaminophen and NSAIDs, Sulfamethoxazole (bacterial infection treatment), Codeine/ analgesic (cough suppressants), and Trimethoprim (urinary tract infection medication). Erythromycin (typically used to treat respiratory tract infections and sexually transmitted diseases), Ranitidine (heartburn medication), and Enalapril (blood pressure ACE inhibitor) have polluted the waters of the San Francisco Bay making it their personal playground; while 43/68 mussels sampled along the California coast tested positive for the antidepressant, Sertraline. Fish in Southern California are overdosing on Diazepam, an anti-anxiety medication.
It is vital to also consider this pharmaceutical soup and how one chemical can compound the next being injurious to marine animals. “A lot of these pharmaceuticals may have either synergistic or additive or maybe even antagonistic effects when combined,” offers Diana Aga, Director of the RENEW (Research and Education in Energy, Environment and Water) Institute at the University at Buffalo, “The same thing can happen in humans taking multiple prescribed or over-the-counter medications, but the scope of drugs in the wild complicates the problem. It’s very difficult to predict what happens in the wild when they’re exposed to hundreds of these pharmaceutical residues at once.”
The Primary Culprit of California’s Pharmaceutical Pollution: Waste Water Treatment Plants
Although the human footprint is widely stamped in the ocean’s pharmaceutical pollution problem; the fingers ultimately point toward the filtration failure of treatment plants and pharmaceutical drug manufacturers. The state of California is not only the home to palm trees, famous landmarks and celebrities; but also boasts the nation’s largest water treatment reclamation plants with the three principal facilities located in Southern California: Hyperion Water Reclamation Plant (one of the world’s largest plants - Los Angeles), A.K. Warren Water Resource Facility (part of a seven-system plant covering 73 cities and unincorporated areas - Los Angeles) and Point Loma Wastewater Treatment Plant (San Diego). Although the California water treatment plants might be girthy and leading the pack in size; they are restrained by technology that isn’t designed to filter pharmaceutical runoff with the necessary upgrades reported to be too costly to implement. Activists regularly find that California’s reclamation plants do not properly dispose of the treated water and without strict governmental rules red-taping the practice: the Pacific Ocean becomes the pharmaceutical pollution capital.
California’s water treatment plants are guilty of a host of issues contributing to pharmaceutical pollution longer than a CVS receipt. Holding real estate near Dockweiler Beach in the Santa Monica Bay (Los Angeles); the Hyperion Water Reclamation Plant has been in operation since 1894 serving much of Los Angeles County plus 29 other contracted cities treating approximately 260 million gallons of water a day. Hyperion has a history of releasing used condoms, syringes, and tampons into the coastal waters and had one of the worst historical sewage spills to date in 2021 discharging 12 million gallons of untreated water into the Pacific costing the city of Los Angeles $20.8 million in fines to the federal government. "This was a major incident, one of the largest spills in our region in decades," Hugh Marley, Assistant Executive Officer of the Los Angeles Regional Water Control Board voiced adding that it, “threatened the health of nearby communities, as well as fish and wildlife, and violated numerous environmental laws and regulations." In 2024, an additional 30,000 gallons of sewage rushed into the ocean due to a pipe malfunction in a West Hollywood neighborhood that overwhelmed the treatment plant. Researchers found that coastal algal communities consumed the organic matter resultant of the sewage spill; causing harmful algal blooms that killed fish in the Los Angeles area devastating the ecosystem. Hyperion is in desperate need of revitalization to bring it up-to-date with modern-technology - having seen little repairs in 40 years.
San Gabriel Valley’s Whittier Narrows Reclamation Plant’s treated water has tested positive for an array of pharmaceutical drugs with antidepressants, pain relievers, and heart rate drugs being directly off-shored 200 miles out into the coastal Los Angeles waters exposing oceanic creatures to these chemicals 24/7 with proof of declining numbers in aquatic ecosystem species.
Studies surrounding Southern California reclamation plants have proven their systems fail to remove hormone-altering drugs from water before ocean disposal with the Point Loma Treatment Plant in San Diego even requesting to amp up its volume release even while knowing that their reclaimed water has been found contaminated with pharmaceutical drugs, beauty products, and even flame retardants. San Diego’s oceanic sediment and local fish populations have regularly tested positive for these toxic chemicals.
Potential ‘Fixes’ to Waste Water Treatment Plants and Pharmaceutical Pollution
The path forward to tackle the issue of pharmaceutical runoff is at the mercy of California’s treatment plants that seemingly turn the cold shoulder when it comes to repairs, technological updates, or system revamps, blaming cost as the barrier to entry. Reverse osmosis or the addition of granular-activated carbon filters to existing reclamation plant systems could completely eradicate the pharmaceutical runoff swimming into California’s waters but good luck in convincing the treatment plants to open their wallets.
California’s governing agencies have implemented some regulatory measures such as banning the use of Lindane (lice treatment) which was shown to cause severe damage to the integrity of oceanic ecosystems. This ban has proven successful with water treatment plans demonstrating a steep drop in Lindane-infested water with physicians no longer prescribing the treatment and it was the first of its kind to make a sweeping pharmaceutical ban directly in respect to water pollution.
In 2019, the Environmental Protection Agency (EPA) made it illegal for all healthcare facilities to flush medication and any hazardous waste into sewage systems including septic tanks in all US states and territories. Tragically, this ban does not impact pharmaceutical drug manufacturers who can continue to discharge their factory water runoff and are merely ‘encouraged’ not to practice such methods.
‘Green Pharmacy’ initiatives are also garnering heightened attention pushing pharmaceutical manufacturers to rethink chemical ingredients in common medications and find alternative, more earth-friendly substitutes. Although companies have been noticeably investing in green research; the execution remains to be seen due to its cost-prohibitive factors.
California’s environmental organizations embolden residents to nullify the practice of flushing medications via toilets/sink or to throw them in trash bins and instead return to drug take-back bins in local and chain pharmacies.
Pharmaceutical pollution is a growing problem in California (and worldwide) that will only escalate without the implementation of pharmaceutical drug filtration systems in treatment plants, without staunch governmental regulations regarding the ingredients and volumes of reclaimed water disposal, with the absence of the banning of specific drugs/chemicals and lacking ingredient substitutes by manufacturers. Without these changes, California’s Pacific oceanic ecosystems face dire consequences and the sea lions of California will continue to display elevated levels of NSAIDs.
Directories/Credits
1: “NSAIDs Detected in Wild California Sea Lion Liver Samples Presented by Dr. Sydney Zotto” YouTube Video format. Published on June 2, 2026 by Pacific Marine Mammal Center
2: “Drugs in the Ocean”, Written by Voice of San Diego. Published on February 18, 2008 by Voice of San Diego
3: “Common Pharmaceuticals in California Water”, Written by Unknown. Published in March 2014 by California Research Bureau
4: “The Impact of Pharmaceuticals Released to the Environment”, Written by Unknown. Published on November 10, 2025 by the United States Environmental Protection Agency
5: “From Prescription to Pollution: The Ecological Consequences of NSAIDs in Aquatic Ecosystems”, Written by Divya Lakshmi S, Vijaya Geetha B, Vibha Murali. Published on December 13, 2024 by Science Direct
6: “What Happens to Wildlife Swimming in a Sea of Our Drug Residues?”, Written by Tara Lohan. Published on August 11, 2021 by The Revelator
7: “Sources, Impacts and Trends of Pharmaceuticals in the Marine and Coastal Environment”, Written by Sally Gaw, Kevin V Thomas, Thomas H Hutchinson. Published on November 19, 2014 by National Library of Medicine
8: “What’s in the Water? Scientists Find Hundreds of Human-Made Chemicals in the Ocean”, Written by Neda Iranpour. Published on March 31, 2026 by CBS8 San Diego News
9: “Outcomes of the California Ban on Pharmaceutical Lindane: Clinical and Ecologic Impacts”, Written by Elizabeth H Humphreys, Sarah Janssen, Ann Heil, Patricia Hiatt, Gina Solomon, Mark D Miller. Published on December 7, 2011 by National Library of Medicine
10: “EPA Bans Flushing All Drugs, Including Hazardous Waste Drugs”, Written by Unknown. Published on Unknown Date by California Water Environment Association
11: “Wastewater Treatment Process at the Warren Facility”, Written by Unknown. Published on Unknown Date by Los Angeles County Sanitation Districts
12: “L.A. Agrees to Pay $20.8 Million in Massive Wastewater Spill into Santa Monica Bay”, Written by Marissa Wenzke. Published on August 20, 2024 by CBS LA
13: “Traces of Prescription Drugs Found in Southland Aquifers”, Written by Marla Cone. Published on January 30, 2006 by Los Angeles Times
14: “The Raw Truth: The Real Deal About Sewage Spills”, Written by Katherine Pease and Alison Xunyi Wu. Published on June 5, 2024 by Heal the Bay
15: “Hyperion Water Reclamation Plant”, Written by Unknown Author. Published on Unknown Date by City of Los Angeles Sanitation
I never realized how much impact NSAIDs passing through waste water facilities would have on marine life and the ecosystem. Makes perfect sense, though. There’s a lot to ponder here!