Contaminants of emerging concern, including pharmaceuticals, personal care products (PPCPs), current use pesticides, and other compounds, are ubiquitous in aquatic environments and are increasingly being detected in coastal marine ecosystems. Given the suite of sources, including wastewater treatment plants, septic systems, sewer overflows, and agricultural runoff, coastal marine organisms may be suffering chronic exposure to many of these compounds, with largely unknown effects. To address the question of whether these compounds are stressors to coastal marine communities, we conducted field and lab studies. We examined spatial and seasonal variability in compound types and concentrations in native Olympia oysters by field sampling wild individuals from two Oregon estuaries. We also conducted tank experiments on algae, mussels, and crabs to examine chronic effects of exposure to field-detected compounds and concentrations on growth, reproduction, condition, and behavior of these marine organisms. Specifically, effects of the antibiotics sulfamethoxazole (SMX), and trimethoprim (TRI), often prescribed together to treat bacterial infections, and detected worldwide in marine and estuarine environments, were studied on microalgae and mussels. The effects of fluoxetine, the active ingredient in the commonly prescribed anti-depressant Prozac, were tested on mussels and crabs.
In field sampled native Olympia oyster (Ostrea lurida) tissue collected from two Oregon estuaries, pharmaceutical suites were detected during each sampling season with variability in contaminant types and concentrations across seasons and between species and media (organisms versus sediment). Detected PPCPs included antibiotic, anti-inflammatory, and antihistamine pharmaceuticals as well as alkylphenol-based surfactant metabolites. In tank experiments, two microalgal species fed to bivalves in aquaculture, Isochrysis galbana and Chaetoceros neogracile, as well as California mussels (Mytilus californianus) experienced reduced growth when exposed to field relevant concentrations of SMX. A third microalgal species, Nanochloropsis oculata, experienced significant reductions in growth with exposure to both SMX and TRI. Fluoxetine suppressed feeding, growth, and reproductive output in California mussels and led to increased activity levels and higher aggression by Oregon shore crabs (Hemigrapsus oregonensis), around their predators, red rock crabs (Cancer productus) and therefore increased mortality. These findings: 1) indicate the limitation of using indicator species and/or sampling annually to determine contaminant loads for a site or specific species, 2) identify potential community-level impacts of emerging contaminants on marine communities and ecosystems; and 3) highlight the potential for emerging contaminants to act as increasing stressors to marine ecosystems as coastal populations and their use of pharmaceutical compounds grow.