The Scents of Pollution: Fish Smell Our Synthetic Waste

Olfaction is essential for fish survival.  The highly sensitive olfactory neurons that enable olfaction are exposed to the environment and are known to be impacted by synthetic organic contaminants. Altering olfactory neurons has the potential to affect downstream olfactory mediated behaviors.  Our lab investigates contaminant impacts on olfaction at the neuron and organism level. At the neuron level, electrophysiological recordings are used to determine whether contaminants either (i) act as odorants or (ii) affect the perception of natural odorants.  At the organism level, avoidance or attraction behaviours before/during/after contaminant exposures provide insight on how tissue level responses translate to fish activities.  We have shown that changes to both olfactory sensitivity and associated behaviors are dependent upon the type of contaminant, and recently, the contaminant mixture.  Mixtures such as wastewater effluent that contain personal care products, pharmaceuticals and herbicides, appear to impair olfaction in a manner similar to mixtures containing herbicides alone. However, behavioral changes associated with both mixtures are quite different: wastewater effluent may evoke avoidance whereas herbicides may evoke attraction.  Our overarching goal is to use fish as the modern day ‘canary in the coal mine’ to detect problem contaminants in global waters.