Flicking fibres: Microfibres act as sensory disruptors in a marine crustacean

Anthropogenic inputs to the environment-including microplastics and microfibres-are global stressors known to impair multiple facets of organismal biology. However, the effects of these pollutants on sensory structures remain critically understudied. Sensory systems mediate organism-environment interactions, and pollution-derived impairment at these interfaces may cascade through bioprocessing, from information acquisition to behaviour and ultimately fitness. Microfibres, in particular, pose an additional threat, potentially physically obstructing sensory organs and chemically interfering with sensory processes. Using an invertebrate model of sensory biology, Pagurus bernhardus, we tested whether dryer lint-a complex, heterogeneous mix of treated microplastic and cellulose fibres, and other anthropogenic contaminants-acts as a sensory disruptor with ecological consequences. Using a repeated-measures design, we exposed crabs to either microfibres or control seawater and quantified two sensory behaviours (antennular flicking and grooming). We examined the extent of microfibre transfer from contaminated to clean seawater and used scanning electron microscopy (SEM) to image ablated antennules and assess structural fouling. Finally, we measured the effects of contaminant exposure on foraging latency, linking microfibre exposure to energy gain and fitness outcomes. Microfibres were transferred between conditions and led to antennular fouling. Exposed individuals increased rates of antennular flicking, but not grooming, and had significantly longer foraging times, consistent with evidence of chemosensory impairment rather than mechanical obstruction. Together, these results demonstrate that microfibres can impair information acquisition and degrade sensory performance. Our findings identify microfibre pollution as a potential source of sensory disruption that may alter energetics and fitness, revealing a previously overlooked mechanism by which global anthropogenic pollutants may reshape ecological interactions and ecosystem functioning.