Sea urchins are resilient to microplastic pollution

Our study, published yesterday, is the 1st to investigate the responses of adult sea urchins to the effects of microplastic pollution. We wanted to know whether short-term storm events would impact the physiology of animals found on the seabed. Storms can resuspend microplastics trapped within sediments back into the overlying seawater.  In addition, increased precipitation (rainfall) occurring during storms can decrease the salinity of seawater. Collectively, these storm event conditions could be stressful for marine animals. To determine how these conditions might impact the physiology of marine animals, we mimicked these stressors in the laboratory and looked at how sea urchins responded. It was encouraging to see that they showed resilience, but we did observe that the sea urchins ate some of the plastics (pictured fluorescing above), adding them to the ever growing list of marine species recorded to ingest microplastic particles.

Here’s some more info about our study:

Suckling, CC & Richard, J. 2020. Short term exposure to storm-like scenario microplastic and salinity conditions does not impact adult sea urchin (Arbacia punctulata) physiology.” Archives of Environmental Contamination and Toxicology.

Abstract: The effects of microplastic pollution on sea urchins has received little attention despite their ecological and economical importance. This is the first study to focus on adult sea urchins (Arbacia punctulata). These organisms were exposed to storm-like sediment resuspension of microplastic concentrations (9-μm polystyrene 25,000 spheres L⁻¹) combined with salinity reductions (salinity 25 vs. 33) associated with high precipitation. Urchins were exposed to these parameters for 24 h before assessing righting times and for 48 h before assessing oxygen consumption rates. No significant impacts on urchin physiology were observed showing resilience to short-term exposures of storm-like induced microplastics and salinity. No microplastic particles blocked the madreporite pores indicating the active removal of particles by cilia and pedicellariae. Gut tissue samples indicated consumption of microplastics. Studies on more species are urgently required to determine their responses to plastic pollution to inform management decision-making processes.