Does the environmental condition affect the tolerance of the bivalve Anomalocardia flexuosa to different intensities and durations of marine heatwaves?

Populations of the clam Anomalocardia flexuosa, subjected to different pollution conditions, were experimentally exposed to marine heatwaves of actual and future intensities and varying durations. We measured physiological and biochemical biomarkers and survival rates of the species under simulated heatwave events of 7 and 11 days. We observed that both the response of A. flexuosa to heatwaves and its baseline values of biomarkers were distinct between populations, demonstrating that the previous exposure to contaminants negatively interferes with the thermal tolerance of this bivalve. The duration and intensities of heatwaves here tested represent a considerable challenge for the survival of coastal bivalves. Our results suggest that the predicted increase in the ocean's average temperature and the frequency and intensity of marine heatwaves, as well as urbanization and increasing occupation of coastal regions, are factors that synergistically make A. flexuosa increasingly vulnerable over the decades.

Automated summary

The research found that populations of the clam Anomalocardia flexuosa subjected to different pollution conditions showed distinct responses to heatwaves and baseline values of biomarkers, with previous exposure to contaminants negatively affecting their thermal tolerance. The duration and intensities of heatwaves tested posed a considerable challenge to the survival of coastal bivalves. The predicted increase in the ocean's average temperature, frequency, and intensity of marine heatwaves, as well as urbanization and increasing occupation of coastal regions, make A. flexuosa increasingly vulnerable over the decades.