Oysters have feelings too and neglecting them could have implications for their health, as well as for that of other sea animals suggests a recent study research done in France. The scraping and shaking that farmed oysters ( Crassostrea gigas ) experience during grading and transportation is stressful and stressed oysters are more susceptible to bacterial infection. Researchers measured levels of the stress hormone noradrenaline and found its production and mortality much higher in shaken oysters. Unshaken oysters injected with noradrenaline were also far more susceptible to a particular bacterial infection than normal oysters.