Researchers analysed noise levels in Canada’s Bay of Fundy during a period of reduced ship traffic following September 11, 2001 .
Researchers measured stress-related metabolites from fecal samples before and after September 11, 2001. Reduced traffic after September 11 led to a six decibel decrease in underwater noise levels and a corresponding decrease in stress-related metabolites. As shipping traffic increased again in subsequent years, noise levels were higher and so were levels of stress related metabolites.
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