'There was a dramatic reduction in ship traffic that day. It was like being on the primal ocean.'
Rosalind Rolland of the New England Aquarium "was at sea in the Bay of Fundy on 11 September 2001 ... [when] ... noise levels from shipping fell by half, as transport was shut down in response the terror attacks" reports Environmental Research Web.
"Whales use sound as their primary sense, just as humans use sight, and their singing enables them to find food, mates and to navigate. They are believed to be able to communicate over hundreds of kilometres. But the frequencies they use largely overlap with the frequencies generated by human activities in the oceans, which have increased tenfold in volume since the 1960s, disrupting their ability to communicate" and inflicting chronic long-term stress due to the man-made noise pollution which endangers their health and life.
Cetaceans are not the only wild creatures who benefit from a drastic reduction in human activity. In that same year, 2001, Foot and Mouth Disease shut down human access to the Cornish coastline, at which point a couple of wild Choughs (Pyrrhocorax pyrrhocorax) chose to alight in the newly peaceful habitat. As Peter Marren was amused to recount in British Wildlife (14:2 pp 77-8):
"The release of captive-bred Choughs ... would, it was hoped, result in the establishment of a resident population ... However, foot-and-mouth restrictions placed the project on hold, and in the meantime some wild Choughs turned up out of the blue on the Lizard. [They] ... promptly nested and raised four chicks."
Maybe the best single thing that we humans, as a mass, could do for wildlife is to learn to sit down and shut up for a change.