And, of course, this add-on:Human-generated noise, predominately caused by shipping, has been rising since at least the 1960s in line with trends in global trade. Now researchers are concerned that this increased noise is masking vocal communication between marine mammals, such as whales and dolphins, limiting the range over which they can communicate.
Obviously, the seal never heard it coming . . .
In response to increased levels of noise in the oceans, recent research suggests that marine species may be changing their behaviour; something which could impact on individual survival and population levels.
Sailing ships are much quieter, but it is hard to carry meet demand for all those iPads, etc when you are facing a transit lasting - what? - several weeks if not months. The sail boat record to Hawaii from LA is about 6 days and that boat wasn't hauling Nissans or Kias.There is also growing evidence to support the idea that climate change will also impact noise levels in the oceans as much of the carbon dioxide linked to global warming is absorbed into sea, causing it to become more acidic. This increased acidity reduces the ocean’s ability to absorb sound, meaning global noise levels may rise in line with trends in carbon dioxide levels.
Personally, I blame "continental drifting" - and whoever caused the continents to be too far apart to allow us to use high speed rail . . . . .
Bring back Pangaea!
It might also help if we could get those damn noisy shrimp to stop their cavitation ruckus and shut up.
At the time of Columbus, during the Mideavel Warm Period, there was no year round Arctic Ice Pack. Yet the Polar Bears and whales seem to have survived several hundred years of that. I suspect there are fewer ships sailing the seas than there was right after WWII. When the 1000 foot ore carriers were introduced into the Great Lakes, each one, because of her larger capacity, faster speed, and self unloading gear, replaced 10 old style ore boats. I would think the same would apply to sea going freighters as well. The large ships have huge, slow turning, screws as well, and Diesel powerplants with mufflers, rather than oil power with ventilation blowers screaming away. Could the greater sound level be because we now have better equipment for analyzing the sounds in the oceanic basins?
ReplyDelete