Many people see the ocean as a sea of serenity. Simply staring at the ocean brings peace and calm. But for creatures living under the water, it's anything but peace and quiet. KPBS Environmental Reporter Ed Joyce tells us noise pollution from cargo ships and oil tankers is deafening.
The gentle sounds of the ocean ... so quiet you can hear the water lapping against the hull of the excursion boat that recorded it.
But many areas of the ocean aren't that quiet.
The bulk of global trade is carried on the seas by cargo ships and those ships create a lot of underwater noise.
Ovetz: Well you can think about it as an equivalent as if your neighbor on one side of your house was running a leafblower and another neighbor on the other side of the house was running a chainsaw and a neighbor on the other side of the house was revving their engine and they were doing it seven days a week, 24 hours a day.
Robert Ovetz is the executive director of Seaflow , a Northern California non-profit group that works to protect marine areas.
Ovetz: And that's an equivalent of what's happening in the ocean. Is more and more ships are being added to the ocean and they're introducing their noise, raising the background levels of noise in the ocean which is disrupting the way of life for some marine mammals.
We've heard how that sounds to our ears.
Let's listen now to how a ship engine sounds to whales and other fish, as recorded by Dr. Roger Brand, an acoustics expert at San Francisco State University.
The intense low-frequency noise from cargo ships is at the same frequency used by whales, seals, sea lions, dolphins and some fish - all depend on their hearing for survival.
Again Robert Ovetz.
Ovetz : What's happening is what we're finding with some species of whales, for example blue whales, that their ability to detect prey, to find mates, to find their migratory routes and even to get out of the way of oncoming cargo vessels is being disrupted by this noise.
Scientists have found at least 55 marine species are hurt by ocean noise.
Ovetz says studies show the background level of noise in the ocean has been doubling every decade since the 1950s.
Ovetz: The number of ships being introduced into the global fleet is growing as we trade more and more cheap goods and send them further distances. Whales are now having to compete with more and more ships in their habitat.
And to large ships, those whales are mere speedbumps on the ocean highway.
Ovetz: Some species of animals have been found by scientists to actually become tone death within the range of noise that overlaps that's being produced by ships with their own hearing and some are just unable to hear the ships that are approaching because of the high level of background noise in the ocean.
He says last year a record number of whales were killed by ships.
In 2006 the National Marine Fisheries Service proposed a rule that would limit ship speeds to reduce ship strikes with the endangered right whale in the Atlantic.
Ovetz says slower speeds should be required in the Pacific too.
Ovetz: What we're advocating - and we're in negotiations with a couple of shipping lines - What we're advocating is a ten knot speed limit for all cargo ships in California's four national marine sanctuaries.
Those areas are the Channel Islands, Monterey Bay, Cordo Bank and the Gulf of the Farallones.
Seaflow also wants regulations to reduce ship noise in the newly planned network of state Marine Protected Areas - including the one off San Diego's coast.
Ovetz says since there's agreement the sanctuaries should be protected, it's a good starting point for a mandatory speed limit.
He says changing ship propeller design and better insulation for the hulls would also help.
Ovetz:
These are the two major sources of noise pollution from ships. And what the interaction is that the faster the ships travel the more noise they make, the more greenhouse gases they emit, and the more whales that they strike and kill. So they're all interconnected. If you slow the vessels down you can solve all those three problems at once.
Ovetz says for the health of all sea creatures, less (tanker noise) and more (quiet ocean) may not be the same as music to the ears of undersea creatures like this blue whale (blue whale) but it would certainly help keep them from going deaf.
Ed Joyce, KPBS News.
NOTE: Seaflow's Vessel Watch Project is heading to the Gulf of the Farallones National Marine Sanctuary on Saturday September 20 and Saturday September 27. The trips allow people to use hydrophones to listen to undersea sounds.
