Under just the right ocean conditions, the low-frequency call of a blue whale off the coast of California can be detected by another whale off the coast of Hawaii. As part of our annual Green Issue, we report this week  on the noise impacts of shipping traffic on marine mammals that rely upon sound for their basic survival behaviors. Click on the player to hear a blue whale call, a form of communication that is often masked by shipping traffic.
Pacific Environment, a nonprofit that leads whale watch excursions featuring hydrophones to capture the underwater noise, has shared this sound clip from one of their ventures to Gulf of the Farallones National Marine Sanctuary. The call below has been sped up so that it can be detected in our hearing range.