We tread silently as possible, but the island has many watchful eyes. Perched above us in an ancient spruce sits a judgment of ravens, who begin delivering raucous reprimands. Emerging onto a mossy ledge, we blink in the morning sun. Fifty feet below a flock of turnstones and tattlers takes to the air. Whirling above the Frederick Sound, the chattering birds draw our gaze to the whale spouts beyond. A mysticete mist hangs in the air, and upon our ears fall the blowing, trumpeting and breaching of humpback whales.
Similar to the watch-keeping birds, we too maintain our vigilance at Five Finger Lighthouse. In past summers Michelle Fournet (Oregon State University) utilized the lighthouse and a pair of hydrophones - underwater microphones - to record and observe foraging humpback whales. She discovered a surprisingly diverse repertoire of social sounds and found evidence that they serve a communicative purpose, perhaps to maintain spatial proximity.
This summer we are pleased to again collaborate with the Juneau Lighthouse Association. A new hydrophone has been built by Cetacean Research Technologies, and is being installed with assistance from the Marine Exchange of Alaska. This system remains anchored by buoy or deployed by boat and sends a wireless signal carrying underwater sounds back to the lighthouse. We plan to continuously monitor the marine environment and make these sounds available live on the Internet. Ultimately, we will gather sounds over a broad range of behavioral contexts and use playback experiments to test our notions concerning call function.
We are pleased that the sounds of Alaska’s underwater wilderness are again coursing into our lives. By listening to these magnificent beings, we become their watch keepers and a voice for ocean health.