Mashable has an alien communication story with an aquatic twist. SETI and the Alaska Whale Foundation practiced for first contact by spending 20 minutes “conversing” with a humpback whale named Twain:
The researchers recorded the call used to engage Twain in “conversation” when they ran into a group of nine humpback whales near their research boat in Alaska. One of the whales was later identified as Twain, a 38-year-old female whale who’d been identified by previous researchers. (The team obtained a permit from the National Oceanic and Atmospheric Administration to conduct this latest whale communication study in a minimally invasive way.)
The scientists recorded the calls with members of the crew of their vessel, the Glacier Seal, along with James Crutchfield, a professor of physics at the University of California, Davis. (Crutchfield co-authored a separate study on the encounter with Twain, which was not written by the other members of the team and focuses on different methods of analyzing the interaction. It has not been published in a scientific journal.)
The team recorded a high-quality call made by one of the whales called a “whup” or “throp,” which researchers think is a “contact call” used between mother and calves to help them locate each other, and is generally used by whales when feeding, as well as in many other contexts. Whales use their “songs” to attract a mate, but non-song calls such as the “whup” seem to be used socially.
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After recording the whale calls, the very next day the team spotted Twain on her own near their boat. Using underwater speakers, they played back the recording of the “whup” call, and after the first few calls, she started responding with a “whup” of her own. During the interaction, the researchers varied the time between the calls. Analysis showed that Twain sometimes matched the changes, particularly towards the beginning of the interaction. She also produced a few calls after the researchers stopped playing their recorded “whup” before eventually swimming away.
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You can read more about the study here, in Peer J Life and Environment.