Where do the fin whales from Elephant Island spend the winter?
While analysing the underwater recordings, the research team discovered another interesting detail: the 20-Hz pulse also contains an accompanying sound with a frequency of 86 Hz. This in turn resembles the fin whale calls that Chilean marine biologists had previously recorded off the coast of central Chile – particularly at the time of year when the instruments at Elephant Island rarely recorded the sounds of the baleen whales. Was it possible that the same whale population produced the sounds in both regions, and that it moved back and forth between the South Shetland Islands, which Elephant Island belongs to, and the Pacific coast of Chile?
“It is believed that fin whales produce population-specific accompanying higher frequency sounds, which can be used to distinguish between different populations. If this is the case, we can likely conclude that those fin whales that inhabit the waters surrounding Elephant Island in the southern summer may give birth to their calves in the warmer waters off Chile’s Pacific coast later in the year, and that these whales regularly travel between the two regions,” says Burkhardt.
However, to verify this, further studies are required. To this end, the Bremerhaven-based research team has installed additional underwater recording devices, which will tentatively be retrieved in 2022, in the vicinity of the island. The marine biologists are currently analysing their underwater recordings from the period since 2016. And the first excerpts are promising: in the summers after 2016, Elephant Island continued to be a favourite gathering place for fin whales.