Antarctic’s opera

SOUND: SCIENTISTS CAN TELL A LOT Spectrograms tell story about movement of marine mammals, geophysics.

In freezing Antarctic waters, amid bobbing chunks of floating ice, the hums, pitches and echoes of life in the deep are helping scientists understand the behaviour and movements of marine mammals.

“There are species which make impressive sounds, literally like Star Wars, they sound like spaceships,” said Colombian scientist Andrea Bonilla, who is carrying out research with underwater microphones off Antarctica’s coast.

The biologist from Cornell University in New York submerges a hydrophone covered in titanium and attached to a buoy, into the frigid water.

Her team, part of a Colombian scientific expedition to the Southern Ocean, picks up devices they left a year prior for analysis.

The research also gives scientists data on how human activity and environmental pollution affect sea life in one of the best conserved parts of the planet.

A humpback whale comes to the surface for some air during a stint in the region for the austral summer – a time for feeding and building up energy before their massive trek to warmer climes in the breeding season.

Bonilla describes the first time she heard whale song underwater as having “changed her life”.

Scientists have warned rising ocean temperatures are impacting whales’ body clock and migration cycles, as well as killing off krill, the tiny crustaceans they need to fatten up.

Whale communication has been found to be impacted by noise from shipping and other activity, which can disorient them.

“In a marine environment sound is essential,” said Bonilla, adding any interruption can affect some species ability to hunt.

Weddell seals and leopard seals also emit high-pitched songs in different tones and often harmonious compositions.

The scientist will use spectrograms – a visual representation of sound – to extract information not only about the movement of marine mammals, but also geophysics.

The hydrophones also capture low frequencies that can pick up the sounds of earthquakes or melting ice.

The research also supports a proposal pushed by Chile and Argentina since 2012 to convert the Antarctic Peninsula into a protected marine area. –

Pictures: AFP SOUND BITES. Colombian Navy divers take samples on Livingston Island in the South Shetland Islands last month.

PRISTINE. An iceberg at the Gerlache Strait, which separates the Palmer Archipelago from the Antarctic Peninsula, in Antarctica.

SPOTTED. A leopard seal, or Hydrurga leptonyx, on Livingston Island.