Do whales get shaken in quakes?
Underwater recordings have caught a rare insight into the impact of an earthquake on marine life.
Last year, Niwa marine ecologist Dr Kim Goetz led a programme to deploy seven acoustic moorings in Cook Strait to record the sounds of marine mammals. The aim was to learn more about their migration paths and behaviour. The seven moorings were underwater when ‘‘the big one’’ hit off the coast of Kaikoura on November 14.
The sound of the quake was too deep and close to be captured by the instruments, but they did catch an insight into underwater wildlife behaviour when disaster strikes, Goetz said.
‘‘There’s a decent amount known about how land mammals respond to earthquakes, but no-one knows anything about marine mammals underwater.
‘‘Just because it goes quiet, doesn’t mean they’re not there.’’
Goetz said analysis would take time and extra staff had been brought in to plough through the six months worth of data.
The devices recorded vocalisations from Antarctic blue whales, Antarctic minke whales and several species of the elusive beaked whale species, including Cuviers, and possibly strapped-tooth and Gray’s beaked whales.
‘‘There is just nothing known about these animals – they are very elusive, deep-diving animals which can spend over an hour on a single dive and surface for a very short time so they are not often documented,’’ Goetz said.
Goetz said the data so far showed that Cook Strait may be segregating different whale populations, with Antarctic blues primarily heard on the east side.
‘‘We have also picked up Antarctic minkes. It matches the time minkes are known to go into Australian waters, but they have never been acoustically recorded here before.’’
She said the long-term aim of her research was to assist the consent process for activities in the Cook Strait.
‘‘Right now we don’t know what’s in the area ... If we can determine what species are there and when, industry can operate in a manner that accommodates [that] species’ presence.’’