Why is photonics (DAS) important for Blue Whales and climate tracking?
Why is photonics (DAS) important for Blue Whales and climate tracking? To find the answer, I'm on a boat just off the coast of #Brisbane, #Australia. I am with my wife and daughter on a tour to spot whales. Stay with me, because, as the video explains, there is a photonics connection. Whales are the largest and most intelligent creatures in the ocean. Recently, marine biologists discovered that during their long lives they also capture tonnes of carbon from the atmosphere, the IMF says has the equivalent economic value of US$1 trillion. Wherever whales are found, so are #phytoplankton. These tiny creatures contribute to at least 50 per cent of all the oxygen in our atmosphere. They also capture about 37 billion tonnes of carbon dioxide. Whale poop has a multiplier effect on phytoplankton as it contains iron and nitrogen, the elements phytoplankton need to grow; so, the more whales, the more oxygen. The problem is nearly half of the great whale species are classified as endangered. With slightly more than 1.3 million whales in the ocean today, numbers have shrunk to just a quarter before commercial whale hunting started. Because whales are highly vocal, acoustic monitoring is a very effective way for us to assess the impact of global warming on our oceans. But despite global efforts by researchers to track the movement of whales, conventional hydrophone recorders are sparse, expensive and unevenly spread. But photonics could change this. For the first time, new studies demonstrate that the same undersea fibre optic cables used for data traffic can be repurposed. The technique is called #DistributedAcousticSensing (DAS), well-known to Optica members busy with pipeline inspection. So by using dark fibre found in all sub-sea telecommunication fibre optic cables, DAS can record vocalizing whales along a 120 km fibre cable with a sensing point every 4 metres. This approach is considerably lower cost, providing terabytes of real-time data for analysis every day Putting such detailed information into the hands of researchers and decision-makers could have a significant impact. Here in Australia, companies like terra15 in Perth lead in distributed acoustic sensing. And as their demo shows - photonic technology could be crucial in tracking the changing movement of the largest animal ever to live, the blue whale. Mind you, the whales we’re seeing on this trip are exciting enough. Isn’t photonics and nature wonderful? Now back to my holiday!
