Imagine living in a world where sound travels more than four times faster than we experience and can carry many thousands of miles. That’s what life’s like for creatures living in the sea.
I’m sitting with Caroline Carter, from the Scottish Association of Marine Science, on the shore of Loch Creran, a few miles north of her laboratory at Oban.We’re looking out on a shale-blue sea, rippled by a light wind blowing from the opposite shore. “Sound travels at around 1,500 metres per second in
water,” she tells me, “and the low-frequency songs of whales can be heard from one side of the Atlantic to the other! “For marine mammals, hearing is their key sense,” says
Caroline, who’s in her first year of an SNH and Scottish Environment Protection Agency funded PhD to investigate whether sea mammals can hear, and therefore avoid, marine renewable devices. “There’s actually very little information about sound levels
in tidally active and coastal areas, as most of the work has been done in areas of deeper water where the military have been interested in sonar devices,” explains Caroline. Her research involves sending hydrophones out to drift
with the currents and measuring the noise landscapes of these areas. This will fill in some of the gaps in our understanding of noise in the marine environment. It should also help with designing and deciding where to put marine renewable devices to reduce the effects on marine mammals to a minimum. But it’s not just in the area of underwater noise that
there’s a lot to discover.We actually know surprisingly little about our coasts and seas, despite how near they are and their importance to our economy.
1
Marine mammals, such as seals, have an incredibly keen sense of hearing.
2
Caroline Carter braves the west coast weather to position drifting hydrophones that can measure underwater sound.
2 Loch Creran
EMEC test site
www.snh.gov.uk
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