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Jun. 29th, 2015 at 11:10 AM
Ah, the fresh exhilarating smell of ocean..... dimethyl sulfide.
Imagine you are standing on a beach, the soft sand between your toes; looking out across the miles of perfect blue ocean, with a gentle sea breeze blowing through your hair. You take a deep breath in, absorbing all that blissful pure sea air. It is uplifting, it is invigorating, it is exhilarating, it is dimethyl sulphide (DMS).
Imagine you are standing on a beach, the soft sand between your toes; looking out across the miles of perfect blue ocean, with a gentle sea breeze blowing through your hair. You take a deep breath in, absorbing all that blissful pure sea air. It is uplifting, it is invigorating, it is exhilarating, it is dimethyl sulphide (DMS).
In the ocean, many of the creatures make a chemical called DMSP (P for Propionate), which is then converted to DMS. These creatures then deposit the DMS into the ocean around them. This could explain how some birds can find their next meal in the apparently featureless ocean. In fact, DMS is part of the natural ‘smell-scape’ of the Southern Ocean.
DMS can act as both a ‘cry for help’ and a ‘homing signal’. For example, tiny phytoplankton release DMS when they are attacked by bigger creatures, such as zooplankton. Some species of crustaceans and seabirds (e.g. petrels and shearwaters) can sense very low levels of DMS and will swoop in, following the smell, to eat the bigger creatures while they are in the act of eating the plankton. The phytoplankton call for help and the petrel flies in and eats their attackers.
Even tiny creatures like bacteria release DMS. In fact, a huge quantity of DMS is released from the ocean—about 30-50 million tonnes per year. The oceans make about 50 percent of all the biological sulphur that gets dumped into the atmosphere. In turn, about 90 percent of the sulphur that comes from the ocean is in the form of DMS. Scientists have been studying how bacteria make DMS and found some genes that control its production—and that DMS could cause the seaside smell.
So, now to being back on that beach, DMS in high concentrations is an irritant to the eyes and mucous membranes—but you’re safe with the levels that you usually get at the beach. Along with various other chemicals including those coming from algae, ice cream, doughnuts, sunscreen, DMS contributes to that very familiar scent of sea air. Some people love it, some don't.
I certainly do.
~ JM
Image Credit: My own taken at Shoalwater Beach, Perth, Western Australia. 23/05/2015
More Info:
Dimethyl sulfide: http://rsc.li/1HeyUfo
Charles, R. J., et al., ‘Oceanic phytoplankton, atmospheric sulphur, cloud albedo and climate’, Nature, 22 April 1987, pp 655-661
Todd, Jonathan D., et al., ‘Structural and regulatory genes required to make gas dimethyl sulfide in bacteria’. Science, 2 February 2007, pp 666-668
(from The Earth Story FB page)
DMS can act as both a ‘cry for help’ and a ‘homing signal’. For example, tiny phytoplankton release DMS when they are attacked by bigger creatures, such as zooplankton. Some species of crustaceans and seabirds (e.g. petrels and shearwaters) can sense very low levels of DMS and will swoop in, following the smell, to eat the bigger creatures while they are in the act of eating the plankton. The phytoplankton call for help and the petrel flies in and eats their attackers.
Even tiny creatures like bacteria release DMS. In fact, a huge quantity of DMS is released from the ocean—about 30-50 million tonnes per year. The oceans make about 50 percent of all the biological sulphur that gets dumped into the atmosphere. In turn, about 90 percent of the sulphur that comes from the ocean is in the form of DMS. Scientists have been studying how bacteria make DMS and found some genes that control its production—and that DMS could cause the seaside smell.
So, now to being back on that beach, DMS in high concentrations is an irritant to the eyes and mucous membranes—but you’re safe with the levels that you usually get at the beach. Along with various other chemicals including those coming from algae, ice cream, doughnuts, sunscreen, DMS contributes to that very familiar scent of sea air. Some people love it, some don't.
I certainly do.
~ JM
Image Credit: My own taken at Shoalwater Beach, Perth, Western Australia. 23/05/2015
More Info:
Dimethyl sulfide: http://rsc.li/1HeyUfo
Charles, R. J., et al., ‘Oceanic phytoplankton, atmospheric sulphur, cloud albedo and climate’, Nature, 22 April 1987, pp 655-661
Todd, Jonathan D., et al., ‘Structural and regulatory genes required to make gas dimethyl sulfide in bacteria’. Science, 2 February 2007, pp 666-668
(from The Earth Story FB page)
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