How do dolphins and whales cope with the bends? What about seals? And sea snakes?

Brainyblonde

Whales don't get the bends like humans do, even though they make relatively deep dives with quick returns to the surface. One whale was recorded as routinely diving to 300 metres. Two factors protect whales from getting the bends. At depth, the air is compressed to a very small volume. As water pressure increases, the ribs, most of which are not strongly connected to the breastbone, collapse inward compressing the lungs and forcing air into nonabsorptive portions of the lung. Lung compression also reduces blood flow to the lungs. Both processes, and perhaps others, minimize absorption of air into the blood, preventing excessive quantities of nitrogen from dissolving in the blood. As the whale ascends, the compressed air expands again, refills the lungs, and blood flow and gas exchange resume. Also, the air the whale begins with is the air it comes up with, unlike SCUBA divers who are taking in compressed air (and compressed nitrogen) during the dive. http://www.royalbcmuseum.bc.ca/programs/whales/t-activity-5.html Nov 13 06, 7:20 PM

Arpeggionist

Well, that explains animals who spend their entire lives in the water, but what about those who spend so much time on land? Also, there are birds who only dive into the depths for the purpose of catching food, and they wouldn't have developed the same anatomical defenses to the bends as whales would. Nov 14 06, 12:58 AM

What-A-Mess

Birds that dives to depths???? Ten feet or less, maybe. Nov 14 06, 1:06 AM

Baloo55th

And the rest - 565 metres according to http://www.aad.gov.au/default.asp?casid=2881 The Emperor Penguin can dive for up to 22 minutes, but mostly only stay down for 3 to 6 minutes. They frequently go down to 100 - 200 metres. These figures have been obtained by equipping penguins with time/depth recorders. Nov 14 06, 7:45 AM

Arpeggionist

Well, that's the point. How do they do it and not feel sick when they get back to the surface? Nov 14 06, 8:56 AM

SOTHC

Sperm whales do get the bends according to http://www.bioedonline.org/news/news.cfm?art=1455 Nov 14 06, 9:16 AM

What-A-Mess

Ah. Did not think of those birds! Nov 14 06, 9:25 AM

SOTHC

Birds with 10 feet would find it difficult to dive W-A-M and I wonder if there is a marine version of Viagra to help those sperm whales suffering with the bends. Nov 14 06, 3:05 PM