This week’s dramatic rescue of a young male great white shark that stranded on a Cape Cod beach demonstrates an effective way to resuscitate a stressed shark, and reminds us that regular CPR could never work on these large predators.
While the shark-saving technique should be left to experts, it shows how sharks breathe and why being out of water — even for short periods — causes such physical trauma.
Here is the shark rescue footage from earlier this week:
Greg Skomal, a biologist from the Massachusetts Division of Marine Fisheries, who helped with the rescue, told CBS Boston that when he and his colleagues approached the great white, it was “still alive but very sluggish, barely moving, so we put a tag on it, and then resuscitated the shark by putting a bridle around it, and with the harbormaster’s help, put it out into deeper water where we were able to resuscitate it and let it go.”
A similar method was used to save a tiger shark last year in waters off of Australia.
Under normal conditions in the water, most sharks breathe using a process known as “ram ventilation.” They rapidly swim forward, forcing water into their mouths and over their gills. The gills then extract dissolved oxygen from water and excrete carbon dioxide.
When sharks and other fish wind up out of water, their gills can gradually collapse under pressure. (In water, gills are near weightless.) Because there is not enough surface area for diffusion to take place, the shark cannot properly breathe. The great white on the beach was close to suffocating to death.