Reports of a great white shark "choking to death" on one of Australia's beaches have been making the web rounds this week. But there is a bit more to this story: sharks can't choke to death like humans can.
This isn't the first time this mouth-breathing mix-up has popped up: last year, media outlets buzzed about dolphins choking to death on fish.
"I'm not sure choking is the right word," marine mammal expert Dr. Chris Parsons told Earth Touch at the time. "The air passages of a [dolphin] don't travel the same route as ours."
Humans eat, breathe and gab through the same hole in our face ... which can lead to coordination problems in the back of the throat (an unfortunate side effect of mouth multitasking). When we choke on a piece of food (or let's be honest ... even our own saliva), it's because it gets into the trachea (or windpipe), blocking the flow of air to our lungs.
But in Chondrichthyans (cartilaginous fishes) like sharks, breathing has nothing to do with the throat. Instead, water moves from the mouth over the gills, where oxygen is absorbed into the bloodstream directly ... meaning that choking is out.
In order to suffocate the shark, the blockage in the oesophegus would have had to stop water from reaching the gills for an extended period of time (which is very unlikely). The more likely scenario is that the over-sized bite damaged one of the shark's internal organs, or that the shark stranded on the beach during the ordeal.
For Western Australia Department of Fisheries lead researcher Dr. Rory McAuley, there was something more interesting about this shark's demise than the cause-of-death. Earlier this year, this very animal was tagged in South Australia – over 3,000 km (roughly 1,800 miles) away from where it washed up on Coronation Beach.
Though this distance doesn't touch the record great white swim, it does show just how mobile the species is. Understanding these movements gives scientists much-needed clues into which areas would most benefit from protection plans.
Whales and Dolphins
Sharks
Sharks
