Shark Week Part 2: Do Sharks Sleep?
Do Sharks Actually Sleep?
Shark Week 2016 is finally upon us, filling our TV sets with endless shark action and excitement since Sunday, June 26. The programming includes tank diving, night stalking and rows of grisly teeth, but no sharks sleeping. All animals need some form of rest, but do sharks actually sleep?
Do Sharks Have To Just Keep Swimming?
Sharks are notoriously difficult to study due to their natural elusiveness and shrinking populations. Despite decades of research, there is still a lot we don't know about sharks - including if and how they sleep.
Some of the confusion stems from the unique way that sharks breathe. We know that sharks need water continually moving over their gills in order to process oxygen and stay alive. Does this mean they never stay still and are therefore unable to stop and sleep?
Shark's Sleeping vs. Sharks Resting
Some sharks have been found motionless in caves and presumed to be sleeping. But, scientists have proven that the shark's eyes can still follow a diver even while the shark is motionless, implying that the shark isn't truly asleep, but is merely resting. Really, it depends on what your definition of "sleep" is, and marine biologists around the world are still researching to learn the exact biological mechanisms at work within the "resting" shark.
No Rest for the Best
Sharks are the rulers of the ocean, and only a few shark species, such as the nurse shark, are able to take breaks for extended periods of time. The Florida Museum of Natural History is home to the Florida Program for Shark Research which focuses "on shark research, fishery management and conservation." Their website provides a list of shark basics, including information about whether or not sharks sleep.
They summarize the "rest" vs. "sleep" debate like this: "Sharks do not sleep like humans do, but instead have active and restful periods."
So, do sharks sleep? No, not like we do.
Since sharks don't sleep, they have more time to celebrate...
...that it's finally Shark Week 2k16.