Surfing Sharks

“Just keep swimming…just keep swimming….”

This is Sandra Tsing Loh with the Loh Down on Science.

Imagine having to constantly walk in order to breathe. Sounds exhausting — but that’s a shark’s reality! Sharks MUST keep swimming to get oxygen over their gills. Do they EVER get a break?

Yannis Papastamatiou from Florida International University and colleagues swam with the sharks to find out. Using both tracking tags and underwater filming, they monitored behavior of almost forty grey reef sharks. 

And? When they weren’t hunting, the sharks gathered in areas with predicted vertical currents. These areas, called updraft zones, appear when currents hit upward slopes of the ocean floor. Based on a computer model, these updrafts reduce a shark’s energy output by up to fifteen percent. 

Every shark needs a timeout! This may explain why they cluster together in areas with strong currents. The team hopes this will guide conservation efforts to protect updraft locations in the ocean. 

Sharks take their power naps by surfing the currents! As for me? I prefer my memory foam! 

Reference: Papastamatiou, Y. P., Iosilevskii, G., di Santo, V., Huveneers, C., Hattab, T., Planes, S., Ballesta, L., & Mourier, J. (2021). Sharks surf the slope: Current updrafts reduce energy expenditure for aggregating marine predators. Journal of Animal Ecology. Published.