Some Jellyfish Can Detect Direction Of Ocean Currents To Swim Against Them

Some jellyfish are not mere drifters as they also possess a unique ability that helps them swim against strong ocean currents, according to a new study. The researchers believe that the latest findings could help them better understand how these marine creatures with umbrella-shaped bell and trailing tentacles form “blooms,” large swarms of jellyfish consisting of hundreds or thousands of individuals.

Scientists said in the study published on Thursday in the Cell Press journal Current Biology that some jellyfish have a remarkable ability to detect the direction of ocean currents and to swim strongly against them. However, scientists are yet to determine exactly how the jellyfish sense changes in water currents.

“Detecting ocean currents without fixed visual reference points is thought to be close to impossible and is not seen, for example, in lots of migrating vertebrates including birds and turtles,” Graeme Hays from Deakin University in Australia and one of the lead researchers, said in a statement. “Jellyfish are not just bags of jelly drifting passively in the oceans. They are incredibly advanced in their orientation abilities.”

As part of the study, the researchers tracked the movements of barrel jellyfish with GPS loggers while they also used GPS-tracked floating sensors to monitor and record the current flows. The scientists also observed the swimming direction of large numbers of jellyfish at the surface of the ocean.

After analyzing all the data collected from various observations, the scientists managed to determine that these jellyfish are capable of swimming against the ocean currents. The researchers are also hopeful that the study’s findings can be useful in predicting and avoiding troublesome jellyfish blooms.

Although it is unclear how jellyfish decide which way to go, scientists said it is possible that the animal sense current across their body surface or they may somehow use the Earth’s magnetic field to assess the direction of the currents.

“Now that we have shown this remarkable behavior by one species, we need to see how broadly it applies to other species of jellyfish,” Hays said in the statement.