A new study conducted by an international team of marine biologists shows that jellyfish have incredibly advanced orientation abilities which include sensing currents and swimming against them whenever necessary. The findings challenge the common belief that these creatures would just let themselves drift with ocean currents.
According to the new study, jellyfish don’t just drift with the current. Actually they swim against it whenever they feel it drifts them away. Researchers explained that the newly found style of orientation may reveal the mysterious mechanism of how jellyfish form “blooms.”
The blooms include between hundreds and millions of jellyfish that compactly swim in an area for months giving headaches to fishermen as well as beachgoers.
The study couldn’t reveal the exact mechanism through which a jellyfish can sense ocean currents. Some researchers speculated that it may sense the shear of water on their bodies.
The findings were published this week in the journal Current Biology.
For their study, the team tagged with GPS data loggers 18 barrel jellyfish in the Bay of Biscay, off the coast of France. The loggers monitored location, acceleration and body orientation.
Prof Graeme Hays, co-author of the study and researcher at the Deakin University, Australia, explained that attaching the tags to the jellyfish was much easier than attaching them to other marine animals.
We loop a cable tie around the peduncle that joins the swimming bell to the trailing arms. It takes seconds, and the tag stays on indefinitely,”
Mr. Hays explained.
The team also used floating GPS devices to measure the current orientation in the area. The loggers revealed that jellyfish do not remain passive when the current drifts them. Instead they actively swim against it to maintain their initial position within the bloom.
Later, researchers used the collected data about both jellyfish and currents to create a computer model of a jellyfish bloom’s movement pattern in the ocean.
Prof Hays disclosed that the model allowed him and his fellow researchers to learn that “active and directed swimming helps maintain blooms.” According to the computer simulation, jellyfish within a bloom do not let themselves being dispersed or washed ashore by currents.
With this knowledge of their behavior we can start to have some predictive capability for bloom dynamics,”
Prof Hays said in a recent interview.
However, the computer model couldn’t help researchers understand how jellyfish navigate. The team now believes that jellyfish either sense marine currents across their bodies, or make use of the Earth’s magnetic field for space orientation like sea-turtles do.
By accurately forecast jellyfish blooms, scientists currently hope that their findings would help people contain them.
Image Source: Fineartamerica
