Why Do Mullet Jump?
Bob McNally 06.03.15
It would seem logical for a coastal marine fish that “free jumps” as much as mullet the fish would be a terror when hooked on rod and reel.
But that’s not the case. Mullet hooked on sporting tackle rarely, if ever, leap. Yet mullet on their own accord are at times aqua jumping jacks, sailing several feet high and soaring for yards across the water. And they often make repeated leaps that would do a snook, tarpon, or ladyfish proud.
So what’s up with that? Why do mullet jump when it would seem so much easier for them to simply, well, swim?
“There are a lot of theories on why mullet jump,” says Dr. Behzad Mahmoudi at the Florida Marine Research Institute in St. Petersburg. “One is that they are escaping predators and are forced to the surface where they simply run out of water and soar into the air.
“Another theory is that they are simply happy. They leap because they like it and are content about, well, being mullet.
“Yet another idea tossed around about mullet leaping is they do it to rid themselves of parasites or sea lice.”
But Mahmoudi says the only scientific paper ever done on jumping mullet concluded that the fish were seeking more oxygen. The researcher discovered that in areas where dissolved oxygen was lacking there were more jumping mullet than in areas with better water quality.
Also, jumping is more prevalent in summer, when dissolved oxygen is more of a problem than in winter. Further, the researcher concluded that because mullet are such large school fish, in areas where dissolved oxygen is lacking mullet are competing for what little bit of oxygen there is in the water–so they jump to get more of it.
“I’m in agreement with that research paper because it makes the most logical sense,” adds Dr. Mahmoudi. “So many times in warm weather you see a mullet jump and there are dozens, hundreds, even thousands of fish in a school nearby. That many fish compete aggressively for dissolved oxygen, and it figures some fish simply need more space–in this case the air–to breathe.”