Diver Says Four Giant Manta Rays Tangled In Fishing Line Each Approached Him For Help

While on a diving expedition in Costa Rica's Bat Islands early last month, Dr. Brian Thompson had one of the most surreal underwater encounters ever caught on film. Midway through one dive, an enormous female manta ray tangled in fishing line approached him, appearing to be asking for help - to which Thompson readily obliged.

click to play video

Before that now-famous rescue even took place, Thompson had another, no less memorable encounter on one of his his first dives of the trip. It all began when a manta ray swam near and seemed to beckon him to follow.

"He was a fairly large male swimming along with us. But then he suddenly stopped in front of me, which was kind of odd. When he did that, I stopped too, and he sort of looked at me. I got the impression that I was suppose to come behind him," Thompson says.

"He started swimming in one direction, and I swam as fast I could behind him. Well, after a while he stopped, then turned and swam quickly out to sea. But as soon as that happened, another ray came toward me from the direction he was going, and she had fishing line wrapped around her. She sort of presented the line to me, so I cut it off her."

Incredibly, just moments later, Thompson says a second tangled manta ray came into view, this one tangled in mesh from a fishing net. He cut her free as well.

"When I got back on the boat, I was ecstatic. I've been diving for ten years, so to have an experience like that was a moment of a lifetime. I was so excited," says Thompson. "But that time, nobody saw me."

It was on a dive in the same area two days later that his rescue of yet another female manta ray was captured in the film above. But Thompson says moments before the video begins, he had been circled by that same large male manta from before.

"It felt like he recognized me. When he saw me, he relaxed. Then, a moment or two later, the ray from the video came and swam directly at me, giving me access to the strings wrapped around her."

After cutting those lines away, the female lingered around Thompson and the other divers for nearly thirty minutes. Thompson says she seemed visibly relieved to be freed of the ropes that had been cutting deep into her skin. But that wasn't the last time he'd see her, nor the last time he'd be called upon to help her kind.

"Five days after that, we went to the Bat Islands again, and I saw the female manta from the video. There was a remora on her back sitting right on the wound, cleaning it out which would help protect it while it healed. The manta was very happy and was swimming around, full of energy," Thompson says.

"A few minutes later, after she swam away, there was a fourth manta. He had six wraps around him on one side and two on the other. I got some of the wraps, but he started to get really fussy, so we let him go."

By then, Thompson was beginning to suspect that his multiple encounters with tangled manta rays may not be just random chance.

"It felt like the manta in the video may have called over this one to have him get rid of the netting that was there," says Thompson.

"There was the sense that the mantas seemed to be communicating with one another. I think the male from the first day had brought me to the two injured females. I think divers had helped them in the past, and he thought, ‘Hey, here's a diver. Maybe if I bring him over here to the females who are hurting, he could help them.' But I don't know for sure."

"When he came to me, and led me to the injured females, I wondered if he recognized that I was carrying a knife. I wear mine right on my belly. I'm wondering if he saw that and knew from past experience that it could cut away rope.

"And to have it happen again two more times - and it wasn't that they were going to the other divers, they were coming specifically to me - it would be such a coincidence. Either I'm the luckiest man in the world, or they were communicating."

Thompson admits his suspicion that these animals knew to come to him for help, and were alerting others to do the same, is based more on sense than science, but a leading expert on manta ray behavior and cognition believes his interpretation of these events could in fact be correct.

Zoologist and neuroscientist Dr. Csilla Ari, director of the Manta Pacific Research Foundation, tells The Dodo that the species may have indeed communicated with one another that Thompson could help them.

"Manta rays have been reported to demonstrate curiosity and interest toward divers. It is possible that not only their general curiosity attracted the mantas toward the diver, but that this was the result of their complex social behavior and they were able to learn from each other where to get `cleaned` from the fishing nets," says Dr. Ari.

"Manta rays often visit places where ‘cleaner fish' gather in groups, so I think it might be possible that they can somehow convey this important information to each other, `where to get cleaned from those life-threatening fishing line-parasites.`"

And in the case of these manta rays, that would have been Brian Thompson.

Ultimately, scientists have only begun to scratch the surface when it comes to understanding manta rays, but Dr. Ari says that ongoing research is revealing them to be far more complex and intelligent than most people ever imagined.

"We know that they have the largest brain of all fish, and the brain anatomy and behavioral observations of manta rays indicate that they are more social than solitary. Those brain parts which are especially enlarged in manta rays imply strong learning abilities and complex social life," says Dr. Ari.

"Recently, I have discovered that they are able to rapidly change the coloration of certain body markings, which is very likely a form of communication. This new finding also highlights how little we know about their basic biology, physiology and behavioral repertoire."