At depths of up to 100 feet, CCMI’s research team implanted 30 individual lionfish with tracking devices, tracing their movements both horizontally and vertically along the reef.
Research scientist Dr. Alli Candelmo shared findings from phase one of the tagging project, including some surprising evidence of predation.
“It’s not what we were looking for in the study, so we are seeing a lot higher mortality in these lionfish than we expected,” she said, via Skype from the CCMI research station in Little Cayman.
She said lionfish tracked in phase one of its lionfish tagging programme were more vulnerable to predation than expected.
“We did lose a percentage of our fish the night of tagging, and we associate a lot of losses with predation. We were actually able to track some of the fish that we lost in the predator, so you could see that it was no longer a lionfish, it was a tag in the stomach of a predator moving fast across the reef,” she said.
Dr. Candelmo said a total of 30 tags were deployed in phase one, surgically implanted in the lionfish by research divers at depths of up to 100 feet. She said data was collected from 22 fish.
“At the moment the batteries are beginning to die, so we only have about five that are active at this stage, and that was expected, but we did lose nine fish over the past four months, so between 22 days post tagging and 140 days post tagging, we have had mortality of the fish, and again we are associating that with also predation,” said Dr. Candelmo.
She suspects some of the initial vulnerability may be due to the after-effects of surgery, and doesn’t think the surgeries themselves are a factor in mortality rates. In phase two, researchers are confining the tagged fish for their own safety until they recover.
“That gives us the ability to say ok, we are not going to release the fish right now because there is a predator actually waiting to get it,” she explained.
Another 30 tags are planned for phase two, which will continue tracking the movement pattern of the fish from deep to shallow water. But with evidence of predation, a curious mind is always looking one step ahead.
“The really interesting thing is also to look at what the natural mortality rates are, and then also potentially try to figure out which predators are eating the lionfish, so that will be the next step,” said Dr. Candelmo.
Dr. Candelmo told Cayman 27 the habits of the individual lionfish tend to vary. Some have been recorded below 300 feet.
She said if migratory patterns are established it could potentially reveal optimum times for culling.