On February 9th I had my first incident of the season. I was hunting lionfish, I had found 3 in this really low swim through and I had to squeeze under there in full SCUBA to get a good shot. After I speared one with my 2ft sling, I started cutting it’s spines off with some scissors. The fish was squirming off the end of my spear. I went to nudge him back on with the scissors, and then…he got me, and he got away! At first the pain wasn’t so bad as I tried to stop the blood flow through my thumb. I squeezed and even sucked at the wound trying to get the poison out before it spread through my blood stream. But soon the fire was burning all the bones in my hand, and it was traveling up my arm. Eventually we called the dive. When we got back to the island, I dunked my hand in scolding hot water. At first the hot water hurt more than the lionfish sting, but soon the pain dissolved with the heat of the water, and for the next 2 hours, I kept my hand in a bowl of piping hot water.
The next day I speared 7 lionfish, I looked inside their bellies and recorded what I found. I first measure the body length of the lionfish, then I cut it open and looked to see if it was a male or female. After that, I cut out the stomach, and like a tube of toothpaste, squeezed everything out. I have found a huge diversity of species that become prey to the lionfish. From file fish, to wrasse, gobi, shrimp and even parrot fish. What I have observed is a high concentration of 1 prey species in each belly, as if they were eating an entire rookery. I found 10 Juvenal blue headed wrasse in one belly, 9 red night shrimp in another. 2 file fish in another. It seems that where ever they are, they eat the most abundant fish in the area.
If you are not familiar with reef fish this may not mean much to you. The thing is, many of these smaller fish like the wrasse, and the parrot fish are important cleaners of parasites, algae, and detritus. As their numbers dwindle there are less animals to clean the reef, making it more susceptible to disease, algae growth and natural disasters. Lionfish are capable of eating animals 3/4 their size, and stretch their stomachs to 30 times it’s size. They are top predators in their native range in the South Pacific, and in the Caribbean nothing hunts them. Their populations are growing to densities not even found in their native habitat .
However, I don’t know what impact this has on the reef. Does it cause more algae to grow? Dose it deplete another predators food source, like eels or grouper? Are we loosing biodiversity? These questions require some investigation. I am proposing a study that would target and survey certain species that are typically found in lionfish (ex. Juvenal wrasse), and see if their numbers are decreasing, I want to see if the stomach content of fish caught between 30-80 ft of water is the same as animals caught between 150-200 ft of water. If they are the same, this suggests that lionfish living in deep areas feed on shallow reefs. This is because their prey dont typically live below 100ft. If this is the case, we could create a management plan that focused it’s efforts of removal during peek feeding hours, to remove the most amount of lionfish in an area.
Similar studies have been done in nations such as the Bahamas, Little Cayman and Bonier. Basically I feel that any effort to learn more about how lionfish are so successful and what we are loosing due to their presence will better equip us to create a management plan that will address the most important areas of their invasion.