UNDERWATER LION FISH SAFARI
This last weekend was the first time in a while when the weather and the seas allowed us to get offshore to do some scuba diving surveys of the lion fish invasion into our live bottom grouper and snapper grounds. We know that we had some reliable reports of significant lion fish populations on ledges and wrecks 40-50 miles offshore but we needed to start checking some other popular areas closer to our artificial reef system to monitor their inshore progress. As I pointed out in my previous columns, lion fish are voracious feeders of small and medium reef fish and do not seem to have a significant predator to keep their populations under control. Also, very little is known about their movements and migration potential in our waters. In the Indo-Pacific, their native area, they will come all the way into the estuaries.
For our first dive we chose a limestone ledge out at the very popular Savannah Snapper Banks, about 40 miles offshore in 110 feet of water. This area is about 10 miles inshore of a wreck that had hundreds of lion fish reported on it three weeks before. We were using a Nitrox air mix in our scuba tanks which allowed us to stay down longer at that depth and I could video tape as much of the ledge as possible. I was video taping the dive in case we came across some significant schools of lion fish and to document what species seem to be doing well. On this site we found less than a dozen visible lion fish but as they are found of caves and crevasses, we did not inspect all of those. These lion fish seemed to be small and somewhat shy as opposed to those in other larger infestations which seemed to be fearless. This ledge had a good representation of all sizes of many of the expected reef fishes and most significantly had a healthy population of big gag grouper and amberjack. If there is any species besides sharks which would have the potential to keep lion fish under control, it would be big grouper although this has not been well documented.
Our next stop was at the R-7 Navy tower about 35 miles out to do some fishing and snorkeling before making another dive. Curt Hennessey, our captain and resident veterinarian managed to jig up a 35 pound cobia from the base of the tower legs. We snorkeled around the tower legs but did not video tape anything but tons of bait, barracudas and amberjack. Snorkeling around the Navy towers is a fascinating and safe experience even if you are not a diver.
Our final dive of the day was in 90 feet of water in another popular live bottom area called the “hump”, about 30 miles offshore. Again we were on a long limestone ledge which I have dove before and documented on videotape in 1995. Visibility was not good enough for video but the ledge still showed a varied and robust population of reef fishes and just a few lion fish. As on the previous site there was also a strong contingent of big gag grouper.
In the coming weeks we plan to sample some more live bottom areas further up the coast in the direction of another reported large infestation at the “North Hole” which is about 10 miles from the Edisto artificial reef. We also plan to drop in on some of the ships and street cars at the Betsy Ross Artificial reef which at 90 feet is one of our deeper local ones and would seem to be a classic invasion site. The bottom water temperature at both of our sites was at the upper end of the normal tolerance of lion fish so as the waters cool this fall we may see some changes in their habitat.