I have always had a fascination for Goliath groupers. When I first met them, they were called jewfish. The biggest one I ever saw was on the wreck of the Rhone, back in the [film] day. </p><p>I have not seen one that big here, but I believe I will pretty soon. His name was Abraham, as I recall, and on the night dive he followed us around and made fish disappear for us. It was magic! All we had to do was shine our light on a fish and boom! Gone.</p><p>I learned about a year later someone had speared him. Hope Abraham gave the spear shooter one heck of a ride.</p><p>This week a Goliath grouper experiment was scheduled for the Aquarius Reef Base mission. I don&#x92;t have much information from that experiment as of my deadline, but I did do a fair amount of research so I could understand what they are doing.</p><p>If you have not done so yet, follow the last days of the mission here: http://aquarius.uncw.edu/ It&#x92;s common knowledge that Goliath groupers were nearly wiped out by overfishing up through the 1980s. They were protected beginning in 1990, and remain so today.</p><p>Nowadays I see some talk from the fishing community that Goliath groupers are becoming so prevalent on the reef it&#x92;s affecting recreational fishing. I read some of the banter on a Florida sports fishing website. I decided to do some research to make sure I have the facts straight. This is, after all, a fish story.</p><p>I downloaded a paper from Endangered Species Research by Loren McClenachan in which she compiled historic photographs and newspaper reports as far back in time as she could find. Her premise was that even though Goliath groupers have staged a comeback &#x97; estimates are about 35 percent compared to earlier populations &#x97; the benchmark figures are inaccurate.</p><p>In other words, a 35 percent comeback based on the wrong number skews the result. That could potentially estimate a healthy enough population to restart fishing. The denominator is too low, which makes the comeback number too high. The stock is nowhere near historical levels, based on her research.</p><p>If fishing is allowed for these gentle giants, it may be too soon, and it could deplete the population more rapidly than is appropriate, or more importantly, sustainable. Interesting paper. You can download it and see it for yourself here: http://www.int-res.com/articles/esr2009/7/n007p175.pdf</p><p>The other main comment I saw berated Goliath groupers for decimating other fish populations. Not true. About 70 percent of their diet is composed of crabs and other crustaceans.</p><p>To confirm this I called Dr. Chris Koenig of Florida State University&#x92;s Coleman and Koenig Laboratory. He&#x92;s the grouper doctor. Their Goliath grouper page contains a wealth of information (http://www.bio.fsu.edu/coleman_lab/goliath_grouper.php). Also see Episode 101 of Changing Seas: http://www.changingseas.tv/episode101.html</p><p>According to Dr. Koenig, the level of the food chain in which Goliath groupers gorge is not high enough up to have a material affect on fish populations. Besides looking at stomach contents, he taught me about stable isotopes, which are sort of like a long term catalog of a fish&#x92;s diet. In this case, stable isotopes of goliath groupers are dominated by crustaceans.</p><p>In fact, where there are Goliath groupers, a native species, other fish populations also tend to be more diverse. They complement each others&#x92; existence, not decimate it. Harmony, not havoc.</p><p>He did say, however, that Goliath groupers are opportunistic feeders, so a fish on a line in distress is easy pickins, just as it is for a barracuda or a shark. So yes, they will pick off fish as they are being reeled in, but otherwise do not chase them around the reef for food. Stable isotopes prove that.</p><p>Another paper from Dr. Koenig and Dr. David Mann described the boom noises Goliath groupers make. The noise is generated by the muscles attached to the swim bladder, which rapidly vibrate to generate the sound. Many fish make noises like this, most notably drums, croakers, trout and toadfish. So the big noise comes from the bigger fish, but is also common in other species. See http://www.int-res.com/articles/esr2009/7/n007p229.pdf for the article.</p><p>There are a variety of reasons for the boom. Communication from males during spawning is the most frequently noted occurrence.</p><p>You can hear it. You can feel it. I experienced it quite closely the other night. In my recent experience I think it was during feeding. We were hanging out together, moving along slowly, and the fish that was swimming right in front of us was not there after the boom. My guess is he either zipped out of our proximity, or he has no zip left.</p><p>There were a couple times when my grouper companion turned towards me and approached, and all I could envision was a big gulp followed by a glimpse of this giant swimming away with my camera hanging out of his mouth. But he was friendly and we continued on.</p><p>The night dive was at Aquarius Reef Base, on the full moon. A group of local divemasters and instructors go out monthly to have some fun and have a relaxing night diving with other pros. I hope I get to go with them again. Quick update on Coral Restoration: Last Friday I went with Ken Nedimyer for a very special event. CRF in now planting nursery-cultivated second generation elkhorn coral on Molasses Reef. For coral restoration, this is a first. See http://coralrestoration.org for more details or to volunteer.</p><p><i>Tim Grollimund is a freelance photographer and PADI divemaster based in Key Largo. He can be reached at tim@timgimages.com or through his web site at www.timgimages.com. Tim is actively involved with the Coral Restoration Foundation and the Aquarius Foundation.</i>