FUTURE OCEANS
Lord of the Rocks BY JEAN-MICHEL COUSTEAU
Larval Goliath Groupers, vulnerable to predation, travel as much as 200 miles (322km) before settling in coastal mangrove nurseries, where they remain for approximately seven years. Photo: Carrie Vonderhaar, Ocean Futures Society.
Of all the magnificent marine life the Ocean Futures expedition team encountered while filming America’s Underwater Treasures (airing September 20 and 27 in High Definition on PBS, check local listings), one creature stands alone garnering our awe and inspiring hope. The goliath grouper captivated us with its formidable size, gentle nature and longevity. This charismatic but worldwide-endangered species makes its home in the protected waters of the Florida Keys National Marine Sanctuary. As we came to know the goliath grouper through scientists and filming, we marveled at the resiliency of this animal to survive a myriad of threats to its life and environment. The goliath grouper’s scientific name - Epinephelus itajara - refers to the clouded, mottled appearance of the fish; itajara comes from a Tupi-Guarani word meaning ‘Lord of the Rocks.’ This refers to adult fish that live a largely solitary life for as long as up to 50 years in water as deep as 150 feet (46m), inhabiting caves and reef structures. What is truly astounding about this grouper is its life cycle. Imagine these colossal beings weighing in at up to 500 pounds (227kg) in large formations of 40 or more, gathering to spawn in late summer under a full moon at shipwrecks, rock ledges, and isolated patch reefs. Females, reproductively mature at four years of age, release eggs while the males, which are mature at seven years of age, release sperm into open offshore waters. After fertilization, the eggs become pelagic fish food, at the mercy of water currents. Upon hatching, the kite-shaped larvae transform into one-inch long (2.5cm) benthic juveniles in only 26 days. And all this happens after a dramatic journey covering as much as 200 miles (322km) from offshore waters to the mangrove nursery. Within the tangle of mangrove roots and shallow brackish water, juveniles in their cloak of camouflage, spend from five to seven years doing what they do best – eating and growing big, slowly. This nursery provides some protection against predators, but the greater threat is human impact. The mangrove forest, once fringing the coastline of southern Florida and the Keys, is under attack from dredging, water pollution and development, along with natural degradation from hurricanes and flooding, which directly affect the grouper’s ability to thrive. 10
DIVER Magazine
Miraculously, goliath groupers do survive into adulthood; their chances now bettered by environmental legislation and conservation efforts. Unfortunately, even with the efforts of the Florida Keys National Marine Sanctuary and other groups, illegal poaching occurs. The goliath grouper’s slow movement, limited home range and territorial behavior make it an easy target for unscrupulous sport and spear fishermen. This pitiful need to kill and bag the fish was evident to my team and I during our expedition. Sadly, some people cannot see that these creatures are much more valuable alive than dead and on the dinner plate, or worse, simply strung up on the dock as a trophy. The selfish act of illegal fishing for goliath groupers robs future generations of experiencing these giants. You only have to be in their presence and sense the distinctly audible rumbling sounds they make when you get close to them during a dive, to know who is ‘boss.’ The sound, generated by muscular contractions of their swim bladder, can travel great distances and can be felt through your entire body. It is used for defense and to communicate with other goliath groupers. If this doesn’t generate respect, then just try staring right into their enormous open maw and watch their quivering body. I guarantee you will quickly develop a newfound appreciation! When it comes to goliath groupers, the Ocean Adventures team was inspired: Fabien Cousteau, Expedition Diver – “Being among these amazing creatures made us feel like Jonah and the whale I guess, because in a sense they could very easily swallow our heads! Just swimming among them was amazing. Some spear fishermen are characterizing these fish as aggressive and dangerous. They are more like cows and, in fact, are not dangerous.” Céline Cousteau, Expedition Diver – “They’re massive, huge fish and so gentle. All these animals that were around us were so peaceful. And they let out a big, booming sound when you get a little bit too close, a communication they’re trying to send – very impressive.” Zim Gervais, Marine Operations Diver– “I was surrounded by these awe inspiring goliath groupers, so huge and yet so graceful. It was kind of perplexing watching them swim and move about, sometimes engulfed in a school of little fish, a neat contrast.”
Don Santee, Expedition Leader – “I think that everybody and everything seemed to come together. We got a lot of good footage. The groupers themselves were cooperative. And just seeing all these big animals down there was pretty amazing.“ Holly Lohuis, Marine Biologist/Diver – “I think we all were very excited to witness this large group of goliath groupers for ourselves, knowing that it is a threatened species throughout its geographic distribution. I thought I could just stay down there for so long, and really look at each individual fish, almost like puppy dogs with their own individual personalities. They only come together during one time of the year. Most of the year they are solitary, off on a deeper reef, swimming around, surviving, and then to see them come together at this special time of year to mate, gives you a sense of respect for this animal’s very complex lifecycle.” You can read more about the goliath grouper and other marine life encountered during our film expedition in Ocean Futures Society’s new book, America’s Underwater Treasures, available for purchase, October 2006. Visit www.oceanfutures.org for more information.
A school of tiny baitfish forms a cloud around this Goliath Grouper. Swimming in close association with groupers may provide some degree of physical protection by making the school or the grouper appear larger. These small fish also benefit from eating the grouper’s ‘leftovers.’ Photo: Carrie Vonderhaar, Ocean Futures Society. The Ocean Adventures X Team, featuring Jean-Michel Cousteau, daughter Céline and son Fabien, encounter one of diving’s symbolic ‘holy grails’ – the Goliath Grouper – in the Florida Keys National Marine Sanctuary. Photo: Carrie Vonderhaar, Ocean Futures Society