As I write this, I have three days left in my internship at the Whale Shark and Oceanic Research Center. I’ve had some wonderful times here, between fighting off an overly curious moray eel, guiding newly-hatched hawksbill turtles into the ocean, and just experiencing life on Utila. But I will leave with one regret, and it’s not that I haven’t seen a whale shark (though I still have one more chance!). My only regret is that I didn’t get a chance to visit 40 years ago when, from all accounts, the reefs were pristine, the fish were bountiful, and the impacts of human development had yet to take their toll.
Decades ago, the reefs of the Caribbean and those in Utila were among the most biodiverse in the world, covered with an abundance of corals and fish to rival anything in the Pacific. The underwater world encountered by the first scuba divers must have been truly awe-inspiring, with an innumerable variety of brilliantly colored corals, all different shapes and sizes, covering every possible surface. Enormous schools of fish, so thick you couldn’t see through them, swirling around every surface, impenetrable but for the holes that sharks bored on their way through the wary swarms. In the minds of many, the Caribbean still looks like this, a result of center spreads in travel magazines and underwater photographers visiting the best, most pristine sites. However, decades of mistreatment, overharvesting of resources, a few region-wide catastrophes, and simple negligence have taken their toll. Much of the Caribbean doesn’t look like the movies anymore, and Utila is no exception. Coral covers are down, algae obscures their brilliance, and sharks, considered an indicator species for the health of a reef, are a rare sighting here. Even groupers and large snappers can be a difficult find on the more well-travelled south side of the Island. So what happened?
Much of what ails the Caribbean can be traced first and foremost to the degradation of corals. Coral cover in large parts of the Caribbean today is as low as 15-20%, a far cry from the 90% often observed in the south Pacific. This disparity is due to a range of factors, but the first blow was dealt by the Diadema die off in the early 80’s. The long-spined sea urchin, Diadema antillarum, may to some be merely a hazard for swimmers and divers, but to the reef it is a crucial grazer, eating algae that would otherwise outcompete and smother the slower-growing corals. Unfortunately, an extremely virulent and still unknown disease swept through the Caribbean in 1983, killing up to 97% of the Diadema urchin population. Diadema densities are only now beginning to recover. The die-off led to many reefs becoming overgrown by algae, while other grazers such as parrotfish were able to pick up some of the slack, the effects of this die off can still be seen in every mottled brown piece of coral.
Another, and in my mind the most enduring, problem to face Caribbean reefs is overfishing. Utila in particular has been hit hard by having too many lines in the water. While only 7000 people call Utila home, few enough that the reef could conceivably support a sustainable local fishery, Utila exports much of the fish caught here, with most going to the US. The explosion in fishing that occurred about 20 years ago, when Utila began exporting fish year-round instead of only a few months a year, combined with a local fad for catching grouper, has demolished populations of large, sought-after predators, with large predatory fish often difficult to come by at many south-side dive sites. This has had an effect on every organism lower down the food chain that calls the reef home, an effect known as the trophic cascade. As the predators disappear, it destabilizes the populations of the fish that they eat, which in turn destabilizes the populations of whatever they eat, causing everything to eat too much or too little of each other and ultimately doing incredible damage to the reef ecosystem as a whole.
The final curse to befall the Caribbean is the invasion of Lionfish. Lionfish are a ravenous, venomous, and all around nasty predator from the Indo-Pacific that are thought to have escaped from an aquarium in Florida in the 90’s and never looked back. Small fish do not recognize the lionfish as predators, attempting to hide in the predator’s spines before being devoured, and large predators do not recognize them as prey, with scant evidence of groupers and sharks hunting them in the wild. As a result, these colorful little demons have taken over reefs from the East Coast of the US all the way down to the Northern shores of South America. The saving grace, however, is that lionfish are delicious, as we at WSORC can all attest. From the Florida Keys down to Bonaire, experienced scuba divers have been spearing them with minimal impact gear, and eating them, selling them to local restaurants, or just getting them out of the water. When done responsibly (Don’t touch the coral. Ever. With any part of your body. Just don’t), it has proven to be an effective method of control, and is practiced here at WSORC. Here on Utila, lionfish are essentially non-existent on the south side of the island. However, spearfishing cannot control lionfish at more remote sites or at depths exceeding 40 meters, the recreational dive limit. It is my hope, however, that as lionfishing grows and matures as a practice and native fish begin to learn how to deal with these foreign predators, the lionfish invasion can be controlled better in the future.
Throughout this post I’ve mentioned the south side of the island. This is the side with the town, the main road, all the dive shops, and all the development and boat traffic. The south side is therefore the most impacted by humans, and home to the least healthy corals. It is the reality, and some fear the future, for much of the Caribbean. The north side, however, is another story. Its coastline is undeveloped, its waters are protected, at least in name, by the Turtle Harbour-Rock Harbour marine sanctuary, and its corals are fed by upwelling currents. Diving the north side is like stepping back in time, as if the surface of the water were a portal taking you to another age. Snappers school, corals cover the walls of drop-offs, clinging to every imaginable surface, and reefs teem with fish, sea turtles, and even a nurse shark or two. It is a reminder of what we have lost, but also of what can be again in the future. The most astounding thing about nature, what truly takes my breath away, is that the second we stop actively making things worse, it usually starts to get better on its own. If Utila were to enforce and expand it’s marine park, reduce fishing pressure and development, and get more divers on board with conservation, the future could look more like the North side than people think.
Call me an optimist, but I think there is reason to hope. The Utilian economy has already shifting towards tourism instead of fishing, and local restaurants and dive shops are at last beginning to talk about sustainability. While the freight train of climate change is barreling towards fragile coral reefs like ours, healthier, more diverse reefs and those in cooler waters, such as the north side, will be better equipped to deal with changing ocean chemistry in the future. So, as I sit here, about to leave paradise, I take nothing with me but memories, and the hope that paradise will still be here, better than ever, when I get back.