Shark Adventures: Tagging Along

filmming caribbean reef sharks- Nassau, Bahamas

3/4/12

 At 6:30 on a Saturday morning most people are enjoying their weekend slumber. I’m chugging coffee, blasting NPR, and clicking my way down US1 towards Islamorada. This time, skimping on sleep is an enthusiastic compromise. Today I’m embarking on a real adventure.

 7:45 am.   Mile marker 85 appears. I turn towards the bay side of the island, find an open gravel spot and park my truck. I’m greeted by several undergrad students from the University of Miami and a school group from Broward County’s Cypress Bay Senior High school also along for the expedition. With several pounds of camera gear dangling from my body, I scramble onto our vessel. The horizon is scowling dark. This might be a rough trip.

 

Today I’m filming sharks. This time it’s above water, from the relative safety of the boat. I’ve been invited to film researchers from the University of Miami’s R.J. Dunlap Marine Conservation Program as they catch, tag and release sharks in Florida Bay. These efforts help gather important information on our ocean’s top predators. The toothy beasts in question are in big trouble. Global shark populations are in serious decline.

But the researchers who will be snatching the prehistoric fish from their watery home, might be their greatest allies.

8:35 am.   The diesel engines rumble to life, and we growl off towards Florida Bay. As we idle down the channel we’re given instructions on maritime dos and don’ts, how to operate the vessel’s head (toilet), and other safety factoids. Trust me, knowing how to operate the lavatory is definitely a safety issue. Next is a quick breakdown on how the sharks will be baited, caught and handled. Don’t worry, the researchers will do most of the handling.

9:15 am.   The clouds are continuing to billow up dark like burning oil, and the captain steers the vessel around the western edge of the front. A heavy line of rain pummels the choppy surface of the bay on our port side. A small funnel cloud touches down. I watch the ocean explode upwards as the water-spout skitters along the bay for a few seconds. Then it draws its finger back up into the atmosphere.

9:35 am.  With the nasty weather behind us, the researchers and undergrad students begin unpacking the tackle and preparing the bait. Greasy hunks of amberjack are skewered by hooks wider than my fist. A generous length of stiff monofilament tethers each baited hook to a drum-buoy. These rigs are then tossed overboard at regular intervals as the boat idles along. The crew works quickly. I’m impressed, however, by how determined and controlled the operation is. Apparently they’ve done this a few times.

10.15 am.  Now we wait for the sharks. We drift along for a bit, and I’m filled in on what it is, exactly, the researchers are doing out here. It turns out that this team, lead by Dr. Neil Hammerschlag, has made an interesting discovery.

Everyone here is absolutely nuts about sharks. It’s a bit contagious. There’s something primeval about the beasts. They are survivors…many species relatively unchanged since T-Rex prowled the earth. In recent years, however, sharks have been on the decline. Their meat is a delicacy in many countries and shark fins, believe it or not, command high prices in parts of Asia. In fact a bowl of shark fin soup can go for as much as $100 in China. That’s 100 bucks, for one portion….in a developing country. It’s estimated that as many as 73 million sharks were killed last year to satisfy the growing demand for the meat. Usually they are simply dragged into the boat to have their fins hacked off. Their rudderless bodies are tossed back into the sea to rot on the ocean floor. Talk to anyone of the people on this boat about this practice and their eyes flash red.

 

Dr. Hammerschlag’s team has found something that might turn the stomachs of future shark-meat consumers. Shark-meat, I learn, is full of toxins. Scientists have known about the high levels of mercury stored in shark flesh for a while, but Dr. Hammerschlag has uncovered another poisonous ingredient. BMAA is a neurotoxin that has been linked to degenerative brain disorders such as Alzheimer’s and Lou Gehrig’s disease. And Sharks are full of it. If you think shark finning is crazy, you’re right. It appears that eating the meat can make you even crazier. Literally.

 10:55 am.  It’s time to begin checking our drum lines. I’m excited to see what’s at the end of those rigs. I have a new sense of urgency and responsibility in all of this, and can’t wait to document the researchers’ work.

 One of the students snags the first buoy with a boat-hook, grabs the thick monofilament line and begins to pull it in by hand. The line is taut, and the student leans back against something sizable in the water. A minute later, the smooth snout of a 4 foot long black-tip shark shatters the surface. In a matter of seconds, the shark is hauled in, writhing and sliding around on the deck. Two more students pounce on the fish, one mounting its back like a bull-rider while the other puts a wrestling hold on its thrashing caudel fin. It’s a thrill to watch. A fourth student wriggles a PVC hose into the shark’s open mouth. Oxygen enriched water surges through its gills. This helps the fish breath.

 

With the shark under control and breathing comfortably, it’s time to take samples. Student volunteers from the high school take turns. One ducks in to take a skin sample with a small coring tool and a second snips a tiny piece of the dorsal fin. A third inserts a small identification tag at the base of the dorsal. At the same time a fourth student performs a stress test by squirting a bit of water in the shark’s eye. The shark reacts by closing its nictitating membrane, a kind of translucent, protective eyelid. This indicates that the animal is not over-stressed.

 The whole process takes less than 2 minutes. The PVC tube is pulled out of the black tip’s mouth and two of the UM students muscle the fish over the side of the boat. The shark slaps into the water, kicks and disappears. A surreal moment for the predator I’m sure…but it’s unhurt and back on the top of the food-chain. The data collected, however, will help reinforce a compelling case for shark conservation.

 

The bulk of the day continues like this. We check the other lines, some of which are untouched, several of which have snagged a shark. In total we catch 3 black tip sharks, a lemon shark, a large nurse shark and a small hammerhead.

 

One line gives us a surprise. After a vigorous fight, the jagged rostrum (snout) of a humongous sawfish thrashes to the surface. It’s an incredibly rare fish…the only endangered fish in Florida waters, and very little is known about it. This one is huge, maybe 13 feet long, and his toothy snout can be deadly. It’s not what we came to catch, but it is an incredible privilege to see. The researchers carefully toss a noose around the rostrum to control it, and then cut the hook with bolt cutters. The enormous fish is released, without ever leaving the water.

 

3:45 pm.  The boat eases back into port. I’m weary, a bit crusty from the sun and the salt, but somehow I feel great. It was an exciting trip, but I might need a bit more footage to complete my video project. Or maybe I’m just making an excuse to tag along on another shark tagging adventure!

Follow this link for more information on sharks and shark conservation: http://www.rsmas.miami.edu/blog/tag/dr-neil-hammerschlag/

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