Category Archives: Cat Island

Happy Centennial!

Today we are set to capture and tag the 100th oceanic whitetip! We motored off, leaving the calm, aqua colored waters of the lagoon for the deep blue rolling waves of the sea. Excitement and anticipation compliment our morning coffee.

With 5 years of data coming in, the SEA Collaborative has already begun to answer important questions about the mysterious oceanic whitetip: Where do they go during the year? Do they come back? Did they get pregnant along the way? Are they having pups? How often?

It turns out that these sharks come back to the same place year after year. This especially holds true if they have round, swollen bellies: Cat Island seems to be a maternity ward for pregnant sharks!

Collecting data on a pregnant oceanic whitetip, including doing an ultrasound! Researcher Debbie Abercrombie maneuvering the shark. Photo by Andy Mann.
Collecting data on a pregnant oceanic whitetip, including doing an ultrasound! Researcher Debbie Abercrombie maneuvering the shark. Photo by Andy Mann.

But tagging sharks is not easy business.

Sometimes the hardest part isn’t their sheer size or razor sharp teeth, it’s finding them!  There were days when we just waited, waited, waited…and waited some more. The routine was the same: cut up dead fish into small chunks; tear the chunks of fish meat apart and toss them over, one at a time, into the choppy waves; scan the bright blue to the horizon for grey shadows; repeat. This part could get a bit monotonous, and, as the day went on and the hunks of fish baked in the sweltering Caribbean sun, quite stinky.  I loved every second.

Someone might take out a knife, jump overboard and “scrape” fish in the water, shredding it into the tiniest of flecks, ensuring the sea’s currents would carry the smell. Sometimes we would drag fishing lines behind the boat (called trolling), hoping to lure sharks up from the depths with promises of a freshly caught fish. Mid-day a huge sparkling yellow and blue trimmed mahi mahi snagged a line, bouncing out of the white spray of the waves, pulled feverishly by the boat. Out of nowhere, a shark emerged from the blue and snapped it in half! Within seconds, the fish and the shark were gone.

Some days, only the laughing gull following the boat would go home full, smirking and snatching hunks of fish not meant for its belly. Sometimes we saw a shark, but it wasn’t interested in our bait. Other days three oceanic whitetips would be swimming around the boat within minutes. This was not that kind of day.

We decide to take a break to fish for bait (and dinner, of course!).  Birds dive on the horizon. We are a couple hundred feet off the shelf break and reef. Lines get dropped in. Within minutes there is a bite on Joey’s line. The once-straight pole curls around towards its base, pointing at the water. Spinning feverishly on the reel, he quickly rolls it in, fighting with the fish on occasion by pulling back on the line ever so gently. The struggle is soon over. It’s a large strawberry grouper – this one’s dinner.

We head to a new location. The distant limestone cliffs of Cat Island are barley visible on the quiet horizon. The chum crate gets thrown over. It is full of fish heads, spines and tails. We began work on preparing today’s menu: frozen bonita with a side of leftover mahi heads. Today, Lucy was adding to the smorgasbord of delicacies by splashing in cups of bloody water from where the fish carcasses were kept. Sound delicious? It does it you are a shark. And that is why we are here after all.

There she was. Like magic. Our spirits rise. Appearing out of the blue as if she were next to the boat all along.

The thing is, once you see a shark, you have to hook it.  And, once you hook a shark then you have to catch it. Then the hard work starts. Including, once you collect your data, unhooking it.

A buoy gets tossed over the boat’s side. It has a line attached to it, with a hook on the other end in the shark’s mouth. She swims away freely and pulls the buoy fast through the water. This extra effort should tire her out and make her easier to tag. Quickly hopping into the small boat, passing over clunky equipment between the crests of big rolling waves, we head toward her.

Catching a shark.  Photo by Andy Mann.
Catching a shark. Photo by Andy Mann.

Tagging a shark requires being agile and deliberate. Most of all, it requires a deep respect for this animal. Jumping in and wrangling a shark will not make it sit quietly along side the boat. You need caution, experience and a lot of care.

The small boat is thoughtfully steered toward the shark: slowly maneuvering around, backing up, turning ever so slightly so the shark is facing the right direction. If she gets spooked, she will take off again. The boat follows the whim of the shark, not the other way around.

When she is secure along the side, the team hurriedly begins its work. The quicker this is done, the less stressed out the shark will be.

Measuring a shark.  Photo by Andy Mann.
Measuring a shark. Photo by Andy Mann.

The team moves about with beauty and precision, working quietly over the shark and each other. Taking exquisite care to not harm her or put themselves in danger. No nervous energy, just deliberate quick, detailed movements. Ready to pull back on a moment’s notice. Skill takes over. Read the shark, anticipate her movements, urges. Over the years, and after many scrapes and bruises, this is something the team understands. Feeling the edges of her belly tense up before she decides to flip up her tail and smack it into your side, burning the top of your thigh with her sandpaper-like skin. Or sensing her agitation and frustration before she rears up her head, swinging it around, just missing your hand.

You must trust your colleagues and trust yourself.

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Mark Bond putting an oceanic whitetip in “tonic” – a hypnotic state when they are rolled on their back. Photo by Andy Mann.

The workup usually takes less than 10 minutes.  We measure it, tag it, take a small skin sample, some blood, and do an ultrasound (yes, the same as pregnant women!), and send it on its way.

Often the sharks are in groups and its friends stick around while it is with the research team. They are usually able to catch one shark after the other, and even recapture the same sharks from one year to the next.

However, this one is alone, and she is special. Our 100th shark captured and tagged! The significance of the milestone seems to escape her as she swims hastily away, engulfed by the blue, never looking back.

Shark swimming away after getting tagged.  Photo by Andy Mann.
Oceanic whitetip under the boat. Photo by Andy Mann.

Fishing blues

It was our first day tagging. I was nervous and excited.

Seven- to ten-foot oceanic whitetips dwarf the baby lemon sharks and bonnetheads I tagged last year. Tagging these larger, far more dangerous, animals requires a lot of skill and knowhow. Good thing the experienced SEA Collaborative (Shark Ecosystem Assessment or SEAC) researchers were running the show! Most of these scientists have been friends since graduate school and have been tagging oceanics for over five years, with many years of planning beforehand. This well-earned trust is relied upon when handling these big sharks: team members know each others’ movements; thoughts — and tagging a shark takes on the air of a well-choreographed dance.  I am learning from some of the best in the field.

Within two minutes of chumming, a ghostly grey shadow moved languidly: a broken, unsure shape glimpsed through the choppy blue surface of the water. A telltale dorsal fin broke the surface. Shark.

Delight burst through me. I jumped up to take pictures and chase the 8 ½ foot shark along the side of the boat. I took over 50 pictures in a minute.  I felt like I was 5 years old again, seeing a pile of perfectly wrapped presents on my birthday.  I thrilled with excitement, awe, wonder. But, as I looked around excitement waned and there was a quiet disappointment seeping from the team. Even from afar, they could tell this wasn’t the one we were looking for, not the infamous oceanic whitetip, just a blue shark.

Blue sharks are commonplace in the waters off New York where I am from. What was it doing all the way in the Caribbean?

As it turns out, blue sharks have the widest range of any shark species. Usually they prefer cooler water and frequent greater numbers in higher latitudes. Whitetips rule the ocean down here.

The shark was a she. On male sharks there are two short appendages that look like white asparagus stems used for mating attached their bottom (pelvic) fin called claspers. Clear evidence of mating scarred her side: a round ring of gashes in her skin made by the teeth of an amorous male blue shark no more than two weeks ago.

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Mating scars on a blue shark. Photo credit: Andy Mann.

Female sharks are actually born with thicker skin than males because they need to withstand the vicious pleasantries of mating. Males bite down hard, curl around the female and rotate her on her back, which puts her in an almost hypnotic state called tonic (a handy method we also employed when working on sharks). They then use their claspers to fertilize her.  Usually the scars heal up in about a month.

Blue sharks and oceanics are very different. But, unfortunately, they share two things in common: they are both targeted in the shark fin trade and often mistakenly killed on hooks and lines meant for other fish.

But why is the oceanic whitetip endangered, and the blue shark not?

Fundamentally the blue shark is much hardier. Many sharks die when accidentally caught on hooks of longlines set out over miles of ocean to target such fish as tuna. Called “bycatch,” this unnecessary killing happens when one species ends up dying from fishing that targets another species. Blue sharks have a much higher survival rate as bycatch when they are caught on the longline. They also reach sexual maturity around 6-8 years old, which is young compared to other sharks.  Perhaps more importantly, blue sharks have lots of babies (called pups!): around 20-50 each year compared to 2-14 for an oceanic whitetip.

Even though they make up about 40% of the shark fin trade, blue sharks are technically sustainable, teetering right on the edge of maximum sustainable yield. There are just enough blues born into the population each year to replenish the ones that die.

After a recent trip to Hong Kong, where 50% of the shark fin trade takes place, Debbie Abercrombie, one of the shark scientists, exclaimed “I can’t even believe there are still blue sharks swimming around in the ocean anymore!” She described four two-story malls filled from top to bottom dried seafood products, “…with bags upon bags of shark fins from mostly blues and some oceanics!”

Blue shark being tagged.  Photo credit: Andy Mann
Blue shark being tagged. Photo credit: Andy Mann

Close encounters

Today I faced one of the most dangerous sharks in the ocean.

It was terrifying. It was absolutely beautiful.

And surreal.

I was above myself, watching a movie, not really there. She looked at me and I looked at her, our eyes locked. Suddenly she was real, she was there. So was I. I gasped through my snorkel. My heart raced. My mind flooded. Was I in the water with an oceanic whitetip? What was she thinking, feeling, wanting from this encounter? Was she really turning and swimming right toward me?

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Swimming with the sharks. Photo courtesy of Andy Mann at http://www.andymann.com.

We had run out of satellite tags for the day. Lucy Howey of Microwave Telemetry, Inc., one of the project founders, was flying in that afternoon with more tags. One of the primary goals of the research expedition is to monitor the movements and behavior of the endangered oceanic whitetip shark. These sharks can migrate over long distances throughout their lifetime, often crossing international and political boundaries. Yet political and ecological boundaries don’t often overlap. Protection efforts in one country can be overshadowed by destructive fishing practices in another. Understanding shark migration patterns across borders is crucial to their overall protection.

Although the oceanic whitetip is endangered, Cat Island remains one of the best places in the North Atlantic where these sharks can be found. It is a unique place with a steep ocean drop off on its eastern side – and one of the few places where whiteips congregate close to shore. In order to study the shark’s movements, behavior, and breeding grounds, the team fits oceanic whitetips with special pop-off satellite archival tags (PSAT’s). The PSAT stays attached to the shark for about a year, at which time it pops off and transmits the recorded data to a satellite. To date the team has put out over 100 satellite tags, with about 1/3 being recaptures. This gives them valuable information about how the shark have grown, where they breed, and where they have pups, and leads to more targeted and effective management practices.

A shark was circling the boat. Mark Bond and Andy Mann were in the water filming a lone female oceanic whitetip. They hopped out of the water at one point because they thought she was being aggressive – coming in fast toward them and poking the camera, circling around and then heading at them again. But, after a few minutes, they splashed into the water again to give it another try. She had calmed down a bit, or they relaxed, or most likely a little of both. After watching Mark and Andy and the shark circle each other for about 15 minutes, I finally worked up the courage to get in myself. I was terrified. This is the first time I’ve been in the water with a big shark.

The cool blue water consumed me. I tried to stay close to the boat in case I had to hop out fast. I quickly took my bearings and looked around me: there was Andy, there was Mark, and there was the shark. She was 20 feet away, looking at me with curious eyes. She swam down deep for a minute and then circled back, continuing to watch us.

Earlier in the day, I had asked John, a NOAA researcher on the trip, what he like most about these sharks. He said, “Their curiosity.” I now understood what he meant.

She glided smoothly straight toward me. Her eyes, almost thoughtful, checking me out as much as I was checking her out. I looked at her head on. I couldn’t see her body, just her grey oval face and white chin. She was silhouetted by the deep blue sea. Strings of light filtered through the water like a comb and slowly dissipated, overtaken by the dark blue from hundreds of feet below. There was nothing around us: just blue.

Oceanic whitetip swimming into the deep blue. Photo credit: Andy Mann
Oceanic whitetip swimming into the deep blue. Photo credit: Andy Mann

This was not my world, it was hers. She was so graceful and sleek; her movements were effortless. As I clumsily fumbled in the water, she almost laughed with her beady eyes that she never took off of me. I waved my arms to push back as she came closer, her body seemed perfectly still, yet she moved faster and with more precision than I ever could. I pushed backward, behind Mark, who had a stick to gently push her away if she got uncomfortably close.

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Christine O’Connell and Mark Bond in the water with an oceanic whitetip.
Christine O'Connell in the water with an oceanic whitetip.
Christine O’Connell and Mark Bond in the water with an oceanic whitetip.
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Christine O’Connell and Mark Bond in the water with an oceanic whitetip.

Her approach entranced me: wide set eyes set apart on the edges of her face, jaw slightly agape, stretching straight across her face with the ends of her mouth curving down a bit, touting a somber grin. She had an emotionless, blank, and surprisingly deliberate look – the kind of look that for a second puts you at ease, calming. There was no feeling behind it, good or bad. It makes you let your guard down for a moment, tricking you into thinking she wouldn’t hurt you if given the chance. This is her lure – her effortless quiet swim, her blank stare, as if she is saving every bit of energy for the exact moment she needs it, for that split second she attacks. She is efficient, fierce, strong. Oceanic whitetips are able to survive and thrive out in the vast open ocean because they are agile hunters and artful scavengers. But for today, for right now, she is our friend. Though, I wonder what would happen if we met under different circumstances…

I realized through my encounter with her what magnificent animals these sharks are and the importance of protecting them. This amazing team of researchers is doing important work.

Our story begins

Our story begins at the same time and place we left off last year, in the turquoise seas of the Bahamas for shark season. But, this time, we have new main character, the ocean whitetip shark.

Oceanic whitetips are one of the fiercest, yet most critically endangered, animals in the deep ocean. As an apex predator, their survival as a species is crucial to the overall health of our ocean environments. The scientific research team here is trying to better understand the behavior and life histories of these magnificent animals to help protect them from their most feared predators: people.

A year ago, I had the good fortune to spend a week with some of the team’s scientists, puttering around in lush green mangroves and blue-green mosaic waters of the Bahamas, tagging baby lemon sharks and bonnetheads. This year, I left the protection of these mangrove sanctuaries, a natural nursery for baby sharks, and ventured with the team into deeper blue waters off Cat Island in search of very grown-up, very large, very feared, yet very fragile, and VERY endangered oceanic whitetip sharks.

Oceanic whitetips are fast and efficient hunters that are most well known for killing hundreds of shipwrecked sailors during World War II after the USS Indianapolis was sunk by a Japanese submarine. The image of the infamous white spot on the tip of their dorsal fin emerging from the blue and slicing through the water floats through tales of the sea. It strikes fear in sailors and boaters alike. Yet, as I’ve come to learn over the past few days, these sharks are also mysterious, gentle, playful curious, and simply beautiful. I even came face to face with one in the water yesterday…but that is for another post.

Oceanic whitecap off Cat Island, Bahamas. Photo courtesy of Andy Mann.
Oceanic whitetip off Cat Island, Bahamas. Photo courtesy of Andy Mann.

Our team of scientists embarked on this project 5 years ago, and it has become one of the biggest shark research tagging expeditions ever! Scientists involved in the Bahamian shark research expedition are doing groundbreaking research on multiple shark species throughout the Bahamas, mapping migratory routes and trying to uncover the mysteries of where they give birth and mate. Their research is translating into conservation of these amazing animals worldwide, including listing the oceanic whitetip on CITES, the international treaty regulating trade of endangered animals like elephants and tigers.

This multi-institutional research partnership is a unique one that involves academia, government, non-profit and private industry, all cooperating to promote ocean science and conservation. Project partners include the Moore Charitable Foundation, Microwave Telemetry Inc., Save our Seas Foundation, Cape Eleuthera Institute, NOAA, University of North Florida and Stony Brook University. This year we are vey lucky to have professional adventure photographer and filmmaker, Andy Mann, on board to document the project (instagram @andy_mann, andymann.com, 3stringspro.com).

Guest Blog: “What a Day!”

By Mark Bond

We woke up to the wind howling! Although the day’s rough seas prevented us from getting any of our Oceanic whitetip research done,  there were still some surprises in store. One of the most exciting things about spending time on boats is that you never quite know what you will see.

With the weather forecast to deliver high wind for the next 4 days we decided to head up the coast in search of more protected anchorage. While we were trolling for pelagic fish to sample for stable isotopes, a rough and otherwise uneventful cruise up the coast quickly turned into a frenzy of excitement. The presence of diving birds on the horizon attracted our attention. When trolling, a successful technique for finding fish is to use birds to indicate where fish are in the waters below.

As we got closer to the birds the ocean suddenly began to boil with activity. We looked down from the bridge and a large, dense bait ball of fish was bubbling excitedly at the surface. Just like an iceberg, most activity of a bait ball occurs below the surface of the waves. When previously trolling we witnessed an oceanic whitetip cruising through a small school of yellow fin tuna so we eagerly scanned the water. Through the whitecaps we could see a dark grey shape below the frantic activity of the fish. At first I couldn’t decide what I was looking at – the opinion amongst the boat was divided. Unfortunately, whatever it was it dove deeper and disappeared from sight leaving us dejected and frustrated that we didn’t really know what we had seen.

Using the birds we chased the bait ball, now a few kilometers away, hoping that whatever we had seen was still following it too.

Once more the dark grey shaped loomed up from the purple-blue water, but this time it came closer to the surface as it searched for food. Almost in unison everybody shouted “whale shark!!” In truth, whale shark may have been preceded with a few expletives as the excitement at seeing something so rarely observed in the Bahamas overcame us. Captain Scott expertly positioned us alongside the school-bus-sized fish and we jumped in for a closer look. The whale shark was estimated to be 20 feet long, still a juvenile as the adults – the biggest fish in the sea – can grow to be 60 feet!

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The whale shark comes close as it attempts to feed. Photo credit: Yuuki Watanabe

Although the whale shark was the star of the show, this was a unique opportunity to observe the ocean’s intricate foodweb in action. The cause of all of this commotion and the lowest in the pecking order were the bait fish. At the surface of the water just below the waves was a layer of finger-sized bait fish 6-10 inches thick and packed with individuals moving as one as they attempted to dodge the onslaught of predators. From above, the seabirds swooped and dove down on the bait fish, their presence being marked by the flurry of webbed feet we could see from under the water. From the below, the bait fish were being picked off by a school of skipjack tuna as they mirrored the motion of the seabirds but in reverse. It was the tuna that caused the bubbling effect we could see from the boat.  Tuna, designed for high speed with their streamlined body-shape, frequently breach the surface as they rocket up from the deep to scoop a mouthful of prey.

Amongst all of these elements, the graceful whale shark made intermittent passes with what looked like barely a beat of her tail. Despite their large appearance, whale sharks are filter feeders and pose no threat to humans. They are well protected internationally, however they are still a target of illegal poachers for both their meat and their large fins for the shark fin soup trade. Their presence in aggregations around the world have developed an economically beneficial eco-tourism trade for many developing countries such as Belize, Mexico and the Philippines.

Still buzzing form our whale shark encounter we pulled the boat into the safety of the dock but the day was not finished yet. Under the dock was a manatee! Like the whale shark the Florida manatee is a species rarely observed in the Bahamas. The Florida manatee is also endangered and warrants protection. The removal of critical sea grass beds and boat collisions have left their numbers diminished in south Florida, their usual home. To get in the water with what can be a very skittish animal was a real treat. She did not seem phased by our presence and was so curious about what must have seemed to her to be these strange uncoordinated guests in her waters. It was proof that even when the weather decides to disrupt the best laid plans the oceans can deliver some unique surprises.

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The curious Florida manatee inspects the camera. Photo credit: Sean Williams

Onward to Cat Island

This next phase of the Bahamian shark research expedition is taking place at Cat Island. I’ve been in contact with the team, who have been tagging oceanic white tip sharks for the past 2 weeks.

Because of the shark fin trade and increased demand for shark fin soup in Asian cultures, populations of oceanic white tips have been decimated around the globe. This makes Cat Island a very unique place. During the months of March-June, Cat Island becomes one of the few places in the world where large aggregations of the oceanic white tip shark can be found.

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Oceanic white tip at Cat Island. Photo credit: Sean Williams

The oceanic white tip is an endangered species. These sharks were recently listed on CITES (www.cites.org), an international trade agreement to make sure endangered species are not sold on the global marketplace. Although the international sale and trade of products derived from oceanic white tips (such as their fins for shark fin soup) is now illegal, they still die from getting caught on lines of other fisheries. There is also an illegal trade of their fins.   Team members Debra Abercrombie and Demian Chapman are trying to stop this, and developed a shark fin guide to help managers and governments identify endangered and illegal species of shark fins that are being sold (www.sharkfinid.com). They have both traveled around the world training governments agencies and law enforcement officials to use the guide and were instrumental in getting oceanic white tips listed on CITES.

The team is putting satellite tags on oceanic white tips to study their movements, including how far down they dive to catch prey and where they are moving around the ocean. They are also hoping to find the shark’s breeding grounds in the Atlantic. Understanding shark behavior and migration patterns, especially across political boundaries, is crucial to their overall protection. Using the satellite tags, the team can study these patterns within the Bahamian shark sanctuary, as well as outside its borders. This information will help determine how ongoing shark fishing in neighboring countries may affect their numbers in the Bahamas.

Team member, Lucy Howey-Jordan, is the lead scientist on the satellite-tagging project. Each tag is about 6 inches long and after about 10-12 months, it detaches from the shark and transmits the data it collected to the team. This animation shows the movements of sharks tagged by the team in 2013. It shows that about 1/3 go north out of the Bahamian shark sanctuary, 1/3 go east and the rest stay in the Bahamas. However, all of them return to the sanctuary each year.