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.

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.

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.

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.

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.

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.

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

Its all about that soup

It’s a strange thing that a regional appetite for soup on the other side of the world brings me and the SEA collaborative (Shark Ecosystem Assessment or SEAC) to the Bahamas to research some of the fiercest sharks in the ocean.

Sharks sit atop the ocean’s food chain and play critical roles in regulating balanced ocean environments. Similar to a wolf in Alaska preying on sick or weak caribou to keep the herd strong, sharks manage fish populations with marked precision. However, even these apex predators are vulnerable to human activities and are in peril throughout most of the world’s oceans.

Tens of millions of sharks are caught annually. This is largely a result of increasing demand for shark fin soup, a popular luxury dish in Asia that can fetch upwards of $100 per bowl. Whilst growing economic prosperity in China has led to increased demand for the dish once known as the ‘Emperor’s dish’, many species, including the oceanic whitetip, have become critically endangered.

Oceanic whitetip fin. Photo courtesy of Debbie Abercrombie.

Pile of shark fins. Photo courtesy of Debbie Abercrombie.

So why shark fins?

People are after thin collagen-like strips in the fin called ceratotrichia, similar in consistency to a fingernail. These strips look like folds in an accordion. Once dried and processed, they produce thin clear noodles that do not actually add any flavor to the soup, simply texture.

Shark fin and shark fin soup. Photo credit: Debbie Abercrombie

Each shark is harvested for just four fins: one on the top (the dorsal), 2 on the sides (paired pectoral), and the lower fork of their tail (lower caudal lobe). The lower tail is the most expensive because it has the most ceratotrichia versus cartilage content. Although it varies on the size and species of shark, each fin makes enough noodles for a cup or two of soup.

Think about the amount of sharks killed to serve each guest a bowl of soup at just one wedding!

Shark fins. Photo courtesy of Debbie Abercrombie.

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?

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

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.

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

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

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 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!

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.

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

Education is key

One of the most important and rewarding parts of the Bahamian shark tagging expedition is not just our work with sharks (although it is pretty exciting), it’s working with the local people. The team takes every opportunity to educate people as to what we are doing and why it is important – whether it be 4^th graders on Nassau or fishermen on Cat Island.

Mark Bond treating students at H.O. Nash Junior High School to a rare photo of a 7-gill shark, one of a critically endangered species the group is trying to protect. The presentation is part of a research and education program sponsored by Moore Bahamas Foundation, in collaboration with BREEF, to educate students on the vital importance of sharks to our marine system.

Each year the team visits local schools and radio stations to get the word out about shark conservation and educate Bahamian’s about this amazing resource they have: the Shark Sanctuary. This year Mark Bond went to 4 different schools and worked with over 300 kids! They kids loved it. Mark spent the day talking with them, answering their questions, and get them excited about sharks and the ocean. He also gave an hour long interview on a local radio station.

When I spoke with Mark, he was beaming about his experience, “It was very rewarding, the kids were awesome.” He explained to the kids why sharks are so cool and their importance in the ecosystem. He told them about the wide range of sharks out there – from the huge whale shark to the small cookie cutter shark. The Bahamas is one of the few places in the world where there is such a large variety of sharks in relatively healthy numbers. “People should be very proud of that and do what they can to protect them,” exclaimed Mark.

Marcia Musgrove, outreach manager for the Bahamas Reef Environment Educational Program, describing the crucial part sharks play in marine ecosystems.

During the school visits, there was this one 7-year old boy who must have asked about 15 questions. He was so excited about sharks and wanted to know as much as he could: What type of mangroves do lemon sharks live in? How far away do baby lemon sharks swim? How long do they live in the mangroves? Mark used this as a lesson in conservation: kids need to protect mangroves because coastal development is destroying these important habitats.

Mark Bond, lead research scientist on recent shark expeditions in the Bahamas, ticking off the various species of sharks found in our waters and the need to protect them.

Mark stressed the amazing marine resources Bahamians have, and why they should be proud (especially since shark tourism brings in about 80 million dollars each year to the Bahamas!).  Many of the shark species that are threatened or endangered around the world are flourishing in the Bahamas. This simple fact demonstrates the effectiveness of the Shark Sanctuary and provides sound scientific support for the development of similar protected areas in other countries. “We can actually come study shark populations here, instead of having to focus on recovery efforts (like in many other parts of the world),” said Mark.

A local newspaper wrote a story about the project and outreach efforts:

http://www.thebahamasweekly.com/publish/community/Moore_Bahamas_Foundation_Stony_Brook_University_SUNY_and_BREEF_Share_Shark_Tales_with_Local_Schools34829.shtml

 

 

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.

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.

 

 

The Berries – part 2

Sunrise at the Pink House.

Mark Bond and Christine O’Connell tagging a lemon shark. Photo credit: Sean Williams.

The Berries are absolutely beautiful, and yesterday the water was perfectly calm. The sea mirrored the sky. The sunrise was stunning. It was bitter-sweet for me since it was my last morning here.

We started the day early and spent the morning at a location Mark named Pink House. It’s a beautiful spot nestled behind some small islands with shallow flats and filled with mangroves. A baby lemon shark paradise. Last year they caught 8 sharks at this site.

We put out the chum crate and cast out our lines. After a while, we ended up hooking a decent size male lemon shark. Mark pulled it along side the boat and I took the DNA sample. I got to put the tag in on this one, which was really exciting. The tag goes right at the base of the dorsal fin, so it is out of the way and doesn’t interfere with the shark at all. The skin around the tag heals up quickly, similar to an earring in the lobe of your ear, and stays with the shark as it grows. We take note of the tag number. If the shark is ever caught, either by a fishermen or a researcher, they will (hopefully) call in the tag number to a special hotline and the team can track the shark’s growth and movements.

Christine O’Connell and the 8 pound mutton snapper she caught.

Mark Bond and Sean Williams on the bow of the boat.

As we were finishing up, the fishing line on the back of the boat started getting pulled out really fast. We hooked another! I jumped up and ran over to it. This one was a struggle to reel in. I stayed with it – pulled the rod tip up slowly when it pulled back, and lowered the rod tip down and reeled in fast when the line went slack. By the way it was pulling, I thought this shark would be a good size. However, as I reeled it in closer, I soon realized that it wasn’t a shark on my line at all, but a huge (for my standards) mutton snapper instead.

We spent a few more hours at various spots in the cove. We caught a small nurse shark, but released it right away. Nurse sharks are actually doing quite well and are not targeted by fisheries, so they are not part of this study. There was another lemon that kept coming close to us, but never took the bait. We gave up around noon and headed back to the boat.

Shark research takes a lot of patience, knowledge and skill. I was lucky to be able to learn from some of the best shark researchers out there. All and all, the team has tagged about 70 sharks over the past 2 years!

I got to take a quick snorkel around the cove while the skiff was being loaded on the big boat. I saw a green sea turtle, a school of small yellowtail, and 2 barracudas.

We left the Berries and headed to Nassau to drop me off (back to NY sadly) and pick up more team members for the Cat Island section with the oceanic whitetips. I’m sad to miss this leg of the trip, but will keep in touch with the team and continue to give updates from field over the next few weeks – so stay tuned!

Sean sitting at the bow of the boat as we took off in the morning.

 

The Berries – part 1

The past 2 days we spent at the Berry Islands – a small, relatively uninhabited patch of islands in the Bahamas. The water here looked like a patchwork of aqua blue and emerald green stained glass. You could see straight down to the bottom. In the distance, the ocean just seemed to melt into the sky. The berries have lots of nooks and crannies, lined with mazes of mangroves that open up into shallow lagoons – perfect habitat for juvenile sharks.

Shadows of the team working on the boat with mangroves in background.

Mangroves and shallow lagoons. The dark areas in the water are sea grass beds.

The mangroves were teeming with wildlife: ibis and osprey flying overhead, manta rays and sting rays gliding through the water, little bait fish schooling beneath us, bigger fish like grouper and barracuda trolling the mangrove edges looking for a meal, and heaps of sea turtles darting back and fourth through the canals. The mangroves are quite the hangout place and lots of different animals use them as nursery grounds, including lemon sharks.

Christine O’Connell with a lemon shark.

We caught and tagged three lemon sharks on Wednesday. We would have had four but one snapped the line. I caught a newborn lemon, it was around 2 feet long and only about one month old! In contrast, Mark caught one of the biggest lemons of the day – over 5 feet, and probably a few years old. As you can imagine, the smaller sharks are much easier to handle, but you still have to be really careful.

When working with sharks, you don’t just have to worry about getting bit, but also getting smacked by the tail (which packs a punch). And, if the shark’s skin scrapes against you fast in the wrong direction, you’ll end up with rug burn. A shark’s “skin” is made up rows of microscopic tooth like scales that lay flat against its body. If you move your hand from the tip of the nose to the tail, it feels smooth and leathery, but if you move your hand back the other way, it pushes up against the scales and feels like sandpaper.

Mark Bond putting a lemon shark in “tonic.”

To make the shark more comfortable while the team is taking their measurements, Mark gently turns the shark on its back with its white belly exposed to the sky. This puts the shark in a meditative state called “tonic.” It also makes it easier for us to work with the shark.

The DNA samples we take from the sharks are being analyzed by Kevin Feldheim, from the Pritzker Lab at the Chicago Field Museum. Kevin was on the first leg of this trip on Grand Bahama Island. So far, members of the team have shown that, although all the same species, there are genetically independent populations of sharks on different islands in the Bahamas. They have seen genetic differences in species as little as 150 km apart (about 93 miles or the distance from New York City to Philadelphia). This means there is surprisingly small-scale genetic structure in lemon sharks, a finding that is unprecedented in shark research. This also means you have to manage sharks on a fine scale. The more places/samples we get – the better the resolution of this genetic diversity.