Underwater we got a better look at the whale shark.  Photo credit:  Sean Williams

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
Smile for the Reefs - Students at H.O. Nash Junior High are all smiles after watching a lively presentation of shark births, migrating patterns and photos of rare species, part of an education and research program sponsored by Moore Bahamas Foundation and BREEF.

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 4th graders on Nassau or fishermen on Cat Island.

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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.

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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.

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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

 

 

Oceanic white tip.  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.

 

 

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The Berries – part 2

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Sunrise at the Pink House.
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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.

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

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

 

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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.

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

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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.

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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.

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Waiting

Today we headed to a different naval buoy to try our luck with the silky sharks again. Silky sharks are a deep-water species that, like the oceanic whitetip, have been severely overfished for their fins and suffered huge population declines from the long-line fisheries. There are not many studies on silkies and we don’t know their migration patterns. The research team hopes to fit silkies with satellite tags to learn more about this elusive shark, including how far they dive down to hunt and where they move. According to Mark, the diving profiles are especially interesting. For sharks, the real data is in how it moves, not where it moves. If sharks are hunting at the same depth as fishing lines, they will likely be caught. Understanding where sharks spend their time is crucial for successful management.

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Naval buoy.

We spent the good part of the morning at the buoy, but didn’t get any bites. It was empty – no sign of marine life other than sea birds. After heading to some fishing sites, we tried another pass at the buoy later in the day. The silkies were still eluding us. Buoys are usually good spots for sharks, but not this time. Later, we found out that this buoy had been removed from the ocean for repairs and just got put back last week. The fish had not re-colonized it yet.

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Setting the lines at the buoy.

Sometimes science isn’t easy. You can have solid methods, background research, the best-laid plans, and do everything right, but when you are dealing with living things (especially sharks), you can’t always count on them to cooperate…or in our case, bite. It can be really frustrating, but also extremely rewarding. You have to be persistent and take what you can from the situation. Even in failed science is discovery.

What did cooperate today was the weather. It was perfect. The ocean was aqua-green, calm and glass like – completely different from the choppy seas of the past few days. The weather was also perfect – cool breeze, blue skies, and little puffy white clouds.

I also got to try my hand at fishing today, which was a lot of fun. Collecting fish samples is another part of the research expedition. The team wants to study what oceanic whitetips are eating and their place in the food web. By taking samples from a bunch of different fish found in the area, they can use stable isotope analysis for carbon and nitrogen and see where the fish fit in the food web.

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Christine O’Connell reeling in a yellow-eyed rockfish.

Fishing takes lots of patience. Sitting there quietly, waiting, dropping the bait down to the bottom, reeling it up a bit, waiting, feeling a nibble, ready to pull the tip of my rod up…then nothing. More waiting. But always cautiously alert. Then a tug, and this time a bite. I quickly began to reel the fish in at the other end. It was a yellow-eyed rockfish, affectionately called for their big yellow eyes and pinky orange skin.

We mostly trolled, but also tried deep dropping at the ledge of the reef. For deep dropping, we put a bunch of hooks on a line with a weight and dropped it down to the bottom, which was about 400-500 feet down. This method is called a “chicken rig,” no one knew why.

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Mark Bond taking measurements and muscle samples.

At the end of the day we caught 6 yellow-eyed rockfish, a small Spanish mackerel and a rockhind, which was brown with strawberry pink spots. We also caught a Nassau grouper – a brown and olive striped fish. As Joey was reeling it in, a huge cubera snapper grabbed it and took a big chunk out of its back! We watched the whole attack from above.

When we got back to the dock, we took some measurements and muscle samples. The rest got cooked up for dinner.

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Happy Earth Day

I’ll put up a post on the shark research later, but since its Earth Day, I wanted to take a minute and talk about something that I care deeply about…garbage.   I’ve done a lot of research on garbage and plastics in the past. Something we found was that Long Islanders (NY), produced nearly twice as much garbage that the average American! Not exactly a statistic we should be proud of. And, much of our garbage these days is made up of plastic. Plastics are a huge problem for our oceans. It is rare that I visit a beach these days and don’t see a plastic water bottle lying in the sand or plastic bags blowing in the wind. From the over populated beaches on Long Island, to the empty beaches on Andros, Bahamas.

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Plastic jug on the beach in Andros, Bahamas.

The problem isn’t just garbage and plastic littering our beaches – most of it ends up in our oceans. Plastic takes a long time to break down. Sea turtles choke on plastic bags that look like a common prey item of theirs – jellyfish. Dolphins and sharks get tangled in old plastic fishing line and drown. Sea birds die from their bellies being stuffed with lighters and bottle caps.

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Plastic littering the beach near Fresh Creek, Andros.

And the story doesn’t get better when plastics finally break down into smaller pieces. These micro-plastics clog the guts of fish, which get eaten by seabirds and larger fish like sharks.

Plastics are everywhere in the oceans. Even as I am writing this post on the back of the boat, I’m watching a plastic bottle bopping up and down in the water, slowly being carried away by the current out sea.

So on this Earth Day, make a pledge to reduce the amount of plastic you use this year. Instead of buying bottled water, get a reusable bottle or use water fountains. Ask for tap water at restaurants – it is often better quality than bottled water anyway. When you take a walk on the beach, make an effort to pick up at least one piece of trash each time (and trust me, you will see more than one piece). Adopt the age-old saying of leaving a place better than you found it.

We need to do better.

 

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