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.

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.

 

When at first you don’t succeed

We drove the big boat south today toward the island of Andros. The winds were up and the sea was choppy. We got tossed around quite a bit – but I enjoyed every second. I really miss being out on the water. As a marine scientist who focuses much of her time on science communication these days, it’s nice to get a chance to go back out in the field. Marine conservation in a passion of mine. Its great to be working on a project that involves cutting edge science that has real management implications for the protection of endangered and threatened shark species throughout the Caribbean.


DSCN1523Why sharks?

Sharks sit atop the ocean’s food chain and play critical roles in sustaining healthy and balanced ocean environments. However, even these apex predators are vulnerable to human activities and are in peril throughout most of the world’s oceans. Sharks have been severely overfished, largely as a result of increasing demand for shark fin soup, a popular luxury dish in Asia that can fetch upwards of $100 per bowl.

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Female blacktip shark by the dock.

Shark conservation efforts face many challenges. Sharks are slow to reach sexual maturity, and are extremely vulnerable to overfishing. They produce relatively few offspring, and, even with strict protections, face long population recovery times.

Areas designated as ‘Shark sanctuaries’, such as the Bahamas, provide sharks with protection from overfishing, and therefore allow shark populations an opportunity to recover. However, these sanctuaries will only be effective if sharks stay within sanctuary borders long enough to reproduce. Dr. Chapman’s research team is mapping critical juvenile shark habitats and nursery sites around the Bahamas and tracking behavior patterns of adult sharks. Once compiled, this information will be shared with the Bahamian government, so that additional protections can be provided to shark populations. If the Bahamian shark sanctuary is shown to be successful, it will serve as a model for other areas in the Caribbean.


Today we left the mangrove nursery grounds of the lemon sharks, and headed out to sea toward an old navel buoy. Fish like to hang out near old buoys – they provide a bit of cover out there in the big ocean. And, where little fish like to hang out, you find big fish. We were looking for a very big fish – a silky shark, Carcharhinus falciformus. Unfortunately, we got there a bit late in the day and didn’t catch anything. We’ll try again tomorrow.

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Jerry pulling the shark in with his bare hands and some fishing line.
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Blacktip shark caught on a line and jumping out of the water.

Later in the day, we pulled up to the marina in Fresh Creek, Andros – our home for the night. There were some fishermen cleaning the day’s catch on the dock. Mark went to have a look thinking there might be some sharks around. There was. A big blacktip shark was circling. Blacktips, Carcharhinus limbatus, are a common coastal species of shark found worldwide that like to hang out near reefs and marinas. Blacktips are fast swimming sharks that can leap out of the water, making them popular catches among recreational fishermen.

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Sean Williams leading in the shark for measurements.

Seeing our excitement, Jerry, a middle-aged Bahamian fisherman who was the dock master, threw a line into the water. The shark bit. It was amazing – watching him pull this shark in with his bare hands! No reel, no rod, just line in hand. It fought and flipped out of the water, but he didn’t let up. Mark grabbed the science kit and we ran over to get some measurements. We hopped into a little boat tied up on the dock as Jerry and Sean guided the shark along the boat’s side. Sean and Mark took a DNA sample and I wrote down the measurements…195 cm – that is over 6 feet long! Sean said it was one of the biggest blacktips he had ever seen.

We tagged the shark and sent in on its way. A good end to the day.

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Mark Bond releasing the shark after we tagged it.

My first shark

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Christine and Mark with a lemon shark.

I caught my first shark today! A juvenile lemon shark. Such a cool experience to handle a shark and be part of a project working to protect these amazing animals.


The ride out this morning was a little rough and overcast. We pulled up to the first, spot and anchored the line. It was promising. A shallow cove surrounded by mangroves with a small channel leading inland. It was the perfect spot for baby sharks.

Lemon sharks stay in shallow waters for their first years of life. The mangroves provide protection as well as a buffet of smaller fish to eat. As the sharks get bigger they move out from the protection of the mangroves to patrol deeper waters. But not until they are 4-5 years old and around 5 feet long. We don’t really know where they go after they leave their mangrove nursery, but aggregations of lemon sharks are found along the eastern seaboard, as far up as North Carolina.

After we set the chum in the water, and baited the lines, we waited patiently, hoping for the sun to peak out from behind the clouds. It had been about 20 minutes and we hadn’t seen anything, not even a nibble. It was perfectly quiet. Then, I got my first bite! I grasped my fishing rod tightly – the little shark on the other end put up a quite a fight. I was so excited reeling it in. I pulled it along side of the boat and Mark Bond, one of the veteran scientists on the project, leaned over to grab it. After the shark settled down, we took 3 measurements. One from the tip of the nose to the notch right before the tail (caudal) fin, then to the fork in the caudal fin, and then to the tip.   My shark was 105 cm, or about 3.4 feet.

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Sean with a bonnethead.

Then Sean Williams, another shark researcher on board, took a small genetic sample, and Mark set the tag right below the base of the dorsal fin. Then the shark swam quickly off, disappearing into the shadows of the mangroves.

We caught another Lemon at that site, a smaller male, and then continued to fish at 4 other locations. At the next site, we saw a few Lemons, but ended up catching a bonnethead – one of the smallest types of hammerhead shark. Bonnetheads have a head that looks like garden trowel and only grow up to about 4 feet.

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Bonnethead after being tagged.

We didn’t have much luck the rest of the day, only catching 2 more bonnetheads, one of which got off right at the side of the boat. At 4:30 pm we headed back to Port Lucaya through some rough seas and a big rain storm. We were a little soaked through, but it was a great day. One I will never forget, catching and tagging my first shark!

Later on we feasted on a home cooked turkey dinner and went to bed with full bellies. Happy Easter.

Demian’s update from the field

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Demian Champan and a blacknose shark, Carcharhinus acronotus

 Dr. Demian Chapman landed in Grand Bahama this week with some of the research team.  They have already tagged some 48 sharks in 3 days, including lemons (above picture), bonnetheads and blacknose sharks! “The two former are subjects of our genetic studies, so this is really great,” said Chapman.

One of the main objectives of this trip is to survey potential nursery areas for juvenile sharks in the Bahamas. Of particular focus is the lemon shark. This project builds on a 20-year research project conducted at the Bimini Biological Field station that has shown that female lemon sharks return to their birthplace to give birth.  The team is visiting different habitats around the islands to find young sharks. This week is Grand Bahama Island.

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Lemon shark being measured.

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