great hammerhead shark – Shark Research & Conservation Program (SRC)

Shark Tagging with Grand Classroom Ohio

March 29, 2016/0 Comments/in Shark Research /by aanstett

By Rachel Skubel, SRC Intern

There was a special feeling among the shark research crew before setting off today – a pregnant fog had rolled over Miami, giving way to a magnificent sunrise as we drove in to the marina. It was the Ides of March, and on this iteration the ocean was so still and glassy it looked like a calm lake. Fortunately for our purposes, these conditions were perfect for heading some miles offshore of Miami into the Atlantic, enhancing our chances of sampling large pelagic species like great hammerhead sharks. Accompanying us was a group of highschool students from Ohio, so we were excited to share the wonders of our subtropical marine environment with these northerners.

Immediately after setting our first round of ten lines, we headed back to line #1 because it was on the move – was something dragging it? Yes! Our first shark of the day was a beautiful great hammerhead shark (Sphyrna lewini), a special and valuable source of blood and morphological samples for our labs’ projects. We had the fortune of witnessing a vibrant sailfish breach next to the boat as we maneuvered this animal in – it appeared that all sorts of oceanic predators were abundant through this fishing site.

A dusky shark (Carcharhinus obscurus). The pump provides the animal with highly oxygenated water throughout the quick workup.

Shortly after releasing this shark, we came upon a massive bull shark – another amazing large coastal shark we are always excited to sample! We seemed to be in great luck with our choice of site. The best, however, was yet to come. The next time we had a fish on a line, we were all excited to see what seemed to be another great hammerhead shark – but why was the dorsal fin smaller? And the coloration seemed bronzy! Indeed, our hopes were confirmed when we pulled in a scalloped hammerhead shark (Sphyrna lewini) – one of only a few our lab has ever worked with! This was a truly rare opportunity for tissue samples and morphological measurements. As excited as we were with this species, we were soon to encounter a dusky shark – the fourth in SRC’s history!

A great hammerhead shark (Sphyrna mokarran) is released after tissue samples and measurements are taken.

Along with these animals, we also sampled a second great hammerhead shark – which we satellite tagged, a nurse shark, and the first sandbar sharks of 2016. Truly, this was an immensely valuable day for our lab’s projects and we were happy to have shared it with a lucky group of highschool students. Stay tuned for this great hammerhead shark’s location on our live satellite-tracking page at https://sharkresearch.rsmas.miami.edu/education/virtual-learning/tracking-sharks!

Shark Tagging with Our Lady of Lourdes Acadamy

November 12, 2015/0 Comments/in Shark Research /by aanstett

By Christopher Brown, RJD Intern

As dawn broke on Saturday, November 7, 2015, eight sharky RSMAS students and one fearless lab manager awoke to the call of the sea. The RJD team assembled at Diver’s Paradise in Crandon Marina at 8:00am to begin loading the boat with the shark-friendly fishing gear that is utilized to conduct tagging and sampling procedures. Everyone was in a great mood because the forecast for the day called for perfect fishing weather. Once the high school students from Our Lady of Lourdes Academy arrived, brief introductions were made, and the crew set out for an eventful day of shark tagging!

As Captain Nick Perni set course for fishing grounds south of Key Biscayne, and the RJD crewmembers cut bait and prepared the drumlines for deployment, lab manager Christian Pankow briefed the high school group on how the fishing equipment is deployed and retrieved throughout an entire day of fieldwork. Even though Our Lady of Lourdes Academy are old hands at tagging and sampling procedures, they were surprised to learn that fish traps are now being utilized by the RJD team to investigate fish morphologies and population assemblages associated with the presence or absence of shark populations. The two fish traps were deployed south of Stiltsville, a group of wood stilt houses positioned on the edge of Biscayne Bay along the sand banks of the Safety Valve. Then, after watching RJD Intern Samantha Owen demonstrate how to safely and properly cast out the baited circle hook and line, Our Lady of Lourdes Academy students helped deploy the remaining nine drumlines.

While the lines “soaked” for an hour, the students assisted with taking environmental measurements, including the salinity and dissolved oxygen content of the surrounding ocean water. Lab manager Christian Pankow gave another briefing to Our Lady of Lourdes Academy to prepare them for the participatory day of shark research, which would include fin clips, measuring, and collecting vital tissue samples and data. However, the briefing was cut short when a blacktip shark was spotted breaching around the first research buoy, which meant a shark was on the line! The first group of students assembled to assist with data collection as the RJD team sprung into action. The 1.46 meter (4.79 ft) blacktip shark, which was one of the smallest sharks of the day, was swiftly and carefully secured onto the stern of the boat and the water pumped was inserted into the shark’s mouth. RJD graduate student Jake Jerome collected a blood sample from the caudal vein and Our Lady of Lourdes Academy students assisted with taking morphological measurements and inserting a dart tag into the shark’s dorsal fin. After completing a successful workup, the blacktip shark was released back into the water in great condition. The breaching blacktip shark was an amazing sight to see and was only the beginning of a fantastic day of shark tagging.

The largest shark of the day was a 2.00 meter (6.56 ft) great hammerhead that was caught while pulling in the second round of drumlines. Great hammerhead sharks are easily stressed and become quite delicate when kept on the line for an extended period of time, so the students watched from the top deck as the RJD team worked up the shark in less than four minutes. RJD graduate student Jake Jerome was able to collect a blood sample from the caudal vein of the great hammerhead for his ongoing Masters’ research, and the crew worked efficiently enough to conduct an entire workup procedure before the great hammerhead needed to be returned to the water.

In total, the RJD team landed a 2.00 meter (6.56 ft) great hammerhead shark, a 1.67 meter (5.47 ft) nurse shark, a 1.25 meter (4.10 ft) black nose shark, and six blacktip sharks ranging from 1.18-1.71 meters (3.87-5.61 ft). Each shark was swiftly and carefully brought to the boat and secured on the platform for a brief sampling and tagging procedure. It is safe to say that Our Lady of Lourdes Academy students are now well practiced in tagging, sampling, and morphological measurement techniques. One of the procedures performed by the students included the nictitating membrane reflex test. The nictitating membrane is a clear, inner eyelid that protects the eye of a shark during feeding events. The reflex of the nictitating membrane is one visual factor that can be used to determine the stress impairment of sharks.

After the remaining drumlines were brought on board, the crew finished the day by checking the fish traps set earlier in the morning. A series of morphological measurements and images was taken of each of the several bony fish caught in the fish traps for future analysis. Overall, the RJD team had a fantastic day out on the water with Our Lady of Lourdes Academy. We hope they enjoyed the opportunity to participate in a day filled with exceptional scientific research and education, and we cannot wait for them to join us again on future shark tagging trips.

Shark Tagging – Scouting New Locations

April 2, 2014/2 Comments/in Shark Research /by aanstett

By Laura Vander Meiden, RJD Intern

I stared at buoy three as it floated further and further away. In my mind there was only one explanation; one of us had mistied a bowline, allowing the buoy to free itself from the weighted drum on the ocean floor eighty feet below. The drum was lost to us and with it the line and baited hook. If a shark got hooked now, there would be no way to free it.

We were an hour into a scouting trip to a deep reef right off of the coast of Miami. We had just finished deploying our first set of ten lines when the captain noticed the wayward buoy. With the Miami skyline in the distance and a glassy, flat ocean all around, it had been shaping up to be a beautiful day, but as the boat turned to go collect the buoy I stressed over such a bad start.

However, as we got closer to the buoy it became very apparent that it was moving in the opposite direction of the current and the buoy hadn’t come free. That could only mean one thing, we had caught something big. In a flurry of movement we prepared to bring the shark in. As one of the interns slowly reeled in the line, a large sickle-shaped dorsal fin broke the surface. One of the interns squealed with excitement, it was a hammerhead.

Taking measurements of our first great hammerhead of the day.

We brought the great hammerhead along the back of the boat and quickly got to work. Hammerheads are particularly susceptible to stress, so instead of completing a full workup we took only cursory measurements and a small fin clip. Then it was time to tag him. Earlier that morning our lab manager Christian had prepared a satellite tag just in case we had a catch like this. In less than a minute, the specially designed hammertag was in place, bobbing along just behind the shark’s dorsal fin as he made his way away from the boat. From then on, every time the shark surfaces, we will receive data through a satellite on his location and other factors.

What a start. We hadn’t officially begun hauling in our first set of lines, and we had already caught a hammerhead. The mood on the boat was decidedly giddy. As we began to bring in the first set of lines, all of the RJD crew, staff and interns alike, could not stop grinning.

Our first few lines came up empty, then we realized we had another runaway. Buoy four was missing. We scoured the ocean around us seeing nothing, until finally the captain made out a tiny red dot halfway to the horizon. Could it be another hammerhead? It was. Out of hammertags, we quickly pulled him in, took our measurements and fin clip and sent him on his way, a standard spaghetti identification tag firmly in place.

The great hammerhead swimming away. You can see the yellow spaghetti tag, just behind its dorsal fin.

The rest of the first set of lines was relatively uneventful, with the exception of a feisty green moray that had decided to latch on to one of our baited hooks. The moray put up a pretty impressive fight, tying itself in endless knots, until finally we were able to get the hook free. He slithered off the boat and back into the water, leaving a trail of yellow slime behind. Green morays are actually blue; their slime gives them their green coloration.

With the second set of lines we caught our third hammerhead of the day, allowing us to reach what we had thought was an ambitious prediction of three hammerheads by RJD intern Pat. We also hauled up a massive nurse shark and a line that had been chewed all the way through by what was most likely a bull shark.

RJD intern Hannah Calich takes a blood sample from the nurse shark.

For the third set of lines Christian decided we should scout out another, shallower location. I was thankful, hauling in over 100 feet of line is no easy job, and everyone’s arms were starting to feel the toll. The set zipped by without a bite until line nine. With barely any pressure on the line, we thought we were just bringing in untouched bait, until we noticed a tiny nurse shark attached to the end. With a total length of just 95 cm, or just over three feet, it was the smallest nurse shark I had ever seen. Everyone gathered around, cooing at it with smiles almost as big as the ones for the hammerhead. Though I thought it must have been pretty young, Christian told us it was probably about three years old. It was our last shark catch, and a great way to end the day.

Check out a video of our satellite tagged great hammerhead here.

Tagging with Bonefish-Tarpon Trust

March 24, 2014/1 Comment/in Shark Research /by aanstett

By Gabi Goodrich, RJD Intern

While our mornings may be early to most, it’s at this time of the day that can be the most exciting for our team. This past Friday’s trip with Bonefish-Tarpon Trust was no exception. As we crossed over the bridge onto Key Biscayne, the beauty of the ocean seemed overwhelming.

This trip was going to be different for me. I had never been on a trip using the boat R/V Maven, however despite this fact the day would prove to be nothing but spectacular. We met on the dock of the Miami Seaquarium and loaded all our gear onto the boat. Today we were going to a new spot that Neil had a “great feeling about.” We greeted our guests and before I knew it we were on our way out to the site. Around an hour later, we were there. The conditions were amazing. The water was so clear you could see every detail of the reef. We promptly set the lines and took the salinity, temperature and dissolved oxygen levels. We then left for Broad Key to pick up the rest of the guests. From there, the excitement started to grow. We headed back to the lines and started pulling them up one by one. On the very first line, a huge 248 cm (8.136 feet) male Nurse Shark had been hooked! I couldn’t believe it! The kids on the boat were so excited! They felt the shark and one exclaimed, “This is the coolest thing I’ve ever done!” From there, our day would get busy. On line four, a beautiful 199 cm (6.528 feet) female tiger shark! Already we were getting a wonderful variety of sharks!

Neil Hammerschlag high fives a student participant.

But it didn’t stop there. Line five of the same set of ten a gorgeous male Nurse Shark. Line eight was one of the most exciting for this set. Pulling in the line on the yoyo (a circular device used to reel in the monofilament), a fin emerged out of the water. Neil got on the highest vantage point and exclaimed with so much excitement that it was a Great Hammerhead Shark. If you know Neil, you know how excited he gets when we hook a Great Hammerhead. This beautiful male was 230 cm (7.545 feet) long and was in amazing shape. The team promptly satellite tagged him, did the work out, and before we knew it we parted ways with him. After, Neil let out a “YAY!!” in rejoice and the excitement was felt throughout the boat. You’d think this would be the most exciting part of the day, right? Well little did we know we had so much more to come. Line ten of this set had another beautiful 180 cm (5.905 feet) female Tiger Shark. I couldn’t believe the variety and diversity of species we had gotten in the first ten lines!

A great hammerhead is reeled in towards the boat.

We deployed the lines again for the next round of ten. After about an hour, we pulled up the first line to find again another Nurse was hooked! This female Nurse Shark was 222 cm (7.283 feet) and a force to be reckoned with. Most people we take on the boat don’t think Nurse Sharks are powerful but they are! We a struggle, we finally got her to the boat. Line six of this set brought us another 240 cm (7.874 feet) female Nurse Shark! I couldn’t believe it! So many sharks! The fun didn’t stop there. The next line brought in a 268 cm (8.792 feet) female Tiger Shark! We had already gotten eight sharks of three different species! On our last round, we deployed five lines. Again the first line we pulled had a shark! This would be a huge 242 cm (7.939 feet) male Bull Shark! 25 lines deployed, nine sharks caught and tagged of 4 different species! Everyone on the boat was overcome with joy and appreciation for what was caught. It was by far one of my favorite trips I had ever been on!

A tiger shark is released back into the water.

Shark tagging with Westminster Christian School

September 10, 2013/1 Comment/in Shark Research /by aanstett

by Dani Escontrela, RJD Intern

It was another wonderful day of shark tagging. I was so excited to head out again I could hardly sleep and ended up waking up extra early. I rode down to the keys with Jake and soon enough we were at captain Curt’s house.

We loaded the boat with the drums, yo-yos, platform and the rest of the gear we would need for a day of shark tagging; we also added extension lines to our drumlines because we were planning on going to a deeper site.

Shark Tagging with Rho Rho Rho

April 23, 2013/0 Comments/in Shark Research /by aanstett

by Nick Perni, RJD Intern
Saturday, April 20th, 2013

Saturday’s trip out of Islamorada was one to remember. Our guests were members of UM’s Marine science honor society Rho Rho Rho. Since their last trip yielded no sharks, the pressure was on to give our fellow classmates an up close encounter to the oceans top predator. On our way out to the reef Rho Rho Rho made sure to let us know just how disappointing it was to not catch a single shark on their previous trip.

When we arrived at the reef we set our drum lines and assured our guests that this would be a more successful trip than their last. After an hour of letting the drums soak we began to pick up our lines. In no time we were hauling up sharks. Our first was a scalloped hammerhead. The students clamored at the stern of the boat knowing too well that this could be their only chance of the day to see a shark. But the day was far from over.

Line after line came up with a shark and our guests were entirely engaged in the tagging and work-up process. By the end of the day we had caught eight sharks. Five were Hammerheads ranging from 9-13 ft (including 3 Scalloped and 2 Great Hammerheads), a new RJD record for Hammerheads caught on a single trip! The other three included two Sandbar sharks between 6 & 7 ft and one 7½ ft Bull shark. This was a spectacular trip for everyone aboard the

R/V Endsley, RJD was able to deploy two satellite tags and Rho Rho Rho finally got their lucky break. Upon our return to shore multiple interns agreed this was the best trip they had ever been on and I’m pretty sure our guests would agree.

The Top 10 RJD Science and Outreach Accomplishments of 2012

December 28, 2012/1 Comment/in Conservation /by aanstett

2012 was a great year for the RJ Dunlap Marine Conservation Program. As it comes to a close, we wanted to share our top 10 science and outreach accomplishments from the past year with you.

10) In December, the RJ Dunlap Marine Conservation Progam’s Facebook Fan Page passed 1,500 fans! Have you become a fan yet? We use the page to share live updates and photos from the field, as well as to share marine science and conservation news from around the world. Like us on Facebook, and, while you’re at it, follow us on twitter, too!

9) We deployed 24 satellite tags in 2012, 8 on bull sharks, 2 on great hammerhead sharks, and the rest on tiger sharks. We also added a new type of satellite tag called a “HammerTag” to our toolbox. The custom-made tag has the ability to recharge its battery via a small solar panel, permitting multi-year deployments You can track all of our satellite tagged sharks from our website.

A tiger shark with a new HammerTag. Photo credit: Jim Abernathy

Shark Tagging with Breakthrough Miami

November 14, 2012/3 Comments/in Shark Research /by aanstett

by Laurel Zaima, RJD Intern
Saturday, November 10^th, 2012

After all of the late nights studying for my tests, and quizzes, Saturday could not have come fast enough! Before I knew it, the count down was finally over and I was driving down to Islamorada with Christine. Unfortunately, when we arrived at Captain Curt’s house, the weather was looking a little grim and the wind just began to pick up. Regardless of the weather, everyone remained optimistic! Captain Curt informed us that we would be going to a shallow site that was approximately 15-22 feet in hopes that the water would be less choppy. Little did we know, we underestimated the power of the waves.

As we waited for our guests to arrive, we each predicted which species of shark we were going to encounter that day. Although there was a little discrepancy about what we were going to catch, we all agreed that this shark tagging expedition had good vibes. Fortunately, we were correct, and the student group was able to have a great educational and hands on experience. We went out with a group that is apart of a program called Breakthrough Miami. This program assists low income and disadvantaged students and their families that reside in the Dade County. The students of the Breakthrough Miami program are taught, supervised, and mentored by high school student volunteers from Palmer Trinity School (grades 6-12). We hosted 15 middle schools students, 3 high school mentors, and the program’s chaperones on Saturday’s trip. We were thrilled to be hosting this program because Leann Winn, one of the RJD trip leaders, is a teacher at Palmer Trinity School, and she raved about how wonderful and intelligent these students are.

Shark tagging with Miami Dade College and friends

July 2, 2012/0 Comments/in Shark Research /by aanstett

Friday, June 22, 2012
Megan Piechowski, RJD Intern

Three weeks ago I imagined spending my summer at home, in Austin, TX. When I was offered an internship with RJ Dunlap I was ecstatic, as this incredible opportunity seemed to piece itself together nicely. Last Friday was my second trip as a member of the team, which was exhilarating as I was able to be truly involved in securing the sharks and collecting samples. We went to the Everglades National Park with a helpful group of Miami Dade College students and an enthusiastic family that bought a satellite tag, or Hammer-tag.

Some say nothing is perfect. I beg to differ

May 8, 2012/1 Comment/in Shark Research /by aanstett

Saturday, May 5th by Virginia Ansaladi, RJD lab manager

It’s that time in the semester again when you can’t even remember what the ocean looks like – or the sun for that matter. 5-Hour Energys are your best friend and all nighters are like that guy from high school who just realized you’re the only one he knows in the chemical oceanography class he’s having trouble with – you can’t avoid them no matter what you do. Needless to say, I was PUMPED about spending a day on the water to get away from it all. Little did I know what a truly amazing day it was going to be.

We RJD folk like to carpool to relieve that monotonous 2 hour drive down to Islamorada where we go fishing, so I was up by 5am collecting my things before heading out to pick up my fellow RJD buddies. Turns out it had been a long week for everyone so I had a couple bobbing heads on the way down that highlighted my own tiredness. Luckily, fellow intern, James Komisarjevsky, is a grade A copilot and supplied me with energizing fruity V8 deliciousness, because as soon as w got there it was go go go. We loaded the boat, collected forms from our participants, and we were off – with quite an eclectic group might I add.

We had members from Shark Whisperers charity, Shark Savers advocacy group, and shark lovers from the community at large out with us today. A really great group to have aboard – lots of questions, lots of interesting conversation, but most of all, lots of enthusiasm.

The conditions were perfect out for sampling one of our deeper sites (a chance we don’t get often), so we attached some extension lines to our drumlines and dropped our first ten 150 feet down into the blue. And what do you know? Not only was the weather cooperating, but so were the fish.

Posts