bull shark – Shark Research & Conservation Program (SRC)

Posts

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 Felix Varela Senior High School

March 21, 2016/0 Comments/in Shark Research /by aanstett

By Shannon Moorhead, SRC Intern

On Saturday March 5^th, the SRC team was joined by students and faculty from Felix Varela Senior High School- and what a day it was! When I arrived at Crandon Marina, I was afraid that questionable weather would keep us inshore, but our trip leader settled on a location: Soldier Key in Biscayne National Park, right on the edge of where Biscayne Bay meets the Atlantic Ocean. It was a spot I had never been to, but my teammates claimed to have caught some very interesting things there, so I was quite excited. The team loaded up the boat and once our guests arrived and the pre-trip introductions were completed, we were off!

When we arrived at Soldier Key, the team deployed our fish trap and the first set of ten drumlines in about ten feet of water. While we waited for the lines to soak, our trip leader Jake Jerome briefed the students on the shark workup procedure and how they would be helping us tag the shark and collect data. The first, and very important, data collection the students helped with was “environmentals”: recordings of the temperature, salinity, and dissolved oxygen content of the seawater around our site. Environmental data is recorded for each set of lines deployed and can give us important insight into factors that may significantly affect shark abundance in the localized area. Once this was complete and the lines had soaked for an hour, we went to retrieve our first set!

The decision to go to Soldier Key immediately paid off when we pulled up a male nurse shark on the very first line! I had the great honor of “jumping head” on this shark, which means I was responsible for keeping its head in place. I never realized how difficult the job was: this shark would not stop moving and it took four of us to secure him to the platform! Once he had settled down, the Varela high students assisted us with the working up the shark, while SRC team members drew blood and took morphological measurements. First, students helped us measure the shark, which came out to 231 cm, about 7 and a half feet! Next, a mark-recapture tag was inserted just beneath the shark’s dorsal fin: this will let us know if we catch the shark again and has the lab’s phone number on it so fishermen can contact us, and hopefully provide us with some data, if they catch the shark. Finally, a student took a small clipping of the shark’s dorsal fin, which can provide us with information on what the shark is eating via stable isotope analysis. When the process was complete, the shark was released back into the water and we moved on to the second line.

A Varela High student helps insert a mark-recapture tag into a nurse shark.

But the fun didn’t stop there: on the second line we discovered a gigantic bull shark! The likely pregnant female was a struggle to get onto the boat, because of how heavy she was, but was very cooperative once we had lifted her on to the platform. She was so big that when Jake tried to switch to the other side of the shark I had to lift his leg over the dorsal fin for him because he couldn’t get it high enough! The big girl measured 287 centimeters, almost 9 and a half feet! After a quick workup, we got her back in the water and retrieved the rest of the first set, but unfortunately there were no more sharks to be seen. We reset the lines and the waiting began again.

SRC graduate student Jake Jerome keeps the head of this massive female bull shark secure during the workup procedure.

When we went to pick up the first drumline of the second set, we ran into a slight problem: we couldn’t find it! After a brief search, we found the line #1 a quarter mile from where we had set it tangled with a crab trap. The team and I were getting very excited; whatever had dragged our 40 pound drum a quarter mile must be huge. And it was: as we pulled in the line a massive female great hammerhead slowly rose to the surface! Once she was alongside the boat, SRC members took charge on the workup. Our lab’s research has found that hammerheads get stressed more quickly than other shark species so during the workup the shark is left in the water and the workup is performed by the SRC staff to make sure it goes as quickly and smoothly as possible. In the interest of time, the shark was not measured, but the team estimated she was 13 feet long because she was longer than our 12 foot platform! Luckily, the team had time to attach an external acoustic tag to the shark’s dorsal fin. Acoustic tags send out a ping which can be picked up by receivers placed underwater around Florida and along the east coast by SRC and other labs. This gives us extremely valuable information about the movement patterns of this highly migratory species. Once the tag was attached this beautiful behemoth of a shark was released successfully!

View from above and below the water as SRC graduate student Robbie Roemer prepares to fix this great hammerhead shark with an external acoustic tag.

We reset line #1 and hauled in and redeployed the rest of set 2, on which there were no more sharks. Set number 3 and our fish traps came up empty as well, but we weren’t very disappointed. It may have only been a three shark day, but we were thrilled. For several of us, those were the largest bull shark and largest hammerhead we had ever seen! The students of Varela High seemed to share our excitement: not every day you get up close and personal with animals of that size! It was an awesome trip, thanks to Varela High for the help and enthusiasm, can’t wait to have you guys out again!

Thanks for a great day Varela High!

Shark Tagging with National Geographic

February 22, 2016/0 Comments/in Shark Research /by aanstett

By Shannon Moorhead, SRC Intern

As I set out for Crandon Marina early Tuesday morning, my hopes were not high: the sky to the north was a dark, foreboding gray; there was a wall of thunderstorms moving towards Miami on the radar; and I had received multiple worried texts from my parents concerning tornado warnings throughout south Florida. Despite the circumstances, I was eager to get out on the water. Today was our second day on the boat with a film crew, who were shooting a hammerhead shark special for Nat Geo Wild’s “Sharkfest”. Unfortunately, the first day of filming was rather windy, confining us to inshore waters where we caught no sharks. It was the first time I had struck out on a trip and I was afraid the morning storms would keep us in the same location.

Just as the team assembled in the parking lot, the storm hit. My fellow interns and I watched from the safety of Diver’s Paradise dive shop as a torrential rain and whipping winds made the marina look like a scene from a disaster movie about hurricanes. But as we waited out the storm, our luck began to turn. First, I received an email that could turn any day from bad to good: it was my acceptance letter into University of Miami’s Rosenstiel School of Marine and Atmospheric Science! I was so excited (and relieved) that my attitude changed, and with it so did the weather. The skies cleared and revealed a beautiful, calm, sunny day: perfect for going offshore. We loaded the gear onto the boat, the film crew arrived, and we set out to tag some sharks! When we reached our location for the day, the team deployed our first set of 10 drumlines, in addition to a fish trap (to better understand the assemblages of fish species in the areas where we fish for sharks), and took environmental readings (data on seawater temperature, salinity, and dissolved oxygen content). Then the waiting began.

SRC interns Robbie Roemer, Jake Jerome, and Shannon Moorhead secure a female hammerhead shark to the platform

After letting the lines soak for an hour, we moved to pick up the first drum. There was a small twinge of disappointment as the first line came up shark-less, but lack of sharks was not a problem we had for long. On the third line of the day we pulled up exactly what we were looking for: a beautiful great hammerhead shark! A wave of excitement washed over the entire crew; it is fishing after all, and we had been unsure of whether or not we’d be able to catch a hammerhead while we had the film crew with us. We got the shark on board (a 251 cm female, over 8 feet long!) and proceeded to do a quick workup: hammerheads get stressed more easily than other shark species, so we wanted to get her back in the water as soon as possible! Luckily, the SRC team performed like a pit crew for sharks and measured, tagged, drew a blood sample, took a fin clipping, and released her within just a few minutes. As the shark briskly swam off, the team celebrated a job well done and moved on to pick up the rest of the first set.

There was little downtime after the first workup, as we discovered a shark on the very next line! Our program’s director, Dr. Neil Hammerschlag, worked on bringing the shark towards the surface and it became apparent by the way it was fighting that this was a big one. As the shark emerged from the depths we identified it as a massive male lemon shark, indicated by the large second dorsal fin, which is similar in size to the first dorsal. He fought hard, but the team was able to work him up onto the platform to be processed. Measurement revealed he was a whopping 266 cm long, just under 9 feet! Much of the team agreed, it was the largest lemon shark most of us had ever seen. After a quick work up, he was successfully released back into the water and we proceeded to check the rest of our lines.

SRC intern Robbie Roemer preps for surgery to implant an acoustic tag in the abdomen of a recently mated female bull shark.

Though line 5 came up empty, set 1 continued to be lucky when we found a bull shark on line 6! At 245 cm, about 8 feet, she was the shortest shark we caught that day, but what she lacked in length, she made up for in girth. As we began to collect data on the female bull, we noticed fresh scars on her pelvic fin: a sign of recent mating! The in-water photographers told us they could see another bull shark circling below the boat; perhaps this was her mate. After the usual workup procedure was completed, an acoustic tag was surgically implanted in the shark’s abdomen. The acoustic tag will “ping” when it comes within a certain distance of receivers placed under the water, allowing for better tracking of the shark’s movements around Miami as part of a study on bull shark utilization of urbanized habitat. The surgical incision was sutured and the girthy female was released in great shape.

SRC interns Rachel Skubel and Shannon Moorhead secure a female nurse shark while SRC director, Dr. Neil Hammerschlag, discusses the shark for the National Geographic film crew.

Just when we were beginning to think set 1 couldn’t get any luckier, we pulled up a large female nurse shark on the very next line: back-to-back sharks twice in one set! She measured 267 cm, nearing 9 feet long. After a quick workup, the shark was returned to the water for a healthy release. The team pulled up and redeployed the rest of set 1 and went back to check on set 2. Unfortunately, the tide had turned between sets and with it our luck: the next 30 lines came up empty. The team remained in good spirits for the strong first set made up for the lackluster rest of the day. We picked up our fish traps and processed what we found inside (a filefish and cottonwick, a species of grunt) then headed for home, thrilled with the data we had collected (on four different species, nonetheless!) and excited to get back on the boat for our third and final day with National Geographic.

SRC director, Dr. Neil Hammerschlag, thrilled after a great day of tagging!

Shark Tagging with Christopher Columbus High School

October 30, 2015/0 Comments/in Shark Research /by aanstett

By Shannon Moorhead, RJD Intern

The sun was just beginning to rise as my fellow intern, Grace Roskar, and I began our drive to Crandon Marina. On a typical day, waking up so early would leave me tired and irritable, but it’s hard not to be in a good mood when you have a day of shark tagging to look forward to. We met with the rest of the RJD team at 8, loaded up Diver’s Paradise with the equipment we’d need for the day, and, once our school group was ready, set out to tag some sharks!

As the team cut bait and prepared the drumlines for deployment, our trip leader Pat Goebel briefed the students on our fishing gear and how they would be assisting in our research. This trip we were joined by Christopher Columbus High School, and they were the most energetic group I’d seen yet! The boys divided themselves into four teams (which they dubbed Banana, Nemo, Clasper, and Pumpkin Spice) to take turns participating in such critical tasks as taking a fin clipping, measuring, and, most importantly, tagging the sharks. After the short trip to Stiltsville, a community of houses built on stilts above the waters of Biscayne Bay and our site for the day, the team set two fish traps. These wire mesh cages are baited to attract nearby fish and give us insight as to what species the sharks are sharing a habitat with. Then, students helped us deploy the first set of 10 drumlines; spirits were high as each line set was met with a round of cheers and applause from the enthusiastic Christopher Columbus High.

With the help of the RJD team, a Christopher Columbus student measures a blacktip shark.

After the students assisted us with some environmental measurements and the lines had soaked for an hour, we returned to the first drum. When a Christopher Columbus student hauled the drum onto the boat, it was apparent we were sharkless for now. However, we didn’t have to wait long. Team Banana, proving the fruit may not be bad luck on boats after all, suggested the use of a banana-colored yo-yo (plastic ring monofilament is wrapped around)to pull in the line on drum #4 and sure enough, there was a shark on! The smallest shark of the day, measuring 1.5 meters (a little over 5 feet), the male blacktip fought hard, running all over the place before we got him on the boat. Once the shark was secured on the platform, Christopher Columbus students assisted the team with data collection while graduate interns drew blood and took morphological measurements. The whole process was done in about five minutes and the blacktip swam off in great condition!

Trip leader Pat Goebel and graduate intern Julia Whidden affix a satellite tag to the dorsal of a huge female bull shark.

There were no sharks to be found on the remaining lines of the first set, but hopes were still high. The boys of Christopher Columbus High kept up the energy by singing, treating the team to rousing renditions of tunes ranging from “Bennie and the Jets” to “Hotline Bling”. “I’ve never met a group of high school boys that likes to sing acapella more” said graduate intern Julia Whidden. Apparently, the sharks enjoyed the music because on the fourth drum of the second set we had another shark; this time it was a massive female bull shark, 2.7 meters (almost 9 feet) long! She was enormous, there was barely enough room for the team on the platform with her. While the RJD team and Christopher Columbus students performed the usual workup, a satellite tag, generously provided by citizen scientist Nika Hosseini, was attached to the shark’s dorsal fin. Satellite tagging a new shark is very exciting because it provides us with data that can help answer important questions about shark movement patterns, habitat preference, and vulnerability.

Undergraduate intern Grace Roskar helps a Christopher Columbus student apply a dart tag to a bull shark.

We stayed very busy the rest of the day, catching a total of 7 sharks! We landed a 1.9 meter (6.5 ft) feisty female nurse shark, a small 1.8 meter (6.2 ft) male bull, and three female blacktips, ranging from 1.6-1.7 meters (5.2-5.7 ft). Once the last drumline was hauled in, we made our way back to the fish traps. The team measured and photographed the fish caught, primarily pinfish, and returned them to the ocean while the boat headed back to the marina. This was a great trip; not only did we gain data on several sharks of three species, but we got to deploy a new satellite tag that will gain valuable data on the movement of the bull shark. The day was made even better by the fantastic attitudes of the students of Christopher Columbus High. Thank you for your hard work and enthusiasm, hope to see you on the boat again soon!

Christopher Columbus High School students and faculty, our citizen scientists, and the RJD team after a long, busy day.

Gulliver Field Studies in Marine Science Students have Amazing Day Shark Tagging with the University of Miami

September 24, 2015/0 Comments/in Shark Research /by aanstett

By Frank Gissoni

On June 19^th 2015, we were greeted at the Diver’s Paradise boat at Crandon Marina by Captain Eric and the University of Miami’s RJ Dunlap Marine Conservation team. Cap and the team went over some basic rules and procedures with us. Our special guest, fishing celebrity Peter Miller, host of the TV show Bass to Billfish and proud Gulliver parent arrived at the dock with a large fresh Amberjack that he caught for our trip while filming an episode the day before. The RJ Dunlap Team briefed the students and the rest of our group. Our team included Luis Ceballos, whose daughter was in the class, and Miller Drive Registrar Miriam Vizoso. Our tasks would include; buoy and bait deployment, measuring the animals, taking a fin clip for future DNA analysis, and tagging the animals. We were also charged with testing the reaction of the shark’s nictitating membrane (eyelid) to determine whether the animal is under any stress during the procedure! If any shark displayed any stress during the tagging and data collection process the team released the animal immediately. The safety of the team and of the sharks was paramount and all information the RJ team convey was intensely absorbed by the students. Before we knew it the engines roared and we were off.

Cruising along at idle speed through the Manatee Zone just outside of the marina, our optimism was palpable. After all, we all had reasons to be optimistic, there were clear blue skies, light wind, calm seas and we were armed with the freshest bait anyone could ask for. As we headed north past Government Cut, signs of life were everywhere. Birds hovered over schools of bait, flying fish took to the air as we passed, and even a free jumping sailfish playfully danced for us in an amazing acrobatic display. Finally we had arrived at the location. We were about 3 miles (4.8KM) offshore in about 150 feet (45M) of water, when we began setting our lines. We were using a drum line setup. First the baited hook and line went in followed by a 35 pound weight and lastly the buoy. The students stepped up one by one to deploy the lines, after all why not get the youngest and strongest involved first. We placed our lines one by one, a line of golden Sargassum Seaweed guided our path like our own yellow brick road. As the team was deploying buoy number nine the Cap called down from the flybridge. We had a shark already on the number eight buoy. The tone was set for the day. There indeed was a shark, a beautiful female sandbar shark golden brown in color and about 7 feet long. Everyone got to work. The students and the UM team worked with the speed and efficiency of a Nascar pit crew, measuring, recording data, taking samples and finally implanting a spaghetti tag. In just a few moments the shark was safely off on her way. The specialized circle hook, designed to catch in the jaw of the shark, did its job as usual and the shark with a powerful sweep of her tail splashed the team at the boat’s stern as she swam off. We barely had time to high five and celebrate when the Cap yelled down again, “buoy number six!” Off we went. This time it was a large bull shark, a powerful stubby nosed dark grey boy 7.5 feet (2.3 m) long. This was what we were looking for, a perfect candidate for a sonic tag. This time only the RJD team worked on the shark. The tag about the size of a thumb drive was implanted in the shark’s abdominal cavity, and after a few stitches he was on his way. This shark was going to be the first specimen of a new research project studying the movement of local populations of bull sharks. We told the RJD team we would be interested in adopting this shark through their adoption program and naming him Gulliver, so we could all watch Gullivers’ travels.

The learning opportunities and cross curricular ties would be enriching for Gulliver Schools. Our day continued at the same frantic pace it began with. Shark after shark was brought onto the boat, another male bull shark, and six more female sandbar sharks all about the same size were caught. Each of these sharks displayed tooth rakes on their heads and sides, the tell-tale signs of mating. These bite marks are the result of sort of a shark embrace and the female is anatomically prepared for this with her extra thick skin. What a day! Muscles were sore, skin was sunburned, gallons of water had been consumed, eight sharks tagged and safely released. The day could get no better, then it did. As we began retrieving the last of the setups, one had a heavy shark on the line. As we got the shark closer we could believe our eyes. It was a very large great hammerhead shark. The whole boat exploded into action. Hammerhead Sharks are particularly sensitive to stress so this shark had to be tagged quickly. Members of the RJD team grabbed hold of the sharks’ body after a safety lasso was secured and the Gulliver team grabbed on to the RJD Team to keep them from going overboard. One member of the RJD team got in the water with his GO Pro and recorded the event. It was controlled mayhem. This shark was to be satellite tagged. The tag was quickly affixed to the dorsal fin of the shark and measurements were taken. The Cap yelled down from the bridge, “My boat is 13 feet across the stern.” We could all see the shark was longer! “Ninety three centimeters across her head from eye to eye” someone yelled out. “Over three feet wide, and her dorsal fin is almost as tall!” We were all amazed! After a few minutes she was ready to go. Pat from the RJD Team was already in the water. He swam her off and gave her a little push, she faded from our view into the cobalt blue water and our experience with the great ocean predator was over. We had accomplished our mission. On the way back to the dock we reflected on our day. Eleventh grader Niles Miller called the day “Epic!” Miriam Vizoso claimed, “What an amazing day for the students!” Jasmin Thernhurr said, “This was a once in a lifetime experience.” Freshman Paula Ceballos gushed, “Best field trip ever Mr. Gisonni.” I could not have agreed more.

Shark Tagging with Trinity Prep

April 17, 2015/0 Comments/in Shark Research /by aanstett

by Pat “Banana” Goebel, RJD student

When I woke up on Saturday morning, I was really excited to be going shark tagging. I couldn’t wait to go on a trip with Trinity Prep as their students are always engaged and willing to help. I snagged everything I needed for the day and headed down to Miami. Little did I know I would be returning from this trip with the nickname “banana.”

The team arrived at Diver’s Paradise at 8 am to load the fishing gear onto the boat. After a few sips of coffee, everyone was ready for an excellent day on the water. The students from Trinity Prep and a couple citizen scientists arrived around 9 am and couldn’t wait to get on the boat and go shark tagging with us. Captain Eric gave a safety briefing followed by David, who gave a detailed explanation of our fishing methods, which is designed to reduce fishing stress.

On the way out to our fishing spot, the team prepped the rest of our gear and cut fresh bait. Once we arrived at our fishing spot, the group came to the back of the boat to see how we deploy the lines. Then they helped us deploy the rest of the first set of ten lines.

A student from Trinity Prep helps us deploy our drumline

After an hour soak time, we headed back to our first drumline. The first set of ten lines had no sharks. On the second set we got a small nurse shark. The third set resulted in one blacktip and one nurse shark that got away.

Now, this is where the story gets interesting! Many fisherman and captains believe bananas are bad mojo on a fishing on boat. Why? Because fisherman and captains are very superstitious, however, I am not. There are many theories on why people believe bananas are bad luck but I won’t go into that. After 35 lines, someone noticed I had banana. Captain Eric and basically everyone else on the boat demanded that I get rid of it. But, it was a good banana and I didn’t want to toss it away. So, I was forced to eat the banana even though I wasn’t hungry!

A student from Trinity Prep takes fin clip

Before the consumption of the banana, we were having a normal day (3-4 sharks). After the banana was disposed of (but was it really if it was in my stomach), we went from an average to well beyond average day. We doubled our catch for the day in five lines. Yep! We went 3 for 5 once the banana was gone. The second line had a blacktip, the fourth line had a large nurse, and the final line of the day had a large bull shark.

I remember thinking to myself, “wow! Did that really just happen? I am never going to hear the end of this one.” So, as you can imagine all the blame was put on me. My name quickly changed from Pat to Banana. But, it didn’t stop there. After the trip, Captain Eric graciously bought me banana suit to wear on the next trip.

The trip on April 11^th will likely be a trip none of us will forget. The students from Trinity Prep were a great help and showed a passion for our research. We left them with a plethora of new knowledge about the importance of the ocean, which hopefully they will share with others. Sharing our knowledge about ocean conservation is truly a remarkable experience. Thanks to all who participated.

P.s. I bring a banana on every trip…

Shark Tagging with Citizen Scientists

March 4, 2015/0 Comments/in Shark Research /by aanstett

by Alison Enchelmeier, RJD student

This past Thursday and Friday, the RJD crew spent two days tagging with a group of citizen scientists. Our guests met us at the boat at 9:00 am and we set off for one of our usual spots, Safety Valve. I’d been on a trip there the previous week and we had caught a variety of sharks, so I was hopeful we would be just as lucky this week. We set out lines and Dr. Hammershlag explained to our guests how we catch sharks, work up sharks, and the research involved for each sample and measurement. After leaving our lines soak for an hour we returned to pull up the first line. Our day began with a nurse shark on line three, but before we could pull it onto the boat it got off the line. The citizen scientists were disheartened by the loss, worried that the lost nurse would be the only shark they would see. Their fears were unfounded as two lines later we caught another nurse. Over the course of the day we remained busy as we caught six more nurse sharks ranging from 2.09 m (6.86 ft) to 2.63m (8.63ft) and one bull shark that came off the line before we could bring it to the boat. With a successful day of seven nurse sharks we returned to Crandon Marina for the evening.

On Friday we decided to fish closer to shore to try and find a different variety of sharks. We set our lines out along Bear Cut and RSMAS and measured water temperature, dissolved oxygen, and salinity while we waited for the lines to soak. All conditions seemed to be in our favor as the very first line we pulled up wriggled with the weight of a shark. As the line reeled in we held our breath, was it a nurse shark or something else? As the fin broke the surface we had our answer, a bull shark!

Measuring bull shark Caption: Citizen scientist helping the RJD Team work up a bull shark

Jake Jerome and Dr. Hammershlag pulled the 2.19m (7.2ft) female onto the boat. We did our usual workup on the shark before Neil implanted an acoustic tag under her skin. The tag will be used for the Urban Shark Project, a study on sharks in urbanized environments. After returning her to the water we continued to pull lines. We didn’t come across anything until line 15. We pulled up another female bull, this one larger than any bull shark I had seen before, 2.9m (9.5ft). After the workup she was fitted with a SPOT tag and released. As we pulled lines that day we could see people swimming and paddle boarders paddling. The fact that both the sharks and beach goers were coexisting in the same area really brought home he fact that humans aren’t on sharks’ menu.

Bull shark aerial view Caption: Jake and Dr. Hammerschlag reeling in a bull shark

Bull shark view Caption: Jake and Dr. Hammerschlag reeling in a bull shark

In two days we caught seven nurse and two bull sharks, quite the successful trip. Thank you to our citizen scientists for joining us on this trip. I’m sure they had as much fun as we did!

Shark Tagging with South Broward 9/26/2014

October 1, 2014/1 Comment/in Shark Research /by aanstett

By Jake Jerome, RJD Graduate Student and Intern

Last Friday marked the first time that RJD went shark tagging out of West Palm Beach, and it proved to be an exciting first! We were joined with one of our more frequent school groups, the South Broward Reef Dogs. After making the trek up to West Palm, we loaded up the Deep Obsession with our gear and set out with the crew from Jim Abernathy’s Scuba Adventures aboard.

With choppy seas and rain falling down on us, we launched our first 10 drumlines in the hopes of catching our first shark in West Palm Beach. Despite the weather conditions, everyone on the boat kept spirits high and we all had a good feeling about the day. After letting the lines soak and collecting some environmental conditions with the help of our guests, we began pulling up our lines.

After a slow start and the rain still pelting down on us, we managed to pull up an Atlantic Sharpnose, the most abundant shark species in South Florida. Once we brought the shark aboard, we began our quick workup to collect data for our over 9 research projects. In less than 4 minutes we were able to collect multiple morphological measurements, a fin clip, draw blood, place an identification tag and perform nictitating membrane stress tests. Once these procedures were completed, we released the shark and returned to pulling in our lines.

A participant helps take a fin clip, a small cartilage sample that will help reveal long-term toxicology and dietary patterns.

After our first shark we seemed to hit a slump going into our second set of drumlines. After switching the crew around, our luck took a drastic turn for the better! While pulling up one of our final drums of the second set, we knew immediately we had something big on the line!

After hearing our captain shout “Shark,” all eyes turned desperately towards the water looking for the animal. Once the shark hit the surface we could see that it was a hammerhead! After we had the large male secured next to the boat, we realized that we had a Scalloped Hammerhead, a species that we rarely get to collect data from. Knowing this, we quickly collected as much data on the animal as possible and then attached a satellite tag so we could follow the shark’s movements after we released him. For the rest of trip, spirits remained high and we were fortunate enough to catch two more sharks, a feisty blacktip and a large bull on our very last line of the day.

Measurements of the scalloped hammerhead are quickly taken while a satellite tag is being attached.

All in all, our first trip out of West Palm Beach proved to be a successful and exciting one. We were able to collect data from four sharks of four different species and were able to satellite tag a Scalloped Hammerhead! Thank you so much to the always awesome South Broward Reef Dogs and the rest of the crew from the day.

Our awesome group for the day, the South Broward Reef Dogs!

Shark Tagging Trip – Oak Ridge High – May 2, 2014

May 9, 2014/0 Comments/in Shark Research /by aanstett

By Lindsay Jennings, RJD Intern

On Friday, May 2^nd, RJD once again set out for a day of shark tagging, this time with the school group, Oak Ridge High. We headed out from the Miami Seaquarium and motored out to our first site, north of Soldier Key, in Biscayne National Park. Once all of the drumlines were baited and ready to go, the students eagerly volunteered to help deploy the first ten lines. While waiting for the first set of lines to soak, we were able to go for a quick swim and snorkel, which was most refreshing since it was beginning to turn into another hot Miami day. When it was time to starting pulling the hooks, the students from Oakland High all helped reel in and reset the lines. As the first three sets didn’t yield any sharks, we had to remind our guests that not catching any sharks is still important for our data collection.

Students helping us take environmental data for dissolved oxygen and salinity.

Despite this setback and just when we thought we weren’t going to catch anything, on our fourth set we reeled in a female bull shark with a total length of 194 centimeters. Interestingly enough, she only had one eye, but still managed to be healthy and strong. Once secured on the platform, our usual workup was conducted with all of the students ready and willing to help at their various tasks such as taking measurements of the shark’s body length and tagging the dorsal fin for future identification. After all of our data was collected and everyone onboard was able to get a good look at the bull shark, the RJD team quickly and safely released her as she swam off in the distance.

Post workup, the female bull shark swims away healthy and happy.

After pulling in a few more lines without any luck, to our surprise, we found ourselves hauling in a fairly large and strong barracuda! As barracuda are one of the main species of bait RJD uses in its research, we decided to keep it for future shark-tagging trips. We proceeded to pick up what lines were left in the water and gathered all our gear back on the boat. It was a sunny and successful day with the Oakland High students and RJD interns both excited and enthusiastic to help out where needed.

Once the boat was docked back in its slip, we took our customary group photo and said goodbye to our student helpers for the day. All in all, it was a successful day as RJD obtained more data for its ongoing research projects and the students from Oakland High were able to become shark researchers for the day! We look forward to seeing them again!

Our awesome group of Oakland High students and RJD interns.

Shark Tagging with Our Lady of Lourdes Academy

March 21, 2014/0 Comments/in Shark Research /by aanstett

By Hannah Calich, RJD Graduate Student and Intern

Despite not being a morning person, I never seem to have a problem waking up on trip days. This past Saturday was no exception. I was especially excited because this was going to be my first trip with the Our Lady of Lourdes Academy (OLLA) and my first overnight trip on Broad Key!

It started as many do, we met OLLA at the Miami Seaquarium and before too long we were on our way. We decided to fish near Stiltsville because the RJD team had a very successful trip there the day before and we had a hunch the sharks were still hanging around. We set our gear, recorded the environmental conditions (temperature, salinity, dissolved oxygen level), and had some lunch while we waited for the lines to soak.

A group shot before we pulled the lines in.

An hour later we checked on our lines and saw that our hunch was right! In the first 10 hooks we caught two male nurse sharks, one of which was one of the largest nurse sharks I’ve ever seen, 3.3 m! Once the RJD team restrained the sharks the OLLA girls went to work collecting data. The OLLA team helped us identify the species, determine the sex, measure the sharks, and collect small fin clip samples for future genetics and diet research. In the next two sets we caught three more nurse sharks (two females and one male) that were all approximately 2 m long. Just like with the first two sharks, the OLLA team went straight to work so we were able to collect our data and quickly release the sharks.

A nurse shark being restrained by the RJD team.

After we pulled our last drum out of the water we headed to Broad Key. We docked, cleaned our gear, and went for a quick kayak trip before dinner. Dinner was a delicious mix of buffalo burgers, mushrooms, corn, salad and even s’mores! After dinner the girls went up on the rooftop and spent the rest of the evening stargazing. Sunday morning we ventured back up to the roof for some sunrise yoga led by RJD’s own yoga instructor, Virginia! After yoga we made breakfast and got back on the boat.

To vary our sampling sites we decided to sample in the Broad Key channel. Despite our best efforts, our first 10 hooks came back empty. Since we hadn’t reached our hour soak time yet, we left our sampling site and the girls went for a quick swim near some mangroves to cool off. We returned to our gear to find a nurse shark! Unfortunately, the nurse shark slipped the hook and swam off before we could get it on the platform. Just as we were beginning to think we were going to be skunked, line 9 came up with a powerful, healthy, 2.1 m long bull shark! Just as before, the OLLA girls sprang into action to help us sample this beautiful animal as quickly as possible.

An OLLA student helping the RJD team take measurements of a bull shark

All in all, it was a successful trip. We caught 7 sharks in total, 6 nurse sharks and 1 bull shark. We got to spend the night at the beautiful Broad Key Research Field Station, and the RJD team got to enjoy the company of another fun and enthusiastic school group. Thank you to all of the OLLA girls, Ms. Taylor, Chris, and our fantastic captain, Eric for all your hard work over the last few days! I can’t wait for the next one!