Shark Tagging with Felix Varela Senior High School

By Shannon Moorhead, SRC Intern

On Saturday March 5th, 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.]

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.

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.

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.

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!

Thanks for a great day Varela High!

National Geographic Filming: Day 1

By Julia Whidden, SRC Intern

On February 15th, a crew of 8 SRC members and 7 National Geographic filmmakers merged together for a 3-day tagging excursion in search of the Ferraris of the ocean: the great hammerhead shark (Sphyrna mokarran). With cloudy skies and a slim chance of rain, we made brief introductions and set off together from Diver’s Paradise at Crandon marina to the shallow waters of Cape Florida Channel. Spoiler alert: we got skunked.

SRC Intern Shannon Moorehead being filmed recording data.

SRC Intern Shannon Moorehead being filmed recording data.

While the etiology of the fishing term ‘skunked’ is debatable, most anglers can agree that catching no fish – oh, the irony – stinks. It was a first for many of the SRC interns on the boat that day, including myself, but we remained hopeful as we pulled in each of the 45 lines set that this next line would be the one. We baited our circle hooks with bonito (of the tuna family Scombridae) and barracuda (of the barracuda family Sphyraenidae, and the 1977 hit by Heart), and had several lines come up with the bait nearly intact! The sharks just weren’t ready for their on-screen close-up. The film crew used their free time to record us doing the less glamorous side of shark fishing, including cutting bait, organizing tools in our beloved “FatMax” toolbox, setting and retrieving (empty) drumlines, recording data, performing interpretive shark dances, and the fishing highlight of our day: retrieving the fish traps. At the beginning of most shark trips, we set out 2 baited fish traps near our fishing site to investigate the species assemblage of the area, or what fish our sharks may be feeding on. Today we baited both traps with cross-hatched jack, which we cut into to release juices and draw in nearby fish. After soaking for nearly 5 hours, we retrieved the 2 traps to find a combined 4 fish, including 2 white grunts, a juvenile redtail parrotfish, and a Houdini fish that escaped my slippery grip before we could identify it. From both a fishing and filming perspective, the day ended quite anticlimactically. However, we took the time to get to know the film crew, and the film crew took some time to learn about obscure and underappreciated sharks, thanks to SRC Intern Rachel Skubel having brought along her copy of “Sharks of the World”. While sound engineer Eddy’s newfound knowledge of lanternsharks did not prove useful over the rest of the trips, the chance to become friends with the film crew on our quiet first day was really valuable. Besides the obvious benefit of knowing someone before you end up in a confined space with them and a shark, talking to the film crew gave me the chance to ask questions about the holy grail of nature journalism that is National Geographic. Having grown up with the magazine being a staple of my family’s coffee table selection, I was beyond thrilled to be even somewhat involved with them, and mentally checked off “do work with Nat Geo” from my bucket list. As it turns out, getting skunked wasn’t so bad after all.

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Film crew sound engineer Eddy reading about the sharks we weren’t catching in “Sharks of the World”.

At the end of the day, we had collected data about the day’s environmental variables, including water temperature, salinity, and dissolved oxygen. Even though we weren’t able to add to it with any shark data, the saying in science goes that “no data is still data”. This means that despite not having caught any sharks in the Cape Florida Channel today, we can still learn something about why the sharks weren’t there or why we weren’t able to catch them, possibly relating to seasonal movement patterns, the day’s weather, species-specific behaviors, feeding and habitat requirements, fishing location, and a variety of other factors. Our crew remained optimistic through 45 lines of empty hooks that tomorrow would bring more action, and that today was the calm before the storm! Spoiler alert: we were right.

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One of the two white grunts that we caught in our fish traps, looking like he’s not happy about his impending physical exam.

Shark Tagging with National Geographic

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

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.

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.

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!

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

Shark Tagging with National Geographic

By Rachel Skubel, SRC Intern

This was our third and final day with the National Geographic film crew. By now, the Nat Geo team was familiar with how our research team operated; I can’t say enough about how fantastic they were to work with. After yesterday’s great hammerhead/bull/lemon/nurse shark progression, we were all optimistic about the day’s outcome.

Captain Eric set a course for Sandbar Palace, a few miles off of Key Biscayne. The depth was up to 100 feet, which meant we were able to deploy our longer drumline setups – and also that chances were good for encountering larger bodies pelagic species! Excitement grew with taking environmental measurements – water temperature was 24°C, certainly warm enough for great hammerheads!

As we pulled in the first set of 10 drumlines, our first animal of the day was to be an energetic nurse shark (GInglyostomo cirratum). We got a tonne of great data from this animal, including a series of morphological measurements, whole blood and plasma samples, and thermal imaging.

The UM shark research team working up a nurse shark

The UM shark research team working up a nurse shark

A few minutes later, as graduate student Jake Jerome was pulling in a drum, our director Neil Hammerschlag noticed the line scoping out – a possible sing of a great hammerhead, as they swim near the surface! Indeed, a beautiful Sphyrna mokarran was brought onto our platform, and was a perfect candidate for a satellite tag. We were even able to take a valuable blood sample, to be used for hormone, energetic, and genetic analyses among others. The amount we can learn from one animal is just astounding, and given their status as endangered, this is critical information for uncovering effective conservation regulation. The satellite tag will let us know where animals of this species migrate to, which (for example) informs policies regarding habitat protection.

Pulling in a great hammerhead shark, before a swift work-up by our team – including the attachment of a satellite tag!

Pulling in a great hammerhead shark, before a swift work-up by our team – including the attachment of a satellite tag!

After releasing this animal back into the water, and watching it swim away in good condition, we were thrilled about what we had caught so far. The day was far from over, as we lucky enough to capture another individual of each species (nurse and great hammerhead) for a total of four sharks! We felt fantastic about all the data we captured these past three days, and are eager to work this into the ongoing projects of the Shark Research and Conservation group. Stay tuned for some exciting publications!

The hardworking research and film teams after our three-day #sharkfest

The hardworking research and film teams after our three-day #sharkfest

If you’d like to follow the journey of the great hammerhead shark we tagged today, we will be releasing a link as soon as we get transmissions!

Shark Tagging with South Broward High School

 

By Grace Roskar, SRC Intern

The morning of February 12th, 2016 was a beautiful day for the SRC team, the Diver’s Paradise captain and crew, and students of South Broward High School to set out for a day of shark tagging. We also had two citizen scientists on board, ten-year-old Tristan and his father Jivan from North Carolina. South Broward has been a participating school group of SRC for several years, and after enduring traffic from the Miami Boat Show, the group was anxious to board the boat and embark on a day of science, sharks, and sunshine.

The waters were calm as we motored out to a certain location among the group of shallow tidal flats known as the Safety Valve in Biscayne Bay. Drumlines were prepared with tuna or jack for bait and set out to let soak for an hour. Many of the South Broward students had been on an SRC trip before, but they were still eager to listen to trip leader Jake’s demonstration of the workup process for a shark. They were already knowledgeable about different shark species, as well as how they breathe by swimming to actively force water through their mouths and over their gills, allowing for the uptake of oxygen, in a process known as ram ventilation.

Trip leader and SRC Master’s student Jake tells students about the workup process for a shark and uses Sharky, the stuffed shark, to demonstrate the procedures

Trip leader and SRC Master’s student Jake tells students about the workup process for a shark and uses Sharky, the stuffed shark, to demonstrate the procedures

After an hour had passed, we set out to retrieve the first set of ten drumlines. On one line was a blacknose shark, which is a smaller species that SRC does not encounter often. This blacknose was a male and about 119 centimeters long, or a little shorter than 4 feet. Due to its small size, Jake and Rock brought the shark directly onto the back of the boat instead of setting up our large platform, and it was safely secured on deck. Next, our citizen scientists and South Broward students assisted the SRC team with a nictitating membrane test to test the shark’s stress levels, several length measurements, taking a sample of the dorsal fin, and inserting a dart tag into the shark’s dorsal fin. Rock took morphological measurements and Hannah swiftly drew blood from the caudal vein of the shark, to be used for several different measurements such as glucose and hematocrit levels, which is valuable data for Jake’s ongoing Master’s thesis. After a quick workup, students were able to take a few moments to touch the shark and feel its dermal denticles, which are scales that are basically modified teeth, as dermal denticles means “small skin teeth.”

A South Broward student quickly pumps seawater into the shark’s eye to watch for its ‘eyelid’, called a nictitating membrane, to pop up. This reflex is a possible measure of stress levels in the animal.

A South Broward student quickly pumps seawater into the shark’s eye to watch for its ‘eyelid’, called a nictitating membrane, to pop up. This reflex is a possible measure of stress levels in the animal.

The blacknose shark was quickly and safely released, and we moved on to set out to retrieve the rest of the drumlines. There were no more sharks on the lines, so they were set out for two more sets. While pulling up one line, Jake felt tension for a moment, thinking it could be a shark, but then the line was released and the tension dissipated. It is possible there was a shark on the line but was not hooked completely and was able to get away. Even with some South Broward students choreographing their own “shark dance” in hopes of good luck, after thirty lines, we had only caught the one shark. With hopes still high, we had time to set out five more lines, but trip leader Jake and Captain Eric decided to try a new spot. We motored closer to Stiltsville, a group of houses built on stilts in a different part of the general area of the Safety Valve. We quickly set out five more baited drumlines and let them soak for about forty-five minutes. To our delight, another blacknose was hooked! It was carefully brought onto the back deck of the boat and secured by Jake and Rock. Our trip guests helped again with the nictitating membrane test, measuring the shark, taking a fin clip, and tagging the shark. Hannah was able to successfully draw blood once more and I helped with morphological measurements, including the span of the shark, clasper measurements, and taking pictures of its fins to be digitized for scale to see how sharks grow over time.

Tristan and Jivan, our citizen scientists for the day, help insert a spaghetti tag into the sharks dorsal fin.

Tristan and Jivan, our citizen scientists for the day, help insert a spaghetti tag into the sharks dorsal fin.

After thirty-five lines, the team and students were elated and grateful to have caught two blacknose sharks, which is a more rare occasion on the SRC boat! With beautiful weather all day, it was overall an exciting day on the water with South Broward High School and our citizen scientists. Although many South Broward students had been on a trip with us before, their excitement to learn about and see these apex predators never faltered. We were honored to have Tristan and Jivan onboard with us and were grateful for their help throughout the day. The SRC team gathered valuable data from the two blacknose sharks and we hope that South Broward will come out with us again soon!

 

 

 

Shark Tagging with Hialeah High School

By Casey Dresbach, SRC Intern

On the fairly windy and overcast morning of December 3rd, the SRC team and honorary audience members set sail on yet another successful venture. The SRC team and I met at Crandon Park at 8 AM, along with high school students from Hialeah High School, and a very special guest, a Canadian documentary filmmaker. As we boarded the boat, the skies began to clear up and ensured a day filled with adventure.

Catherine Macdonald, the trip leader for the day, and Jake Jerome, my fellow intern, began to speak to the students about our fishing methods and why we use such specific gear. The two briefed the students on why SRC does what we do and how each and every one of them were about to help in collecting crucial data which impacts both shark research and management. While the explanation took place, I, along with the rest of the team began to set up the gear, bait the hooks, and deploy the drums. This was repeated three times, a total of 30 deployed drums for the day. After the first set of ten, we held tight to let the bait soak in the water for about an hour. Upon waiting, I got to speak with a couple of the students and their very enthusiastic teacher. For some students, it was their first time seeing sharks, let alone being aboard a boat! Having such an avid educator on board made all the difference; the energy was wonderful and not only did the team respond, but the sharks were pretty responsive too! Our first cartilaginous friend hooked onto line four to join our educational soirée. The beautiful male Black Tip came aboard at around 170 cm, about five and a half feet long. To avoid setting up the platform in such rough seas, we landed the shark onto the boat. Little did we know that this little guy would foreshadow the rest of our catches… all to whom were in fact Black Tips! I’m honored to say I took part in such a remarkable set of catches! Teams of four students were set up and each one got to take part in the four primal procedures: nictitating the eye membrane, measuring the shark, taking a fin clip sample, and of course, tagging the shark.

A student conducts a reflex test on the shark’s eye with a stream of ocean water, checking for its ‘eyelid’ called a nictitating membrane. This reflex is being tested as a possible measure of stress levels.

A student conducts a reflex test on the shark’s eye with a stream of ocean water, checking for its ‘eyelid’ called a nictitating membrane. This reflex is being tested as a possible measure of stress levels.

The rest of the day seemed to go by fairly quick; five more sharks were caught throughout the next several hours. We landed a male Black Tip at 157 centimeters (a little over five feet), followed by a male Black Tip at 159 centimeters (a little over five feet), yet another male at 170 centimeters (about five and a half feet), and two female: one with a total length of 170 cm and another at 173 centimeters (almost 6 feet!). The team aided the participants in their tasks, snapped photos of each to get accurate measurements to scale, and drew blood from each shark, which that was taken to the back of the boat and examined by my fellow intern, Stephen Cain. Eager students head back to join him and soak in his masterly shark blood handling. Catch after catch I was able to see the spark in each and every one of the students. In being apart of such an incredible Shark Research Program, I have learned to appreciate the most satisfying recognition: inspiring high school students to take in new knowledge.

A student assists intern, Casey Dresbach, with measurements of the shark.

A student assists intern, Casey Dresbach, with measurements of the shark.

Honorary Hialeah High School’s biology teacher helps pull in a line, with Blacktip hooked on!

Honorary Hialeah High School’s biology teacher helps pull in a line, with Blacktip hooked on!

Overall, we had an extraordinary day on the sea with Hialeah High School and the Canadian documentary team, in spite of the choppy waters. After catching a record six Black Tips, I can only presume that everyone on board left feeling satisfied and content with the day. The SRC team was able to gain valuable data from our catches and workups. The trip was made best because of the enthusiasm instilled in all of the students, thank you for your hard work and energy! We only hope you continue to instill your passion in the future; it truly is remarkable. Hope to you again soon!