Shark tagging with Firebrand Events

 

By Julia Whidden, SRC Intern

On Monday, March 14th, the SRC Crew went to sea with assistance from Firebrand events. We fished the shallow waters (~ 10 feet deep) of Safety Valve, an area of sand flats and tidal channels that connect Biscayne Bay to the Atlantic Ocean. Research dates the formation of this bay to between 5,000 and 2,400 years ago, while it was only “discovered” to European forces by the Spanish explorer Juan Ponce de Léon in 1513. It was around this time that explorers and fishers of the sea began to record their varied superstitions. Their expeditions were plagued by many sources, including – but not limited to: garlic, actual plagues, the number 13, and bananas.

An aerial photo of Safety Valve, the region of shallow sand flats and tidal channels that delimit the entrance of the Atlantic Ocean to Biscayne Bay. The SRC team fishes this spot often.

An aerial photo of Safety Valve, the region of shallow sand flats and tidal channels that delimit the entrance of the Atlantic Ocean to Biscayne Bay. The SRC team fishes this spot often.

While the choppy water kept us from the high seas, and our fishing was for research purposes and not sustenance, we managed to fall victim to the old sailor’s curse of the bananas. Believe it or not, SRC and Diver’s Paradise boat Captains strictly enforce the “NO BANANAS” rule. Not only are they forbidden in the contract that our passengers sign, but even mention of them by SRC grad student and banana-enthusiast Pat Goebel is usually enough to get the team riled up. On this fateful Monday, SRC crew discovered – after pulling up the first set of 10 lines empty – that each of the nearly 20 Firebrand passengers had been packed lunches with… (cue dramatic music)… bananas. Diver’s Paradise Captain Eric Cartaya took matters into his own hands and collected the remaining evil fruit from a very confused set of passengers. The bananas were piled on the bait-cutting table, smashed to bits, and swiftly tossed out to sea. The passengers remained confused. After explaining to them some of the varied and nonsensical origin stories of the banana curse, we had made it back to buoy 1 of the second set of lines.

Diver’s Paradise Captain Eric Cartaya rids our boat of the evil bananas.

Diver’s Paradise Captain Eric Cartaya rids our boat of the evil bananas.

Lo and behold, our luck changed and we caught a 1.52 m blacktip shark! This male blacktip was very freshly caught, having only been on the line for 8 minutes. We conducted a full work-up with assistance from our Firebrand crew, including measuring, tagging, fin clipping, and reflex testing. After releasing this blacktip in great condition, we sped off towards our next buoy.

SRC crew Robbie Roemer and Julia Whidden release our first catch of the day, a male blacktip shark.

SRC crew Robbie Roemer and Julia Whidden release our first catch of the day, a male blacktip shark.

We pulled up another 8 empty lines before feeling any tension on our last line of the second set. This time, we had caught a 2.3 m male nurse shark. The most interesting characteristic of this male nurse was its recently mated claspers. Claspers are the external sexual organs of male elasmobranchs (sharks, skates and rays), and have friendly features such as hooks and barbs that are used to hold onto the female during copulation. Males may only copulate successfully with a female once it has reached sexual maturity, which is physically manifested as fully calcified (hardened) claspers. In male nurse sharks, sexual maturity is reached when the total body length is around 2.1 m. This male nurse shark that we processed showed signs of having recently copulated, which appear as fresh mating scars on the male’s claspers. This type of sexual maturity data is useful in identifying the breeding requirements, including seasonality and habitat preferences, of local shark populations. After finishing the workup, the SRC team released the nurse shark in great condition.

1522975_10154598895858265_5957864302636001621_o (1)

The mating scars seen on our second catch of the day, a male nurse shark.

Our final 10 lines of the day proved fruitless, but the SRC crew and Firebrand passengers felt lucky to have caught even 2 sharks considering the bad luck that started their day. While it’s difficult to know precisely which life lessons were learned by passengers and crew of the boat, ie. don’t get between a boat Captain and a banana, I personally took this opportunity to learn “The Bananas Aboard Repentance Prayer,” in case I ever need to appeel to the shark gods again.

The Bananas Aboard Repentance Prayer

Oh great Konpira
please, hear my plea
I am sorry for my mistake
A banana I brought to sea

it was an honest gesture
a noble means of nutrition
I had no ill intent
I brought fruit of my own volition

Please forgive my idiocy
I meant my friends no harm
We just want to go fishing
and go home with a sore arm

We beg of you to release the curse
upon which I have brought
In your honor I consume these bananas
a sacrifice all for nought!

Sources:
http://miamifishing.com/bananas-and-fishing-boats

http://www.discoverbiscaynebay.org/history-and-ecology.htm
https://upload.wikimedia.org/wikipedia/commons/6/6f/Biscayne_Bay_Safety_Valve.png

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.

160214_225010_84_NatGeo

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.

160214_235657_90_NatGeo

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 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!

Shark Tagging with Our Lady of Lourdes Acadamy

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.

12194585_10154273741933265_6267211585698325101_o

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.

12195121_10154273741568265_4225978268090667961_o

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.

12240299_10154273742208265_8332997024173751382_o

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.

11251858_10154273740793265_6760234590326572440_o

Shark Tagging With Palmer Trinity High School

By Melissa Soto, RJD Intern

It was a warm November morning as the students from Palmer Trinity high school made their way onto the boat. This was my first trip of the semester so I was just as eager as they were to see sharks. After placing all the gear onto the boat, RJD and our guests were off to tag some sharks.

A Palmer Trinity student kissing the bait for luck.

A Palmer Trinity student kissing the bait for luck.

Our trip leader for the day was Christian Pankow, who kindly greeted everyone on board and continued by explaining the work up the team does on the sharks. After a calm thirty-minute boat ride we started deploying the 10 drumlines around Stiltsville, off of Key Biscayne.

Screen Shot 2015-11-09 at 4.21.01 PM

A student carefully released a drumline into the water.

After waiting an hour, we started to check the drumlines and after a three tries, we found ourselves a shark. A female black tip was safely worked up on the platform. The students broke up into groups of five and began the work up consisting of fin clip, tagging, measuring and two nictitating membrane tests. This beautiful shark was 1.65 meters and healthy. Once the work up was completed, the shark was released.

Screen Shot 2015-11-09 at 4.22.04 PM

Students and the RJD crew quickly work up the blacktip.

We continued to check and redeploy the drumlines but they were no sharks. Our second and third sets of deployments were a success. Three more black tips with lengths of 1.67 meters, 1.58 meters, 1.62 meters and a 2.35-meter nurse shark were pulled up. These four female sharks were worked up with the help of the students and RJD.

Another bait kiss for luck.

Another bait kiss for luck.

After pulling up the rest of the drumlines we made our way back to marina and took some group photos. Palmer Trinity was a great group of enthusiastic children and chaperones. We hope that they come out for another trip soon.