Shark Tagging with the Children’s Wish Foundation

By Tim Hogan, SRC Intern

On the morning of Friday, April 8th, a crew of 10 SRC interns and their captain gathered together to prepare for a day of serendipity and many sharks. Our guests, associated with the Children’s Wish Foundation of Canada, came along to meet our team leader, David Shiffman, and get some hands-on experience with the boat and sharks. The volunteer’s enthusiasm and eagerness to learn made them fit right in with the rest of the crew. After preparations were made, the Diver’s Paradise made its way to the Sandbar Palace, a deep reef with high productivity. It had previously been the site of very successful, high-catch trips, and hoped the same would occur on this day.

The second line we pulled up had tension, meaning that something was on the line. As it neared the boat, he was identified as a nurse shark, one of the more commonly caught species. This one, however, was extremely energetic and acrobatic, and began taking various evasive maneuvers, primarily consisting of twirls, flips, and twists. Eventually, he fulfilled his dream of becoming an escape artist, detaching from our line with no damage done to itself. Even though we couldn’t get any data from it, the early shark enhanced our optimism, the anticipation built with each retrieved line.

Our patience was quickly rewarded 5 lines later, as an even larger nurse was brought in with the buoy. This time, we managed to bring it onto the platform, and got the chance to collect our measurements and a blood sample. Our volunteers were eager to get involved and helped with the workup. During the downtime between lines, the volunteers took the opportunity to observe the blood analysis procedure, and also measured water samples.

 Shark Intern Leila AtallahBenson showing volunteers our blood analysis protocol

Shark Intern Leila AtallahBenson showing volunteers our blood analysis protocol

As the day progressed, we only seemed to get luckier with each drumline we pulled. On the second line on the third set, we could see the distinct dorsal fin of a great hammerhead approach the boat from the surface. The titan measured up to 328 cm (about 10’9” in the imperial system, which is basically twice my height), and it was released in good condition after our protocol. Less than five lines later, as if we received the blessings from the ocean itself, we brought in a scalloped hammerhead. Distinguished by a more curved head, it is one of the rarest sharks found on trips, and is caught three to five times a year. We went through our protocol quickly and cautiously to ensure it returned to the ocean in the best possible condition.

While we were perfectly content with our first two sets, our final ten lines had us end with a bang. Starting strong, we brought in the namesake of our site, the sandbar shark. The personal favorite of David, he was ecstatic beyond description as we went through our protocol. It was easy to see why, with its faint, iridescent skin and gorgeous color. Two lines later, we managed to pull in the most common shark in South Florida, the Atlantic sharpnose shark. Sharpnoses are typically much smaller out of most of the other species we catch. This one was in particular had a length of 116.5 centimeters, which is almost a meter shorter than the next smallest one.

The sharpnose is the most common shark in South Florida, and is also one of the smallest. The pump flows oxygenated water over its gills, ensuring that it can breathe while we do our workup

The sharpnose is the most common shark in South Florida, and is also one of the smallest. The pump flows oxygenated water over its gills, ensuring that it can breathe while we do our workup

The remaining time was more calm, though we did manage to bring in another nurse shark. At the end of the day, it was difficult to not appreciate the sheer diversity of sharks. Of the nine sharks we brought in, there were four nurses, two great hammerheads, one sandbar, one sharpnose, and one scalloped hammerhead. Our volunteers were able to see sharks in their many shapes, sizes, and functions. We returned to shore knowing the day was extremely successful, and more than grateful that we got as lucky as we did.

Our volunteers gathered around one of our Nurse Sharks after taking data and measurements, with interns Jake Jerome, team leader David Schiffman, and intern Emily Nelson

Our volunteers gathered around one of our Nurse Sharks after taking data and measurements, with interns Jake Jerome, team leader David Shiffman, and intern Emily Nelson

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.

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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

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!

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 MAST Academy

By Grace Roskar, SRC Intern

On the overcast morning of November 15th, the SRC team, the Diver’s Paradise captain and crew, and students of MAST Academy gathered at Crandon Marina to brave wind, clouds, and light rain to embark on a day of shark tagging. MAST Academy is one of our oldest participating school groups and although the weather was not the typical Miami sunshine, the students were eager to board the boat and get underway. We motored out through choppy waters to the Safety Valve in Biscayne Bay, which is a group of shallow sand flats that is intersected by the tides flowing in and out. After some quick introductions and a briefing on the process of deploying drumlines, the equipment was set out and allowed to soak for an hour. In the meantime, trip leader Christian Pankow demonstrated the process of working up the sharks to the MAST students. When an hour had passed, we set out to retrieve the first set of ten drumlines. To no avail, there were not any sharks on the first ten lines, so they were set back in the water after being reloaded with fresh pieces of bait. However, several of the hooks came up with the chunk of barracuda steak missing and two lines had bite marks and shredding on the tough monofilament line, so it seemed that sharks could be somewhere close. The second set of ten drumlines was pulled up and again, no sharks. They were set back into the water and were allowed to soak a little bit longer.

A MAST Academy student tosses the barracuda bait into the water.

A MAST Academy student tosses the barracuda bait into the water.

On the 21st line, a blacktip had been hooked! To avoid setting up the platform in such rough seas, the 1.64 meter male shark was brought directly onto the stern of the boat by Christian and grad student Robbie. Once secured, MAST students assisted the SRC team with several length measurements, taking a sample of the dorsal fin, and inserting a dart tag into the shark’s dorsal fin. The shark was swiftly released back into the water in great condition. Since time allowed, a fourth set of drumlines was deployed, bringing our total to 40 drumlines for the day. Another blacktip, slightly smaller at 1.53 meters, was pulled up and worked up via the same process on the back of the boat. Students were able to assist in the work-up process again and also touch the shark, feeling the unique texture of their dermal denticles. Another line later had a nurse shark on the hook, but just as Christian and Robbie were pulling it up to secure it onto the boat, it simply spit the hook out of its mouth and swam off! Although it was disappointing to be so close to pulling in our third shark of the day, Christian was able to estimate it at 1.5 meters in length and the students were glad to still be able to see the day’s second shark species at the surface of the water.

A student helps test the reflex of the shark’s ‘eyelid,’ or nictitating membrane, to measure the shark’s stress level.

A student helps test the reflex of the shark’s ‘eyelid,’ or nictitating membrane, to measure the shark’s stress level.

A student helps measure the total length of the shark.

A student helps measure the total length of the shark.

For the remainder of the trip, Christian dissected a barracuda eye as a demonstration for the students, and the SRC fish traps that had been deployed at the beginning of the trip were pulled up. The fish in the traps, including two filefish, were measured and photographed for the SRC’s ongoing study of fish populations associated with shark populations in the area. Although the weather was a bit less pleasant than we’re used to, it was still a great day out on the water with MAST Academy. For some students, it was their first time seeing sharks, and the whole group seemed pleased and more knowledgeable about these important apex predators after the day was over. The SRC team was able to gain valuable data from the two blacktip sharks and we hope to have MAST Academy back out with us soon!

Thank you MAST Academy for joining us for a day of shark tagging!

Thank you MAST Academy for joining us for a day of shark tagging!