Recap of the Bull Shark Research Trip – January 2012

February 3, 2012

The bull shark gliding inches above the sand with ease...


The trip to Playa Del Carmen, Mexico was a great success! We teamed up with Fins Attached and were able to deploy one Smart Position and Temperature (SPOT) tag and two internal acoustic tags. The data collected from these tags and future ones will be used to determine the migratory patterns of the bull sharks and ultimately find their birthing grounds. We hope to present this information to whomever controls those birthing grounds and work on getting those waters protected.

The diving was terrific and being able to observe bull sharks was a great experience. We saw tons of life! Here’s a short list of what we saw: African Pompanos (and other members of the Jack family), Southern Stingrays, Spotted Moray Eels, Lobsters, Spider Crabs, Loggerhead and Hawksbill Turtles, Remoras, a 0.5″ baby Scorpionfish, and of course the Bull Sharks. It was amazing to see how cautious the bull sharks were considering that they are one of the most aggressive types of shark. They were timid and clearly analyzed the situation. It is obvious that bull sharks do not blindly charge in, attacking whatever they see as much of the world believes. Our underwater attempts at tagging the bull sharks were unsuccessful as a result of their cautious behavior, yet I still gleaned a ton of experience and information though diving with them.

Because we were unable to attach an external acoustic tag, we were not able to complete the 24 hour exact tracking mission that we had planned. We were however, able to use the tracking equipment and learn how it works. Ben, Alex, I assisted Dr. Antoniou in setting up the sensor and I successfully navigated our boat to our classmates who were underwater with the tag attempting to attach it to a shark.

Tagging above the water was a different story. Two of the four days that we used a fishing boat we caught a shark. We split the team up into two boats and watched, filmed, or assisted in the attempts. Attaching the internal tags was a delicate process. The shark had to have an approximate five centimeter incision through the extremely thick muscle but not so far that the scalpel would penetrate the internal organs. Two blades broke while creating the incisions and it is always sad to see the shark have to bleed a little bit. Once the incision was made the internal acoustic tag was slid inside and the wound was stapled shut to aid the healing process, which is incredibly fast for sharks. On the second and smaller of the two sharks we attached the SPOT tag to the dorsal fin. In order for data to be collected, it had to be placed so that its antennae rose above the top of the fin. This had to be done on the side of the boat with the shark right-side-up in the water. We were not sure how difficult this would be, because sharks only go into tonic immobility when they are placed upside-down. Luckily this bull shark was extremely cooperative and gave us no troubles at all. We tagged her, measured her at just over six feet, and then sent her on her way. Later we decided on the name Sydnee for the shark because Sydnee was the only female student on the trip.

In the coming weeks, acoustic receptors will be set around Playa Del Carmen to pick up the movements of the two sharks we were able to tag. I hope to return next year to do some more tagging maybe even see one of our sharks again. It was a great trip and I truly enjoyed working with Fins Attached. I hope we are able to generate enough data soon in order to get the birthing grounds protected!

-JP Griffith


Playa del Carmen shark research trip 2012 days 3-5

February 2, 2012

On Monday Mrs. Mendelow woke up early to go on the fishing boat Dr. Antoniou and Dr. Hoyos had chartered to catch a bull shark so that they could implant an internal tracking tag. When the rest of us woke, we learned that they had successfully tagged a pregnant female. We went to the same dive site as the day before and dove with the sharks again. One of them came within an arm’s length of our group, and the others were not much further away. The star of the dive was a little sea turtle that sat on the bottom right behind us, almost as if it were just another diver.

On Tuesday, we all rose early to join the fishing expedition. Sydney went on the boat with the scientists, while the rest of us stayed close by on a separate vessel. Unfortunately the sharks were not biting, so we were unable to deploy the tag. Tuesday afternoon, Connor, Marcus, Sydnee, Dr. Burke, and Mrs. Mendelow went diving with sharks again with Dr. Hoyos, who was hoping to deploy an external tag on a bull shark. Alex, JP, Dr. Antoniou, and I waited on a second boat for the tag to be set. The plan was for them to follow the shark’s signal using an acoustic receiver overnight. However, the sharks didn’t come close enough to be tagged.

Today, the schedule was similar to yesterday’s. We went out to watch the fishing take place, this time with Marcus with the scientists. After over an hour of waiting, they got a bite, and pulled in a six-foot female bull shark. They attached a spot tag to the dorsal fin, which transmits data to a satellite whenever the fin is above the water, and inserted an internal acoustic tag, which transmits data to receivers located strategically throughout the area. Later on in the day, we went on another dive with and tried to attach an external acoustic tag so we could track them with a boat, but unfortunately no sharks were present.

This trip has been a terrific learning experience, and I have enjoyed working with Fins Attached.

-Ben Lehr and Alex Wissmann and the rest of the T4O crew

Playa del Carmen Shark Research Day 1 & 2

January 30, 2012

We arrived in Cancun Saturday afternoon and drove to Playa del Carmen. We ate dinner, went shopping, and then went to sleep.

Sunday morning, we met with Dr. Antoniou of Fins Attached, a shark conservation organization, and Dr. Hoyos, a Mexican shark researcher, and discussed the current bull shark research they are undertaking. The scientists think bull sharks,Carcharhinus leucas, are using this area to feed before going to their pupping grounds to give birth to live young. If they can follow the sharks using satellite tags, they may be able to find these pupping grounds and convince governments to protect them. After the talk, we worked assembling external tags.

We broke for lunch, then returned to the dive shop to prepare for the shark dive. We took a short boat trip to the dive site, and jumped in. Eighty feet down, we waited at the bottom for the sharks to come. Even though the sharks stayed away at first there was a lot to see. We saw Spider crabs, Stenorhynchus seticornus, spotted moray eels, Gymnothorax moringa, After fifteen minutes, we were worried that they weren’t going to come, but eventually three female bull sharks approached and swam around us. They seemed more afraid of us than we were of them! We ascended to the surface and went home, glad to have seen sharks.

T4O at Aquarius

July 5, 2011

Teens4Oceans brought down a group of students to Key Largo, Florida in June 2011 to complete the second part of the Aquarius Install Project. In addition to focusing on the deployment of our two high-def cameras on the Aquarius Reef Base, Teens4Oceans was busy getting more of their students PADI certified. Ocean First Divers successfully helped Teens4Oceans get 8 students their PADI Advanced Open Water Certification, as well as 2 students their PADI Open Water Certification. Teens4Oceans was ecstatic to be joined by two students and their teacher from the New York Harbor School. The relationship between Teens4Oceans and the New York Harbor School started in Washington, D.C. during the Blue Vision Summit. Cesar, Jericsson, and their instructor Joe were extremely helpful and a great addition to the Teens4Oceans crew. Prior to the install, we were fortunate enough to visit the onshore Aquarius Control Station, and get a briefing for our dives on the Aquarius site. The diving on the trip was exceptional, including dives on the Aquarius Reef Base, a shipwreck called the Spiegal, and numerous reefs surrounding the Key Largo area. For most of the students, the dive on Spiegal got them to their deepest depth in their scuba diving career, some students getting to depths around 100 ft. After all the diving was complete and the two cameras were deployed, the group ventured south to Bahia Honda, Florida. A transect survey of the reef there was conducted as well as a maintenance check to the Teens4Oceans camera located there. The trip was extremely successful on many fronts and we are excited to use the cameras to produce education content in the near future. In addition, Teens4Oceans looks forward to continuing to build its relationship with the New York Harbor School.

T4O is going to Washington DC!

May 14, 2011

Six T4O students will travel with their education and outreach coordinator, and two T4O board members to Washington DC to attend the Blue Vision Summit. Look for lots of information on our blog and website next weekend.

From the website:

TODAY THERE IS DESPERATE NEED to develop and expand not only our biological knowledge of the seas, but also an active and educated political constituency to protect the oceans’ living resources.

There are two major new reports on the state of America’s seas, the first of their kind in over thirty years. They are from the independent Pew Oceans Commission and the federal US Commission on Ocean Policy. Both recognize that or marine ecosystems are in crisis. “A 9/11 in the ocean is sitting there waiting to happen if we let it,” warns Admiral James Watkins, head of the federal commission.

Among their recommendations is passage of an American Oceans Act. Like the Clean Air and Clean Water acts of the 20 th century, this would help assure the continued life, health and use of a vital public resource. There’s also a call for an independent ocean agency, a kind of EPA for the seas, and a doubling of ocean science support (today’s funding for ocean exploration is roughly one one-thousandth of NASA’s space budget). Still, government action is unlikely without an upsurge of citizen action to demand change.

The Blue Frontier Campaign is working to link seaweed activists and concerned citizens who, getting so much from the sea in terms of recreation, transportation, food, security, livelihood and spiritual renewal, are now ready to give something back.

The Blue Frontier Campaign has produced dozens of print, radio and television reports on America’s last great wilderness range: Its imperiled living seas. Along with addressing the latest controversies surrounding beach closures, collapsing fish stocks, killer algae, hurricanes and oil spills, the campaign seeks solutions, It does this by educating the public about a “seaweed rebellion” of coastal citizen-activists, local governments, and waterfront communities who are working to protect and restore the sea’s health and our own.

The Campaign also provides public speakers to the nations leading aquariums, to journalism and science conferences, on college campuses and to maritime and ocean activist organizations.

If you’d like to have a speaker address your group you can arrange it through the Blue Frontier Campaign, (202) 387-8030 or

Akumal: April 1

April 2, 2011

This morning we awoke to find that we could finally complete our open water dives in the ocean, and not have to go impromptu to another cenote. We decided to go in two groups to finish our certifications. One was in the morning and the other in the afternoon. Our excitement mounted as we gathered our gear, checked our tanks, regulators and BCD’s, and loaded everything onto the boats. The first group went out to the dive site, a little past the reef offshore, where we descended down the rope about 50 feet to the sandy bottom. We started our skills course, manually inflating our BCD’s and clearing our masks of water. We then took a tour around the backside of the reef, which is an extension of the larger Yucatan Fringe Reef. We saw a variety of sea life, including indigenous fish, coral species, and a stingray. We finished the first dive with our CESA (Controlled Emergency Swimming Ascent), and went up to the boat. After switching our air tanks onshore, we went right into our second dive. The final dive of the morning was shorter, and we practiced navigating by compass, remaining neutrally buoyant and removing our masks. Ben also saw a sea turtle. We returned to the surface, and the instructors congratulated us on becoming Open Water Divers.

In the afternoon, the second group did the same two dives as the first. We saw several beautiful but invasive lionfish, a couple of large sea turtles, and some Caribbean reef squid. We completed the same skills as the first group in order to finish our certification process. Despite our seasickness on the boat rides, we matured as open water divers and had an incredible experience exploring the deep blue.

Akumal: March 31

March 31, 2011


Sacha and Mr. M talked with the dive operator this morning and it was still too rough and windy to dive off the back of the reef slope. The weather tomorrow hopefully will get better or we will finish our certification in Cenoto Ponderosa!. Today we will go the lagoon that lies inside the fringe reef, right off the beach at Caribe. The plan for today is for each of us to design a field experiment, collect data, and then share our findings with each other. We will start with a seagrass survey that involves running transect lines through a seagrass bed and collecting sediment samples from the sea floor along the lines.  To perform this test, we will lay transect lines using dive weights and rope and use the pythagorean to ensure that the two lines are perpendicular to each other.  Students will then measure increments of a meter and a half along the transect lines and collect samples (The area is about 30 meters by 40 meters). We will be testing the hypothesis that seagrass beds stabilize sediments and we predict that we will find finer sediments in the patch of grass.   We will then use two ingenious PVC pipe sampling tools (designed by Mr. Mendelow) to collect sediment.


We learned that seagrass beds are important refuges for many larval stages of fish, benthic organisms, and other invertebrates. They also allow organisms to settle from the zooplankton. We saw two species of seagrass in the lagoon, and it seems that the green turtles have heavily grazed the wider bladed Thalassia. When we finish collecting data we will post the results to the blog.  Currently, we are sifting the sediments that we collected and are analyzing our data.

Even later:

Crunching data…