Expedition leaders: Dr. Tristan Guttridge, Dr. Phil Matich and Clark Morgan

Crew: Betsy, Deirdre, Hannah, Lindsay, Malcolm and Nicholas - Hannah, a conservationist, had her position on the expedition fully sponsored by Saving the Blue. Saving the Blue also invited two Bahamians, one of which is a marine science student, to join our team for full day experiences.

Introduction

We just returned from the third Saving the Blue research expedition of 2021, at the Bahamian Island Andros. It was filled with lots of laughter, sharks, blue hole adventures and a moment with a great hammerhead that we’ll ever forget! Over the six-day adventure, we tagged and released 13 sharks from four different species.

Day 1

The day we were all waiting for had arrived – Saving the Blue’s third trip to Andros in 2021! We travelled from different parts of the United States and met for the first time in Ft. Lauderdale’s executive airport, where we would depart from for our Bahamian adventure. Prior to our flight, we introduced ourselves, talked about prior experiences in marine biology and abroad, and expectations for the week. If our trips from January were any indication of what was in store for us, there was no way to predict how many sharks we would encounter, and how unique those encounters would be – spoiler alert: this would be the trip of a lifetime for all of us!

After some discussion on protocols for the week, we grabbed our bags and headed to the charter plane for our flight across the Gulf Stream and the waters of The Bahamas. After an hour, the west side of Andros appeared, shrouded by partly cloudy skies that fed the growing suspense. As our altitude decreased, the remote landscape of Andros appeared, full of tidal creeks and blue holes, some of which we would explore on this trip. After we landed, cleared customs and immigration, and took our taxis to the Andros Island Bonefish Lodge, we all unpacked and settled into our home for the next week.

We had a quick lunch, then gathered our snorkeling gear and headed to a local blue hole for some adventuring since the wind was too strong to venture out on the boat. After a short hike through the bush, we found ourselves at a blue hole, more aptly named green hole because of its color. Everyone plunged into the brackish mix of fresh and salt water, and started exploring. Dog snapper, school master snapper, and other species emerged from the shadows as we worked on our freediving skills, and a colony of blennies perched themselves along the eastern wall of the blue hole allowing us to get within inches of them before darting into their hidey-holes.

We stayed at the blue hole for an hour or so getting comfortable with our in-water abilities, then headed back to the lodge for a delicious dinner of locally-sourced conch. We relaxed and enjoyed the amenities of the lodge, then headed to bed in hopes of some exciting encounters tomorrow.

Day 2

We awoke with the coconut trees swaying, indicating that the wind had not yet died down and we would need to access the water via vehicle today. After enjoying our ready-to-order breakfasts, we grabbed our snorkeling gear once again and headed north to Blue Holes National Park. The blue hole from yesterday was a good warmup for today’s snorkeling adventure at Captain Bill’s Blue Hole, which sports a launch pad for aerial entries into this seemingly bottomless body of water in the middle of the forest. We spent a couple hours jumping into the blue hole and snorkeling around before deciding to head over to a local spot for some lunch. Sami’s is known for its seafood and chicken wings, and we sampled a variety of dishes like grouper fingers, conch fritters, and of course the chicken wings, while enjoying a view of the turquoise waters from the beach.

After lunch, we began fulfilling Saving the Blue’s mission of ocean conservation and outreach from the shore. We grabbed some trash bags, and started cleaning the beach under the supervision of sponsored team member Hannah Testa (https://www.hannah4change.org/). We spent the next two hours picking up plastic bottles, old ropes, and other debris that had washed up on the beach. Some of the items had clearly been there for months-years based on their level of degradation, and some required some extra human power. A large fishing net and an old, buried kayak were extracted from the sand, and along with the other trash, were transported to the local dump where it will not find its way back to the ocean, nor pose a threat to marine wildlife or ecosystems. The team was elated by this conservation work, and another beach cleanup was scheduled for later in the week to further this mission to help preserve Andros’s natural habitats.

While the blue hole free diving, local lunch treat, and beach cleanup constituted a full day, we sought to spend some time with the sharks that call Andros home. As such, we headed to a beach south of Fresh Creek and hiked to one of its tidal creeks, where we went for a snorkel to seek out juvenile lemon sharks and potentially a sawfish. While very rare, sawfish use mangrove-lined creeks as refuge from predators and ideal locations to seek out small-bodied fishes as prey. The soft sediment of these creeks allows them to perfectly blend into their surroundings, so we kept our eyes peeled.

Although no sawfish showed up, we found ourselves surrounded by an abundance of life. Not only was this a perfect mixing spot of primary producers like mangroves, seagrass, and macroalgae, but an array of fish and invertebrates like snapper, mojarra, pufferfish, sea urchins, and a lionfish. Upon our return to the mouth of the creek, we were given a treat – close encounters with five juvenile lemon sharks who used the creek during low tide to avoid being stranded in deeper waters where they may become prey of larger sharks that cruise the banks like some of the tiger sharks we’ve tagged in previous trips. The sharks swam around the mouth of the creek for more than 30 minutes, allowing us to observe their agility in the shallow waters, as well as the hierarchy among the larger and smaller individuals.

It was the perfect end to the day, and everyone was ready for a delicious dinner, and a lecture on the sharks of the Bahamas, which we hoped to see more of tomorrow.

Day 3

Saving the Blue has been conducting research in Andros for nearly two years, and across the previous seven trips we have caught and tagged more than 250 sharks. Caribbean reef, nurse, and blacknose sharks are among the most common in shallow, nearshore waters, but another one of our focal species, the great hammerhead, is also known to cruise these waters. In January we had the privilege of catching and successfully releasing two of these amazing animals, one called Boo who has a GPS transmitter affixed to her dorsal fin that has allowed us to track her from the bottom of the Tongue of the Ocean all the way to the west coast of Florida. While every shark provides excitement, hammerheads often move us to a higher level of adrenaline, and today would quite possibly be the most exciting encounter in Saving the Blue history to date.

Upon waking up, we realized the wind had died down over night, and today would be our first opportunity to explore Andros from the boat. Prior to departure, we enjoyed another ready-to-order breakfast, packed our lunch, and headed out for some water-based action. The first half of the day was spent deploying exploratory cameras to see if any hammerheads were cruising a nearby hotspot based on recent tracking data. Over the next 4 hours, we deployed remote cameras that recorded all the fish and sharks that were in the area. Inspection of the footage later revealed that the usual suspects – nurse sharks, blacknose sharks, and a feisty blacktip – checked out many of our cameras, but no hammerheads.

After draining all of the camera batteries, we sought to continue our in-water exploration from yesterday by going for a snorkel. Previous experiences led us to believe that lemon sharks, blacknose, and nurse sharks might show up, adding two new species to our list for the trip. Upon our arrival to the snorkeling spot, however, we were surprise by two spotted eagle rays slowly cruising across the patch reefs, potentially in search of a meal. The eagle rays were wary and kept their distance, so we watched them glide across the water effortless from a distance. Hoping the eagle rays might be curious, we anchored the boat and hopped in the water with our snorkeling gear. Several minutes later, we were met not by the eagle rays, but a 2-meter lemon shark and two blacknose, who swam around in the shallows with us for the next 20 minutes before the blacknose left the area. The lemon shark stayed, which suggested that there might be a large shark in the area that caused the blacknose to leave, and people on the boat believed they spotted a dark silhouette in the distance.

Upon aerial confirmation, everyone in the water became increasingly excited. The dark coloration and large body size could only be one of a few species, and the distinct shape of its head revealed that there was a 3-meter great hammerhead swimming less than 100 meters away. In moments like these, it’s tempting to swim toward an animal to seek out a close encounter, but this can actually induce stress and scare wildlife. As such, we stayed where we were with hopes it would swim closer, and indeed it did! As the shark approached, its dorsal and caudal fins broke the surface, creating a small wake as it swam in our direction. Within seconds, the hammerhead passed within two meters of us, unsure how to react to our presence. Everyone was motionless, trying to avoid startling it. The hammerhead proceeded to make several sharp turns and swim past us multiple times, keeping a respectful distance, but giving us a front row seat to observe the elegance of its maneuverability amidst its power and speed. Video footage later revealed this was a male great hammerhead, which may have been sighted several weeks prior during some diving and camera deployments. The hammerhead swam near us for only 2-3 minutes, but this left everyone breathless. This was the closest encounter Saving the Blue has had with a great hammerhead that we have not tagged, and we’re curious to know if this shark will stay around and give us the opportunity to track its movements later this year.

After the hammerhead’s departure, we explored the area, snorkeling in a nearby seagrass bed full of conch, sea stars, and sea cucumbers. The sharks in the area kept their distance, but upon returning to the boat, we noticed the large lemon shark was still in the area and had been joined by a 1.5 meter Caribbean reef shark. We stayed in the water with these sharks for another 30 minutes, then returned back to the boat, stunned by our earlier experience. We headed back to the lodge to clean up for the day, download the videos from our camera deployments, and enjoy another delicious three-course dinner. A lecture on research methods proceeded dinner, but all anyone could think about was our interaction with the hammerhead, replaying in everyone’s minds until we all fell asleep later that night.

Day 4

Today we would assess an area that Saving the Blue has only briefly sampled in previous trips. But based on its habitats and abundance of fish, this area promised to have more sharks, and potentially another hammerhead.

After breakfast and packing our lunch, we gathered our gear and hopped on the boat for our northward destination. After a 30-minute boat ride along the east coast of Andros, we arrived at our location, and started deploying our exploratory cameras, hoping to find another hammerhead on video. Similar to yesterday, we spent the morning deploying cameras and enjoying the new scenery above and below the water. Assessment of the videos that evening revealed that while no hammerheads showed up, a large number of nurse sharks and reef sharks made appearances along with a diversity of grouper, snapper, and other reef fish. And one Caribbean reef shark showed signed of mating, with scars above her gill slits, suggesting that she could be carrying early forms of pups as she curiously approached one of our cameras.

After lunch, we hopped in the water in hopes of another first-hand encounter with a great hammerhead, and although we weren’t as lucky as yesterday, we saw some snapper and barracuda, suggesting there may be some sharks in the area, but they were keeping their distance. To end the day, we stopped at a popular blue hole called coffin, and donned our snorkeling gear one more time for the day to see what the habitat had in store for us. Angelfish, parrotfish, and other animals swam around and in the various holes that populated the seascape, and some of us took turns exploring these areas below the surface. Everyone enjoyed viewing the diversity of coral, which was in contrast to our previous days snorkeling in seagrass beds and mangrove channels, and the array of colors was beautiful. Once everyone was satisfied with their experience, we returned to the lodge, and enjoyed another dinner of locally caught seafood (mahi mahi). After dinner, Clark gave a lecture on his recent research activities in Florida using acoustic telemetry, which would be our primary focuses for tomorrow.

Day 5

Today we woke up a bit earlier to get as much time on the water as possible before our COVID-19 antigen test scheduled for later in the day. Our mission this morning was to locate, download data from, and redeploy a series of acoustic receivers located along the fore reef used to track sharks tagged with acoustic transmitters. Clark and Phil spent the morning plunging into and climbing out of the water, gathering the receivers and placing new receivers and new marker buoys in their place. Meanwhile, the team cleaned the receivers of organisms that had grown on them like worms and algae, then downloaded the data. The data revealed that numerous silky sharks and Fenton, a large dusky shark tagged and adopted in November 2019, had been using the area for the last 5 months. This was exciting, because these receivers were deployed one year ago as an exploratory study to assess connectivity between pelagic and coastal ecosystems. And based on the data there is clearly a connection that Saving the Blue will continue to investigate. During the morning, the team also found itself gifted with another rare event – two loggerhead sea turtles mating at the surface. The team didn’t stay long so as to not disturb the event, but it was another amazing moment for this trip.

After completing the receiver retrievals and redeployments, we made our way back to the lodge to clean up and have lunch before driving north to be tested for COVID-19. All the team members were cleared (i.e. not positive), and traveled to a nearby beach for another cleanup event supported by Earth Breeze. We spent the next 1-2 hours cleaning trash from the beach and shoreline, then took some time to explore the area, including an old lighthouse guarded by some cannons that lost their function many years ago.

After dropping off the trash at another local dump, we headed back to the lodge for dinner and to discuss our plans for tomorrow when we would start catching and tagging sharks. During the discussion, the team reviewed the tagging equipment and basic tagging procedures to ensure everyone was prepared if we encountered any sharks – spoiler #2: we did!

Day 6

This was our earliest wake-up to maximize our time on the water in hopes of catching and tagging some sharks. After a quick breakfast and packing our lunch, we made our way out to a buoy where pelagic fish and sharks aggregate at certain times of year. Everyone was very excited and full of anticipation – what would today hold? As we approached the buoy, we noticed activity at the surface – there were two small silky sharks cruising the area – and it didn’t take long for more to show up. Within 10 minutes we had 7 sharks swimming around the boat, including 2 that were previously captured and tagged earlier in 2020 based on the presence of external tags that indicate they are being studied for scientific research. After 5 more minutes, we started to catch and tag the sharks. As expected, the first was a feisty 1.5 meter shark, but the team managed to secure, measure, tag, and release her in less than ten minutes, including surgically implanting an acoustic transmitter that will allow Saving the Blue to track her movements for the next 10 years. Two more sharks were quickly caught, 1.7 and 1.2 meters respectively, and each quickly implanted with acoustic transmitters to track their movements. The fourth shark of the day was a recapture from July 2020 – she measured in at 1.5 meters, nearly 1 foot larger than ~7 months prior suggesting these sharks grow quite quickly in their earlier years. This shark already had an acoustic transmitter implanted, so the team quickly took length measurements and released her back into the blue.

Throughout the morning, the team were very excited to finally be tagging sharks. And while each presented excitement and challenge, the sizes of these first four sharks (1.2-1.6 meters) was manageable for quickly securing the sharks alongside the boat and releasing them after taking measurements and tagging. However, during these tagging events, several team members noticed some larger sharks swimming below the surface. Often we think that the larger an animal is the bolder it will be. But regularly larger sharks are more wary, which has suited them well considering how long they have lived. After releasing the fourth shark of the day, large silhouettes started appearing from the deep. Anticipation grew, and the team hoped they would have an opportunity to tag a large silky shark, which have been rare since the project began in 2019. Yet Andros held one more trick up its sleeve – a marlin made an appearance for a moment, with part of its tail breaking the surface. The fish quickly disappeared, but soon after a large silky shark came close to the boat, and after passing by the bait a few times, took one of the hooks and rapidly pulled the line and the buoy clear of the boat and deep into the water.

The buoys at the end of the line nearly disappeared from view, only showing a glimmer of orange and white for minutes before resurfacing. The team pulled the shark up toward the surface several times, but when she approached the boat dove again, pulling the gear down with her. After several minutes, the team worked up the strength to bring her alongside the boat and secure her tail to ensure her safety and the safety of the team while they tagged her. Everyone quickly jumped into action, and she was released with both internal and external identification tags, along with an acoustic transmitter. Two more silky sharks were caught and tagged, totaling seven for the morning and five with acoustic transmitters, one just over 2 meters. And the large female that pulled the buoys down measuring more than 2.8 meters in length. 

The team was elated, and to celebrate, everyone hopped in the water for a quick snorkel in the blue water of the Tongue of the Ocean. No more sharks appeared, but there were a variety of fish, and the sheer volume of water beneath was a serene cerulean blue that put the trip into perspective – the team only just scratched the surface of what Andros has to offer.

Later in the day we moved in closer to shore and did some sampling of the sharks that spend time on the fore reef and back reef habitats adjacent to the buoy. We hit the tide right, and added four reef sharks, one blacknose, and one nurse shark to our list of sharks sampled, tagged, and released. The sampling today took a physical toll, but it was well worth the effort knowing that we learned a little more about the sharks of Andros, and will be tracking many of them for years to come.

Day 7

Today was our last day in Andros. And in an effort to give back one more time for the amazing experiences from this past week, some of the team traveled to the local high school in Fresh Creek. Sponsored team member Hannah gave a lecture to the students and instructors on plastic pollution and the importance of conservation, which STB advisory board member Khyrs Carroll emphasized from his personal experience living on Andros. Sharing our passion with these students and their instructors was a bittersweet end to the trip of a lifetime – Saving the Blue’s goal is not only to understand the sharks of Andros in an effort to better protect them, but to reinforce this mission across the community. We cannot wait to be back in the coming weeks, and are excited about what our future trips have in store.

Thank you

Thank you to our research trip leaders Dr. Phil Matich and Clark Morgan for guiding the team through an incredibly successful week. A huge thank you to our research assistants for their passion, determination and endless enthusiasm to work hard, learn and produce results. We would also like to thank the Andros Island Bonefish Club for their hospitality, and the hardworking and ever professional Cole from PFO Charters for his top class boating and captaining skills.

Gratitude must also go to all on the trip, particularly Clark Morgan, for their generosity in allowing us to use their images in this blog.

Early results

Blacknose - 1

Caribbean Reef - 4

Nurse shark - 1

Silky shark - 7

Total shark count for the week: 13