Expedition leaders: Dr. Phil Matich and Sorantaa Bain

Crew: Dani, David, Gabby, Jesse, Matt, Sami and Stevano - Saving the Blue also hosted local marine science students Skye and Tayshaun from BAMSI, for multiple day experiences with our team.

Day 1

Day 1 started early with an 8am flight. After loading the crew, their bags, and our research gear we were off to our destination for the week. Fifty minutes later, the scenic landscapes and seascapes of Andros emerged and we enjoyed the flight across the island, observing the blue holes the island is known for.

Upon touching down and clearing customs and immigration, we drove down to the Bonefish Lodge in Cargill Creek, had a discussion about our goals for the week, and ate a quick lunch so we could get to work. Our first research stop for the trip was the Tongue of the Ocean to seek out one of our target species – silky sharks. And we weren’t disappointed, upon arriving, we were met with a welcoming party of eight juvenile and adult sharks.

We had hopes of snorkeling with the sharks before we began tagging them, but the current was incredibly strong, so we got the fishing and tagging gear ready. Once the equiptment went in the water, the sharks started to bite and we hooked a huge 2.8 meter silky shark. We quickly measured and tagged her before releasing her back into the deep blue, then sought out more sharks. But as quickly as they had appeared, the sharks were gone. So we transitioned to our second objective – recovering a deep water acoustic receiver that had been recording the presence of our acoustically tagged sharks for the last 16 months. For many of our receivers we snorkel or scuba dive to deploy and recover them, but the Tongue of the Ocean exceeds our depth limits, so the receiver was attached to an acoustic release – a device that when trigged will detach the receiver from its anchor, allowing it to float to the surface with the buoy it is attached to. Using a transducer that signaled the release, we connected and sent the release code. Because the receiver was so far down, it took some time for it to surface, and there was some concern that it was still at the bottom. But a few minutes later, we spotted and recovered it, everyone smiling because of our success. Downloading the receiver later that night would reveal that more than 20 sharks had been detected on the receiver over the 16 months, some repeatedly using the area for the duration of the deployment.

It's not clear if it was our patience or diverting our attention to another objective, but after recovering the receiver, the sharks returned. We were fortunate to catch and tag another silky shark with an acoustic transmitter before concluding our day in the Tongue of the Ocean. Only two sharks, but it was a great start, and we were excited about the next six days. After returning to the lodge and having dinner, everyone relaxed and prepared for the next day.

Day 2

We awoke and the palm trees at the lodge told us that the wind was starting to pick up, so staying inshore was the plan for the day with the aim to deploy more acoustic transmitters, but on another species – Caribbean reef sharks. Unlike day one, it took some time before the sharks showed up. We set block rigs throughout the morning, and as we persisted we were met with our first nearshore species of the trip, a nurse shark.

We would catch and tag another later that afternoon, but the highlight of the day was a juvenile tiger shark. This pint-sized version of its older brothers and sisters had brilliant stripes that are the characteristic for which the species is named, and after the initial capture event, it was very calm as we measured and tagged the 1 meter shark. We continued to fish after releasing the tiger shark, and our persistence paid off – we hooked up with two reef sharks, one that was large enough for us to acoustically tag.

While we implant identification tags in all sharks we catch, we generally reserve acoustic tags for larger individuals for the safety of the animal and because of our research goals. But we hope to expand our work to the smaller individuals that play an important role in the coral reefs of Andros. After tagging our fifth shark for the day and with the sunlight waning, we headed back to the lodge for a delicious dinner and hopes that our good luck would continue into Day 3.

Day 3

As with Day 2, we awoke to increasingly windy conditions and darker skies. The forecast was questionable for the afternoon, so we stayed near the lodge in the back reef habitat to seek out more reef sharks to deploy acoustic transmitters in. And we weren’t disappointed – two Caribbean reef sharks took our bait, totaling five acoustic transmitter deployments in 48 hours!

In addition to these reef sharks, we also caught and tagged a small, but mature female blacknose. These sharks are lower on the pecking order than reef sharks, but are important predators of fishes that connect the back reef and seagrass flats of east Andros through their hunting actions. Individuals with their characteristic black-smudged nose makes them relatively easy to identify. Shortly after releasing the blacknose, we noticed the sky getting even darker and clouds starting to converge on our position.

We recognized a rainstorm was heading our way and we quickly hauled our gear as water started falling from the sky. The experienced crew made light work of breaking down the gear, and we drove back to the lodge amidst a deluge. The silver lining was that all of the gear (and us) had been given a thorough freshwater rinse, so cleanup would be easier. Because the weather was questionable for the rest of the day, we stayed at the lodge, relaxed, played some games, and prepared for tomorrow.

Day 4

The windy weather that challenged us for the first half of the week didn’t stop, and we were unfortunately unable to go out on the water. Taking advantage of the shore-based day, some of us traveled to north Andros to collect some tissue samples for diet analysis to better understand what resources are important for the sharks in Andros, while others relaxed, reviewed photos from earlier in the trip, and took in the scenery that surrounds the lodge. Upon returning, we decided to go on a bit of an adventure.

One of the advantageous aspects of Andros is that we can almost always find sharks even when we’re unable to do so via boat. In the afternoon we made an excursion to a nearby beach, where we often see lemon sharks swimming near and in the mangroves. After a short hike along the beach we arrived at our spot and were fortunate to find one shy, little lemon shark. Everyone was so calm that the shark was taken aback once it realized it was swimming next to us. We also saw a variety of fish, including a gang of checkered pufferfishes that were many of our favorites for the day because of their curious nature.

After returning back to the truck, we drove to a restaurant for dinner, and enjoyed the Bahamian cuisine. The sharks were few and far between today, but we all enjoyed the opportunity to explore the island from the land and a little local flavor. We returned to the lodge, enjoyed the evening, including the lemon sharks that use the waters of Cargill Creek, and headed off to bed in preparation for tomorrow.

Day 5

The wind was still upon us, but we would not be denied and headed out to one of the major waterways that bisects northern and southern Andros. We deployed blockrigs throughout the day with the hopes of catching and tagging a variety of sharks known to use the backwater flats of the island.

We deployed blockrigs and checked them. Redeployed blockrigs and checked them again! And eventually we caught a rambunctious nurse shark. After securing it alongside the boat, we measured its length and outfitted the shark with an internal identification tag prior to releasing it back into the water. The lack of sharks led us to believe that there could have been a large tiger or hammerhead shark cruising the flats, deterring the other sharks from taking our bait. But if that big shark was around, we didn’t see it or tag it. The nurse shark was our only shark for the day, but tomorrow would be a different story. We headed back to the lodge to clean up, have dinner, and prepare for what would be a sharky Day 6.

Day 6

Despite the long week with only 11 sharks tagged to this point, the crew were optimistic and for good reason – we were heading to a location where we would be protected from the wind and that was known to be a hot spot for sharks that cruise along Andros’s coral reefs. We set off early and started to deploy our blockrigs.

And it didn’t take long for the action to start. Before 9 am we caught and tagged a nurse shark and a mature male reef shark, the latter being outfitted with an acoustic transmitter to track its movements across the reef. This reef shark was nearly 2 meters, and surely a seasoned predator in these waters. After our first reef shark for the day, we caught another nurse shark, quickly measuring, tagging and releasing this male in anticipation of the next sharks that would be on our lines soon. But we waited a bit.

The shifting tide gave us a break, but not for long. Soon two more reef sharks took our bait, and we deployed acoustic transmitters with each of them, totaling five reef sharks acoustically tagged for the trip. Then we were met with a species that is unusual for us to catch on the reef – lemon sharks. The first was huge – a 2.6 meter female that was very rotund, a sign that she could have been pregnant. Because of the unusually flexible nature of lemon sharks, the crew were extra careful to secure, measure, and tag her before releasing her back into the water. Shortly after the first lemon shark, we hooked another large lemon!

Most sharks swim away from the sampling site after they are tagged in order to recover. But not all sharks. We caught the same male nurse shark from earlier in the day for the second time! He obviously had not grown, but must have really liked our bait or been hungry enough that taking our bait was worth the risk of another capture. Recapture rates are about 5% for sharks, meaning that we have a 1 in 20 chance of catching the same shark more than once. But this is generally for the entirety of a research project, not in a single day. The recapture of this nurse shark was very unusual and indicated the tagging process did not deter him from staying in the area and continuing to feed.

We’ll be looking for this shark in future trips to see if he has a proclivity for our fishing method, and if we do the data will be valuable to assess if he uses the same habitat throughout the year. After a shark-filled day, we decided to treat ourselves with a snorkel on the nearby coral reef. We had been on the boat or on land for the trip, so this was a nice way to mix things up and enjoy the local fauna from a different perspective.

The corals were gorgeous and we had the opportunity to practice our freediving as we sought to get closer to the fish that resided along the reef. After getting our fill of snorkeling, we returned to the boat, traveled back to the lodge, and enjoyed our dinner and last night in Andros with the company of the local lemons sharks.

Day 7

Considering our success throughout the week catching and tagging 19 sharks across six different species, we decided to enjoy them from a different perspective today. After breakfast, we travelled to a nearby area that often has sharks that will swim near the boat. Unfortunately we only found some snapper, but the beautiful scenery was something to enjoy during our last hours on the boat.

We returned to the lodge for lunch and to pack our bags before heading to the airport for a return flight that seemed all too soon. Many of us had been to Andros before and we looked forward to returning, hopefully during a less windy week. As the plane took off, we enjoyed the vistas of Andros one more time before crossing the Bahamas Bank and landing in Fort Lauderdale. Until next time.

Thank you

Thank you to our research trip leaders Dr. Phil Matich and Sorantaa Bainfor 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 Stevano for his top class boating and captaining skills.

Gratitude must also go to Gabby Lozada for her generosity in allowing us to use her imagery in this blog.