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Unraveling the mysteries of the Saba Bank

Nick and Caroline Robertson-Brown

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For the first time on the Saba Bank, an expedition team was able to successfully assess the shark diversity by attaching five satellite tags and confirming pregnancy stages by ultrasound of two species of sharks. This research advancement resulted in assessing 56 sharks, including 16 Tiger sharks with one confirmed early-stage pregnancy, and the first tagged male in the region. These details indicate that the Saba Bank’s important role in the shark populations of the North-Eastern and wider Caribbean Region have yet to be unlocked. This information is crucial to better protect sharks within the Dutch Caribbean’s Yarari Marine Mammal and Shark Sanctuary as well as beyond.

Dutch Caribbean Nature Alliance (DCNA) along with the Protected Area Management Organizations of the Dutch Caribbean: Saba Conservation Foundation (SCF), Nature Foundation St. Maarten (NFSXM), St. Eustatius National Parks (STENAPA), STINAPA Bonaire, the Aruba National Parks Foundation (FPNA), the Dutch Caribbean Nature Alliance (DCNA) and World Wildlife Fund for Nature- The Netherlands (WWF-NL) led a team on the Saba Bank in collaboration with Arizona State University, University of Groningen, Beneath the Waves and funded by the Biodiversity Fund of the World Wildlife Fund for Nature- The Netherlands (WWF-NL) .

This week-long ocean research expedition aimed to understand the stages of the reproductive cycle of tiger sharks on the Saba Bank. Tadzio Bervoets, Director of DCNA and expedition leader adds: “It is critical to collect the data necessary to advance the conservation actions for species of sharks in the Caribbean Region and with the data collected over the last week we have been able to get a clear picture of the important role the Saba Bank plays.”

This expedition built upon previous research and expertise from collaborating scientists.

Throughout the week, the team was able to deploy five satellite tags on the dorsal fin of tiger sharks which will allow tracking of the animals over an extended period of time. The ultrasounds which were taken using high technology imagery to determine the maturity and pregnancy stage supported by Brooke Anderson, Ph.D. candidate of Dr. James Sulikowski’s Lab, Arizona State University show that the Saba Bank is a reproductive area for IUCN Near Threatened listed species tiger and the IUCN endangered listed Caribbean Reef Shark. One of the female tiger sharks was confirmed with an early stage pregnancy and boasted a total length of 251cm. This multidisciplinary research approach is necessary for taking the first steps in understanding the reproductive life cycle for the species in the region.

One of the mysteries which resulted was the first tagged male on the Saba Bank sized at 306 cm and later named Maestro Angelo. While it is common to find females, it was surprising to encounter male tiger sharks during the research. Due to the lack of research done previously on these sharks on the Saba Bank, it became evident as to why there is a need to emphasize the importance and need for scientific research into these species.

Expeditions brought forward by the protected area management organizations, such as this one, support the necessary research needed for data-driven management solutions. These results will be used to help steer future research activities, inform local governments on the significant impact these species and their habitats have on ecotourism, and ultimately strengthen conservation policies. Ayumi Kuramae, Saba Bank Management Unit Officer shared the importance of this study:

“Through previous tagging expeditions it was clear that the tiger sharks tagged on the Saba Bank can travel as far south as Grenada, crossing many nations’ borders. This shows the importance of protecting the species not only in our waters, but region wide. Seeing male and female tiger sharks together of different life stages, shows us that protection of these species in our water is vital since we may be protecting the future generation of tiger sharks in the region. A decrease in the number of sharks can affect the overall fish stocks which leads to a disturbed natural balance in the sea. Saba, for example, highly depends on fisheries and dive tourism as part of the local economy which also relies on a healthy fish stocks. Thus, understanding the role of these apex predators is extremely important.”

After gazetting, the Yarari Marine Mammal and Shark Sanctuary will encompass the exclusive economic zone waters of the Saba Bank along with Saba, Bonaire and Statia. This sanctuary has the intention to provide a safe place for these animals, but without supportive data and knowledge, it is difficult to ensure they receive the appropriate protection measures. In order to survive, tiger sharks may use the Saba Bank as a key habitat for different stages of their life cycle but are known to travel to other regions during different life stages, making them a transboundary species. This expedition will help identify where larger, multi-national marine protected areas across the Caribbean should be to protect these species during their whole life cycle.

For more information about the work of the DCNA visit their website by clicking here

Images: Daniel Norwood

Nick and Caroline (Frogfish Photography) are a married couple of conservation driven underwater photo-journalists and authors. Both have honours degrees from Manchester University, in Environmental Biology and Biology respectively, with Nick being a Fellow of the Royal Photographic Society, a former high school science teacher with a DipEd in Teaching Studies. Caroline has an MSc in Animal Behaviour specializing in Caribbean Ecology. They are multiple award-winning photographers and along with 4 published books, feature regularly in the diving, wildlife and international press They are the Underwater Photography and Deputy Editors at Scubaverse and Dive Travel Adventures. Winners of the Caribbean Tourism Organization Photo-journalist of the Year for a feature on Shark Diving in The Bahamas, and they have been placed in every year they have entered. Nick and Caroline regularly use their free time to visit schools, both in the UK and on their travels, to discuss the important issues of marine conservation, sharks and plastic pollution. They are ambassadors for Sharks4Kids and founders of SeaStraw. They are Dive Ambassadors for The Islands of The Bahamas and they are supported by Mares, Paralenz, Nauticam and Olympus. To find out more visit www.frogfishphotography.com

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Lovin’ Saint Lucia: Two wreck dives and a wedding (part 3)

Nick and Caroline Robertson-Brown

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Whilst we have been lucky enough to dive in much of the Caribbean, Saint Lucia was still on our wish list. Until November when we got a chance to visit this beautiful island on a 6-night diving trip that would see us enjoy with incredible scenery both above and below the waves. We were able to sample three different hotels, dined at a host of local eateries, spoke to local school kids about the ocean and even took a tour into the rainforest canopy. Find out all about this trip over this series of three blogs on Caribbean Dive Adventures.


Our final day of diving saw us heading south again to the wreck of the Lesleen M. The wreck was sunk as an artificial reef in 1986. It sits upright in the water just off Anse Cochon in about 20m of water at its deepest point. AS it has been in the water for over 3 decades, it is now covered in marine life. Yellow and purple sponges rise up from the deck and off railings. Gorgonian corals created huge curtains across the walkways and on the bow and stern. The prop is covered in orange sponges and cup corals. Barracuda and porcupinefish cruise the middle section of the boat. Schools of reef fish live in the covered section of the stern. There is life everywhere you look. To make the most of this dive, bring a light, as the colours are incredible.

We were lucky to have been able to dive the wreck as a buddy pair, without any other groups. But we loved the dive so much we asked if we could join the group for another dive on the wreck as our final dive of the trip. However, the group we were going to dive with were a little bit special! Two of the group had got married the day before. Nine of the family (mum, dad, the happy couple, sisters, brothers, and their partners) who had come to Saint Lucia for the wedding were on our boat. We offered to take an underwater photo of them. Getting the shot was not as easy as we had first thought though! Getting them all still, in the same place, not blowing bubbles at inappropriate times turned out to be a challenge! It was, however, a joyous way to finish off our diving on Saint Lucia.

Our final day saw us heading to new heights, via a cable car experience into the rainforest canopy. Not only does this trip offer stunning views over the island, but our guide was so knowledgeable we also learned plenty about the local fauna and flora of the island. This is the perfect activity for the non-diving day at the end of a trip. A final cocktail in the beautiful setting of the Harbor Club as the sun set saw us reflect on a super trip. We barely scratched the surface of what Saint Lucia has to offer. Alas we never got to experience the diving in the north of the island, so we will have to return to rectify that. Hopefully sometime soon!


Nick and Caroline were hosted by:

Eastern Caribbean Diving

Bay Gardens Marina Haven & Bay Gardens Beach Resort and Spa

The Harbor Club

Travel Saint Lucia

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Blogs

Lovin’ Saint Lucia: Kids and Critters (Part 2)

Nick and Caroline Robertson-Brown

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Whilst we have been lucky enough to dive in much of the Caribbean, Saint Lucia was still on our wish list. Until November when we got a chance to visit this beautiful island on a 6-night diving trip that would see us enjoy with incredible scenery both above and below the waves. We were able to sample three different hotels, dined at a host of local eateries, spoke to local school kids about the ocean and even took a tour into the rainforest canopy. Find out all about this trip over this series of three blogs on Caribbean Dive Adventures.


After our first two days of diving in the south of the island, below the magnificent Piton mountains, it was time for a day off. Usually we would pack in a much diving as possible on a short trip like this, we had been invited to speak at a local school. Our hotel, Bay Gardens Beach Hotel and Spa, already support the school with a breakfast club to ensure the kids start the day with a good meal. They asked us if we might go and speak about the ocean, marine life, conservation and our work. As the school did not have a room big enough to hold all the kids, we setup in the local church. The kids filed in and sat in rows of pews and we chatted about the marine life that can be found both in the waters surrounding Saint Lucia and further afield. They knowledge of shark species was incredible! They even identified a Basking Shark correctly! We were stunned when they presented us with a huge box of local fruits they had picked from their gardens as a thank you. Our driver then took us for a drive around the north of the island to show us some of the plentiful beauty spots.

Back diving again, we still headed south, but to sample some different diving from our first two days. We were delighted to dive over a healthy seagrass bed that was home to a host of marine life. Snake eels skimmed along through the blades of grass, flounder lay camouflaged, and several species of crustacean could be found once you got your eye in. A huge Southern Stingray lay buried in the sand and our guide, Mervin, was delighted to find a seahorse (that did not want to be photographed). Dotted throughout the seagrass bed, coral bommies were a haven for small marine life critters. Eels and lobster hid in the crevices, while small juvenile fish darted through the coral and sponges.

Whilst we were on an all-inclusive basis at our hotels, we love to get out and about to try local establishments where we can. So each evening we would take a stroll to the waterfront to sample some excellent food and a local beer or cocktail, whilst watching the sun go down. The perfect way to finish off a great day of diving.


Nick and Caroline were hosted by:

Eastern Caribbean Diving

Bay Gardens Marina Haven & Bay Gardens Beach Resort and Spa

The Harbor Club

Travel Saint Lucia

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