Two Dutch Caribbean Tagged Tiger Sharks Follow Similar Migration Patterns in the Caribbean

captured shark on a hook

Two years ago the Dutch Caribbean Nature Alliance (DCNA) organized the first of its kind shark tagging expedition to the Saba Bank and St Maarten as part of the Dutch Postcode Lottery funded “Save our Sharks” project. Eight shark researchers with a support crew and two camera teams captured and tagged tiger sharks on St Maarten and the Saba Bank using an expedition ship. During the expedition, scientists and conservationists from the Saba Conservation Foundation (SCF), Nature Foundation St. Maarten (NFSXM), Florida International University (FIU) and Sharks4Kids equipped five tiger sharks with satellite tags in order to track their movements and presence to determine how best to manage and protect these important apex predators.

plot of a tagged shark
The track of Tiger shark Quinty through the Caribbean

Wildlife Computer SPOT (Smart Position or Temperature Transmitting) satellite tags were attached to the first dorsal fin of large tiger sharks. These tags transmit to satellites, which allow the sharks to be tracked through the ARGOS satellite system for up to 4 years. The tag uses radio transmissions, so the satellite unit must be exposed to air in order to transmit. Each time the dorsal fin breaks the surface a geo location provides an approximate location with an accuracy of up to 250 meters.

Up to now, two tiger sharks with satellite tags named ‘Sea fairy’ and ‘Quinty’ have provided the research team with some interesting preliminary results. The sharks indicate a similar migration track following the Aves ridge, a ridge in the Eastern Caribbean Sea of about 500 km in length probably of volcanic arc origin.

“The preliminary data we have been receiving is starting to show some interesting results in terms of the migratory patterns of tiger sharks in the Eastern Caribbean Sea. Not only is this data important but it is also critical for the transboundary management of a marine species critical to the health of our Caribbean Sea. Sharks are apex predators and as such keep the ocean food chain healthy, a food chain which in turn supports regional fisheries for example. With recent shark finning and fishing activities occurring in the wider Caribbean including incidents in Curacao, Dominica and Aruba it behoves nation states in the Caribbean to establish a Wider Caribbean Managemant Plan for the species,” commented Tadzio Bervoets, Project Manager for the Dutch Caribbean Alliance Save our Shark Project.

Shark Quinty was tagged under the supervision of Dr. Mike Heithaus on the Saba Bank. This 3.43 meter female tiger shark provided regular location updates. Quinty left the Saba Bank following the Aves ridge down south and subsequently swam all the way to Trinidad and Tobago, a territory known for its shark finning activities. The last received location of Quinty was close to Barbados about a year ago.

Another Shark dubbed Sea fairy was the first shark which was equipped with a satellite tag in this region and surfaced very frequently, providing researchers with a wealth of location and movement information. Sea fairy was a 2.40 meter female tiger shark at the moment it was tagged in the waters of St Maarten. She stayed the first months around St Maarten while doing forays to Anguilla, St Barths, Saba and the Saba Bank. In May 2017 Sea fairy migrated south following the Aves ridge in a similar movement pattern as tiger shark Quinty. After spending two months at the Aves ridge Sea Fairy explored the open Caribbean Sea and headed to Puerto Rico and Dominican Republic. The last location received for Sea Fairy was close to Puerto Rico also about a year ago.

“Sea fairy’s movement patterns can indicate a nursing area for tiger sharks around St Maarten, spending their juvenile years in sand and seagrass habitat before migrating around the Caribbean when large enough in size and maturity. It is interesting to see that both actively tracked sharks are showing similar migration routes following the Aves ridge, which may supply the sharks with an abundant food source” stated Nature Foundation’s Project Officer Melanie Meijer zu Schlochtern.

“In the coming year, we will expand our shark movement study and will install another satellite tag on a tiger shark on St Maarten and two more sharks will be equipped with a satellite tag on Aruba. This research will improve our understanding of the life characteristics of sharks and will provide knowledge about the population structure, abundance and migration of sharks in the Caribbean” explained Melanie Meijer zu Schlochtern.

Sharks are often portrayed as being dangerous killing machines, however the facts show the opposite. Occasionally shark bites do happen, however no unprovoked attack has been ever recorded on St. Maarten. It is more likely that one gets killed by a coconut falling on ones head than by a shark. The species are actually the victims of human impacts such as poaching, finning, overfishing and irresponsible coastal development pressure. Worldwide over 100 million sharks are killed per year resulting in half of all shark species being threatened or endangered with extinction.

captured shark on a hook
A tiger shark being tagged in St Maarten waters (photo credit: Melanie Meijer zu Schlochtern)

Shark Finning video from Curacao surfaces on Internet

Cole Bay, 22 October 2018, A video showing a group of men heavily mutilating and finning a live shark was posted on Facebook. The recoding was allegedly made in the waters of Curacao and shows a group of 5 men, who have apparently caught a shark on a fishing line, repeatedly stabbing it in the head and slicing of the tail while the animal is still alive.

“The total lack of respect for marine life displayed by these men is shocking” says Tadzio Bervoets, dedicated shark conservationist and chair of the Shark Committee of the Dutch Caribbean Nature Alliance. “Sharks play an essential role in our oceans, as top predators they regulate the whole ecosystem. We should be thankful we have sharks in our waters as they keep our reefs healthy and full of fish. But here we see a helpless animal left to die a gruesome death while people cheer and laugh.”

Shark Finning, the slicing off, of a shark’s fins and discarding the body at sea, is a cruel and wasteful practice that has been banned in most of the world’s fisheries. Curacao has signed on to international legislation banning finning in its waters several years ago (through ICCAT fisheries laws). Furthermore in 2016, during a Caribbean shark conservation meeting on Sint Maarten the government of Curacao vowed to pass legislation to create a shark sanctuary in their waters which protect sharks from human exploitation. However, to date, no such measures have been taken.

As large predators, sharks are key contributors to healthy marine ecosystems, adding to their biodiversity and durable functioning. The presence of diverse and abundant shark populations indicates the marine system is in a good ecological state. And moreover, the presence of large characteristic species forms a valuable commercial asset for Caribbean communities as an attraction for dive tourists. Shocking images and videos of shark fishing and finning on Curacao have been circulating on social media over the last couple of years, repeatedly causing a public outcry.

“In 2015, the DCNA launches the Save Our Sharks on all Dutch Caribbean islands and the Netherlands.” says Bervoets “The project worked towards protecting declining shark populations by improving knowledge about the sharks in our waters, get better protective legislation and educate people about the importance of shark conservation. Many positive results were obtained, including the declaration of several protected areas, and even regional protection of 9 species of sharks and rays. However, this video shows us a lot of work remains to be done in legislation and control but most of all in education. People need to understand sharks are worth so much more alive!”

reef shark
a Caribbean Reef Shark swimming in the Dutch Caribbean Waters

Nature Foundation’s ‘Adopt a Shark St Maarten’ Program Continues Due to Great Success!

The St Maarten Nature Foundation launched the Adopt a Shark program during St Maarten Shark Week in June 2018, but due to the continued demand of adopting a shark the Foundation decided to extend the program up to the end of this year. “It is important that we work together to ensure the survival of our shark population, with the ‘Adopt a Shark’ program we are trying to engage the community in our efforts to protect sharks and give them the opportunity to be involved in a large scale scientific research project on St. Maarten. We certainly think this a great opportunity for kids and people interested in science to learn more about research, sharks and marine life on St. Maarten” stated Nature Foundation’s Project Officer Melanie Meijer zu Schlochtern.

Different tags are being applied on adopted sharks; such PIT tags, FLOY tags and even high-tech acoustic tags have been deployed on certain sharks. A PIT tag is a microchip which gives us a unique live time barcode and a Floy tag is used to identify the shark by anyone who catches or sees the shark close-up. An acoustic tag sends out acoustic signals which are detected with acoustic receivers, thereby giving information on how much time the shark spends around a certain location, providing us valuable information about their movement patterns. DNA samples will provide information about the sharks its relationships and their length measurements provide the knowledge about the ages and growth of the sharks.

“By donating a contribution to the Nature Foundation you can adopt a St Maarten shark, you will receive a certificate of adoption and can decide on the name of the shark. As soon as the shark is tagged updates and pictures about the shark will be sent to you. With the support of ‘Adopting a Shark’ we can continue our shark research and tagging activities, we will learn more about the sharks in our waters, providing us the knowledge to better protect them” explained Melanie Meijer zu Schlochtern.

Worldwide sharks are the most misunderstood species on the planet as they are repeatedly displayed as villains and being dangerous; however they are actually the victims of humans poaching, finning, overfishing and coastal development activities. Worldwide over 100 million sharks are killed per year; as a result half of all shark species are threatened or endangered. Sharks, as top predators, play a crucial role in maintaining balance and health within our aquatic ecosystem. Besides, they are important for tourism; many divers would like to see sharks, which makes a shark worth more alive ($200,000) than dead ($50).

The’ Adopt a Shark St Maarten’ Program is part of the Dutch Caribbean Nature Alliance ‘Save our Sharks’ project funded by the Dutch National Postcode Lottery. Interested persons can send an email to naturefoundationprojects@gmail.com.

shark caught on a line
professional freediver Guillaume Jorakhae with adopted and tagged tiger shark ‘Yvje’.

Aruba, St. Eustatius Join Sint Maarten Nature Foundation in Conducting Shark Research Training

As part of the Dutch Caribbean Nature Alliance Save our Sharks Project marine conservation practitioners from St. Eustatius and Aruba joined with the Sint Maarten Nature Foundation in learning scientific research techniques related to shark conservation and research. Representatives from the St. Eustatius National Parks Office and the Aruba Arikok National Park spent a week with the Nature Foundation learning shark research methods, including shark tagging techniques, DNA sampling, biological measurements and the handling of the species. “We had an excellent week training together and learning from each other on the best ways to collect scientific data from various species of shark,” commented Sint Maarten Nature Foundation Manager and Save our Sharks Project leader Tadzio Bervoets. “Aruba and St. Eustatius are in the process of setting up their own shark research and conservation programs, so we thought it would be great for Aruba and St. Eustatius to come here to learn from the things we are doing on St. Maarten. At the same time we also learned from our colleagues and were able to add to our own data collection efforts here. Additionally, it is only through sound, properly gathered and strong information that we can continue to advocate for the protection of sharks locally and regionally,” continued Bervoets.

Both Aruba and St. Eustatius will be applying the techniques learned in St. Maarten in their own locations; “Caribbean Shark Conservation requires a regional effort, and this week was a step in the right direction,” commented Giancarlo Nunes, Research and Conservation Manager at the Arikok National Park in Aruba. “The team from St. Eustatius is very grateful for the opportunity to participate in shark research training. It was a good week with great learning experiences and we are eager to get started in St. Eustatius putting this all in practice,” commented Jessica Berkel, St. Eustatius Marine Park Manager.

The DCNA Save Our Sharks Project, funded by the Dutch National Postcode Lottery, has placed the focus on the conservation of sharks and rays in both the Caribbean and European part of the Kingdom of the Netherlands. The project has used science, education and community outreach and lobbying to establish shark sanctuaries, initiate science programs, and educate the public on the importance of sharks in the wider Caribbean. Initial data from satellite tags deployed on Saba and St. Maarten have shown that there is significant regional movement of the species in the wider Caribbean; “We need to have more research initiatives such as our project here and in Saba and the coming projects in St. Eustatius and Aruba so that we can get a better idea on the status of the species, their migratory patterns and their local distribution in the wider Caribbean. Sharks are critical to the health of the Caribbean Sea but are also one of the most threatened Large Marine Species on the planet,” concluded Bervoets.

Shark Killed Illegally Within Man of War Shoal Marine Protected Area

dead shark on coral reef

Nature Foundation, Authorities Investigating Incident

The lifeless body of a juvenile Caribbean Reef Shark was confiscated by the Sint Maarten Nature Foundation after divers reported it on a reef just within the Man of War Shoal Marine Protected Area. The intentional hunting and harming of sharks has been made illegal in Sint Maarten Waters since 2011. Since 2012 there were 7 incidents of sharks being harmed or killed in the waters surrounding St. Maarten, two of which occurred in the Man of War Shoal Marine Park. The practice of intentionally fishing for sharks has been forbidden since October 12th 2011, when the Ministry TEATT banned the practice of intentionally poaching sharks in the territorial waters of St. Maarten. The act of trying to catch by  tracking, stalking, baiting, chasing, trapping, hooking, netting, shooting or otherwise hunting –  sharks, rays and skates is prohibited and therefore the animals may not be wounded, caught, landed, or killed. Violators may be punished with jail and a considerable fine may be issued. If Sharks are accidentally caught all steps should be taken to release the animal with as little harm as possible. The ban on intentionally harming sharks was further reinforced in June 2016 with Government announcing St. Maarten’s territorial waters as a shark sanctuary.

“It seems as if this animal was caught while fishermen were fishing illegally just inside the Marine Park at night. Instead of letting the animal go the fishermen killed the animal and threw it back on the reef. This is a complete waste and is illegal based on the protected status of sharks on the island. We have been working hard in changing the perception within the community in general and the fishing community specifically about the importance of sharks to our economy and to keeping healthy fish stock in balance,” commented Tadzio Bervoets, Nature Foundation Manager.

Previous Nature Foundation research has shown that a single live shark is worth up to USD $884,000 to the economy of the island, as is opposed to just a few dollars dead. “The majority of divers who come to the island pay top dollar to see sharks in their Natural Environment. These divers also rent cars, stay in hotels, eat at restaurants and drink in bars. Taking all of that into account and based on research conducted by the Nature Foundation a single live shark contributes $884,000 to the economy of St. Maarten annually. Sharks are an apex predator and are essential to the health of local coral reefs. If we do not have sharks we will lose our coral reef ecosystem. Sharks keep the reefs clean of unhealthy fish which in turn keeps the ecosystem in balance,”

The Nature Foundation is investigating the incident together with local law enforcement organizations.

Nature Foundation Resumes Shark Telemetry Study on St Maarten

Recently the Nature Foundation installed three new acoustic receivers to research the movement patterns of sharks in Sint Maarten waters.  Due to Hurricane Irma seven receivers were lost, stagnating the Foundation’s research into shark abundance and movement patters around the island, a project which started in October 2015. This telemetry study is part of the ‘Save our Sharks’ project and executed in collaboration with scientist Dr. Erwin Winter from Wageningen Marine Research of the Wageningen University. It is also part of a larger shark study around Saba, St Eustatius and the Saba Bank and funded by the Dutch Postcode Lottery.

“Due to additional funding made available from the Wageningen Marine Research, we were able to replace three acoustic receivers on the dive sites the Bridge, the Gregory and Carib Cargo. Four sharks are tagged with small electronic devises (acoustic transmitters) on St Maarten, these transmitters are sending out a unique signal continuously and when it is within 500-800m to a receiver, the shark is detected! This research will provide use essential information about movement patterns of sharks and the size of areas they use, which will help to better protect these significant species and understand their behaviour,”  stated Nature Foundations projects Officer Melanie Meijer zu Schlochtern.

The foundation will look into additional funding to replace another four acoustic receivers to extend the study back to its original size. Previous results of the study already suggested very local movement patterns of Caribbean Reef sharks and Nurse Sharks and movement patterns of tagged juvenile tigers sharks still need to be analysed.

Scuba divers are asked to keep their distance to the installed receivers and their setup, in order to be able to collect data successfully.

Picture: Nature Foundations projects Officer installs an acoustic receiver on the dive site ‘the Gregory’ (photo credit Ocean Explorers Dive Center).

Fish Bowl

Fish Bowl is the most easterly dive site within the Man of War Shoal Marine Park. As the name implies, this circular dive site that sits at approximately 60 feet (20 m) of water hosts a large amount of fish life, including numerous Caribbean Reef and Nurse Sharks.

nurse shark
Nurse shark

Reef Depth: 45-60 ft (15-20 m)