ISSUE 25 - 2019 Bionews BIONEWS ISSUE 25
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BIONEwS ISSUE 25 - 2019 BIONEWS ISSUE 25 2 Editor’s Letter Editor’s Letter Dutch Caribbean, July 2019 3 At least ten reef-associated shark species in the Dutch Caribbean 5 Dutch Government Announces Wageningen Marine Research reported ten reef- waters home, only 4 have been known to nest here: New International Shark Strategy associated shark species in the Dutch Caribbean in a loggerhead, leatherback, green and hawksbill turtles. recent published study as part of DCNA’s Save Our Read this article to learn more about the 2019 sea turtle 6 Kick off for the 2019 Sharks Project. The most common species are the nesting activities so far. Sea Turtle Nesting Season nurse shark and the Caribbean reef shark. Overall, more sharks were observed in conservation areas than in Also in this edition we share an article by Gabriel 8 Turtuga film unprotected areas, highlighting the importance of these Martina who is doing crowdfunding for the nature movie zones in shark conservation. Turtuga ‘The survival of Humanity’. This movie will show 9 Bonaire Caves and beautiful sea turtle shots and the problems that sea Karst Nature Reserve Update Good news for our sharks! The Dutch Ministry of turtles face in Curaçao. Agriculture, Nature and Food Quality (LNV) has recently 11 Research Overview published a strategy to manage and protect sharks The Bonaire Caves and Karst Nature Reserve has been and rays within waters of the Netherlands, Caribbean established to ensure the sustainable use and protection 13 Long-Term Projects Overview Netherlands and international waters. This new strategy of Bonaire’s vast cave system, using as main tools officially makes fishing for or possessing shark parts scientific research, education and sounds management. 20 Monitoring Overview punishable by law in Bonaire, St. Eustatius and Saba. These caves provide crucial habitat for several important animal species, especially five species of the island’s 24 Monitoring & Research Wishlist Sea turtle season has officially started and each of only native terrestrial mammals, the bats. In this the Dutch Caribbean Islands has reported their first article you can read about the recent activities and Editor’s photo: Letter © Marion Haarsma 29 List of Acronyms hatchlings of the year. Officially running between accomplishments of the Bonaire Caves and Karst April and December, with slight variances between Nature Reserve project. Reports and Publications the islands, a variety of different species of sea turtles 30 Cover photo: © GuidoLeurs use these islands to lay their nests. Although there Enjoy! 31 Calendar are officially 5 different species which call these The DCNA Team 32 Members and Contact BioNews 25 - Content 2 3 4 5 6 ... At least ten reef-associated shark species in the Dutch Caribbean Wageningen Marine Research reported ten Respect, not fear, sharks There were two methods used by the researchers reef-associated shark species in the Dutch Sharks are some of the most misunderstood to study sharks. One method used Baited Remote Caribbean in a recent published study as part species. For generations sharks had an undeserved Underwater Video (BRUV) which used a device of Dutch Caribbean Nature Alliance (DCNA)’s bad reputation. People tend to see them as consisting of two cameras set in front of a baited Save Our Sharks Project. The most common terrifying animals that pose a danger to everything feed bag. The idea is that as sharks come near the species are the nurse shark and the Caribbean that swims in the ocean, including humans. But bait bag to feed, video footage can be collected reef shark. Overall, more sharks were observed we now know that is very far from the truth; these to identify and count local shark populations. The in conservation areas than in unprotected areas, magnificent creatures are essential to healthy other method was acoustic telemetry to track highlighting the importance of these zones in oceans and risks to humans are small. sharks. In this method, a small acoustic tracking shark conservation. device is implanted within the shark. Acoustic DCNA’s Save Our Sharks Project receivers are installed at specific locations, and More than 100 million sharks are killed each year There is a lack of knowledge concerning the whenever sharks with these transmitters travel as a result of fishing and shark finning activities, distribution and abundance of shark and ray near the receiver (within a range of 450 to 850 twice the rate at which they can reproduce. The species throughout the Dutch Caribbean. metres) they are recorded. demand for fins and other shark products has To combat this knowledge gap, from 2015- driven a number of species close to extinction. 2018, DCNA ran the “Save our Sharks” (SOS) The first studies using BRUV were conducted Sharks are especially vulnerable to overfishing and project for the Dutch Caribbean, funded by the on Saba, Saba Bank and St. Eustatius to better habitat degradation as they are late to mature and Dutch Postcode Lottery. In this project DCNA understand the local population of sharks and rays produce few young. The main threats to sharks collaborated with local fisherman and scientists and their relative abundances, and were funded in our waters are accidental bycatch, habitat and aimed to build popular support for shark and by the Dutch Government. Starting in 2015, as degradation and the risk of a shark fin market ray conservation amongst the local community, as part of the SOS project, additional studies were developing, which would lead to targeted fishing well as increasing knowledge about shark and ray conducted to include the waters around Bonaire, of sharks. species within the region by conducting a number Curaçao and Sint Maarten. In 2017 a BRUV survey of research projects. was done at Aruba, financed by Global Finprint. We need healthy oceans and healthy oceans need sharks Shark Research In addition, as part of the SOS project, acoustic Sharks keep our oceans healthy. These top A recently published study by Wageningen telemetry was also used to better understand predators remove sick or weak members of Marine Research as part of DCNA’s SOS Project the movements of sharks, habitat use, migration their prey populations. A decrease in number of established a baseline for current shark diversity, and connectivity between islands. The telemetry sharks leads to a disturbed natural balance in the distribution, abundance, spatial behaviour and study tracked two shark species, Caribbean sea. This can affect the overall fish population, population structure for inshore reefs around the reef shark (Carcharhinus perezi) and nurse shark and good fish stocks are not only important for Dutch Caribbean islands. (Ginglymostoma cirratum) around Saba (from fishermen that depend on fishing but also for 2014) and then around Saba Bank, Sint Maarten (dive) tourism and the local community. and Sint Eustatius (from 2015). Nurse shark on the Saba Bank which is part of the Yarari Marine Mammal and Shark Sanctuary. Photo by: © Hans Leijnse BioNews 25 - Content 2 3 4 5 6 ... Findings journeys back and forth, whereas the nurse shark In BRUVs deployed around Sint Maarten, Curaçao after two years absence showed up atthe Saba and Bonaire the most common detected shark Bank before returning to Saba. One nurse shark species were Caribbean reef shark, with Sint from another study on the US Virgin Islands was Maarten also frequently showing nurse sharks. detected in the network on the Saba Bank, a Overall, more sharks were observed in marine distance of at least 160 kilometres. parks or areas of conservation than in unprotected areas, highlighting the importance of these Importance of Protected Areas zones in shark conservation. Furthermore, when Both the BRUV and acoustic telemetry studies comparing the BRUV surveys from Sint Maarten, showed higher presence of reef associated sharks Curaçao and Bonaire to previous BRUV studies within the conservation zones, along with high from Aruba, Saba, Sint Eustatius and Saba Bank, it site fidelity and small home ranges. Furthermore, showed that the Aruba survey had the largest shark as some longer distance movements were also diversity (8 species) and the Bonaire survey the documented, interconnectivity between these lowest (2 species). The Saba survey documented areas is just beginning to be understood. The 5 shark species, Saba bank had 4 shark species ongoing study on acoustic telemetry (funded with Curaçao, Sint Eustatius and Sint Maarten by the Ministry of Agriculture, Nature and Food each registering 3 shark species. There was an Quality (LNV)) will yield more data on this. additional BRUV submarine test at 300 metres Therefore, not only are local marine parks crucial deep off Curaçao which found an additional shark for the conservation efforts of sharks and rays, species (Cuban dogfish). In total, at least 10 shark but larger conservation networks, such as the species were seen within the Dutch Caribbean in Yarari Marine Mammal and Shark Sanctuary the different BRUV surveys. which compromises all the waters of Bonaire, Saba and Sint Eustatius, are vital to protect entire The acoustic telemetry studies demonstrated that populations. both the Caribbean reef shark and nurse shark have small home ranges and strong site fidelity. Large More information crossings between areas were rare, and found for Winter, H.V., de Graaf, M. (2019). Diversity, two Caribbean reef sharks and one nurse shark abundance, distribution and habitat use reef- which travelled between Saba and Saba bank. The associated sharks in the Dutch Caribbean. two Caribbean reef sharks made short directed Wageningen University & Research report C105/18. Caribbean reef shark in the Man of War Shoal Marine Park , Sint Maarten. Photo by: © Melanie Meijer zu Schlochtern Would you like to share a news item? 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