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Marine Life & Conservation

First study of Zebra Sharks in Africa reveals new hotspot in need of protection

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A new study by Marine Megafauna Foundation (MMF), in collaboration with Swansea University and All Out Africa, is the first to describe a population of endangered zebra sharks (also commonly called leopard sharks) in Africa. The study reveals a key global hotspot and potential breeding area. Based on these findings, scientists recommend species-level protection and expansion of marine protected areas, to safeguard this charismatic species.

The study used structured underwater surveys and identification photos submitted by scuba diver “citizen scientists” to track individual sharks. Additionally, interviews with 100 local fishermen were used to identify potential zebra shark habitats, who are unfortunately most likely to encounter the animals as bycatch in gillnets. Information from underwater surveys created similar distribution maps and habitat modeling also identified new possible hotspot locations that merit future underwater surveys.

Whatever it is, the way you tell your story online can make all the difference.

Lead author, Saoirse Pottie explains, “This study adds credibility to using a multi-faceted approach to collect baseline data for marine species. When used in combination, fishers’ observations and dive surveys can complement each other. Fisher surveys can collect sightings information at a wider spatial scale than underwater surveys, yet dive surveys are capable of providing more in-depth information on the movement and behavior of individuals.”

The authors hope to inspire other researchers working in data-deficient locations. “This approach could be applied in other regions to highlight areas of interest, prioritize research activities, and inform conservation actions. The inclusion of local knowledge also provides an opportunity to enrich our understanding of social-ecological systems, engage local communities, and make environmental decisions that are more inclusive,” continues Pottie.

Photos taken by scientists and recreational scuba divers between 2010 and 2018 identified 90 individual sharks of both sexes. 38% of sharks were seen in multiple years, indicating an affinity for the area. Over 62% of the sharks were mature. The high frequency of both male and female adult sharks in a small area indicates a breeding area, which is a prime habitat for protection.

Whatever it is, the way you tell your story online can make all the difference.

While zebra sharks are listed as endangered by the IUCN Red List of Threatened Species, they lack formal protection in Mozambique, and the majority of the suitable zebra shark habitat identified in this study remains unprotected. According to co-author Anna Flam, an MMF scientist, “This is one of the world’s largest identified populations of zebra sharks and we should protect them, otherwise, we could see them disappear, as has happened in parts of Southeast Asia.”

Recreational scuba divers also assisted in data collection. Zebra sharks have unique spot patterns that can be used to identify individuals and track them over time. Identification photos contributed by scuba divers allowed researchers to increase the scope of data capture. Over the course of this study, the researchers helped create the Wildbook for Leopard Sharks, a global online database that allows scuba divers to submit their photos to support research around the world.

Click here to read the full study published in the journal Ocean and Coastal Management.

For more information about the Marine Megafauna Foundation visit their website by clicking here.

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 are supported by Mares, Paralenz, Nauticam and Olympus. To find out more visit www.frogfishphotography.com

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Evolution of Manatees in Florida

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Op-ed by Beth Brady, PhD, Senior Science and Conservation Associate, Save the Manatee® Club

Recent news articles and broadcasts have claimed that manatees are not native to Florida or only arrived on Florida’s west coast in the 1950s. These claims, based on limited anthropological records, point to where manatees were historically exploited by humans and assume that a lack of evidence means manatees were absent from certain areas. However, absence of evidence is not evidence of absence—it’s like looking for stars in the daytime; just because you can’t see them doesn’t mean they’re not there. Moreover, genetic and fossil evidence indicate manatees have been present in Florida for the last 12,000 years.

The Florida Fish and Wildlife Conservation Commission (FWC), which manages Florida manatee populations, has created a manatee timeline highlighting key dates and notable information about manatee presence in Florida (https://myfwc.com/education/wildlife/manatee/timeline/). Historical records suggest that manatees have been observed in Florida as far back as the 1500s, with some details presented by the Florida Fish and Wildlife timeline aligning with evidence presented in the publication.

manatee

Manatee species, such as the African manatee and the Antillean manatee, continue to be poached by humans (Marsh et al., 2022). As a result, these species are difficult to observe in the wild and may adapt by foraging at night to avoid human encounters (Rycyk et al., 2021). This behavior could help explain why historical Florida manatee populations that were hunted by humans are absent from middens and rarely mentioned in historical accounts.

Further, the publication only briefly touches on the paleontological record and genetic evidence, which indicate that manatees have existed in Florida for a much longer period. Fossil and genetic evidence reveal a rich history of manatees in Florida. Manatees belong to the order Sirenia, which includes the Amazonian, African, and West Indian manatee species. While Sirenian fossils have been found globally, only Florida and the Caribbean contain specimens from every epoch over the past 50 million years (Reep and Bonde, 2006). The modern manatee, as we know it, emerged in the Caribbean about 2 million years ago (Domning, 1982).

The evolution of manatees during the Pleistocene epoch provides valuable insights into how environmental changes shaped their distribution and genetic diversity. During the Pleistocene epoch (2.59 million to 11,700 years ago), there were roughly 20 cycles of long glacial periods (40,000–100,000 years) followed by shorter interglacial periods lasting around 20,000 years. At the start of these warmer periods, Caribbean manatees migrated northward with the warming waters (Reep and Bonde, 2006). Water currents and thermal barriers isolated these manatees from populations in Mexico and the Caribbean, leading to genetic divergence. Fossil evidence indicates that Trichechus manatus bakerorum lived in Florida and North Carolina about 125,000 years ago but did not survive the last glacial period, which began 100,000 to 85,000 years ago (Domning, 2005). This subspecies was eventually replaced by modern Florida manatees.

This evolutionary theory is further supported by genetic evidence. Research indicates that Florida manatees trace their evolutionary origins to Caribbean ancestors that migrated northward over the past 12,000 years (Garcia-Rodriguez et al., 1998). A 2012 study by Tucker et al. reinforces this theory, showing higher genetic diversity in manatees on Florida’s west coast compared to those on the east. Over time, core populations migrated northward, with some groups moving south and east along the Florida coastline before heading north along the Atlantic. This migration pattern left the west coast population with greater genetic diversity, while the east coast population retained only a smaller subset. These findings suggest that the founding population of Florida manatees—arriving approximately 12,000 years ago—originated along Florida’s southwestern coast, which became the center of the state’s manatee population (Reep and Bonde, 2006). The process of vicariance further supports this hypothesis; as geographic and ecological barriers emerged, they likely isolated the Florida manatee populations from their Caribbean ancestors. This isolation likely limited migration back and forth between regions, fostering the establishment of local populations in southwestern Florida.

manatee

Manatees are not only a cherished symbol of Florida’s natural heritage but also a species with deep evolutionary and historical ties to the region. In sum, despite recent claims questioning their nativity, extensive fossil and genetic evidence confirms that manatees have been present in Florida’s waters for thousands of years, with ancestors dating back over 12,000 years. We agree with the authors of the published article that protecting these iconic creatures and their habitats is essential to preserving Florida’s unique ecological identity for future generations

Beth Brady is the Senior Science and Conservation Associate at Save the Manatee Club whose work focuses on manatee biology and conservation. She has her PhD from Florida Atlantic University and her Master’s in Marine Science from Nova Southeastern University.

savethemanatee.org

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Marine Life & Conservation

Paul Watson Released as Denmark Blocks Japan’s Extradition Bid

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Renowned anti-whaling activist Paul Watson has been released from custody in Greenland after spending five months in detention. Denmark’s Justice Ministry rejected Japan’s request for his extradition, citing insufficient guarantees that his time already served in custody would be credited against any potential sentence.

The 74-year-old Canadian-American was arrested on July 21 in Nuuk, Greenland’s capital, when his ship docked to refuel. His arrest was based on a 2012 Japanese warrant related to a 2010 encounter in Antarctic waters. Japan alleged Watson obstructed operations and caused damage to a whaling research ship during efforts to disrupt illegal whaling. Watson has consistently denied these claims, maintaining his commitment to marine conservation.

Denmark, which oversees extradition matters for Greenland, concluded that while the legal conditions for extradition were met, the lack of assurances from Japan regarding time-served credit made extradition untenable.

In a video shared by his foundation, Watson expressed gratitude and relief, saying, “After five months, it’s good to be out… and good to know they’re not sending me to Japan.” He added that the most difficult part of his time in custody was being separated from his two young sons.

Watson is a pioneering figure in marine conservation, known for founding the Captain Paul Watson Foundation in 2022 after decades of activism with the Sea Shepherd Conservation Society. His bold efforts to defend marine life have earned him widespread support, including from celebrities and conservationists. His work has also been featured in the acclaimed reality TV series Whale Wars.

Watson’s lawyer, Jonas Christoffersen, praised the decision, stating, “We are happy and relieved that Paul Watson is now free.” He added that Watson is eager to reunite with his family and continue his vital work.

The arrest occurred while Watson’s vessel, the M/Y John Paul DeJoria, was en route to the North Pacific with a team of 26 volunteers to intercept a Japanese whaling ship. His foundation described the arrest as politically motivated and emphasized that Watson’s actions were focused on ending illegal whaling practices.

Japan resumed commercial whaling in 2019 after leaving the International Whaling Commission, asserting that whale meat is a cultural tradition. Conservationists, however, continue to challenge these practices, highlighting their impact on marine ecosystems.

Despite the challenges, Watson remains steadfast in his mission to protect marine life and bring attention to whaling practices. His dedication to ocean conservation has made him a globally respected advocate for the environment.

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