Bull shark in Dutch lake?


In this 31 March 2016 video, a Dutch wildlife warden talks about the Kolkven lake in the Kampina nature reserve in North Brabant province. Recently, a photo was made of a shark‘s fin protruding out of the water there. Probably, a bull shark, a species often held in aquariums, has been freed in the lake after growing too big for the aquarium.

Stay tuned, the warden says.

However, it turned out to be an April Fools’ Day joke. So, a ´bullshit´ shark.

This video says about itself:

9 March 2015

This documentary looks at the bull shark (Carcharhinus leucas), also known as the Zambezi shark or, unofficially, as Zambi in Africa and Nicaragua shark in Nicaragua. It is a requiem shark commonly found worldwide in warm, shallow waters along coasts and in rivers. The bull shark is known for its aggressive nature, predilection for warm shallow water, and presence in brackish and freshwater systems including estuaries and rivers. This is the full bull shark documentary.

Bull sharks can thrive in both saltwater and freshwater and can travel far up rivers. They have even been known to travel as far up the Mississippi River as Illinois, although there have been few recorded freshwater attacks. They are probably responsible for the majority of near-shore shark attacks, including many attacks attributed to other species.

Unlike the river sharks of the genus Glyphis, bull sharks are not true freshwater sharks, despite their ability to survive in freshwater habitats.

Sharks’ social networks, new research


Sand tiger sharks' social networks

From the American Geophysical Union in the USA:

New research reveals surprising social networks of sharks

February 22, 2016

Although historically seen as solitary animals, new research being presented here shows sharks may have a more complex social structure than previously thought. Using tracking devices to trace the movements of individual animals in the open ocean, researchers found that Sand Tiger sharks form complex social networks that are typically seen in mammals but rarely observed in fish.

“Higher-order decision-making processes are often associated with mammals, or species that we think of as really smart – dolphins, elephants, or chimpanzees,” said Danielle Haulsee, a PhD candidate in oceanography at the University of Delaware in Lewes. “Our research shows that it is important for the scientific community to not rule out these types of behaviors in non-mammalian species, as behavior can often give us insight on how species interact with their ecosystems and how resources that humans depend on are distributed around the world.”

Sand Tiger , top predators that live in coastal waters off the Eastern United States, have experienced drastic population declines over the past several decades. Sand tigers are important regulators of but have been historically understudied, according to Haulsee.

In the summer, Sand Tigers congregate together in the shallow waters of the Delaware Bay, but little is known about their movements and how they interact with one another in the during the rest of the year, Haulsee said. Understanding how these sharks move and interact could help biologists better conserve this species and determine how vulnerable they are to human activities such as fishing and dredging.

Haulsee and her research team used acoustic tags to track the movements of over 300 individual Sand Tiger sharks and record shark-shark interactions over the course of a year. Previous studies have looked at shark interactions in laboratories or species contained in pens, but this the first study to record interactions for almost a year in free-swimming sharks, Haulsee said.

Initial data from two individual sharks show they encountered nearly 200 other sand tigers throughout the year, as well as several individuals from other shark species.

These sharks exhibit fission-fusion social behavior, meaning that the number of sharks in a group and the individuals that are part of the group change by location and time of year. Haulsee and her team found that groups of Sand Tigers stay together for certain times of the year and fall apart during other times. They also found that Sand Tigers re-encounter the same sharks throughout the year.

One surprise was a sudden lack of encounters with other Sand Tigers in the late winter and early spring, Haulsee said. Up until that point, both Sand Tigers were encountering other sharks regularly, but in the late winter, both seemed to enter a dispersal phase where they encountered very few other sharks. According to Haulsee, this could be related to other aspects of the sharks’ lives, such as mating and searching for food, which suggests that they could be performing a kind of social cost-benefit analysis.

Although this type of social behavior has been suggested in sharks before, the change in the group composition on an individual basis has not been documented in this way, according to Haulsee.

“If you’re living with a group, there could be some kind of protection or information sharing that comes with being in that group,” she said. “But if there’s a lot of competition for food resources or mating resources, then it’s not beneficial anymore to be in a group, and you might swim away from your group and go off on your own.”

Haulsee will be presenting initial data from the study today at the 2016 Ocean Sciences Meeting co-sponsored by the Association for the Sciences of Limnology and Oceanography, The Oceanography Society and the American Geophysical Union.

The researchers hope to use their results to answer questions about whether Sand Tigers form family groups or whether sharks of similar size and sex form distinct groupings. They also hope that defining critical locations where sharks congregate together will help build conservation plans to better protect this species.

“If we know where and when the population is grouped, we can focus on limiting human-induced disturbances in those times and places,” Haulsee said. “For example, if we know there are certain times and places where breeding females, or even more importantly the pregnant females, are aggregated together, we can devote resources into those areas to protect those sharks.”

Save sharks and rays, new initiative


This video is called The Secret World of Sharks and Rays – Nature Documentary.

From Wildlife Extra:

New global strategy to save sharks and rays

A group of international conservation organizations launched a new strategy today to combat the decline of sharks and closely related rays, while warning that the rays are even more threatened and less protected than the higher profile sharks.

The call for greater inclusion of rays in conservation action plans is part of “Global Priorities for Conserving Sharks and Rays: A 2015-2025 Strategy,” released today in conjunction with a Convention on Migratory Species (CMS) meeting on shark conservation currently underway in San José, Costa Rica.

While calling on countries across the globe to take urgently needed actions to conserve and rebuild vulnerable populations of both sharks and rays, the 10-year strategy document emphasizes that, as a group, rays – including skates, stingrays, sawfishes, guitarfishes and devil rays – should receive as much attention and investment as their better known relatives, the sharks.

The approximately 650 species of rays include shark-like rays, such as the critically endangered smalltooth sawfish and Brazilian guitarfish.

Overfishing due to under-management is the single most important threat to sharks and rays,” said WCS Sharks and Rays Coordinator Amie Bräutigam. “Improvements in fisheries management and expansion of conservation efforts – for rays in particular – form a major part of this new strategy.”

The global strategy was produced on the basis of extensive data analysis and synthesis by experts from Shark Advocates International, Shark Trust, TRAFFIC, Wildlife Conservation Society (WCS), and WWF, with technical guidance and input from the International Union for Conservation of Nature (IUCN) Shark Specialist Group. These organizations have partnered to implement this strategy through the Global Sharks and Rays Initiative.

“We are eager to share our global shark and ray conservation strategy with governments, and to discuss concrete steps toward the many shared goals that are ripe for action,” said Sonja Fordham, President of Shark Advocates International. “Although the challenges are daunting and many questions remain, the tools and resources are already sufficient to meet CMS obligations for protecting many endangered rays and limit the catch of many heavily fished sharks.”

Along with highlighting the need for more attention to rays, the strategy emphasizes that science-based limits on shark and ray fishing and trade are urgently needed to end overfishing and ensure sustainability.

“Some shark and ray populations are capable of supporting fisheries in the long term,” said Ali Hood, the Shark Trust’s Director of Conservation. “Sustainable use is a pragmatic approach to conservation, which values the natural world, the importance of livelihoods, the cultural significance of products, and the need to minimize waste through full utilization. It also requires a genuine commitment to science-based management of populations – a key objective of this global ten-year strategy.”

Glenn Sant, TRAFFIC’s Fisheries Programme Leader, cautioned: “Shark and ray protection measures are only as good as their actual implementation. Ensuring the traceability of fisheries products along the trade chain is essential to assess the effectiveness of any regulations and ultimately in bringing about real conservation benefits for the species affected.”

For shark and ray species listed under the Convention of Migratory Species, the authors have called on member countries to ensure that several key steps are taken in line with convention obligations, including: establishing strict national protections for all five endangered sawfish species and all manta and devil rays; and adopting national and regional fishing limits for heavily-fished, highly migratory sharks, such as mako, hammerhead, and thresher sharks.

Demand for shark fin in Asia has long been considered the major driver for the overfishing of sharks, but the strategy highlights recent findings that market demand for shark and ray meat is also significant, and on the rise.

“The volumes of shark and ray meat traded internationally have doubled since the 1990s and are now considered as important as shark fin in driving overfishing of these animals,” noted Andy Cornish, Shark and Ray Initiative Leader of WWF International. “Driving major reductions in the global demand for shark and ray fins and meat, the vast majority of which are currently from unsustainable and untraceable sources, is an integral part of the strategy.”

The strategy also emphasizes that nearly half of the world’s shark and ray species have been classified by the IUCN as “Data Deficient,” meaning that information is insufficient to assess the health of their populations, which can further hinder conservation action.

“Our analyses for the IUCN Red List of Threatened Species reveal a quarter of the world’s cartilaginous fishes as at risk of extinction. A major shift in effort is needed to prevent the extinction of 70 most endangered species – sawfishes, guitarfishes, wedgefishes, freshwater sharks and rays – and to clarify the conservation status and needs of the 600 Data Deficient and newly discovered species,” said IUCN SSG co-chairs Nick Dulvy and Colin Simpfendorfer.

The Global Sharks and Rays Initiative is supported in part by the John D. and Catherine T. MacArthur Foundation and the Leonardo DiCaprio Foundation.

Great white shark attacks, video


This video says about itself:

Giant Great White Shark ATTACKS! – Super Giant Animals – BBC

12 February 2016

Steve Backshall is on the look out for a great white shark to measure how much of a super giant this enormous predator is!

Sharks at active underwater volcano


This video says about itself:

8 July 2015

Ocean engineer and National Geographic Explorer Brennan Phillips and his team surveyed underwater volcano Kavachi, located near the Solomon Islands. They encountered a surprising amount of sea life, including the rarely filmed Pacific sleeper shark. Phillips believes the high-definition images of this elusive shark represent only the third—and maybe the best—video of the shark ever made.

Click here to read more about this rare discovery.

From Wildlife Extra about this:

Sharks Found Inside An Active Volcano… Alive

Kavachi is one of the most active underwater volcanoes in the southwest Pacific Ocean. It’s surrounded by hot, acidic seawater that can make it too dangerous for human divers — and that’s when it’s not erupting explosively.

But when a team of scientists recently sent down camera-equipped robots, they not only found animals surviving in and around the volcano; they found a surprising amount of biodiversity, including silky sharks, hammerhead sharks and the rarely seen Pacific sleeper shark, which had previously been caught on video just twice.

The sharkcano is located south of Vangunu in the Solomon Islands, where researchers funded by the National Geographic Society recently embarked on a risky trip to explore Kavachi. The volcano is very active, having experienced a minor eruption in 2014 as well as more explosive outbursts in 2007 and 2004.

“Nobody actually knows how often Kavachi erupts,” team member Brennan Phillips tells National Geographic. And even when it’s not launching lava, ash and steam above the surface, he adds, it can be too extreme for divers to explore. “Divers who have gotten close to the outer edge of the volcano have had to back away because of how hot it is or because they were getting mild skin burns from the acid water.”

To avoid that risk, Phillips and his colleagues sent down submersible robots with underwater cameras to explore Kavachi’s inhospitable environment. Despite the extreme conditions, the robots spotted a variety of wildlife living around Kavachi, including jellyfish, crabs, stingrays and the aforementioned sharks.

On top of the volcano-dwelling silky and hammerhead sharks, the team was also psyched to see a Pacific sleeper shark swimming near Kavachi. These enigmatic fish are normally found in the North Atlantic, the North Pacific and around Antarctica, but they’ve never been seen near the Solomon Islands before. Phillips says this is only the third time the species has been caught on video anywhere, and his HD footage may represent the highest-quality glimpse in history. Watch the footage above.

Another year of science closes, giving us pause to review those new species of sharks described in the scientific literature, bringing the total number of known shark species to 512. Perhaps it’s a hollow victory to have so many different species known at a time when sharks populations worldwide are either in decline or in a complete population tailspin. But as taxonomists continue to kick ass and give names, our knowledge of shark evolution, biogeography, and ecology continue to get richer. Meet the new sharks of 2015: here.

Shark nursery discovery off New York


This video from the USA says about itself:

27 June 2014

Another exciting Shark Academy introduces viewers to the Sand Tiger shark, an animal with a confusing name and the peculiar reproductive strategy known as “intrauterine cannibalism.”

From Blue York in the USA:

Shark Nursery Discovered Off New York

January 5, 2016

Turns out juvenile sand tiger sharks cut their (many) teeth in the New York area.

Scientists and veterinarians working for WCS‘s New York Aquarium have discovered a nursery ground for the fearsome-looking but non-aggressive fish in the near shore waters of Long Island’s Great South Bay.

“Sand tiger shark pups are not born here but migrate from down south to spend the summers as juveniles in New York’s coastal waters,” said Dr. Merry Camhi, Director of the NY Seascape program, WCS’s local marine conservation program.

The Great South Bay shark nursery provides juvenile sand tiger sharks ranging from several months to five years in age with a place to feed and grow. A nursery also gives juvenile sharks protection from predators, including other sharks.

After birth off the southeastern United States (sand tiger sharks give birth to live young as opposed to laying eggs), the juvenile sharks migrate north in the spring and spend the summer in New York waters before returning south in the fall.

Only a handful of sand tiger shark nursery grounds have been identified, one of which is in the waters of Massachusetts.

The discovery was made by researchers who have collected a wealth of information on sharks in local waters over the past four years through the use of acoustic tags, devices that enable scientists to remotely track marine animals as the animals move about.

There are still many unknowns about the nursery. Scientists are not sure how much of the bay is used by these sharks, the number of young sharks in the bay each summer, or what the sharks are eating.

Ninja lanternshark discovered in Pacific ocean


This video says about itself:

23 December 2015

In the Pacific Ocean, near the coasts of Costa Rica, Panama and Nicaragua, scientists discovered a new species of shark: Ninja Lanternshark. The species was named Etmopterus benchley, in honor of Peter Benchley, author of Jaws. Etmopterus benchley is a small shark, growing up to 50 cm, and lives at depths ranging between 836 and 1443 meters. In the darks of the ocean, Etmopterus benchleyi emits a faint glow.

By Miriam Kramer, 23 December 2015:

‘Ninja lanternshark’ found lurking in the Pacific Ocean

A newly-discovered species of shark with jet black skin and a faint glow is a master of stealth.

The shark, appropriately given the common name “Ninja Lanternshark,” lives in the Pacific Ocean, off the coast of Central America in waters from
2,742 feet to 4,734 feet, or 836 to 1443 meters, deep.

The animal owes its unique name to the young cousins of Vicky Vásquez, one of the scientists on the team that detailed the new shark finding in a study published in the Journal of the Ocean Science Foundation.

See also: 5 ways you can track sharks live from your computer

“The common name we have suggested, Ninja Lanternshark, refers to the shark’s color which is a uniform sleek black as well as the fact that it has fewer photophores [organs that emit light] than other species of lanternsharks,” Vásquez told Mashable via email.

“Based on that, we felt those unique characteristics would make this species stealthy like a ninja. The common name was actually proposed by my little cousins (ages 8 to 14 yrs. old).”

While glowing in the ocean may not sound like a great way to keep yourself hidden, scientists think it works well for lanternsharks like the Ninja.

According to Vásquez, lanternsharks glow enough to hide their shadows, likely as a form of camouflage.

Scientists are still trying to learn more about Ninja Lanternsharks. So far, researchers have found about eight specimens of the new shark, with the first discovered in 2010.

If researchers are able to study more of these sharks up-close they might be able to answer some basic questions about their biology.

“If more were found, we could really start to explore biology details of this shark like, ‘What is the maximum size?’ Our biggest specimen is only 515 millimeters long, but since it had eggs we know that this was an adult size,” Vásquez said.

“However, we did not find an adult male. If anyone is working off the coast of Central America (on the Pacific Ocean side), they could certainly help by letting us know if they find another one.”

The shark’s scientific name — Etmoterus benchleyi — also has a fun origin story.

It was named for Peter Benchley, the writer of Jaws.

“Although a lot of people are aware of the negative backlash that the movie created for sharks, most are not aware that Mr. Benchley took positive action by creating the Benchley Awards, which seeks to recognize people that have made lasting contributions to ocean conservation,” Vásquez said.

Vásquez refers to the Ninja Lanternshark as a “lost shark,” which are species of shark that get “overshadowed” by other, more charismatic sharks like the Great White.

From 2000 to 2009 scientists “were discovering about 18 new species of Chondrichthyans (sharks and their relatives like stingrays, skates and ghost sharks) every year,” Vásquez said.