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Sharks
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Mod
https://metro.co.uk/2018/07/14/why-ar...
Not mentioned in this article, by law in UK any shark landed by fishermen must have fins-on at the quay. No separate fins may be landed. This is to stop the malign practice of finning and dumping. Shark meat is mostly cartilage and not worth a lot, but may be used in joint health supplements.
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And a nice lively fiction about keeping a Great White shark in captivity. This is a highly educational book.
The SeaLand Incident: The Story Behind One Zoo's Infamous Attempt to House a Great White Shark
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The article coves a few of such rarities.
https://earther.gizmodo.com/mysteriou...
I'm going to be picky here:
" There’s also the Borneo shark (Carcharhinus borneensis), described in 1858 from a single specimen near the eponymous Indonesian island. "
That's not how to use eponymous. The island of Borneo has the shark named after it, not the other way around.
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https://earther.gizmodo.com/shark-eat...
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https://www.care2.com/causes/canadas-...
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This link is not viewable in my region.
www.discovery.com/.../shark.../shark....-...
Newsweek:
https://www.newsweek.com/there-could-...
Telegraph: from 2008 but a well researched article.
https://www.telegraph.co.uk/news/ukne...
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https://www.independent.ie/videos/wat...
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https://www.smh.com.au/national/weste...
Thanks to Patty Jansen for that news.
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https://www.ecowatch.com/walking-shar...
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https://www.ecowatch.com/blue-sharks-...
Originally posted:
https://theconversation.com/tagging-d...
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"The ban has almost completely halted targeted fishing for these sharks, so in this sense it has been very successful.
"However, continued bycatch is a problem not only because of the direct impact on this vulnerable species, but also because it makes it tempting for fishers to get round the ban.
"Because it is easy to conceal threshers as other shark species, by cutting fins off before landing, fishers can sell them easily and the ban can be hard for authorities to enforce."
https://phys.org/news/2020-12-shark-f...
More information: Claire Collins et al, Using perceptions to examine human responses to blanket bans: The case of the thresher shark landing-ban in Sri Lanka, Marine Policy (2020). DOI: 10.1016/j.marpol.2020.104198
Journal information: Marine Policy
Provided by University of Exeter
Mod
https://www.goodreads.com/author_blog...
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https://www.irishexaminer.com/news/mu...
"Though they are endangered, hundreds of the sharks have been spotted off the Clare coast earlier this week.
The sharks are a fully protected species in the UK, Malta, and New Zealand, but not here in Ireland, which is something groups like the Irish Basking Shark Group have been calling for in recent years."
Mod
Here is Sea Shepherd to tell us about this request.
https://www.seashepherdglobal.org/lat...
I have signed at this screen.
https://eci.ec.europa.eu/012/public/#...
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Just when you thought it was safe to get back in the water....
https://phys.org/news/2022-01-tiger-s...
" "Given their role as apex predators, these changes to tiger shark movements may alter predator-prey interactions, leading to ecological imbalances, and more frequent encounters with humans." said Hammerschlag."
More information: "Ocean warming alters the distributional range, migratory timing, and spatial protections of an apex predator, the tiger shark (Galeocerdo cuvier)" Global Change Biology (2022). DOI: 10.1111/gcb.16045
Journal information: Global Change Biology
Provided by University of Miami
Mod
One was found on a beach in Cornwall recently, unfortunately, dead. The necropsy has provided new info about this creature.
https://www.rte.ie/news/newslens/2022...
"A century-old Greenland shark found washed up on a Cornish beach died of meningitis, a post mortem has found.
The Greenland shark is incredibly rare and can live to over 400 years old and the female found just outside Newlyn Harbour in mid-March is still considered a "juvenile" by marine biologists.
Very little is known about the species, they usually over 2.5km below the surface of the Arctic and North Atlantic oceans, and the autopsy is thought to be the first of its kind undertaken in the UK.
...
"The post-mortem was conducted by the Cornwall Marine Pathology Team, which is part of the Zoological Society of London’s (ZSL) Cetacean Strandings Investigation Programme (CSIP)."
Mod
https://gizmodo.com/a-mysterious-arct...
"Though these sharks are typically thought to spend most of their time in the frigid waters of the Arctic, some populations do seem to migrate, and there have been occasional sightings around the tropics in recent years, including in the Caribbean. This latest sighting adds another wrinkle, though, since the team was much closer to the shore than other teams have been when they stumbled upon their tropical sleeper. But because the reef has waters that reach as far down as 9,500 feet, there is a plausible source of cold temperatures available for these sharks to live comfortably. Since we know so little about these sharks, they could be much more widely distributed around the world than currently documented."
Mod
"Rarely observed circling behaviors of endangered basking sharks have now been explained as "shark speed dating" courtship displays, thanks to a new study.
Marine biologists from the Marine Biological Association (MBA), the Irish Basking Shark Group and colleagues have led ground-breaking research which reveals the circles of basking sharks seen off western Ireland are engaged in annual reproductive behavior, the first place in the world where this has been verified."
More information: David W. Sims et al, Circles in the sea: annual courtship "torus" behaviour of basking sharks Cetorhinus maximus identified in the eastern North Atlantic Ocean, Journal of Fish Biology (2022). DOI: 10.1111/jfb.15187
Journal information: Journal of Fish Biology
Mod
https://phys.org/news/2023-06-whale-s...
"This newly observed behavior comes courtesy of one individual whale captured on the video. Filmed in water just six meters deep, the shark pushes its head down to the sea bottom, opens its mouth and begins sucking as it moves across the sea floor. This sucking action, the researchers note, is nearly identical to the type used when foraging at the sea surface. The shark is then seen spitting out residue before resuming bottom feeding.
The researchers suggest the shark seems to be looking for benthic creatures that live just below the sea bottom. They also suggest it appears the specimen in the video is actively attempting to feed on amphipods, tiny crustaceans that live on the seafloor."
More information: Darren A. Whitehead et al, First record of bottom‐feeding behaviour in the whale shark (Rhincodon typus), Journal of Fish Biology (2023). DOI: 10.1111/jfb.15457
Journal information: Journal of Fish Biology
Mod
"Approximately 99.9% of fish and shark species are "cold-blooded," meaning their body tissues generally match the temperature of the water they swim in—but researchers have just discovered the mighty basking shark is a one-in-a-thousand exception. Instead, these sharks keep the core regions of their bodies warmer than the water like the most athletic swimmers in the sea such as great white sharks, mako sharks and tuna.
The latter examples are so-called "regional endotherms" and are all fast swimming, apex predators at the top of the food chain. Scientists have long reasoned that their ability to keep warm helped with this athletic predatory lifestyle, and that evolution had shaped their physiology to match their requirements.
However, an international team of researchers led by those from Trinity College Dublin, has now shown that gentle, plankton-feeding basking sharks are also regional endotherms despite having very different lifestyles to white sharks and tunas."
More information: HR Dolton et al, Regionally endothermic traits in planktivorous basking sharks Cetorhinus maximus, Endangered Species Research (2023). DOI: 10.3354/esr01257
Provided by Trinity College Dublin
wow! great shark posts. Loved the video of the walking shark!I heard Peter Benchley - the author of Jaws, says he would give up everything he earned from it if there was a way to undo the damage his book did to the sharks' reputations.
I kayak among sharks and they are the most timid of all megafauna in this bay. I see them often but rarely got close enough to film them. They abscond as soon as they know I'm there.
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"Fishermen who accidentally caught a two-and-a-half-tonne basking shark (Cetorhinus maximus) managed to release it unharmed after several hours of unravelling their nets.
The Jávea-based crew on board the Cap Prim Segon were in the Ibiza Channel – a well-known fishing ground for the Marina Alta’s famous red prawn – when they realised their nets were too heavy to haul up.
Full report in Friday’s Costa Blanca News "
Mod
"A marine biologist at the University of Miami's Rosenstiel School of Marine, Atmospheric, and Earth Science, has documented a case of a silky shark with a regenerated dorsal fin, after much of it was lost due to maiming by an unknown person. In her paper published in Journal of Marine Sciences, Chelsea Black describes how the shark came to her attention and how she was able to observe the fin regrowth."
More information: Chelsea Black et al, Resilience in the Depths: First Example of Fin Regeneration in a Silky Shark (Carcharhinus falciformis) following Traumatic Injury, Journal of Marine Sciences (2023). DOI: 10.1155/2023/6639805
Mod
"Researchers have been putting these devices on basking sharks in Kerry for several years.
However, the primary goal was to learn about their natural behaviour, such as feeding habits.
Mr Payne said an incident in April where one of the sharks was struck by a boat allowed the team to capture the new data.
He said that the research gathered was "quite grim viewing".
"We recorded approximately four or five hours of video before the animals were hit by the boat and then about six or seven hours after that incident and the change in behaviour of the animal was dramatic.
"Before the boat collided with it, the animal was up feeding at the surface almost constantly for about four hours, which is what they normally do when the conditions are right for them as it was that day.
"But then, as soon as it was hit by the boat, it tumbled in the water. It swam very quickly, down about 40 metres deep, and it didn't then resume feeding for the rest of the day.
"So it was a very drastic change in behaviour.""
Mod
"Heithaus has spent his career studying the ecological role of sharks. His two decades of work in Shark Bay, Australia is the most detailed study of the ecological role of sharks in the world and has been used as the underpinning for affecting positive policy changes.
There, he documented top-down roles, including keeping prey populations from growing too large or eating too much. When sharks scare off prey, like turtles and sea cows, these grazers don't overeat seagrass or other needed marine vegetation, giving it time to grow and recover before the grazers return.
"We're not saying big sharks are the only ones that matter. There's a lot more that sharks of all kinds are doing to shape entire ecosystems," said Simon Dedman, FIU marine scientist and co-lead author of the study.
"But what we do know is that big sharks of some species are playing an oversized role in ocean health and need better protection. It's time to have a conversation about everything sharks are doing to maintain ocean health so we can better prioritize conservation efforts and have the biggest impact."
Besides helping to maintain balance in food webs, sharks feed in offshore waters and bring nutrients back to the reef. Others move nutrients around that are used at the base of the food chain. Sharks can also serve as food for other species and even as scratching posts for fish to remove parasites.
The problem is shark abundance has plummeted by 71% for oceanic species in the past 50 years. Populations of the top five reef shark species have been depleted by 63%.
"This study verifies what we've long suspected—sharks are critical to ocean health," said Lee Crockett, executive director of the Shark Conservation Fundy."
More information: Simon Dedman et al, Ecological roles and importance of sharks in the Anthropocene Ocean, Science (2024).
https://www.science.org/doi/10.1126/s...
Journal information: Science
Provided by Florida International University
Mod
"Lead author Dr. Chris Henderson and a team of researchers analyzed more than 60 years of catch data from Queensland's Shark Control Program (QSCP), noting a substantial loss in the functional diversity of targeted species like tiger sharks, great whites and whalers. The paper is published in the journal Communications Biology.
"There's been a range of studies looking at declining shark numbers, but we wanted to look at it from an ecosystem perspective, and that is what looking at changes in functional diversity allows us to do," Dr. Henderson said.
"And what we've seen is a decline over time in the abundance and more crucially, the diversity of targeted apex shark species, which means we are at risk of losing sharks that perform crucial roles in our coastal ecosystem, reducing its functioning and resilience.""
More information: Christopher J. Henderson et al, Long term declines in the functional diversity of sharks in the coastal oceans of eastern Australia, Communications Biology (2024).
https://www.nature.com/articles/s4200...
Journal information: Communications Biology
Provided by University of the Sunshine Coast
Mod
https://phys.org/news/2024-09-large-s...
"We need to continue studying predator interactions, to estimate how often large sharks hunt each other. This will help us uncover what cascading impacts these interactions could have on the ecosystem."
More information: First evidence of predation on an adult porbeagle equipped with a pop-off satellite archival tag in the Northwest Atlantic, Frontiers in Marine Science (2024).
https://www.frontiersin.org/journals/...
Journal information: Frontiers in Marine Science
Mod
"The focus of a unique research project trying to find out if great white sharks frequent Irish waters has moved from the ocean to the laboratory.
A group of Irish shark scientists have been working with OCEARCH, a US shark research organisation, with the goal of trying to document the apex predator off the coast of Ireland for the first time.
A week-long search at sea off Na Blascaodaí (the Blasket Islands) in Co Kerry ended without a sighting earlier this month.
However, it's hoped the expedition could still yield significant results, thanks to new technology called environmental DNA, or eDNA.
It involves collecting genetic material from the environment, as opposed to within a living organism."
Mod
https://phys.org/news/2025-03-ecosyst...
""The loss of this iconic apex predator has led to an increase in sightings of Cape fur seals and sevengill sharks, which in turn has coincided with a decline in the species that they rely on for food," said Neil Hammerschlag, Ph.D., the study's lead author.
Hammerschlag conducted the research while at the Shark Research and Conservation Program at the University of Miami Rosenstiel School. "These changes align with long-established ecological theories that predict the removal of a top predator, leading to cascading effects on the marine food web."
"The use of underwater video surveys conducted more than a decade apart provided us with a snapshot of the food web both before and after the disappearance of white sharks from False Bay," said Yakira Herskowitz, a co-author of the study and a Rosenstiel School former graduate student that analyzed underwater video data."
More information: Neil Hammerschlag et al. Evidence of cascading ecosystem effects following the loss of white sharks from False Bay, South Africa, Frontiers in Marine Science (2025).
https://www.frontiersin.org/journals/...
Journal information: Frontiers in Marine Science
Mod
"Now, writing in Frontiers in Fish Science, researchers describe an unusual aggregation of sharks coming together to feed on a carcass that had decayed to mostly flesh and blubber.
"To our knowledge, this is the first study to document a feeding aggregation of tiger sharks and oceanic whitetip sharks scavenging concurrently, and peacefully, on a carcass," said first author Dr. Molly Scott, a marine researcher at the University of Hawaii at Manoa. "These species are rarely seen together in the wild because of the vastly different habitats they occupy.""
More information: Novel observations of an oceanic whitetip and tiger shark scavenging event, Frontiers in Fish Science (2025).
https://www.frontiersin.org/journals/...
Sharks are probably one of the most publicized but misunderstood species. They get a lot of bad publicity because bad shark stories sell quite well. This creates a public interest in their demise instead of their existence.
Mod
"Hammerhead Shark
We recently celebrated shark week, with scary movies and internet turbulence about sharks, so I’ve been thinking about them, and came up with this month’s weird and wonderful animal: the hammerhead shark. Weird looking doesn’t even begin to describe this beauty, so the illustrating and research were really fun for me.
Speaking of fun, here are the fun facts:
Their strange shaped heads are called cephalofoils. They come in handy in a lot of ways, like using their heads to ram into prey fish, to tire them out, so the shark can more easily eat the prey.
Their eyes are at the ends of the wide head, so they can see all around, except for a blind spot in center front. A diver once reported that he saw a small fish hiding right in front of a hammerhead’s nose, and the shark couldn’t see it.
They live about 20-30 years, and can grow up to 20 feet.
They eat small fish, octopus, and stingrays. Stingrays are their favorite meal, and the stingray’s barb and sting don’t affect them. Many divers have said they’ve seen hammerheads with pieces of stingray barbs sticking out of them, and they seem fine.
Hammerhead sharks have been around for 20-25 million years, but they’re still considered the “new kids on the block” in the shark evolution story, because most other shark species can be traced back 420 million years.
Hammerheads like to hang out in shallow water, and sometimes get a suntan, turning their skin from light grey to dark grey. The good news is they never get skin cancer. Scientists are studying to learn why they don’t, hoping to find a preventative or cure for skin cancer in humans.
In some species of hammerheads, the females can have babies without a male shark. She fertilizes her own eggs.
Females are pregnant for 8-10 months, and can have up to 50 babies at once. From the minute they’re born, they’re on their own. The mother doesn’t take care of them at all.
During the day, they swim in schools of up to 500 sharks, but at night, form small groups, or go solo. No one knows why."
Green Group
Books mentioned in this topic
Orangutan: A Day in the Rainforest Canopy (other topics)Agent H2O Rides the Water Cycle (other topics)
Jackson's History Adventure (other topics)
Rhonda's Amazing Feet (other topics)
Shark Fin Soup: A Novel (2) (other topics)
More...
Authors mentioned in this topic
Rita Goldner (other topics)Robin Barefield (other topics)
Patty Jansen (other topics)
Sharks mature slowly, may produce one to eight young a year, and are at risk while young. They may grow into apex predators along with the orca, while some species such as whale shark and basking shark eat plankton.
Industrial fishing is wiping out shark species faster than they can reproduce.
https://metro.co.uk/2018/07/14/withou...