Displaying items by tag: sharks
Japanese researchers have found that whale sharks have protective “armour” around their eyeballs in the form of tiny teeth.
Japan's Okinawa Churashima Research Centre scientists studied the eyes of both living and dead whale sharks, which can grow to 18-metres and have eyes on the sides of their head.
The sharks, which eat mainly plankton, can retract their eyes to protect them from other creatures in the sea, and don’t have eyelids.
Their eyes are protected in a casing, which bulges out into the water, and the researchers found that these casings are covered in dermal denticles or tiny teeth. The denticles have an “oak-like shape” similar to human molars, they say.
Dermal denticles have been found in previous research on other parts of the whale shark’s body. The researchers found each whale shark eye covering has approximately 3,000 denticles, and most densely packed near the irises.
They suggest these may serve to protect the whale shark eyes from attacks by other sea creatures.
More details of the research are on the open-access website, Plos One here
Tralee Bay is a “major nursery” for sharks and rays in Irish waters, says a local marine wildlife expert.
And Kevin Flannery insists the important breeding ground for the likes of angel sharks and porbeagle sharks needs protection.
Marine biologist Flannery, of Dingle OceanWorld, described the little-known nursery off the Kerry coast as “a Serengeti of the Atlantic for rays and sharks”.
And as National Biodiversity Week begins, he’s calling for Tralee Bay to be designated as a marine protected area to provide a safe haven for the many species that lay their eggs there in summer months.
The Irish Mirror has more on the story HERE.
Experts in shark biology, data and mapping recently met at the Marine Institute’s headquarters in Oranmore, Co Galway to map the distribution of deepwater sharks, skates and chimaeras in the North-East Atlantic Ocean.
This included nearly 30 years of data collected by Irish scientists on board the Marine Institute’s RV Celtic Explorer and commercial vessels.
The WKSHARKS Workshop included experts from Ireland, the United Kingdom, Portugal, France and Denmark, with other experts contributing remotely from Norway, Iceland and the Netherlands.
And their aim was to produce maps that indicate the area and depth of 25 species of deepwater sharks, skates and chimaeras — information that will assist in understanding the range and habitat of these marine wildlife species, underpinning future management decisions.
It will also be considered by the Convention for the Protection of the Marine Environment of the North-East Atlantic (OSPAR) and the North-East Atlantic Fisheries Commission (NEAFC) to determine future action to sustainably manage these populations.
These two organisations have a joint interest in the open North Atlantic, while ICES scientists have unique knowledge of the deepwater fisheries and species in this area, which focuses on waters off Ireland, Portugal and Iceland.
Maurice Clarke, fisheries scientist at the Marine Institute and WKSHARKS Workshop chair, said: “Sharks and rays have an important function in maintaining balanced and healthy marine ecosystems. Providing scientific advice is essential to protecting these marine species in the North-East Atlantic.
“For many of these species, this is the first time that data from European surveys is being collated and analysed for this purpose.”
Irish waters are home to 71 species of sharks, skates, rays and chimaeras. These species include some of the latest maturing and slowest reproducing of all vertebrates, resulting in very low population growth rates with little capacity to recover from overfishing and other threats such as pollution or habitat destruction.
ICES received a joint request from the Convention for the Protection of the Marine Environment of the North-East Atlantic (OSPAR) and the North-East Atlantic Fisheries Commission (NEAFC) to develop distribution maps of deep-sea sharks, rays and skates, and also to advise on methods of mitigating bycatch of these species.
A shark species previously unrecorded in Irish waters has been sighted in the Celtic Sea.
The sighting was made by experienced marine mammal observer John Power and bird observer Paul Connaughton during the Marine Institute’s Western European Shelf Pelagic Acoustic Survey (WESPAS).
“While scanning the ocean surface, we sighted a dorsal fin unlike anything we had encountered before,” said Power.
“It was quite different to the fins seen on basking sharks and blue sharks. After consulting available ID keys, we agreed that the shark must be a smooth hammerhead.”
The large, tall and slender dorsal fin of the smooth hammerhead shark distinguishes it from other shark species. The smooth hammerhead also has a single-notch in the centre of its rounded head and is up to four metres in length.
The species gives birth to live young and the pups are usually found in the shallow sandy waters near Florida, the Caribbean and West Africa. However, the species has been recorded as far north as England and Wales.
The smooth hammerhead was sighted during the WESPAS survey, which surveys the waters from France to Scotland and the West of Ireland each year.
Marine scientists collect acoustic and biological data on herring, boarfish and horse mackerel, which is used to provide an independent measure of these fish stocks in Irish waters. Scientists also monitor plankton, sea birds and marine mammals during this survey.
This is an exciting encounter, especially since a rare deep-water shark nursery was discovered by Irish scientists last year
Dr Paul Connolly, director of fisheries and ecosystems services at the Marine Institute, said: “Our Irish waters support a range of marine life and diverse ecosystems, including 35 known species of sharks.
“This is an exciting encounter, especially since a rare deep-water shark nursery, 200 miles west of Ireland, was discovered by Irish scientists last year using the Marine Institute's Remotely Operated Vehicle [ROV Holland 1].”
He added: “This sighting of a new shark species shows the importance of our fishery surveys to monitor our marine environment, and to observe changes in our oceans and marine ecosystems.
“Observing and understanding a changing ocean, is essential for protecting and managing our marine ecosystems for the future.”
The hammerhead shark poses little risk to humans, and there have been no known fatalities from hammerhead sharks anywhere in the world to date.
The species is listed as Vulnerable on the International Union for Conservation of Nature (IUCN) Red List of Threatened Species, and is being increasingly targeted for the shark fin trade as its large fins are highly valued.
Thirty-five species of sharks have been recorded in Irish waters, including the blue shark, porbeagle shark, lesser spotted dogfish and the second-largest shark in the world, the basking shark — a regular visitor inshore during the summer months.
The pupils completed a project module on sharks in Irish waters as part of the Marine Institute’s Explorers Education Programme, and also had the opportunity to visit the State research vessel.
Outreach officer Padraic Creedon of the Explorers Education Programme said one if the programme’s unique elements “is the content and support provided to teachers in the classroom in an easy and fun way.
“The students were inspired by the discovery of a rare shark nursery 200 miles off the west coast of Ireland in 2018, and we were delighted to create lessons, interactive experiments and discussion about the ocean, sharks and their environment for the class.”
While on board the RV Celtic Explorer, pupils met with the captain and scientists and saw what it might be like to work on a research vessel.
Students spoke with Captain Denis Ronan about the Celtic Explorer, and learn more about the acoustically silent ship that can stay out at sea for up to 35 days.
The pupils were excited to tour the vessel and speak with marine scientists to discover more about shark species, seabed mapping, shipwrecks and the marine environment.
Visiting the dry and wet labs, the pupils saw various fish species from recent surveys and shark species, such as dogfish and the tope shark.
Clár Ní Bhraonáin, teacher at Scoil Shéamais Naofa, said: “It has been an amazing experience … Students don’t forget days like this.”
The Explorers programme offers a range of materials including lesson plans to conduct experiments in class, watching films that helps generate discussion, and peer learning among pupils.
“Because of the students’ enthusiasm to learn more about sharks, we have been able to incorporate marine themes across the curriculum, where they have excelled and produced some incredible work, from writing books about sharks to a series of posters and artwork,” Ní Bhraonáin added.
“This project has really helped myself and the students learn more about the ocean.”
For more information on the Explorers Education outreach centres, visit the Explorers Contacts page at Explorers.ie. The programme is supported by the Marine Institute and is funded under the Marine Research Programme by the Government.
The event is the brainchild of Ballycotton-born Pearse Flynn, an experienced deep-sea angler who was determined to attract the world’s top competitors to an East Cork town already renowned for its big fish records.
Prizes are set to be awarded for biggest shark landed, as well as for the boat that lands the greater number of sharks ever the course of the tournament.
But only big spending anglers need apply, as the entry fee is a whopping €5,000 per head.
The Irish Times has more on the story HERE.
Members of the Marine Institute, INFOMAR and Explorers Education teams, as well as the chief scientist of the SeaRover survey, will be at the Galway Science and Technology Festival this Sunday (25 November) highlighting the recent discovery of a rare shark nursery in deep waters off the West of Ireland.
The shark-themed stand — All About Sharks, Sharks and More Sharks — will also provide children and their families an insight into the life of a marine scientist, what seabed mapping involves and how this led to the discovery of the shark nursery.
“It was incredible, real David Attenborough stuff,” David O'Sullivan, chief scientist for the SeaRover survey, told the Guardian. “This is a major biological find and a story of this magnitude would have been on Blue Planet if they'd known about it. Very, very little is known on a global scale about deep-sea shark nurseries.”
The SeaRover suvey, using the Marine Institute’s remotely operated vehicle (ROV) Holland 1 onboard the ILV Granuaile, took place during the summer 2018 off the Irish coast.
And its findings show the significance of documenting sensitive marine habitats, which will assist in a better understanding of the biology of these animals and their ecosystem function in Ireland’s Biologically Sensitive Area.
If you’re interested in learning more about the discovery of the sailfin sharks, you will find the experts at the back of the Bailey Allen Hall at NUI Galway from 10am to 6pm. Entry is free of charge and open to the public.
#MarineWildlife - A whopping 71 species of shark can be found swimming in Irish waters.
That’s according to the new New Red List of Cartilaginous Fish, as reported by TheJournal.ie, which adds that half of all sharks in Europe can be found swimming around the Irish coast.
Eleven of these species are classified as either ‘endangered' ’critically endangered’, such as the porbeagle shark, the Portuguese dogfish and the basking shark — the second-largest fish in the oceans and a frequent visitor to Irish inshore waters.
And it also notes that outside of Ireland, where angling for such species is predominantly catch-and-release, recreational fishing poses a growing threat to cartilaginous fish like sharks, skates and rays.
TheJournal.ie has more on the story HERE.
#Surfing - An Irishman has been praised for his heroism after saving his best friend from an attack by a great white shark in Australia just over a year ago.
"It really is like you see in the Jaws movies," said Wexford man de Roiste recalling that fateful day in August 2015. "The person is just shaken around in the water.”
Carr finally fought off the shark by jamming a thug into one of its eyes, but we was left with a severe bite on his thigh and was losing a lot of blood.
De Roiste remained with his friend throughout, paddling him back to shore and using laces from the fins of Carr's body board to keep the wound closed till help arrived.
The Irishman has now been nominated by his friend for a Pride of Australia award, the winners of which will be announced this November.
The attack just over a year ago was one of a number of incidents reported in the eastern Australian state in the latter half of 2015.
#MarineWildlife - Sharks have been filmed devouring a whale carcass at the ocean's surface in waters close to Britain and Ireland for the first time.
The results of the documentary expedition were broadcast last Friday as part of the UTV series Britain's Whales, available for catch-up the rest of this week.
As the Plymouth Herald reports, the groundbreaking experiment was headed by West Country marine biologist Dr Nicholas Higgs along with presenters Ellie Harrison and Ben Fogle, who sailed out to the Celtic Deep between Ireland, Cornwall and Wales with the carcass of a humpback whale in tow.
Their documentary crew were then able to film an "unprecedented" feeding frenzy by hundreds of blue sharks before the carcass was sunk for further study to examine the various creatures, from sharks to tiny 'zombie worms', that thrive on dead cetaceans as they drop to the ocean floor.
"I would never have predicted that you'd have this many sharks eating this much of the whale at the surface," said Dr Higgs. The Plymouth Herald has more on the story HERE.
In other cetacean news, Japan has disappointed global authorities by confirming hundreds of whale kills on its most recent expedition to the Antarctic.
Some 333 minke whales, including pregnant females, were poached between since December and last Friday (25 March), according to the Guardian.
As previously reported on Afloat.ie, Ireland recently joined an international demarche expressing "serious concern" at Japan's decision to resume whaling for what it claims are scientific purposes, claims that are not supported by the International Whaling Commission.