By freedivinguae

A large population of whale sharks has been discovered in the waters off Madagascar

Thanks to its historic isolation, Madagascar has long been famed for its unique wildlife, ranging from lemurs and rare chameleons to exotic birds and the carnivorous, cat-like fossa. But now a new study published in the journal Endangered Species Research has revealed that the island nation is also a hotspot for whale sharks (the world’s largest fish).

Portrait of a whale shark
The whale shark population is thriving off the coast of Madagascar © Andrey Nekrasov / Barcroft Media via Getty Images)

A single season survey, part of the Madagascar Whale Shark Project (a collaboration of researchers from Mada Megafauna, Marine Megafauna Foundation and Florida International University), identified 85 juvenile whale sharks swimming in an area around the island of Nosy Be in the country’s far northwest. These waters had previously been noted for sea turtles, manta rays and migrating humpback whales, but the sheer number of whale sharks that arrived to feed during the September to December period was a huge surprise. Also of importance was the fact that these individuals represented an undiscovered population – they were not simply displaced from other known feeding areas in the Indian Ocean – Mozambique, Tanzania, Djibouti, Seychelles and the Maldives – that have experienced a decrease in whale shark populations. This information came to light after the marine biologists uploaded images of the new sharks’ unique spotted patterns to the Wildbook for Whale Sharks global database and discovered no overlap.

Several of the whale sharks that were observed were also tagged to track their movements, and the team discovered a second Madagascan hotspot near Pointe d’Analalava, some 180 km to the south of Nosy Be. Other data revealed that five of the sharks swam as far as the Comoros Islands, while another two migrated some 2150km to the southern tip of Madagascar. One of the latter two made the return journey, thus covering about 4300km, an impressive figure given these slow swimmers cover only 20km or so each day.

Divers photograph a whale shark
Divers with whale shark. Photo by: Michael Aw/Lonely Planet

It’s hoped the whale sharks can be a major asset for Madagascar, particularly if access is well managed by the country’s burgeoning ecotourism industry. In recent decades overfishing (including accidental catches) and boat strikes have put whale sharks on the RIUCN RedList as a globally endangered species.

By freedivinguae

The timer called out the seconds: “Plus 7, plus 8, plus 9, plus 10. … Plus 20.”

Shelby Eisenberg had just 10 seconds to let go of the gray tube bobbing off the coast of Grand Cayman and plunge into the depths of the Caribbean. Just 10 seconds to begin her attempt to go deeper than any American woman had ever dove while using only the oxygen in her lungs.

Her window was closing, creating more pressure on her than she would feel at her target depth of 85 meters, under 22,400 gallons of water. Yet to go that far, it was imperative she remain calm.

“I knew it was my last chance, my last day. I had to take a couple of relaxed breaths,” Eisenberg, a Santa Cruz native, said. “I just had to tell myself — because I can stay there breathing all day long — I had to tell myself, ‘OK, you’re ready. One more breath won’t make you more ready.’”

Eisenberg put her hands up, then she dove down, a graceful mermaid leveraging her monofin through the clear, cobalt water. When she reached her target depth, she snatched a tag off a weight tethered to a rope, then sped her way back to the surface. As she emerged into the glorious, oxygen-rich air, the smile on her face said it all.

She had just set the national record for a controlled weight freedive, ending a six-year-plus monopoly on the mark held by Ashley Futral Chapman of North Carolina. Chapman held the record at various depths before setting her personal best, 84 meters, in September 2016.

After breaching the surface, Eisenberg still had to wait another 30 seconds to go through a brief series of tests and have the judges confirm her record, but she wasn’t worried.

“I knew I had it because I felt completely in control,” Eisenberg, 27, said. “I had a coach at the surface smiling back at me and judges smiling back at me, so I knew I was OK. It was just, ‘OK, don’t get too excited.’”

She stayed calm. The same couldn’t be said for the judges and safety personnel who witnessed the feat Sunday at the Deja Blue International Diving Festival. They circled around her and broke into whoops and splashes once the judges flashed the white cards that signaled the dive was legitimate.

Francesca Koe of San Francisco, who is well-acquainted with Eisenberg because of their Bay Area connection, was among the three judges in the water that day.

“Everyone has aspirations and dreams, we just didn’t realize she was training for weeks on end since January trying to do this,” Koe said. “We were all on pins and needles. She looked super strong and super clean.”

The record-setting dive came as a surprise to many. Eisenberg, who goes by the nickname “Shell,” has only been freediving for six years and competing for four.

A former Westside resident — her parents Sandy and Geoff still live there — she attended the University of Hawaii after graduating from Kirby School in 2009. There she began experimenting with freediving as a way to get a better look at reef and sealife. In 2012, she took her first freediving course (similar to SCUBA diving, participants must be certified) and she entered her first competition in 2014. Last year Eisenberg became a professional freediving instructor for Performance Freediving International, a company that trains and certifies people in the sport, including the cast of the upcoming “Avatar” sequel.

“It’s something that’s always been really difficult for me to describe and put words to,” Eisenberg said of the freediving experience. “You’re deep in the ocean, deep in nature. Even though there are a lot of people on the dive, there’s a feeling that it’s just you in the water, and it seems to get clearer as I go deeper.

“There’s not a lot of emotion down there, just peace.”

Though she had previously set two records for pool diving, which is measured by length, her personal-best ocean depth before arriving in the Grand Cayman last week was 74 meters, which many believed did not put her in striking distance of Chapman’s mark.

Over the course of the weeklong competition, she drew closer and closer. Then, in her last dive before setting the record, she missed an attempt. Knowing she had just one more dive before returning to her home in Hawaii, however, Eisenberg decided to go for the gusto.

“Shel’s 85-meter dive was incredible on so many levels,” John Hullverson, president of USA Freediving, said in a statement. “Not only was she able to withstand the nine atmospheres of pressure her body was under at that depth, but for her to endure the hypoxia, increased lactic acid buildup in her muscles and urge to breathe throughout the nearly three-minute dive — and then complete her surface protocol so cleanly — is a testament to what kind of shape she’s in.

“I don’t think we’ve seen the last national record for Shel.”

Eisenberg doesn’t think so either. She’d like to tack on another meter or two this year alone. But she has no intention of plateauing there.

While 104 meters is the women’s constant-weight world record, only a couple of U.S. men have reached 100 meters, and no U.S. women. Eisenberg would like to be the first, but she said she wouldn’t mind if someone else beat her to it.

“One hundred meters is the life goal, but I’m not in a rush,” she said. “It’s easy to get excited and that’s how people get hurt. Of course, it’s on my mind. I’ve got to get to 90 meters before I get to 100, and that’s a little more on my mind. … Then we’ll see where we go from there.”

Her motto now is the same as it was when time was running out on her record attempt: Take a breath, then take the plunge.

Contact Julie Jag at 831-706-3257.

For the Record: Freediving marks

Constant Weight

World: 129 meters, Alexey Molchanov, Russia, 2017

World women’s: 104 meters, Alessia Zecchini, Italy, 2017

U.S. men’s: 101 meters, Kurt Chambers, Hawaii, 2016

U.S. women’s: 85 meters, Shelby Eisenberg, Hawaii, 2018

 

SOURCE: https://www.mercurynews.com/2018/05/18/85-meters-freediving-national-record-set-by-santa-cruz-native/

By freedivinguae

Hawaii diving instructor breaks U.S. freediving record

Shelby Eisenberg begins her record-setting descent in waters off Grand Cayman. (Courtesy: Joakim Hjelm )
Shelby Eisenberg begins her record-setting descent in waters off Grand Cayman. (Courtesy: Joakim Hjelm )
KONA, HAWAII (HawaiiNewsNow) –A Kona resident set the U.S. freediving record on Saturday in Grand Cayman, according to USA Freediving, the sport’s governing body.

Shelby “Shell” Eisenberg, a freediving instructor who lives and works in Kona, broke the Women’s National Record in the Constant Weight division, meaning the diver must ascend with the same weight that he or she descends with.

Eisenberg dove to a distance of 85 meters, or 279 feet, on a single breath, breaking the national record by three feet. The entire dive took 2 minutes and 51 seconds.

“I was very nervous going into the dive and on the way up, I was able to stay focused and stay focused to the end,” said Eisenberg. “So once I got to the surface and saw my coach at the surface, it was at that point I knew I had it, and I was just overwhelmed with happiness, really.”

USA Freediving says it’s the third national record for Eisenberg, who has also set a pair of pool-based freediving records.

 

source: http://www.hawaiinewsnow.com/story/38199284/hawaii-diving-instructor-breaks-us-freediving-record

By freedivinguae

‘Whale sharks found off Gujarat stay in Arabian Sea’

Ahmedabad: The satellite tagging of two whale sharks off the Gujarat coast by scientists of the Wildlife Trust of India (WTI) and the Gujarat forest department, some time ago, has allowed researchers a 350 -day and a 150-day peek into the lives of the world’s largest fish.

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The whale shark is among the least studied fish species. These satellite tags have busted the myth that whale sharks generally live near Australian shores and come to the Indian Ocean to breed. The two tagged whale sharks were found to be moving about in the Arabian Sea near Oman and Somalia, owing to the better food availability and conducive breeding conditions there.

Interestingly, these initial findings of WTI officials corroborate the findings of the International Union for Conservation of Nature (IUCN).

A 2016 IUCN report had stated that whale sharks found in the Atlantic and the Indian and Pacific oceans are not cousins but are ‘functionally separate’. The report acknowledged that whale sharks found along the Indian coast, including the coast of Gujarat, have no connection with those found in the Atlantic.

The WTI, with permission from the forest department, is now planning to tag another three or four whale sharks to get more data.

The WTI will soon move a proposal with the forest department, said sources.

Sajan John, the WTI researcher who analysed the satellite data, said, “Data from these tags, which remained operational for 350 days and 150 days, revealed that these animals remained mainly in the Arabian Sea and did not move toward the east coast of India. Their movements were confined to the Arabian Sea and towards Oman and the Somali coast.” He added that a detailed study is being prepared and will be published soon.

Forest department officials said whale sharks move between the Saurashtra coast and the Arabian peninsula due to relatively better availability of food. Whale sharks consume plankton — which includes copepods, krill and fish eggs — which is relatively abundant in the Arabian Sea.

Officials said a comparative genetic study of whale sharks found off the Gujarat coast and off Australian coasts revealed that these populations are not related to each other in a manner to be considered as different parts of the same population.

The latest two tags

Forest department officials said the tag which lasted 350 days was on a female whale shark tagged off the Saurashtra coast in December 2016. Data from it showed that the animal had travelled all the way to the Somalia coast and returned to the India coast. The signal for the tag was then lost, with the latest location putting the animal just off the southernmost part of India.

The tag that lasted 150 days, fitted last November, went all the way to the Oman coast before its signal was lost.

 Officials said an earlier WTI and forest department study, which had tagged six whale sharks in 2014, showed the animals travelling from off the Porbandar coast to near the Lakshadweep islands.

Life of the tags

The satellite tag signals get cut off when their battery runs out. Officials said the normal life of a tag is two years. These tags are imported and the research agency has to refrigerate them in storage. They also have to be switched on and off every 15 days in storage and this reduces their life. The effective life when the tag is applied is thus not certain.

By freedivinguae

Coral World Participates in Rescue of Injured Green Sea Turtle

On Friday May 4, Patrick Cena, a local resident, spotted an injured green sea turtle washing ashore in Christmas Cove.  According to Erica Palmer, a Coral World veterinary technician, who is also a sea turtle assistance and rescue responder, “Patrick contacted Coral World for assistance.  He then transported Matt Tartaglio, Coral World assistant curator, and me on his boat to Christmas Cove to see what we could do for the turtle.”  Apparently, the same injured turtle had been spotted on May 1 swimming in shallow waters off Little St. James, but the turtle spooked when the individual who tried to come to the turtle’s aid entered the water.  Cena made the next sighting three days later.

Palmer said, “When we found the turtle it was extremely weak, lethargic and had no use of its rear flippers. We took it back to Coral World where we administered emergency medications to combat anemia and infection because of a large fracture of its carapace and associated blood loss.  We think the turtle had been injured close to a week earlier because there was dying bone and soft tissues involved.”  The staff monitored the turtle 24 hours a day for the first 48 hours.

“We provided supportive care and medications during the weekend while we lined up a CT scan with Dr. Jeffrey Guller at St. Thomas Radiology for Monday to assess the extent of the damage.  A veterinary radiologist in the states informed us that the scan revealed a severed spinal cord and massive inflammation, as well as several missing vertebrae,” said Palmer.

The most likely cause of the injuries was blunt-force trauma by a boat strike. “We hate to lose a turtle, but the long-term prognosis for survival was so poor in this case because of the severity of the injuries, we made the difficult decision, in consultation with our consulting veterinarian, to humanely euthanize the turtle,” she said.

According to Palmer, who has seen many injured turtles during her work as a STAR responder, blunt-force trauma from boat impact or propellers are a significant threat to sea turtles and other marine animals.  All sea turtles are designated as either threatened or endangered under the U.S. Endangered Species Act of 1973.  Violations can result in up to one year in prison, up to a $100,000 fine, and the confiscation of any equipment used during the criminal act.

 

Rescuers lifting injured turtle

STAR is a collaboration of NGO’s, territorial and federal agencies, veterinarians and community volunteers. These groups and individuals have joined together to help injured sea turtles to provide better protection through the collection and dissemination information on stranded turtles.  Palmer emphasized, “STAR relies on many community volunteers, local veterinarians, and other donated resources like those offered by Coral World, but the most important participant in STAR is you.  Please report any entrapped, disoriented, sick, injured or dead sea turtle by calling the hotline at 690-0474.  You can find out more about STAR at  STAR-Sea Turtle Assistance and Rescue.”

Coral World is the only approved Sea Turtle Rehabilitation Facility in the Virgin Islands. It has been conducting and funding turtle rehabilitation since it reopened in 1997 as part of its mission to educate, entertain and inspire appreciation for the Caribbean marine environment.

 

 

source:  https://stthomassource.com/content/2018/05/13/coral-world-participates-in-rescue-of-injured-green-sea-turtle/

By freedivinguae

Home to nest: Sea turtles finally coming ashore

HARLINGEN — They came, they dug and they laid.

The first big day of sea turtle nesting season on Texas beaches Monday resulted in 41 total nests confirmed from San Jose Island near Rockport south to Boca Chica Beach.

On South Padre Island, Sea Turtle Inc. reported 13 turtle nests confirmed, along with an additional two nests on Boca Chica.

At Padre Island National Seashore, 22 turtle nests were discovered on Monday inside the National Park Service boundaries. Two additional nests were found on San Jose Island, one on North Padre Island to the north of the national seashore and one found on Mustang Island.

All the nesting females are critically endangered Kemp’s ridley sea turtles.

A juvenile loggerhead turtle was rescued on North Padre Island and taken to the Animal Rehabilitation Keep (ARK) in Port Aransas.

Donna Shaver, chief of the Division of Sea Turtle Science and Recovery at Padre Island National Seashore, said an additional two nests were found yesterday taking the early toll this season to 52 Kemp’s ridleys for the entire Texas coast.

“I still am reserving judgment, although this was the largest day that we’ve had in the month of April,” she said yesterday. “It still was late in the month so our year-to-date total lags much behind last year.”

It is possible, she said, the high number of cold fronts which have occurred in South Texas this spring have pushed back the typical dates for turtle nesting.

“The nesting season in Texas has been documented for Kemp’s ridleys through mid-July, the 15th of July, but the majority of nests are found through the third week of June. So we have about seven weeks left in the peak part of the nesting season,” she added.

“If it’s going to be a good year, it’s going to be quite busy for those seven weeks,” Shaver said. “They’re going to be very important in terms of how it all turns out.”

A total of 27,000 Kemp’s ridley nests were recorded last year along the western coast of the Gulf of Mexico. Practically all of those nests were found on Playa de Rancho Nuevo in Tamaulipas, Mexico.

In Texas, 353 Kemp’s ridley nests were recorded last year, with the national seashore marking 219 nests, South Padre Island recording 70 and Boca Chica coming in with 23.

Sea turtle females don’t necessarily nest every year, which is a complicating factor in attempting to assess a species’ total number. Shaver has said previously the latest research shows Kemp’s ridley females are nesting every 3.5 years on average.

 

SOURCE: http://www.brownsvilleherald.com/news/local/home-to-nest-sea-turtles-finally-coming-ashore/article_db0a5dcb-c892-5147-8783-faec5c6499e6.html

By freedivinguae

Study warns of dolphin tourism risks

New research led by University of Otago scientists indicates there is growing evidence that whale and dolphin-watching activities can adversely affect the marine mammals.

The study “Behavioural responses of spinner dolphins to human interactions” was  published recently by the journal Royal Society Open Science.

The research focused on populations of spinner dolphins off the coast of Egypt, where a variety of regulations over tourist interactions with dolphins applied in different areas.

Prof Liz Slooten, of the Otago zoology department, said Egypt could learn from New Zealand over limiting the number of boats and visits, as well as using licences, and codes of conduct, to protect marine mammals from adverse effects.

New Zealand could also learn from Egypt’s “area-based approach, with zones for boats, zones for swimmers and zones with only dolphins”, she said.

The Otago researchers said it was time to act on the scientific evidence on the effects of dolphin-watching on wild animals and any unregulated increase in dolphin tourism should be discouraged.

Dolphin groups should also be fully protected while calving, feeding and resting, and well before “populations are compromised”. Researchers from Italy, Hong Kong and the Falkland Islands also contributed to the study, together with first author Dr Maddalena Fumagalli and Prof Slooten, of the Otago department, and Associate Prof John Harraway, of the Otago mathematics and statistics department.

Dr Fumagalli conducted the research as part of her Otago PhD studies.  She said the Egyptian study focused on three areas, one with no tourism, and the others with controlled, and uncontrolled tourist activities, respectively.

Spinner dolphins rested and slept only in daylight, and in the shallow, protected waters of reef lagoons. Human interactions in these lagoons “caused disruptions to the dolphins’ resting patterns”, Dr Fumagalli said.

Where there were restrictions on how close boats and swimmers were allowed to approach the dolphins’ resting area, the dolphin rest needs appeared to be met.

But at the uncontrolled access site dolphins could find it “impossible to rest”, causing “great concern”.

Repeated sleep and rest loss could eventually result in population decline or displacement, she said.

 

 

SOURCE: https://www.odt.co.nz/news/dunedin/campus/university-of-otago/study-warns-dolphin-tourism-risks

By freedivinguae

Dream of swimming with whale sharks? Know that it’s a nightmare for them

 

 

In 2016, the International Union for Conservation of Nature moved the whale shark from ‘vulnerable’ status to ‘endangered’ after concluding that its population had fallen by about 50 per cent in the past 75 years.

SIMON J. PIERCE

The Maldives, a sandy necklace of islands that stretches 750 kilometres across the Indian Ocean, just north of the Equator, is a paradise for snorkellers and scuba divers. The star attractions are manta rays, sundry sharks and whale sharks, fish so big they are sometimes mistaken for whales and so rare that spotting one is a once-in-a-lifetime event for most submerged tourists.

On a holiday in April, aboard a 50-metre yacht with 30 guests, we saw several manta rays, graceful creatures three or four metres across, that cruised near us as if slow-moving albatrosses. We saw so many sharks – mostly whitetips, blacktips and nurse sharks – that we got bored with them. We could have seen a whale shark, but we – that is, I and some of my incensed friends – refused to jump overboard when one was found.

We felt that way because the whale-shark-watching event that would have been the highlight of our week-long trip had quickly turned into a mob scene, at the expense of the poor beast in the water. All suited-up and ready to dive, we just couldn’t bring ourselves to be part of it.

In a wide, deep channel in South Ari Atoll, about 70 km south of the Maldives capital, Malé, several dozen boats, ranging from five-metre skiffs to proper yachts, were dashing back and forth looking for whale sharks. Our dive boat was among them.

Whale sharks – Rhincodon typus – often cruise just below the surface, warming their bodies before making deep dives, making them easy to spot. They are the biggest fish and can reach a length of 12 metres and weigh more than 20 tonnes – the size of a bus. While they have many tiny teeth, they cannot harm a diver unless he or she swims into the arc of their enormously powerful tail fins. These placid beasts, known as filter feeders, mostly consume plankton.

When one of the boat captains spotted a whale shark, the entire armada patrolling the channel converged at once, propellers thrashing. Our captain wisely decided to stay on the periphery of the traffic jam. An instant later, 100 divers and snorkellers, maybe more, flung themselves into the water to chase the animal. One diver we talked to said he spotted another diver using his camera, mounted on an extension stick, to poke the fish’s head. The whale shark, evidently scared by the mob, dove away.

Mohamed (Mox) Ismael, our highly experienced dive master – he does 800 dives a year – was one member of our group who refused to join the watery crowd scene. Perched on the upper deck of our boat, he just shook his head in despair. He called it “irresponsible tourism,” explaining that the whale-shark-tour captains, having taken big money from tourists, feel they can’t hold their clients back when a whale shark is spotted. “The whale shark dives are becoming more and more money-oriented,” he said. “We are seeing evasive behaviour from the sharks. They’re afraid.”

He said many of the sharks have spiral wounds on their backs, evidence that they have been hit by propellers. Indeed, the Maldives Whale Shark Research Programme (MWSRP), a research and conservation charity, says that 29 per cent of the 368 whale sharks recorded in its database have suffered “major injury.” While they are sturdy creatures, it is not known how many, if any, have died from their injuries.

What is known is that whale sharks are in rapid decline. In 2016, the International Union for Conservation of Nature (IUCN) moved the animal from “vulnerable” status to “endangered” – meaning it faces an extremely high risk of extinction – after concluding that its population had fallen by about 50 per cent in the past 75 years. On the global database compiled by whaleshark.org, there are only 9,095 identified living whale sharks, about two thirds of them in Indo-Pacific waters (Maldives, Philippines, Thailand, Western Australia, among other spots), the rest in the Atlantic.

Simon Pierce, biologist at the Marine Megafauna Foundation, a science and conservation group that focuses on large, threatened ocean creatures such as mantas and sea turtles, says most of the whale sharks’ decline has come since the mid-1980s. “The main threat to whale sharks is overfishing,” he said. “There have been several large commercial fisheries for whale sharks and they are still caught routinely in China. Elsewhere, whale sharks are caught accidentally in gill-net and tuna purse-seine fisheries.”

Recognizing that tourism drives their economy, the Maldives protected the whale shark in 1995 – they are off-limits to fishermen (15 years later, the Maldives banned the capture of any species of shark). Dive masters, conservation groups and environmentally aware tourists think setting regulations to protect the whale shark from mass-tourism harassment and propeller injuries should be the next step in protecting the species. Several charities have been working with the Maldives government to try to set whale-watching regulations that would create a sustainable ecotourism model. But progress has been slow.

The government may be wary about regulations that would limit whale-shark tourism. “Having spent a lot of money to go on the excursion, guests will expect to see a whale shark,” said James Hancock, operations manager for the MWSRP. “This is translated into pressure that is felt by guides, the tour companies and before you know it, a see-at-all-costs situation emerges in which best-practice encounter behaviour becomes secondary.”

Various ideas to protect the Maldives whale sharks from mass tourism are being floated. One would see permits issued to the boat captains, allowing them to visit whale shark hot spots only at certain times, on certain days, to prevent overcrowding. The system could be monitored by government rangers, or employees of an international organization such as UNESCO.

In the meantime, groups such as MWSRP are hosting training days for whale-shark guides, urging them to give the sharks plenty of space to manoeuvre and prevent divers from touching them or using flash cameras that can startle them, among other practices.

But self-regulation may not be enough to protect the whale sharks as more resorts fill the 1,200 islands in the Maldives and tourist numbers rise; most of those tourists want to see big fish and a selfie with a whale shark is the ultimate prize.

Jacob Dalhoff Steensen, the chief marketing officer for Paralenz, a Danish maker of underwater digital cameras, and a former scuba-diving instructor in the Maldives, says he sees fewer whale sharks in the archipelago every year and thinks a permit system should be the minimum requirement. But what he really thinks is that these majestic and endangered giants should be ignored. “We should really just leave them alone,” he said. “They’re so rare.”

 

 

SOURCE: https://www.theglobeandmail.com/life/travel/article-dream-of-swimming-with-whale-sharks-know-that-its-a-nightmare-for/

By freedivinguae

Whale shark tracked travelling furthest distance ever recorded

A whale shark has made the longest migration journey ever recorded travelling 12,000 miles across the Pacific Ocean.

The large fish, named Anne by scientists, was tracked making the mammoth migration from near Panama in the south eastern Pacific, to an area close to the Philippines in the Indo-Pacific.

Experts at the Smithsonian Tropical Research Institute followed her signal from Panamanian waters, past Clipperton Island and Costa Rica’s Cocos Island, en-route to Darwin Island in the Galapagos, a site known to attract groups of sharks.

After 266 days of tracking, Anne’s signal disappeared as she went into deep waters, before resurfacing again 235 days later south of Hawaii.

She then made her way to the Marianas Trench – a canyon in the ocean floor where movie director James Cameron located the deepest point on the Earth’s surface almost 11,000 metres below sea level.

The trip was the first recorded evidence of a trans-Pacific migration route for the species of the largest living fish.

Marine biologist Dr Héctor Guzmán, who first tagged Anne near Coiba Island in Panama, said: “We have very little information about why whale sharks migrate.

“Are they searching for food, seeking breeding opportunities or driven by some other impulse?”

Genetic studies show that whale sharks across the globe are closely related, suggesting they must travel long distances to mate. An adult female can travel around 40 miles per day and can dive more than 1,900 metres.

 

SOURCE:

https://www.independent.co.uk/news/science/whale-shark-migration-furthest-recorded-tracked-panama-philippines-12000-miles-a8325711.html

By freedivinguae

Whale shark logs longest-recorded trans-Pacific migration

Whale sharks are filter feeders, eating plankton, fish eggs, krill, crab larvae as well as small squid and fish that enter their large mouths. They cannot digest plastic garbage.

Credit: Kevan Mantell

Little is known about the world’s largest living fish, gentle giants reaching 12 meters (40 feet) in length. Researchers from the Smithsonian Tropical Research Institute (STRI) and colleagues tracked a female whale shark from the eastern Pacific to the western Indo-Pacific for 20,142 kilometers (more than 12,000 miles), the longest whale shark migration route ever recorded.

STRI marine biologist Héctor M. Guzmán tagged a female whale shark (Rhincodon typus) near Coiba Island in Panama, the largest island off of the coast of Central America, a National Park, World Heritage Site and marine protected area. His team named the shark Anne for conservationist Anne McEnany, president and CEO of the International Community Foundation (ICF). The multi-year project also tagged 45 additional sharks in Panama with sponsorship from Christy Walton’s Candeo Fund at the ICF, along with STRI and Panama’s science and technology bureau (SENACYT).

Guzmán estimated Anne’s position based on signals from a Smart Position and Temperature (SPOT) tag tethered to the shark, received by the Advanced Research and Global Observation Satellite (ARGOS). The tag only communicates with the satellite when the shark swims near the surface. Anne remained in Panamanian waters for 116 days, then swam toward Clipperton Island (France), nearing Cocos Island (Costa Rica) en route to Darwin Island in the Galapagos (Ecuador), a site known to attract groups of sharks. 266 days after she was tagged, the signal disappeared, indicating that Anne was too deep to track. After 235 days of silence, transmissions began again, south of Hawaii. After a nine-day stay, she continued through the Marshall Islands until she arrived at the Marianas Trench, a canyon in the ocean floor near Guam in the Western Pacific where movie director James Cameron located the deepest point on the Earth’s surface almost 11,000 meters (36,000 feet) below sea level.

Whale sharks dive to more than 1900 meters (6000 feet). But it is unknown what the animal was doing in this area.

“We have very little information about why whale sharks migrate,” said Guzmán. “Are they searching for food, seeking breeding opportunities or driven by some other impulse?”

“Despite being the world’s largest fish, it’s amazing to me how little we know about this species,” said Scott Eckert, co-author and biology professor at Principia College. “When I first began working on them, their taxonomy was debated, and it still wasn’t clear how they reproduced.”

Found in warm, tropical and sub-tropical waters, it is thought that about a quarter of whale sharks live primarily in the Atlantic, whereas about three-fourths live in the Indo-Pacific. Tourists are drawn to sites where 500 or more whale sharks gather: in Oman, Australia, Galapagos, Mexico, Mozambique and the Seychelles. Large groups are also reported from Taiwan, Southern China and the Gujarat coast of India.

Genetic studies show that whale sharks across the globe are closely related, indicating that they must travel long distances to mate. Whale sharks have been tracked for shorter distances along similar routes, but this report is the longest-recorded migration to date and the first evidence of a potential trans-Pacific route. Like Anne, other whale sharks appear to follow the North Equatorial Current for most of the distance. Large females can swim an average of 67 kilometers (about 40 miles) per day.

The whale shark is one of only three known filter-feeding sharks, feeding on plankton, fish eggs, krill, crab larvae as well as small squid and fish (and, accidentally, plastic, which they cannot digest). As such, they are not considered to be particularly dangerous, and tourism companies that offer the opportunity to swim very close to whale sharks are common near areas where they aggregate in large numbers. But their size also attracts fishing boats. They are sought after for their fins and meat, for their teeth (used for crafts and sold to tourists) and for cartilage and oil with purported medicinal value. Juvenile whale sharks often end up as bycatch in tuna and other fisheries.

Whale sharks were classified as endangered in 2016. During the past 75 years, it is estimated that nearly half of the world’s whale sharks have disappeared. In many parts of the world, whale sharks have legal protection, but regulations are often not enforced. Guzman’s data were used to design and draft local and regional policies for the protection of the species. Fishing, capture and sale of whale sharks are prohibited in Panama by Executive Decree No. 9, signed in 2009. In 2014, Panama’s environmental authority passed an additional resolution regulating whale shark watching in Coiba National Park and the Isla Canales de Afuera marine reserve. The resolution includes a Whale Shark Watching Manual but unfortunately, tourism activities are not well organized and the authorities are not present to enforce the regulations.

“Whale sharks in Coiba have already changed their behavior to avoid the surface and tourists,” Guzman said. “These studies are critical as we design international policy to protect transboundary species like the whale sharks and other highly migratory marine species.”

SOURCE: https://www.sciencedaily.com/releases/2018/04/180426180007.htm