A team of researchers headed by Taylor Chapple, a UC Davis doctoral student, has made the first rigorous scientific estimate of White shark (Carcharodon carcharias) numbers in the northeast Pacific Ocean.
The researchers used small boats to reach spots in the Pacific Ocean where white whales congregate and lured them into photo range with a fake seal attached to a fishing line. Out of all the photographs taken, 321 photos showed dorsal fin edges. The dorsal fin edges of white sharks are jagged and each individual displays its own unique pattern. The photographs could therefore be used to identify individual sharks – 131 in total.
The research team then entered this information into statistical models to estimate the number of sharks in the region. According to their estimate, there are 219 adult* and sub-adult** white sharks in this area.
“This low number was a real surprise,” says Chapple. “It’s lower than we expected, and also substantially smaller than populations of other large marine predators, such as killer whales and polar bears. However, this estimate only represents a single point in time; further research will tell us if this number represents a healthy, viable population, or one critically in danger of collapse, or something in-between.”
The white shark population in the northeast Pacific Ocean is one of three known white shark populations in the world; the other two are found off the coast of South Africa and off Australia/New Zealand, respectively.
Earlier studies using satellite tagging have shown that the white sharks of the northeast Pacific Ocean have an annual migration pattern. Each year, they move from the region off the coast of central California and Mexico’s Guadalupe Island to the Hawaiian Islands or to an area of open ocean located between the Baja Peninsula and Hawaii. The latter destination has even been dubbed “White Shark Café” due to its popularity among white sharks. After spending some time away from the mainland, the sharks journey back to coastal waters.
“We’ve found that these white sharks return to the same regions of the coast year after year,” says Barbara Block, marine biologist at Stanford University and one of the co-authors of the pioneering white shark census. “It is this fact that makes it possible to estimate their numbers. Our goal is to keep track of our ocean predators.”
The paper “A first estimate of white shark, Carcharodon carcharias, abundance off Central California” (http://dx.doi.org/10.1098/rsbl.2011.0124) has been published in the journal Biology Letters (http://rsbl.royalsocietypublishing.org).
* Adult white sharks are the ones that have reached sexual maturity, something which happens when the male is roughly 13 feet and the female is about 15 feet in length.
**Sub-adults are roughly 8 feet or longer (but has not reached sexual maturity); at this size their dietary focus shifts from mostly fish to mostly marine mammals.
Using satellite tag technology, research assistant professor Neil Hammerschlag and his colleagues have tracked a hammerhead shark during 62 days, as it journeyed from the southern coast of Florida to the middle of the Atlantic off the coast of New Jersey.
The straight line point-to-point distance turned out to be 1 200 kilometers (745 miles).
“This animal made an extraordinary large movement in a short amount of time,” says Hammerschlag, director of the R.J. Dunlap Marine Conservation Program at the University of Miami Rosenstiel School of Marine & Atmospheric Science. “This single observation is a starting point, it shows we need to expand our efforts to learn more about them.”
The hammerhead is believed to have been following prey fish off the continental slope, and it was probably prey that caused it to enter the Gulf Stream current and open-ocean waters of the northwestern Atlantic.
The study headed by Hammerschlag is a part of a larger effort to satellite track tropical sharks to find out if any areas are especially important for their hunting, mating and rearing of young. Hammerschlag also wish to document their migration routes.
“This study provides evidence that great hammerheads can migrate into international waters, where these sharks are vulnerable to illegal fishing,” says Hammerschlag. “By knowing the areas where they are vulnerable to exploitation we can help generate information useful for conservation and management of this species.”
More information can be found in the paper “Range extension of the Endangered great hammerhead shark Sphyrna mokarran in the Northwest Atlantic: preliminary data and significance for conservation“, published in the current issue of Endangered Species Research. The paper’s co-authors include Hammerschlag, Austin J. Gallagher and Dominique M. Lazarre of the University of Miami and Curt Slonim of Curt-A-Sea Fishing Charters.
The government, no doubt panicking over the effects of recent shark attacks on tourism, is destroying the delicate ecological balance in the coastal regions of South Sinai, as well as hurting tourism, Sharm experts and divers have charged.
Some leading figures in the Sharm El-Sheikh’s diving community are now pointing the finger at the government, accusing them of going on a witch hunt, albeit for sharks, which is indiscriminate and involves more shark massacre than was ever publicly announced.
The divers have gone so far as to even launch their own Facebook group, complete with online petition, calling on the support of everyone in stopping authorities from engaging in shark genocide.
“They killed eight sharks in an area of 10 square kilometers,” director of the Aquamarine Diving And Water Sports Club, Dr. Amr Aboulfat’h, commented to Ahram Online. “Four were killed by the National Park Authorities, and four were killed by the National Institute for Oceanography and Fisheries (NIOF).”
Another source, who has requested to remain anonymous, has shed some additional light on the subject, saying that four of the sharks have been seen on Travco Jetty, and were later given over to Alexandria’s NIOF this past Monday.
The government doesn’t have much to say on the subject, except to deny any and all allegations about the shark massacre. The killing has to stop, but no one is taking responsibility.
“Who decided that it was one shark initially, and then two? And now more? And how come an authority that is responsible for protecting marine life assume the responsibility of such slaughter,” exclaimed a disdained Dr. Aboulfat’h.
Only time will tell what will become of the poor sharks.
Hunters taking advantage of a Japanese delicacy are thought to be the reason that shark stocks have drastically declined off the Gold Coast beaches.
Some astounding numbers revealed yesterday that shark nets had reeled in forty less sharks in the past year, compared to the same time frame in 2001/02.
Trevor Long, director of marine sciences for Sea World, revealed last night that over fishing by thriteen commercial shark hunters in the area had led to the steep decline in the shark population.
It is common knowledge that hunters have been reeling in sharks to harvest their valuable shark fins, which are part of the “shark fin soup” craze sweeping Japan.
In the 2001-02 fiscal year, seventy-eight sharks were reeled in in nets off the Coast, however by 2009-10 that number had dropped to thirty-seven.
This year, between the months of January and September, twenty-five sharks have been reeled in in shark nets and drumlines.
The largest shark reeled in was an impressive three-point-nine meter male greater hammerhead and ten were over two meters long.
Mr Long has commented that the shark populations declining was not the world’s best thing for the health of the world’s oceans.
“If we didn’t have sharks the whole marine ecosystem would become unbalanced – they are the top of the food chain and ensure the survival of the fittest,” Mr Long explained.
“It’s a worrying trend that shark numbers all over the world are dropping.”
The big question is, is it worth making an entire species extinct to get a bowl full of an exotic soup? Some say yes, others say no, however the general consensus is that we should take the poor shark off our dinner menus, before it’s too late.
Who’s looking forward to Shark Week? Well in Brooklyn it’s going to be all year long!
The New York Aquarium has announced this past Tuesday that it will build a $125 million structure to become the home of a gigantic shark tank – giving them the means to give a home to five times as many sharks.
“The current shark tank exhibit is old and tiny, so we’re very excited to replace it,” commented Jon Dohlin, the New York Aquarium director, who is hoping to begin the project by 2012.
The Coney Island attraction’s new structure will be comprised of aluminum which glows in the dark which will be visible from W. Fifth to W. Eighth streets and be the first of the Aquarium’s seven sectors which you will be able to get into from the Boardwalk.
This new structure is planned to come to fruition by 2015, when seven different kinds of sharks will be served up to the public eye.
“Usually, the cry of ‘shark’ means fewer people on the waterfront, but here in Brooklyn, it’ll mean more,” commented Markowitz, Borough President.
As recently as 2008, The Beep was badmouthing the Wildlife Conservation Society, which was in charge of the Aquarium and the zoos of the city, for supposedly not devoting enough funding to the shark house.
All that has changed now, and no one can complain about the $49 million in funding the project has received, however it still needs another $75 million to finish the project…
A blue shark which had been tagged was reeled in by a longliner off the south east coast of Africa. What’s so interesting about this tagged shark is that is has broken the record for distance traveled by any shark recorded by the GameFish Tagging Program.
The previous record holder was held by a blue shark which was released off Kilcuda (VIC) and was later reeled in again in the Indian Ocean, and swam a remarkable 2,400 nautical miles.
This new blue shark broke that record with a distance of 5,073 nautical miles, having made a voyage across the Indian Ocean from the time it was first let go at Port MacDonnell (SA) some five years ago.
The blue shark was originally let go by Paul Williams, an Adelaide GFC member, off of Port MacDonnnell back on the 20th of May 2005. The shark was guessed to be about 18 pounds when it was first tagged. When the shark was recaptured, it weighed in at around 94 pounds.
In a related stories, Nikol Bay SFC boat Tourettes has been hard at work, tagging tiger sharks for the past year and eight months, in Western Australia waters. Kevin Deacon’s team has managed to tag some 33 tiger sharks in this time.
Sharks are rather difficult to tag, but recent advancements in technology, along with a bit of elbow grease, has yielded really good results, and we now have an accurate way to study these magnificent creatures.
A marine biologist from Sharm El Sheik has blown a conspiracy theory out of the water involving sharks. It appears that some people believe that some shark attacks last week oof the South Sinai resort of Sharm El-Sheikh were orchestrated by the Mossad, in a bid to try and ruin the tourist industry in Egypt. (far fetched isnt it)
A professor of marine biology with the Suez Canal University, Mahmoud Hanafy, has reported to Ahram Online that it is “sad” that an Egyptian national TV station has helped to spread such ludicrous accusations.
Captain Mustafa Ismail, a famous diver from Sharm El Sheik, was seen speaking on “Egypt Today” – a popular public TV show in the area – commenting that the sharks who were involved in the attack were normal ocean sharks and do not reside in the waters of Egypt. He was seen as posing the question then of how the sharks got there.
He went on to comment that they received a report from an Israeli diver in Eilat saying they had discovered a small shark which was implanted with a GPS device. Then the idea was posed these devices were used to track the sharks while they were attacking Egypt.
Hanafy rebutted these accusations, commenting that the Oceanic White Tip – which has been blamed for the attacks – does actually reside in the waters of Egypt. He also added that the use of GPS devices is quite common amongst marine biologists to help study the life in the sea.
It should also be pointed out, that while you can track using a GPS device, you would not be able to “control” the sharks in the same manner..
So, was it a ploy? Not likely. It looks like someone is going to have egg on their face come morning….
A brazilian nonprofit Organization, known as The Environmental Justice Institute which happens to be located in Porto Alegre, has just initiated its fourth lawsuit against the industry of illegal shark finning. This time the trial will be held at the Federal Court in Belem, which is the capital of the Amazonian State of Para.
The case has already seen the confiscation of three and a half tons of shark fins, which amounts to a staggering number of some 40,000 sharks. The Environmental Justice Institute is asking for $120,000,000 in damages, and that is just the start.
“Usually, when people talk of the Amazon, they only think about the forests. Belém do Pará however is one of the main hotspots of finning in Latin America. We know also that the killing of dolphins for shark bait is commonplace in the region, and this too is an unacceptable crime”, explains Director of IJA, Crstiano Pacheco.
This fourth lawsuit is following two other lawsuits started in the Federal Court of Rio Grande, and another one in Belem, which is asking for the princely sum of $900,000,000 from SIGEL do Brasil, one of the biggest players in the fishing industry in the area. While they are based out of Panama, they do have a local office in Brazil, and that is where the case is being based from.
It is a long road for those involved in the case, but with the worldwide ban on shark finning, the plaintiffs are confident they can strike a blow for the sharks, and keep their fins firmly planted on their backs, where they belong.
Shark Advocates International is giving a warm welcome to progress towards helping conserve sharks. This progress was made at the annual meeting of the International Commission for the Conservation of Atlantic Tunas (ICCAT) this week.
There were a record number – six to be exact – proposals for shark measures, the parties of the ICCAT agreed to put a stop to the retention of oceanic whitetip sharks, prohibit exploiting of hammerheads, and set up a process for punishing countries who do not get with the program and accurately report catches and reduce fishing pressure on shortfin mako sharks. The proposals to stop the retention of abundant thresher and porbeagle sharks were thrown out as a measure to help ICCAT gain a stronger position to ban shark “finning” by prohibiting removing the fins of a shark at sea.
“ICCAT has taken significant steps toward safeguarding sharks this week, but much more must be done to effectively conserve this highly vulnerable species,” explained President of Shark Advocates International, Sonja Fordham, who serves on the US ICCAT Advisory Committee and has participated in ICCAT meetings since 2004. “We are particularly pleased with the agreements aimed at protecting oceanic whitetip sharks and reducing international trade in the fins of hammerhead sharks, as well as US efforts to conserve mako sharks.”
It’s good to see that progress is being made, and all parties involved are rather pleased that the meetings have gone so well so far. Hopefully, this means a better world for sharks.
After a stint of nineteen years in the park, the only sawfish at Six Flags Discovery Kingdom, which is thought to be somewhere in the vicinity of eighty years of age, has been sent off to a breeding program in New Orleans, officials have commented.
Michael Mraco, the park Animal Care Director, has commented that this particular species of shark can live for two centuries “so he’s not the old man we thought he was”.
“Buzz” has been living among five or six shark species at the Shark Experience in the park until this past Friday when he headed for his new home.
“We all feel this is good for Buzz and good for the species, which is endangered,” commented John Schultz, Curator of Fish for the park.
Muraco has explained how this transfer came to take place, and just how an eight decade old shark makes its way to a breeding program.
“This led to a conversation with the Autobahn Aquarium in New Orleans, and they mentioned there are only a handful of these animals left in United States and that they’re at risk in the wild and they asked how we’d feel about a cooperative breeding program,” Muraco explained.
And there you have it.. That is how an eighty year old shark is getting the chance to get his groove back on, and help save his species from extinction. It’s a tough job, but “Buzz” certainly seems up to the task.