White Shark - Terry Gross

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.

Study co-authors

• Taylor K. Chapple, Wildlife, Fish and Conservation Biology, University of California Davis, USA and Max Planck Institute, Germanyhttp://www.topp.org/user/taylorchapple
• Salvador J. Jorgensen, Hopkins Marine Station of Stanford University, USA and Monterey Bay Aquarium, USAhttp://www.topp.org/blog/salvo
• Scot D. Anderson, Point Reyes National Seashore, USA
• Paul E. Kanive, Department of Ecology, Montana State University, USA
• A. Peter Klimley, Wildlife, Fish and Conservation Biology, University of California Davis, USAhttp://wfcb.ucdavis.edu/people/faculty/klimley.php
• Louis W. Botsford, Wildlife, Fish and Conservation Biology, University of California Davis, USAhttp://wfcb.ucdavis.edu/people/faculty/botsford.php
• Barbara A. Block, Hopkins Marine Station of Stanford University, USAhttp://www-marine.stanford.edu/block.htm

Funding

• The National Oceanic and Atmospheric Association (NOAA) Fisheries through the Partnership for Education in Marine Resource and Ecosystem Management (PEMREM) and the NOAA Fisheries/Sea Grant Fellowship Program
• The Gordon and Betty Moore Foundation
• The National Parks Service’s Pacific Coast Science and Learning Center
• Monterey Bay Aquarium
• UC Davis Bodega Marine Laboratory
• Patricia King, member of the Point Reyes National Seashore Association



Shark fins

A high class restaurant situated in Tsim Sha Tsui, the Sun Tung Lok – which also happens to be very famous for its shark fin soup – has just gotten the honor of being the first restaurant, not part of a hotel, to be given three Michelin stars.

“After no less than eight visits in the past year by our inspectors, we decided that with its new chef, Joe Chan, the restaurant was a three star,” director of Michelin guides, Jean-Luc Naret explained.
“The chef has visited different parts of the mainland and incorporated ideas into the menu.”

Roughly eighty percent of the menu is Cantonese, which stems to include stuffed crab shell, roast suckling pig and beef rib with house gravy.

The price of the succulent shark fin soup ranges from $20 USD to $650.

The group of caterers opened up their branch in Tsim Sha Tsui four decades after the grand opening of their first restaurant in Happy Valley.

The soup has been popular amongst rather famous patrons of the restaurant such as Stanly Ho Hung-Sun, casino mogul, Lee Heung-kam, an actress, and Alex Fong Lik-sun, a singer.

A food critic and chef from Hong Kong, Lau Kin-Wai, has commented that the Sun Tung Lok deserves the highest rating as the quality of the soup is outstanding, and of course the innovative menu as well.

However, the soup is not sitting well with conservationist groups such as the WWF and PETA. The WWF has commented that is is rather disappointed for the three star rating, as it is rewarding bad behavior.

“Since the Michelin Guide is popular with diners, it may induce more shark fin consumption and further impact marine ecosystems,” a spokeswoman commented.

Hammerhead shark by Suneko

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.

Shark fins

Individuals involved in the European Parliament have commenced an initiative to more heavily enforce the EU ban on shark finning. Shark finning is a barbaric practice which involves capturing a shark, ripping of its fins, and tossing the rest overboard.

The shark finning ban in the EU is one of the least enforced in the world, as it contains loopholes which prevent law enforcement officials from properly enforcing it. You see, the regulation which bans shark finning in the EU also has a derogation which allows different states of the EU to give out licenses to “process” sharks, and remove their fin on ocean faring vessels.

The most effective, and easiest, way to have a ban on shark finning would dictate that sharks need to be reeled in intact, meaning that fishermen can’t just bring in the fins in their hauls.

“For too many European fisheries, the EU ban on finning is the only measure in place that helps curb excessive killing of sharks. The ban must be strengthened to ensure that this incredibly wasteful practice is prevented,” explained Chris Davies MEP. “France has long supported strong bans on shark finning, in European waters as well as in our overseas territories,” said Jean-Paul Besset MEP “French fishermen are already leaving the fins attached to sharks caught in oceans all over the world, demonstrating that this strategy is entirely feasible. We cannot wait any longer to enforce robust protection for these important predators, which are so key to the balance of life in the sea.”

It’s good to see that someone in the parliament is finally making a stand for the poor sharks. Let us hope that something is done soon to protect the poor creatures more effectively.

Shark fins

Both local and international conservations groups and organizations are banding together to help protect sharks which call the Bahamian waters home, after an article published in Tribune exposed the potential for shark finning practices in Andros.

James Mackey, Chief Executive Officer of Sunco Wholesale Seafood Limited, told the Tribune that the company was thinking of expanding their operation of sea cucumber export in Mastic Point, North Andros, to encompass the exportation of shark fins to eager clients in Hong Kong.

Well, that was obviously a BIG mistake.. The comments he made, and subsequently were published, really created an uproar from different groups and conservationists not only from the Bahamas, but from round the globe. This comes in response to shark populations declining up to 80% around the world, due to the $200 per kilogram delicacy being fished out of our worlds’ oceans.

Interestingly enough, and what caused most of the ruckus, is that the Bahamas is home to the most biologically diverse and pristine shark populations which the Atlantic has to offer. This is due to the fact that the commercial fishers have never really taken an interest in them, that is until now.

However, the outcry comes from the fact that the Bahamas National Trust, in conjunction with the Pew Environment Group which is in the midst of launching a campaign that would hopefully make the fishing and finning of sharks illegal.

The world’s first shark sanctuary will be created by Palau, a small island nation in the Pacific Ocean. The sanctuary will measure 240,000 square miles and be a haven for vulnerable shark species like Leopard shark, Hammerhead, and Oceanic Whitetip. Over 135 different species of shark and ray is known to live in this biological hotspot.

“Palau will declare its territorial waters and extended economic zone to be the first officially recognized sanctuary for sharks,” said Palauan President Johnson Toribiong.

Unfortunately, this tiny nation with a population of 20,000 people has only one patrol boat to protect the immense sanctuary from fishermen.

While acknowledging the difficulties, the president still hopes that others will respect Palauan territorial waters – and that the shark haven will inspire more such conservation efforts globally.

“We’ll do the very best we can, given our resources,” he said. “The purpose of this is to call attention to the world to the killing of sharks for commercial purposes, including to get the fins to make shark fin soups, and then they throw the bodies in the water.”

Toribiong said a recent flyover by Australian aircraft showed more than 70 vessels fishing in Palau waters, many of them illegally.

Thousands of Greenland sharks get caught and die in nest off Greenland each year, but their meat is toxic to humans and the carcasses are therefore thrown back into the sea.

Researchers at the Arctic Technology Centre (ARTEK) in Sisimiut in western Greenland now hope to find a way of turning the oily flesh of these enormous fishes into biogas for Eskimos.

The Greenland shark can reach a length of seven meters (23 feet) and weigh up to a tonne.

“I think this is an alternative where we can use the thousands of tonnes of leftovers of products from the sea,

including those of the numerous sharks,” says Marianne Willemoes Joergensen of ARTEK’s branch at the Technical University of Denmark.

Joergensen, who is in charge of a pilot project based in the Uummannaq village in northwestern Greenland, says a mixture of shark meat, macro-algae and household wastewater could serve as biomass for biofuel production.

“Biofuel is the best solution for this kind of organic waste, which can be used to produce electricity and heating with a carbon neutral method,” she explains.

According to estimates, biofuel from the sea could supply Uummannaq’s 2,450 inhabitants with 13 percent of their energy consumption.

But the biofuel project is not uncontroversial.

“[It] is not a good idea, not at all“, says Danish WWF ocean mammal specialist Anne-Marie Bjerg who wants to see other sustainable energy projects undertaken instead.

“We know very little about the Greenland shark, which lives in a limited geographic zone, the Arctic,” she said. “We are opposed to the commercial use of marine mammals*, such as the Greenland shark, which is not universal and whose population size is unknown.“

AC Comment:

*The Greenland shark is not a mammal since it does not feed its young milk. Mammals are animals whose females are characterized by the possession of mammary glands. The Greenland shark does however give birth to live young. Just like many other sharks, it is an ovoviviparous species. Much remains unknown of the Greenland shark’s reproduction and life cycle.

Shark tours have become increasingly popular in Hawaiian waters, but tour operators that feed shark to assure their presence are now facing opposition from several different directions.

Sharks are an integral part of Hawaiian folklore and some Native Hawaiians consider sharks to be ancestral gods, aumakua, who helps fishermen by chasing fish into nets and guiding canoes safely back to shore. Tour boats feeding sharks for entertainment is therefore viewed as disrespectful by many.

“The disrespect of the aumakua, that’s what hurts us the most,” said Leighton Tseu, a Native Hawaiian who considers sharks ancestral gods.

Surfers and swimmers are on the other hand more worried about the potential hazards of teaching sharks to associate people with food. There are also fears that shark feeding will attract larger numbers of sharks to these waters and that the practise of feeding them will lure them closer to shore than before.

A third concern has been raised by environmentalists – how does daily shark feedings affects the ecological balance of Hawaiian waters? George Burgess, shark researcher at the University of Florida, says shark populations are likely to increase in areas where tours feed sharks daily, and that an inflated shark population might consume more prey, depleting other marine life. Burgess also fears that the feedings may attract so many sharks to those spots that sharks become scarce in other regions. This is naturally a large problem, since sharks are apex predators necessary for the overall balance of the ecosystems in which they exist.

Carl Meyer of the Hawaii Institute of Marine Biology does not share Burgess’s concerns, at least not for Hawaiian waters. Research carried out by Meyer shows that a majority of the sharks found at Haleiwa, a popular tour site, are Galapagos and Sandbar sharks – two types of sharks rarely documented attacking humans. Most of Hawaii shark attacks are carried out by Tiger sharks, and these sharks only account for 2 percent of the tour site’s sharks. Meyer’s research also shows that sharks at the North Shore tour site have not made any changes to their seasonal breeding and migration cycles since the feedings started.

Legal matters
Feeding sharks in Hawaiian waters is prohibited by state law, while federal law – which governs waters between 3 miles to 200 miles from the coast – prohibits the feeding of sharks off Hawaii and Pacific island territories like American Samoa. Fishermen are however allowed to bait sharks, and scientists engaging in government-funded research are also exempt from the ban.

The National Marine Fisheries Service in Honolulu is currently investigating Hawaiian tour operators offering shark safaris.

No less than 215 anglers from throughout the UK participated in the 2009 Scottish Sharkatag organised by the Scottish Sea Angling Conservation Network (SSACN).

The Sharkatag had three goals:

– To highlight the perilous state of the endangered shark species.

– To gather data to support claims for their protection.

– To press politicians and fisheries managers to recognize the needs of the sea angling community and its contribution to the Scottish economy.

The information gathered during the Sharkatag will feed into SSACN’s Scottish Shark

Tagging Programme; a program dedicated to broaden our knowledge of shark, skate and ray stocks in Scottish coastal waters.

Attending anglers caught, tagged and released various shark species from boats, kayaks and the shoreline of Solway in South West Scotland, and what they found was worse than expected.

“It really worries me that many of the tope packs have failed to

show this year“, says Ian Burrett, SSACN’s Project Director. “The whole region seems to be void of the expected male breeding stock and the fish caught were mostly immature females, typically under twenty pounds and a few solitary females in the 50-60 pound range; Luce Bay was especially poor for the time of year.”

The Tope shark (Galeorinus galeus), also known as the School shark, Soupfin shark and Snapper shark, is a type of hound shark found at depths down to 550 metres (1800 feet). It can reach a length of 2 metres (6.5 feet) and is listed as Vulnerable at the IUCN Red List of Threatened Species.

The situation was equally worrisome for several other species of shark and ray.

“Around two hundred tope, smoothhound and bull huss were tagged over the three days and that can only be described as poor compared to what the total should have been, says Burrett. “Combined with the lack of rays tagged, only three throughout Sharkatag, it shows how urgently plans are needed to helpprotect and regenerate the stocks. Twenty year ago virtuallyevery boat would have recorded several mature tope and rays.”

You can find more information at the Scottish Sea Angling Conservation Network’s website www.ssacn.org and the website of SSACN’s Scottish Shark Tagging Programme www.tagsharks.com.

Scientists tagging sharks off the Irish coast have tagged a surprisingly high number of Basking sharks this year: 50 specimens in just three days.

“I would normally expect to be lucky if we tagged 50 in a whole year,” said Dr Simon Berrow of the Irish Whale and Dolphin Group.

Basking SharkA record

Together with National Parks and Wildlife Service conservation ranger Emmett Johnston, Dr Berrow set out earlier this week to tag sharks off Donegal, as part of a project funded by the Heritage Council.

“In two hours last Monday we tagged 23 sharks, and we found 19 the following day – four of which had been tagged the day before,” Dr Berrow said. By the third day, they had tagged their 50^th basking shark.

Basking sharks were once a significant source of income for Irish whalers and the coastal towns of Galway and Waterford did for instance have street lights lit with basking shark oil as early as the 18^th century.

The importance of Basking sharks in Irish culture is evident in the number of names and monikers give to these peculiar creatures. In Irish, this “monster with sails” is known under the names Liabhán chor gréine (Great fish of the sun), Liop an dá (unwieldy beast with two finns) and Liabhán mór (great leviathan) – just to mention a few. The epithets “Fish of the sun” and “Sunfish” both pertains to its fondness of swimming just under the surface.

In the mid-1970s the Irish stopped their whaling, but the problems weren’t over for these sharks since they frequently ended up as by-catch in drift nets; a fishing method now outlawed in Irish waters. In addition to this, Norwegian whalers continued to hunt for shark off the Irish coast until 1986.

The Basking shark (Cetorhinus maximus) is listed as Vulnerable on the IUCN Red List of Threatened Species, and is a protected species in Great Britain but not in Ireland. However, the European Union has just placed a moratorium on fishing for Basking sharks in these waters.

If you spot a Basking shark in Irish waters, the Irish Whale and Dolphin Group would very much like to know any details about the sighting. You can find more information at www.baskingshark.ie.

Want to know more about Basking sharks and where they head when the Northern Seas become too cold for comfort? Check out our earlier blog post on Sharks of the Caribbean.