Just like dolphins, sharks can be trained to roll over to be cuddled by humans. In experiments carried out in the United States, several species of shark allowed themselves to be picked up from the water and cuddled by their trainers.

The U.S. trainers used coloured boards and sounds to train their sharks to respond to commands. No one had attempted to train sharks in this way before and the results are truly ground breaking. Shark keepers now hope that the new technique will give sharks a higher quality of life in captivity. When sharks ned to be moved, the normal practise is to chase them around, but a trained shark could instead be thought to just gently swim to a certain spot.

“The US team has shown that many varieties of sharks can quickly learn to respond to a combination of audible and visual signals”, says Carey Duckhouse of UK’s Sea Life Centres.

Keepers at the UK’s Sea Life Centres are planning to use the methods developed in the U.S. to train sharks kept in British facilities. Colour boards and sounds will be used to show each shark when it is his or her turn to receive food. If everything goes according to plan, the fastest learners in the shark tanks will grasp the idea within three months.

When a shark have learned to associate particular colours and sounds with food, the signals will make it approach its keeper who will be holding a “target stick” against which the shark will rub its nose in hope of getting a tasty treat.

”Some species, such as zebra sharks, will even roll over to have their tummies scratched or allow themselves to be lifted from the water without any kind of struggle,” says Dickhouse.

“We are not asking fishermen to stop fishing, only asking them to start releasing their catch,” says marine scientist Edd Brooks.

Brooks is a scientific advisor for the not-for-profit Company Shark-Free Marina Initiative, SFMI, who has just instigated a new strategy for preventing the deaths of millions of sharks belonging to vulnerable or endangered species.

The Shark-Free Marina Initiative works by prohibiting the landing of any caught shark at a participating marina. The initiative is based on the Atlantic billfish model which banned the mortal take of billfish in the 1980’s to give severely depleted populations a chance to recover.

By promoting catch-and-release and working closely with marinas and game fishing societies, SFMI hopes to win over the fishing community. Other important allies in the endeavour are competition sponsors and tackle producers.

Collaborating with the Fisheries Conservation Foundation in the USA and the Cape Eleuthera Institute in the Bahamas, SFMI has already gained the attention of marinas and non-profits nation-wide.

Enlisting the aid of anglers
By practising catch-and-release, sport fishers can not only decrease their impact on shark species; they can also actively aid ongoing research studies by collecting valuable data.

“Although the number of sharks killed by recreational fishermen each year is dwarfed by commercial catches, the current crisis facing shark stocks requires action wherever possible.” says Brooks.

During the last five years, the average number of sharks harvested annually by sport- and recreational anglers in the United States exceeded half a million. The outlook for these shark populations seem even graver when you take into account that many of the sharks targeted by fishermen are large, breeding age specimens belonging to endangered or vulnerable species. Removing so many sexually mature specimens from a population each year naturally has a major impact on its chances of long-term survival.

“Shark-Free Marinas is a necessary response to the culture of mature shark harvest” says SFMI’s Board Director, Marine Biologist Luke Tipple “Our effect will be immediate, measurable and, together with saving millions of sharks, will establish a new global standard for responsible ocean management. There’s a lot of talk about the atrocity of shark fining and fishing worldwide, but not a lot of measurable action towards reversing the damage. The time has come to stop simply ‘raising awareness’ and start implementing sensible management techniques to protect vulnerable species of sharks from inevitable destruction.”

You can find more information at www.sharkfreemarinas.com.
Help the project!

Four Pacific Angel sharks have been born at the Aquarium of the Bay in San Francisco, USA. The pups weighed between 115 and 120 grams at birth and measured 21-24 cm.

“We’re thrilled to have these rare births at Aquarium of the Bay,” said Christina Slager, Director of Husbandry at the Aquarium. “Very little is known about the reproductive behavior of these beautiful sharks, so the information we gather from these pups will be really valuable.”

The Pacific Angel shark (Squatina californica) is found from South Eastern Alaska to the Gulf of California and the San Francisco birth coincides with the pupping season for many local shark species.

The newborns have been moved from the exhibition to more secluded nursery tanks where they will be able to enjoy some peace and quite while being monitored by the husbandry team.

The Aquarium of the Bay is the only nature centre to consistently exhibit, study and care for Pacific Angel Sharks. The Aquarium of the Bay Foundation is currently funding a research project related to Angel sharks, where the collected data on breeding patterns and migration will be made available to government agencies, with the hope of protecting the animals’ habitat.

If you want to learn more about how the charismatic creatures known as stingrays feed, you should check out a new study published in the most recent issue of Neotropical Ichthyology.

While spending days and nights scuba diving and snorkelling in the upper Paraná River of Brazil, researchers Domingos Garrone-Neto and Ivan Sazima made 132 observations of freshwater stingrays and noticed three different forms of foraging behaviour.

Picture of Motoro Sting Ray, Ocellate river stingray – Potamotrygon motoro.
Copyright www.jjphoto.dk

The first hunting technique involved hovering close to the bottom, or even settle on top of it, while undulating the disc margins. By doing so, the stingray would stir up the substrate, unveiling small invertebrates. The invertebrates – typically snails, crabs and larval insects – could not escape from under the ray’s disc and ended up as food.

When using its second hunting technique, the stingray would slowly approach shallow water while keeping its eyes on suitable prey items that concentrate in such environments. When it got close enough, it would make a rapid attack; stunning the prey or trapping it under its disc. This hunting technique did not target tiny invertebrates hiding in the sand; it focused on tetras and freshwater shrimps instead. The studied stingrays only used this method during the night when they could sneak up on prey without being seen.

The third technique observed relied on the presence of vertical or inclined surfaces in the water, such as boulders and tree stumps, including man-made structures like concrete slabs. On this type of objects a lot of different organisms, e.g. snails, like to crawl around or attach themselves. The hunter would simply position itself with the anterior part of its disc above the water’s edge and start picking the animals off the surface, one at a time.

The two studied species were Potamotrygon falkneri and Potamotrygon motoro; both belonging to a genus of freshwater stingrays found exclusively in South America.

As mentioned above, you can find the paper in Neotropical Ichthyology 7.

Garrone-Neto, D and I Sazima (2009) Stirring, charging, and picking:

hunting tactics of potamotrygonid rays in the upper Paraná River. Neotropical Ichthyology 7, pp. 113–116.

Shark fin soup has traditionally been a must-have among well-to-do Asians and an essential part of the menu at commemorative dinners, such as wedding banquets and New Years celebrations in countries like China, Thailand, Taiwan, Malaysia and Indonesia.

However, as awareness grows about the precarious situation many species of shark are facing in the wild due to over-harvesting; many Asians – especially young ones –are substituting the shark fin soup with alternative dishes at their celebratory events.

Singaporean groom Han Songguang and his scuba diving bride are just one example of this trend; when they tied the knot in December last year they served their guests lobster soup and placed explanatory postcards depicting a dead shark on each seat.

“If we can do our part to save ‘X’ number of sharks … why not?” said Han, a geography teacher.

A symbol of wealth and status in several Asian cultures, shark fin soup consumption has traditionally been a delight available for a comparatively low number of Asian upper-class families only. Hand-in-hand with rising affluence in East Asia and the development of a prosperous middle class segment of society, demand has however soared rapidly in the late 20^th and early 21^st century and about 20 percent of all shark species are now endangered, partly due to them being over-fished to satisfy the Asian markets.

“They live a long time. They have a low reproductive rate. In other words they produce just a few young every year or every few years. So you just can’t take a lot,” says Yvonne Sadovy, a biology professor at the University of Hong Kong.

As more and more young Asians opt for lobsters and other alternatives to shark fins, market demands have dropped noticeably in recent years. After peaking at 897,000 metric tonnes in 2003, the world wide shark consumption has sunk to 758,000 in 2006, according to the U.N. Food and Agriculture Organisation. British wildlife group TRAFFIC says shark fins now make up an increasingly small percentage of the total consumption.

“Students and people in their 20s wouldn’t go to a shark eatery, and $15 for a dish is no cheap price,” says Joyce Wu, programme officer with TRAFFIC.

Shang-kuan Liang-chi, a National Taiwan University student agrees. “University students never go in there,” he says, referring to a shark fin restaurant near campus.

The decline is not only due to shark fins becoming increasingly out of vogue among environmentally concerned youngsters; the global financial crisis and its effects in Asia has caused many Asian to cut down on restaurant visits or order less expensive dishes.

Another sure sign of the declining popularity of shark fin soup in Asian is the menu for Singapore’s Annual Chefs’ Association dinner – it is now completely void of shark fin dishes.

“It is much harder to stop serving shark’s fin in our restaurants as the consumers still demand it. However, in our personal capacity, we can make a stand,” said Otto Weibel, a food manager at one of Singapore’s top hotels.

Is ritual slaughtering of animals on the beach to blame for two fatal shark attacks in the waters off Port St Johns this year?

After two young men died after being attacked by sharks, a task team was set up to investigate the attacks and their conclusion, presented in an official report released on Tuesday, is that the sharks were attracted to the beach by the smell of blood and other animal remains from the ritual slaughtering of animals.

Both the Zambezi shark (Carcharhinus leucas, also known as Bull shark) and the Tiger shark (Galeocerdo cuvier) are notorious scavengers and the smell of blood in the water attracts them to places where they can feast on animal remains.

Also conducive to the shark attacks was the beach’s proximity to the Umzimvubu River, “a well known nursery ground for Zambezi sharks”, said the Natal Sharks Board team of experts. In a statement issued jointly with the department of environmental affairs and tourism, the team said newborn and juvenile Zambezi sharks had been captured in the Umzimvubu River.

The team also stated that sewerage entering the river or the sea probably wasn’t a significant factor in the attacks.

Picture by: Andy Murch diver photographer  (CC3)

To prevent future attacks, the team recommended having the rituals moved away from this popular beach and not to be carried out on any other beach used by swimmers and surfers. In addition to this, signs ought to be erected warning visitors of the possibility of shark attacks. The team recommends any swimmers to stick together in groups and not to venture far out from the shoreline.

Tree deaths in two years; two of them in 2009

In January, Wild Coast Coast lifeguard Sikhanyiso Bangilizwe, 27, was fatally attacked by a shark off Port St Johns, making him the second lifeguard fatally attacked by sharks in this area in two years. Just two months after the January attack, a 16-year-old died of his injuries 30 minutes after being wounded by a shark in the same region.

After the death of Bangilizwe, his nephew, Lumka Bangilizwe, also a lifeguard, blamed the attack on an absence of shark nets and the animal rituals conducted there by traditional healers.

“Then what do you expect? Sharks smell all of that and come near where people are swimming,” he said claiming the municipality knew about the practice, but did nothing to stop it.

Environmental experts, meanwhile, suggested that untreated sewage entering the water might have attracted smaller fish which in turned lured the sharks near, but the municipality denied any spillage of sewage into the ocean.

While conducting magnetic experiments in 2006, the company SharkDefense Technologies discovered how certain metal alloys would keep sharks away by affecting the shark’s electric sense.

After extensive testing on several different shark species, SharkDefense Technologies and HEFA Rare Earth Canada, Co. Ltd are now finally ready to put their product on the market: metal alloy thingamajigs that keep sharks away from fishing gear by generating a small voltage as soon as the product is placed in saltwater.

Unlike popular food fishes like tuna and swordfish, sharks are equipped with an electric sense organ and will therefore stay clear of this type of voltage generating alloys. By placing a small piece of metal alloy near the bait at each hook, you cause sharks to shun your fishing equipment like the plague. This is a win-win situation for fishermen and sharks, since the fishermen will able to focus on more expensive target species and the sharks will avoid getting entangled in fishing gear and die.

Continuously submerged in seawater, the metal alloys continue to emit electricity for up to 48 hours.

The Spanish police have seized 11 tonnes of shark fins in destined to be shipped to Hong Kong.

According to a statement from the police, the shark fins did not appear to come from a protected species but were found in a warehouse that lacked authorization to export shark fins.

The confiscation took place in Huelva in south-western Spain, to where the fins had been transported from a port in Galicia in the north-western part of the country.

The shark fins have an estimated value of 136,800 Euros (186,335 USD). European Union countries are the main exporters of shark fins to China.

In many markets, shark meat does not yield a high price and fishermen therefore normally remove the fin from caught sharks and let the shark back to the sea. Without its fin the shark can no longer swim and will sink to the bottom where it either dies from suffocation (sharks need to swim to breathe) or gets eaten alive by other aquatic animals.

In parts of Asia, shark fins are used in folk remedies and to make traditional shark fin soup. As the standard of living rises in China, more and more people can afford to purchase shark fins and one pound of dried shark fin can now retail for over 300 USD.

Basking sharks have surprised researchers by leaving the cold waters of the north Atlantic during fall and head down to Bahamas and the Caribbean.

“While commonly sighted in surface waters during summer and autumn months, the disappearance of basking sharks during winter has been a great source of debate ever since an article in 1954 suggested that they hibernate on the ocean floor during this time,” said Gregory Skomal of Massachusetts Marine Fisheries. “Some 50 years later, we have helped to solve the mystery while completely re-defining the known distribution of this species.”

Basking Shark

Basking sharks are notoriously difficult to study for several reasons. They feed exclusively on plankton which means you can’t catch them using traditional rod-and-reel methods and they disappear down to deep waters for extended periods of time. During the part of the year when they do stay close to the surface, they are only found in cool waters teaming with plankton where the underwater visibility is close to zilch.

This situation has led to a lot of speculation about their life style and where they actually spend the winters. Despite being the second largest fish in the world, the basking shark is remarkably elusive and mysterious.

What finally solved the puzzle was the aid of new satellite-based tagging technology and a novel geolocation system which made it possible to track the basking whales as they commenced their annual migration. Data sent out from the tags unveiled that basking sharks migrates to warm tropical waters in fall. Their migrations have been able to go undetected until know since the sharks travel at depths of 200 to 1,000 meters and sometimes remain at those depths for weeks or even months at a time.

Skomal said he and his fellow researchers were absolutely surprised when they first received a signal from the tagged sharks coming from the tropical waters of the western Atlantic, since virtually everyone assumed basking sharks to be cool-water dwellers found in temperate regions only.

This new breakthrough show just how little we still know about even the largest marine animals inhabiting the world’s oceans. The basking shark can reach a length of 10 metres and weigh up to seven metric tons, yet it has managed to spend every summer in the Caribbean without anyone noticing it.

You can find more information in the report published on May 7 in Current Biology.

The elusive Megamouth shark (Megachasma pelagios) is such an uncommon sight that only 42 confirmed reports of this fish exists since the species was first scientifically described in 1976.

The most recent report, the 42nd one, comes from a group of Philippine fishermen from the city of Donsol who accidently caught a four-metre long specimen while trawling for mackerel.

Mega mouth shark exhibited at the Aburatsubo Marine

Worldwide Fund for Nature project manager Elson Aca examined the fish and identified it as a megamouth shark. The shark weighed an estimated 500 kg and was captured at a depth of 200 metres off the eastern coast of Burias Isle. This wasn’t the shark’s first encounter with fishing gear; it had scars on its face from gill nets.

Soon after being landed at Barangay Dancalan in Donsol, the shark died. Aca entreated the fishermen not to butcher the shark, but the fishermen had a more traditional than scientific approach to caught fish and promptly cooked it with coconut milk, malunggay leaves and chilli to make a Philipine dish known as kinunot.

According to Aca, the the Donsol-Masbate region deserve more attention from conversationalists.

“The presence of two of the world’s three filter feeding sharks warrants special attention for the Donsol-Masbate region”, Aca said. “Whale and megamouth sharks, manta rays, dolphins and other charismatic giants indicate that the region’s ecosystem is still relatively healthy. By protecting megafauna, we help maintain the dynamic balance of our seas, and ensure the entire ecosystem’s resilience and natural productivity.”