Jumping the shark

Jumping the shark - Wikipedia, the free encyclopedia

Jumping the shark is an idiom used to denote the point in a television program's history where the plot spins off into absurd storylines or unlikely characterizations. These changes were often the result of efforts to revive interest in a show whose audience had begun to decline.

The phrase jump the shark refers to the climactic scene in 'Hollywood', of the American TV series Happy Days in September 1977. In this story, the central characters visit Los Angeles, where Fonzie (Henry Winkler), wearing swimming trunks and his leather jacket, jumps over a confined shark on water skis, answering a challenge to demonstrate his bravery. The series continued for nearly seven years after that, with a number of changes in cast and situations.

Jon Hein explained the concept as follows: 'It's a moment. A defining moment when you know that your favorite television program has reached its peak. That instant that you know from now on...it's all downhill. Some call it the climax. We call it 'Jumping the Shark.' From that moment on, the program will simply never be the same.'

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Scientists fear mass extinction as oceans choke

Scientists fear mass extinction as oceans choke - ABC News
Updated Wed Dec 1, 2010 12:20am AEDT

Australian scientists fear the planet is on the brink of another mass extinction as ocean dead zones continue to grow in size and number.

More than 400 ocean dead zones - areas so low in oxygen that sea life cannot survive - have been reported by oceanographers around the world between 2000 and 2008.

That is compared with 300 in the 1990s and 120 in the 1980s.

Professor Ove Hoegh-Guldberg, of the ARC Centre of Excellence for Coral Reef Studies (CoECRS) and from the University of Queensland, says there is growing evidence that declining oxygen levels in the ocean have played a major role in at least four of the planet's five mass extinctions.

'Until recently the best hypothesis for them was a meteor strike,' he said.

'So 65 million years ago they've got very good evidence of the cretaceous exctinction event.

'But with the four other mass extinction events, one of the best explanations now is that these periods were preceded by an increase of volcanic activity, and that volcanic activity caused a change in ocean circulation.

'Just as we are seeing at a smaller scale today, huge parts of the ocean became anoxic at depth.

'The consequence of that is that you had increased amounts of rotten egg gas, hydrogen sulfide, going up into the atmosphere, and that is thought to be what may have caused some of these other extinction events.'

Professor Hoegh-Guldberg says up to 90 per cent of life has perished in previous mass extinctions and that a similar loss of life could occur in the next 100 years.

'We're already having another mass extinction due to humans wiping out life and so on, but it looks like it could get as high as those previous events,' he said.

'So it's the combination of this alteration to coastlines, climate change and everything, that has a lot of us worried we are going to drive the sixth extinction event and it will happen over the next 100 years because we are interfering with the things that keep species alive.

'Ocean ecosystems are in a lot of trouble and it all bears the hallmarks of human interference.

'We are changing the way the Earth's oceans work, shifting them to entirely new states, which we have not seen before.'

He says while it is impossible to predict the future, in a century from now the world will be vastly different.

'A world without the Great Barrier Reef, where you don't have the pleasure of going to see wild places any more,' he said.

'We might be able to struggle on with much lower population densities, but ultimately it won't be the world we have today.

'The idea of walking in the Daintree will be a forgotten concept because these changes have occurred.'

Hearts and lungs

Scientists say ocean dead zones, which vary in size from one square kilometre to 70,000 square kilometres, have been found all over the world.

Particular hotspots include the Gulf of Mexico, off Namibia in the South Atlantic, in the Bay of Bengal, in the Baltic, the Black Sea, the tropical South Pacific, off China and south-eastern Australia.

'We're seeing an expansion of areas of the ocean which are very low in oxygen and also very low in nutrients,' Professor Hoegh-Guldberg said.

'Climate change is driving changes to water circulation - so winds, strange weather patterns, have a consequence for how the ocean turns over and aerates and so on, and it's the winds which are delivering a lot of organic compounds into the deep sea.

'At the same time we are putting a lot of fertiliser off coastlines, those sorts of things are incubating these deep water anoxic zones.

'So it's the combination of those two things that are having a big change on how the ocean works.'

He says organic matter building up in the sea is a huge problem.

'You get enormous amounts of organic carbon building up at depth, bacteria then likes to break down that organic matter and bacteria uses up the oxygen,' he said.

'So then what you get is a substantial drop in oxygen - that then has the consequences for fishers, for the productivity of coastlines and so on.'

Destructive path

Associate Professor Mark McCormick, also of CoECRS and from James Cook University, says low oxygen levels increase stress on fish.

'We know from our recent work that increases in stress result in deformities, leading to poorer survival of fish larvae,' he said.

'It has also been found they can cause fish to have smaller ovaries, produce fewer eggs, so larvae are also smaller and less likely to survive.'

Professor Hoegh-Guldberg says the problem is not as significant in Australia as other parts of the world, but that it is heading along the same, destructive path.

'We've been altering coastal areas, delivering nutrients into the ocean, and of course you see the Great Barrier Reef, which has been quite damaged due to nutrient run-off,' he said.

'But the point is that our activities on land have a big influence on what goes on in the oceans and now we are starting to reap the harvest of those changes.'

He says the heart and lungs of the planet are being tampered with.

'We are starting to see changes in the ocean's ability to produce oxygen and to produce food and produce all of the ecosystem's services that are so important to not only us, but all of the other organisms on the planet,' he said.

'It's mucking around with the heart and lungs of the planet - that's essentially what the oceans are, a huge respiratory system.

'We damage them, the consequences could be very serious.'

Professor Hoegh-Guldberg says while the dead zones may only exist in pockets of ocean today, it will affect a far greater area in the future unless steps are taken to reduce the impact of human activities on the world's oceans and their life.

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Fisherman investigated after illegal shark catch

Fisherman investigated after illegal shark catch - ABC News

The Department of Fisheries is investigating a Sunshine Coast fisherman who breached new shark laws.

The man caught a 2.8 metre bull shark at Eenie Creek in Noosa last month and failed to release it. The amazing thing about this catch is that the location was 14km from the ocean and the creek was estimated at only 3m wide and 5m deep where it was caught!

Under a state law brought in six months ago, the giant shark was almost twice the legal size of 1.5 metres.

Greg Bowness from Fisheries Queensland says if found guilty, the man faces a maximum penalty of up to $100,000.

'There are a number of options open to the department in relation to these issues so we'll look at the evidence before us and make a decision based on that,' he said.

'There has been a whole raft of changes made to fisheries legislation.

'It is really important for people who are going fishing that they are aware of the specific rules that apply to catching fish and that includes size and bag limits, closed areas and apparatus restriction.'

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Shark attacks don't warrant increased cull

Shark attacks don't warrant increased cull - ABC News

Australia is not alone in having large sharks near populated beaches or for having a reputation for shark attacks.

South Africa is the world's hotspot for great white sharks. It is where documentary makers come to film the dramatic scenes of white sharks breaching in the chase for Cape fur seals and it is the centre of the great white shark cage diving tourism industry where, on a daily basis, fleets of boats head out of the tourism centres packed with people wanting to view a great white shark from the safety of a cage.

In terms of documented attacks, there were six in the period from 1951 to 1970, 25 incidents between 1981 and 1990, 23 incidents reported from 1991 to 2000, and 11 reported great white attacks in the first half of this decade.

In some years, there were anomalously high numbers of attacks, such as Black December in 1957 when five people were bitten by sharks south of Durban, or 1998 when a total of 18 attacks were recorded in South Africa.

The longer term trend of rising incidents since the 50s and 60s mirrors an increase in beach use but cannot explain the year-to-year variations. To date, science cannot conclusively say why there are higher numbers of shark incidents in some years compared to others. It is likely that an array of oceanographic, ecological or behavioural factors are to blame for bringing more or fewer sharks in contact with people in any particular year, but the specific causes remain unknown.

Already it looks like 2009 will go down in the record books as having an anomalously high number of shark attacks in Australia and in the Sydney region in particular. Just as with South Africa, more people in the water increases the chance of an interaction. A cleaner Sydney harbour also increases the chance of finding sharks as well as fish, but it is not clear what other biological, environmental or behavioural factors, if any, are adding to the high recent number of attacks.

There is no doubt that any shark attack is a terribly unfortunate and traumatic incident. Our sympathies are with the victims and their families. On a global scale, elephants, bees, crocodiles and lightning strikes kill more people each year than shark attacks, and beachgoers are at a far greater risk of death by drowning from rips or surf, yet the thought of being attacked by a shark remains a terrifying prospect.

Actions that can help ensure bather safety include increased investment in education and awareness program so that people understand basic rules. Some of these include avoid swimming alone, avoid being in the water when there are low light levels or reduced visibility, don't swim in waters with known effluents or sewage and stay away from fish or gull feeding areas.

Increased investment is needed in research and development, and testing of options such as observer programs, use of electromagnetic field technology and new shark repellent advances in concert with research into sharks, so that we understand more about the behaviour, ecology and environmental cues that affect these species. Together these will allow bather safety programs to be designed to be as targeted and effective as possible without also causing the deaths of marine creatures such as dolphins and turtles that also call the ocean home.

Of the more than 300 species of shark found in Australian waters, there are only a couple of species, most notably the great white shark and bull shark, that are recorded as attacking humans. The vast majority of sharks are shy elusive creatures that appear in a range of often bizarre shapes and sizes, patrolling reefs and open oceans where they fulfil a critically important role at the top of the food chain.

In terms of their reproduction, sharks are long-lived, slow growing and produce relatively few young, which gives them a population dynamic that is more similar to whales and dolphins than to fish. This makes shark populations vulnerable to over-fishing.

The history of shark fisheries the world over is one of 'boom and bust' where excessive fishing pressure causes populations to crash.

The result is that shark species are increasingly finding their way onto the lists of at-risk or endangered species, almost as quickly as new species are being described.

The high price being paid for shark fin in the Asian marketplace appears to be driving a gold rush type mentality around shark fisheries in Queensland and New South Wales. Opportunistic fishers push fisheries managers to increase shark catches and create new shark fishing licences, despite there being no scientific basis that such levels of take are within safe limits for the large numbers of species involved.

With sharks very much in the spotlight, cool heads need to prevail.

The calls for an increase to the shark fishing quota in NSW are driven by this opportunism. Some fishers are using the current media feeding frenzy around sharks to call for an increase in shark hunting levels and are making claims that have no scientific basis. They should be ignored.

Many of the sharks they already catch are docile creatures that are not involved in attacks on bathers. Some of the populations of shark species that these fishers pull out of the water for their fins and flesh are in steep decline.

This is not to deny that we need to find ways to ease the interaction between sharks and humans along our beaches. There needs to be an investment in education, awareness and research and development, so that bather safety programs can be as effective as possible.

But equally, we need to protect the dwindling populations of sharks that have lived in our planet's seas for millions of years. There is no justification for increasing a fishing quota that could see these ancient creatures disappear from our oceans.

Dr Gilly Llewellyn is World Wildlife Fund-Australia's oceans program leader

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NSW releases shark attack proposals

NSW releases shark attack proposals - ABC News

The New South Wales Government has released a number of new proposals to prevent shark attacks, as it defends itself against claims it is failing to protect swimmers after three attacks in Sydney in as many weeks.

The measures include a new shark tagging program, the use of GPS to monitor shark nets and a list of shark attacks by beach since 1900.

The Government is also considering upgrading shark fishing gear and researching shark movements, attacks and population trends to try to identify hotspots and high-risk periods.

The proposals are part of the first review of the long-standing shark net program since 1972. They also include publishing an annual report about the nets' performance.

Primary Industries Minister Ian Macdonald says the Government will also consult with surf lifesavers.

'The Government in the past has provided a number of jet skis to surf lifesavers that have helped them monitor and deter sharks and we'll be discussing these on Thursday,' he said.

The Opposition says the Government has not done enough to protect swimmers and surfers. It says shark nets are deteriorating, the shark fishing quota should be increased and beaches need more aerial patrols.

But Mr Macdonald says aerial patrols do not spot sharks at dawn and dusk, the high-risk periods when the three latest shark attacks occurred. He says the patrols sometimes confuse big fish with sharks.

The Minister also says only 4.2 per cent of sharks caught in the fishing quota are dangerous.

In the latest shark attack, 15-year-old Andrew Lindop was bitten on the leg while surfing with his father, a veteran lifesaver, at Sydney's Avalon Beach at dawn on Sunday.

The boy is recovering in a stable condition in hospital after being rescued by his father.

This year's first Sydney victim, elite Navy diver Paul de Gelder, lost a hand and a leg after being attacked by a bull shark at dawn off Garden Island in Sydney Harbour on February 11.

The following day, surfer Glenn Orgias was mauled by a great white shark at the southern end of Bondi Beach at dusk.

His hand was hanging off his wrist by a three-centimetre piece of skin but doctors have managed to save it in what they have described as a 'minor miracle'.

The proposals will be made open to public consultation next month.

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Mexican Shark Decline

Shark Diver Magazine Blog

Holbox Island was once a shark fisherman's paradise. Everyone on the island used to fish for sharks. In the 50's and 60's, they would sell the shark oil, in the 70's, it was their skin and oil, the vendors were after, in the mid 80's and above, it was the fins. Now the vendors want the entire shark. The 'coyote', that is the name of the guy who purchases sharks on the island. He takes the sharks and the sharks ultimately end up getting cut up and sold to different countries in Florida. Nice! Of course the islanders are not fishing for sharks anymore. They decimated the entire population of local and migratory sharks, to the point that the island can only sustain 3 to 4 shark fishermen now.

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Why Study Shark Attacks

Because they provide a glimpse - a window - into the world of sharks and their behaviors. By understanding when and why sharks sometimes bite humans it is possible to lessen the likelihood of such accidents. Humans are familiar with predators found on land; we know enough not to walk into a pride of lions and we don't try to pet a growling dog that is baring its teeth. Similarly, we need to recognize and avoid potentially dangerous situations in the water. The individual case histories provide insights about specific geographical areas and their indigenous species of sharks. However, when all known case histories are examined, much is revealed about species behavior, and specific patterns emerge.

Most of the incidents in the Global Shark Attack File have nothing to do with predation. Some incidents are motivated by displacement or are a territorial behavior, or when the shark feels threatened; still others are the result of the shark responding to sensory predatory input (i.e., overwhelmed by the presence of many fishes) and environmental conditions (murky water) which may cause the animal to respond in a reflexive response to stimuli. Sharks also exhibit curiosity and may investigate unknown or unfamiliar objects; they learn by exploring their environment, and - lacking hands - they use their mouths and teeth to examine unfamiliar objects.

A very small percentage of shark species, about two dozen, are considered potentially dangerous to humans because of their size and dentition. Yet each year, for every human killed by a shark, our species slaughters more than 10 million sharks - about 100 million sharks last year. We are stripping the world's oceans of one of its most valuable predators - animals that play a critical role in maintaining the health of the world's oceans. An unreasonable fear of sharks has been implanted in our minds by the hype that surrounds the rare shark attack and by movies that exploit our primal fears. It is the mission of the Global Shark Attack File to present facts about these events, thus enabling them to be put in perspective. Sharks are necessary and vital to the ocean ecosystem. Without sharks our planet's ocean could eventually become a watery graveyard, with little sustainable life. This is not the legacy the Global Shark Attack File and the Shark Research Institute wishes to leave our children and our children's children.

The Global Shark Attack File was created to provide medical personnel, shark behaviorists, lifesavers, and the media with meaningful information resulting from the scientific forensic examination of shark accidents. Whenever possible, GSAF investigators conduct personal interviews with patients and witnesses, medical personnel and other professionals, and conduct examinations of the incident site. Weather and sea conditions and environmental data are evaluated in an attempt to identify factors that contributed to the incident.

Early on, we became aware that the word "attack" was usually a misnomer. An "attack" by a shark is an extremely rare event, even less likely than statistics suggest. When a shark bites a surfboard, leaving the surfer unharmed, it was historically recorded as an "attack". Collisions between humans and sharks in low visibility water were also recorded as "attacks".

When a shark grabs a person by the hand/wrist and tows them along the surface, tosses a surfboard (or a Frisbee as in case 1968.08.24) it is probably "play behavior", not aggression. How can case 1971.04.11 which the swimmer was repeatedly bitten by a large shark and case 1985.01.04 in which the diver's injury necessitated a Band-aid be compared? It is akin to comparing a head-on high-speed vehicular collision with a shopping cart ding on the door of a parked car. Global Shark Attack File believes the only way to sort fact from hype is by forensic examination of each incident.

Although incidents that occur in remote areas may go unrecorded, the Global Shark Attack File is a compilation of a number of data sources, and we have a team of qualified researchers throughout the world that actively investigate these incidents. One of our objectives is to provide a clear picture of the actual threat presented by sharks to humans. In this regard, we remind our visitors that more people drown in a single year in the United States than have been killed by sharks throughout the entire world in the last two centuries. 

Source: Global Shark Attack File

Website: http://www.sharkattackfile.net