Wednesday, 01 October 2008
Friday, 19 September 2008
Friday, 22 June 2007
Gastronomic gastropods or just plain goners
It’s not recorded when the first human stepped into the frigid waters of South Africa’s Cape coast, fished out an abalone and ate it. Certainly it couldn’t have been an enjoyable experience, by today’s standards, yet as a source of protein these distant relatives of snails were excellent. Before long, hunter gathers throughout the region were dipping into the resource, leaving dozens of large middens along the coast piled high with the discarded, soup bowl-shaped shells of their catch.
For 125 000 years abalone, or perlemoen as it is referred to locally, survived well under this subsistence level of exploitation. But in more recent times its subtle flavour and the East’s insatiable appetite for seafood, have created a huge demand. Prices have sky rocketed, reaching R300 a kilogram and more, for the dried flesh. With the promise of such rewards, abalone populations are reeling under heavy exploitation from licensed operators and poachers alike. It’s estimated that poachers could be doubling the recommended legal quotas for the fishery; a situation exacerbated by the poor, previously, disadvantaged, communities that live in the coastal areas abutting the resource. “With poachers potentially able to earn R5 000 a night, its no wonder that people are flaunting the regulations, in this new age, aquatic, gold rush,” says Marcelle Kroese, Marine and Coastal Management’s (MCM) assistant director of compliance.
Kroese and his team of inspectors are tasked with enforcing MCM’s regulations for a suite of commercially important and recreationally targeted species. But few of these are as thorny and difficult to tackle as abalone. Operation Neptune for instance, the combined operation to kerb abalone poaching between MCM and the South African Police Service, regularly faces armed gangs of poachers. Kroese is adamant, however, that the success of this operation and the others like it, is vital to the future of the abalone resource.
Professor George Branch of the Marine Biology Research Institute of the University of Cape Town shares these sentiments. He argues that the outlook is bleak for a species that is intrinsically susceptible to over exploitation.
Abalone are particularly susceptible because they are slow growing and relatively long lived, with some large individuals reaching 30 years old. It takes seven years for an individual to reach maturity and eight years to reach the legal size limit imposed by MCM. But poachers are not concerned with regulations and many of the abalone being removed, are well below the legal size. This means they are unlikely to have reproduced, and will therefore not have contributed to future generations - a tragedy in terms of MCM’s management strategy. Susceptibility is further increased by the shallow water distribution of the species. As professor Branch points out: “just about anybody can enter the water with a mask, snorkel and perlemoen lifter and be successful.”
As if these problems aren’t enough, there are a host of natural changes also occurring in the region. Professor Branch and his team have documented changes in the structure and functioning of shallow water reef communities along the Cape South Coast largely due to a steady, and fairly recent, influx of rock lobsters. These voracious predators have reduced the number of urchins and other grazers by as much as 98 percent in places, which in turn has had knock on effects on algae, with densities increasing by as much as 270 per cent. Unfortunately these changes seem to have had severe effects on the ability of juvenile abalone to survive.
Juvenile abalone shelter under urchins in order to escape being preyed upon by their natural predators. Without this shelter, they’re incredibly susceptible and their chances of survival diminish severely. A concomitant effect of the reduction in urchin numbers has also been an increased level of siltation on shallow reefs.
“This increased siltation interferes with both the growth of coralline algae and the ability of abalone spat to settle,” says Professor Branch. This is a double-edged sword for abalone, which only settle on certain species of coralline algae, and never where the surface is silted up. The bottom line for abalone is: not only are the breeding stocks of adults being severely depleted by over exploitation, but the reproductive success of the species is being severely hampered by natural biological processes.
It was these processes, which prompted Professor Branch to suggest an innovative solution to the poaching problem a number of years ago. He suggested offering local communities and in particular poachers, legitimate rock lobster fishing permits. Rock lobsters occur in sufficient numbers to warrant a low level of commercial exploitation and in exchange for the permit, holders would’ve guaranteed to lay off the abalone. It seemed a win-win situation. Poaching would decline thereby decreasing the mortality of abalone breeding stocks, while at the same time crayfish numbers would be reduced limiting their impacts on the shallow water reef communities and thus increasing recruitment success of juveniles. Unfortunately officials were reluctant to try the experiment. Local fishers became disillusioned with the government’s attempts at dishing out quotas and poaching continued unabated; abalone stocks continued their slippery slide towards extinction.
“And therein lies the real tragedy,” says Rob Tarr an abalone researcher from MCM. “Not only is a valuable resource being fished to extinction, but an entire community is operating outside the law - their children growing up in a climate of lawlessness. What chance do they have of a normal upbringing under these circumstances?” asks Tarr. “It doesn’t bode well for the future of the community or for our attempts at controlling the wonton destruction of the abalone resource.”
Ultimately scientists and managers agree there simply aren’t enough abalone to go round. What’s more, coastal resources such as abalone will not lift everyone in the nearby coastal communities out of poverty, contrary to what certain fishing organisations may argue. The only real future for a viable abalone industry lies in a well-managed fishery, with effective, heavily enforced quotas to prevent over exploitation and poaching. Currently it’s a tragedy of the commons scenario and unless the situation improves, the golden gastropod will soon be gone.
It’s not recorded when the first human stepped into the frigid waters of South Africa’s Cape coast, fished out an abalone and ate it. Certainly it couldn’t have been an enjoyable experience, by today’s standards, yet as a source of protein these distant relatives of snails were excellent. Before long, hunter gathers throughout the region were dipping into the resource, leaving dozens of large middens along the coast piled high with the discarded, soup bowl-shaped shells of their catch.
For 125 000 years abalone, or perlemoen as it is referred to locally, survived well under this subsistence level of exploitation. But in more recent times its subtle flavour and the East’s insatiable appetite for seafood, have created a huge demand. Prices have sky rocketed, reaching R300 a kilogram and more, for the dried flesh. With the promise of such rewards, abalone populations are reeling under heavy exploitation from licensed operators and poachers alike. It’s estimated that poachers could be doubling the recommended legal quotas for the fishery; a situation exacerbated by the poor, previously, disadvantaged, communities that live in the coastal areas abutting the resource. “With poachers potentially able to earn R5 000 a night, its no wonder that people are flaunting the regulations, in this new age, aquatic, gold rush,” says Marcelle Kroese, Marine and Coastal Management’s (MCM) assistant director of compliance.
Kroese and his team of inspectors are tasked with enforcing MCM’s regulations for a suite of commercially important and recreationally targeted species. But few of these are as thorny and difficult to tackle as abalone. Operation Neptune for instance, the combined operation to kerb abalone poaching between MCM and the South African Police Service, regularly faces armed gangs of poachers. Kroese is adamant, however, that the success of this operation and the others like it, is vital to the future of the abalone resource.
Professor George Branch of the Marine Biology Research Institute of the University of Cape Town shares these sentiments. He argues that the outlook is bleak for a species that is intrinsically susceptible to over exploitation.
Abalone are particularly susceptible because they are slow growing and relatively long lived, with some large individuals reaching 30 years old. It takes seven years for an individual to reach maturity and eight years to reach the legal size limit imposed by MCM. But poachers are not concerned with regulations and many of the abalone being removed, are well below the legal size. This means they are unlikely to have reproduced, and will therefore not have contributed to future generations - a tragedy in terms of MCM’s management strategy. Susceptibility is further increased by the shallow water distribution of the species. As professor Branch points out: “just about anybody can enter the water with a mask, snorkel and perlemoen lifter and be successful.”
As if these problems aren’t enough, there are a host of natural changes also occurring in the region. Professor Branch and his team have documented changes in the structure and functioning of shallow water reef communities along the Cape South Coast largely due to a steady, and fairly recent, influx of rock lobsters. These voracious predators have reduced the number of urchins and other grazers by as much as 98 percent in places, which in turn has had knock on effects on algae, with densities increasing by as much as 270 per cent. Unfortunately these changes seem to have had severe effects on the ability of juvenile abalone to survive.
Juvenile abalone shelter under urchins in order to escape being preyed upon by their natural predators. Without this shelter, they’re incredibly susceptible and their chances of survival diminish severely. A concomitant effect of the reduction in urchin numbers has also been an increased level of siltation on shallow reefs.
“This increased siltation interferes with both the growth of coralline algae and the ability of abalone spat to settle,” says Professor Branch. This is a double-edged sword for abalone, which only settle on certain species of coralline algae, and never where the surface is silted up. The bottom line for abalone is: not only are the breeding stocks of adults being severely depleted by over exploitation, but the reproductive success of the species is being severely hampered by natural biological processes.
It was these processes, which prompted Professor Branch to suggest an innovative solution to the poaching problem a number of years ago. He suggested offering local communities and in particular poachers, legitimate rock lobster fishing permits. Rock lobsters occur in sufficient numbers to warrant a low level of commercial exploitation and in exchange for the permit, holders would’ve guaranteed to lay off the abalone. It seemed a win-win situation. Poaching would decline thereby decreasing the mortality of abalone breeding stocks, while at the same time crayfish numbers would be reduced limiting their impacts on the shallow water reef communities and thus increasing recruitment success of juveniles. Unfortunately officials were reluctant to try the experiment. Local fishers became disillusioned with the government’s attempts at dishing out quotas and poaching continued unabated; abalone stocks continued their slippery slide towards extinction.
“And therein lies the real tragedy,” says Rob Tarr an abalone researcher from MCM. “Not only is a valuable resource being fished to extinction, but an entire community is operating outside the law - their children growing up in a climate of lawlessness. What chance do they have of a normal upbringing under these circumstances?” asks Tarr. “It doesn’t bode well for the future of the community or for our attempts at controlling the wonton destruction of the abalone resource.”
Ultimately scientists and managers agree there simply aren’t enough abalone to go round. What’s more, coastal resources such as abalone will not lift everyone in the nearby coastal communities out of poverty, contrary to what certain fishing organisations may argue. The only real future for a viable abalone industry lies in a well-managed fishery, with effective, heavily enforced quotas to prevent over exploitation and poaching. Currently it’s a tragedy of the commons scenario and unless the situation improves, the golden gastropod will soon be gone.
Thursday, 07 June 2007
GREAT WHITE SHARK
You are a thousand times more likely to die hanging your Christmas lights than to be attacked by a great white shark. Even dogs - our best friend - killed more people worldwide last year than have been killed by all species of sharks in the past hundred. With approximately 150 scalps a year, coconuts are positively bloodthirsty by comparison.
Even so, as a journalist entering the shark-infested waters off Dyer Island, near Gansbaai at the south-eastern point of Walker Bay (close to where the Birkenhead went down), I was particularly anxious. If there's one group of people sharks should be peeved at, it's us. No other group has spread more falsehoods and hyperbole than the media ... with the possible exception of Hollywood directors that is. If sharks were Americans, they'd sue … and if I were a movie director I'd be safely ensconced somewhere high and dry in the Sahara.
Anxiety soon fled, however, as Brian McFarlane helped me and underwater photographer Geoff Spiby into the metal cage bobbing on the surface next to Predator II, the 12-metre catamaran he uses to take tourists shark-cage diving. He asked us to leave the scuba rigs on board and breathe using only our snorkels, as the mechanical sounds made by demand valves tend to scare the sharks - that's right, I said scare the sharks.
Unfortunately it was summer, not the best season for cage diving, but as we slipped into the cage the signs we'd have a good encounter were promising - a five-and-a-half metre female was mooching around. Let me say it again in case you glossed over that statistic… FIVE-AND-A-HALF METRES - bigger and heavier than a long-wheelbase bakkie.
As we submerged, peeping out from the bars and holding our breaths, the shark appeared out of the gloom. Passing within touching distance, she glided by effortlessly, propelled by imperceptible movements of her tail. It looked almost artificial... as if she were a model toy driven by a little engine. The eyes were not those of a puppet, however. They were alive, assessing us, unfamiliar visitors to her aquatic realm.
Rice cake or rump steak?
Sharks are attracted to dive boats by chum: the evil-smelling concoction of fish blood and oil that Brian had been ladling into the water since we anchored. This forms an oily slick behind the boat. Supreme opportunists that they are, whites follow the feint trail, hoping for a windfall-a dead whale, seal or big fish. All they find at these boats, however, is a tuna head tied to a rope. And, what's more, the operators usually drag this toward the boats preventing the shark from getting it.
This chumming and baiting has concerned other coastal users since cage-diving operations began. It's banned in the USA and many people in South Mrica would feel happier if this were the case here too.
"There is no clear evidence that shark-cage operators are responsible for the perceived increase in shark activity and shark attacks in recent years," affirmed shark expert Dr Len Compagno. I caught up with him in his cluttered office - festooned with remnants of old wetsuit, pictures and other shark paraphernalia - at the South African Museum where he is curator of fishes.
"Chumming is not a new activity - fishers have disposed of fish guts and blood into the water round their boats since fishing began, so to suddenly get hot under the collar about 10 or so licensed operators using chum, is unfortunate."
Not surprisingly, the shark-diving operators agree. "It's ridiculous," said JP Botha, co-owner of Marine Dynamics, one of the licensed operators working out of Gansbaai.
"We've been blamed for attacks that happened over a thousand kilometres away, involving different species of sharks. Luckily, with the scarcity of evidence, all the hoo-ha is beginning to subside."
Chumming for sharks isn't the Lotto. Certain areas tend to be good for sharks - Dyer Island off-shore of Gansbaai is arguably the best place to dive with white sharks anywhere in the world. But if you drop chum into the water at random, you could wait a really long rime before any whites pop by for a visit.
Of course that's not to say whites have a limited distribution. They occur in temperate coastal waters worldwide, yet have a penchant for turning up where they're not expected. Debbie Smith, who runs the Rocktail Bay Dive Centre in Maputaland, has seen two whites while out with dive groups: one in Ponta do Ouro in Mozambique, the other off Rocktail Bay, south of Kosi Bay.
"I had drifted over the reef to check on a hole where we normally find turtles and came face to face with a three-metre female white shark. Keeping the group close, we watched as she circled us serenely. She then passed roughly a metre from us, before disappearing into the deep blue. It was magic, she was not aggressive at all, probably just curious."
Unfortunately, this curiosity is probably the root cause of most negative interactions between sharks and humans. Let's not call them attacks, because that has sinister connotations.
"White sharks are curious, intelligent, apex predators," said Len Compagno. "They actively investigate new items in their surroundings and it isn't uncommon for them to investigate floating objects. Some of these behaviours, and I am hesitant to say this, may even be playful. We've seen sharks pick up floating planks and toss them, once twice and more - without a rational explanation. It's kinda like they're bored and kicking a can about.
"But, and herein lies the problem with their human interactions, their major manipulatory organ is their mouth. So when they investigate you in the water, they can do excessive damage, even if to the shark it was only gently mouthing you to see what you are. To be sure, if it was a full-blown predatory attack they'd easily cut you in half - big sharks have been known to slice 200-kilogram bull-seals in two."
Apex predators are those at the very top of the food web - very simply: eat everything and fear nothing. Yet they face the same problems all predators do - every predatory interaction has to be seen as a cost benefit decision involving the amount of effort exerted in the 'chase,' for the amount of energy returned by eating the prey item. Basically, do you chow the stationary rice cake or the galloping rump steak? In this scenario humans are, luckily for us, rice cakes.
Sharks make split-second decisions on the energy content of a prey item as soon as they bite into it. If they bite you they immediately assess you as something not worth eating and so are unlikely to finish you off. If you were a seal with a high percentage of energy-rich blubber, however....
There have, of course, been instances of sharks eating people; such as the white captured in the Mediterranean with the bodies of two adults and a child in it. But these are relatively rare and probably have lots to do with the nutritional state of the shark in question. If the shark is half starved, then rice cakes make a welcome snack until something blubberier comes along.
Back off - that girl's mine!
Scientists are also beginning to understand more about the behavioural interactions between white sharks. However, research in this direction is slow and frustrating according to Ryan Jordan, a PhD student from the University of Pretoria currently studying white shark biology.
"There are just so many unknowns - we are really just discovering aspects of the very complex lifestyles these animals lead. A little bit here, a little bit there."
Some of the interesting trends scientists such as Ryan are beginning to notice, however, is sharks definitely interact with each other and communicate using body language. For instance, stiff, arched bodies and gaping mouths (underwater) seem to be threat displays, warning off other sharks.
These same behaviours interest Andre Hartman, another co-owner of Marine Dynamics. Andre, it must be said, is God's gift to the media - a real old man of the sea and seemingly fearless shark man. He has been featured in numerous documentaries and was one of the central characters in the National Geographic cover story of April 2000. He has lived and worked with whites his whole life and now regularly dives with white sharks outside of protective cages.
In this very high-risk activity, understanding what the whites are trying to communicate is the difference between a nice dive and Davey Jones's locker.
Andre was also the first person known to have placed his hand on a white shark's snout, by accident originally, and notice that the shark went into a kind of trance. With his hand on their snouts, sharks stand on their tails in the water between the engines of his boat, head out, motionless. Why and how this works no-one is quite sure. But possibly it has something to do with the over-stimulation of the organs of Lorenzini - or the complex sensory array in their snouts capable of detecting miniscule electoral pulses, which aid the shark in hunting. Whatever the reason, it's still dramatic to see two-and-a-half tons tamed by this Daniel of the ocean.
In summer, however, Andre has noticed the sharks are much more skittish and weary. "Everybody down there seems to get a little stressed out and so I tend to be far more cautious. Even the snout trick doesn't usually work," he told me.
I asked Len Compagno about this, who said he wasn't sure of the exact causes, but did mention that many sharks have a definite mating season. During this time males assert their dominance. This is especially true when receptive females are in the vicinity. For ragged-tooth sharks at least, this seems to happen in the southern summer.
Is this also a factor in white shark behaviour? It's hard to tell as mating white sharks have never been documented. However, the pattern fits. What this means of course, is white sharks kicking round Southern Africa during the summer holiday are not only more likely to encounter people, but could be feeling a little aggro when they do.
Could this explain the recent spate of interactions between surf-skiers in the Western Cape and great whites? No-one can say for sure, but think of it this way: surf-skis are six-odd-metre intruders. If there were females in the 'vicinity, males could easily be saying: "Hey dude back off, that girl's mine."
This aggressive, dominance behaviour could also help explain the attack on Craig Bovim off Scarborough on the Cape Peninsula, Christmas eve.
He was in the water diving for lobsters, when he noticed a four-metre shark, initially thought to be a raggie but more likely a great white. The shark did not attack immediately but hung around - possibly issuing threats Craig didn't understand. Keeping it in sight, he tried to head into the relative safety of the kelp, but too late. The shark 'investigated' him and in the process, unfortunately, Craig stuffed his arms down the shark's throat.
He pummelled it with his knees and the shark, realising its error, released him and departed. His arms, however, were already badly lacerated and he was losing blood fast. Craig headed for the beach, from where he was rushed to hospital by air ambulance. I am glad to report that Craig is recovering.
The rapid response of medical-rescue services has been the number one factor in decreasing the percentage of fatal interactions - attacks if you must - between sharks and humans. "The best way to deal with the shark issue is to remain calm and emotionless. It is far too easy to shout: bring in shark nets or kill all sharks - both of which amount to an environmental disaster," according to Compagno. "The reality is, we are in their world and in some ways we have to accept the consequences. That doesn't mean we should stand idle. Rescue services should be trained and prepared to deal with the trauma of shark 'attacks'."
Sharks are not killers but, rather, they have killed. And therein lies a subtle difference. Killer implies ruthless, cold-blooded and malicious. None of which apply to whites. They kill to survive, as do we.
Worldwide shark populations are in alarming decline. White sharks, in particular, seem to be threatened, even though they are protected in large parts of their range. This is due to the price on their heads. Shark-fin soup made from white's fins fetches top-dollar; a set of jaws could bring in a couple of thousand dollars. With that sort of reward an active black-market exists.
As Ryan Jordan pointed out: "That is only the direct mortality. It's hard to quantify the effects of over-fishing, which reduces available prey and by-catch, or sharks caught incidentally while fishing for other species. These are probably even more detrimental to population numbers."
That there should be any doubt of the survival of white sharks is a tragedy. After my experiences diving in the shark cages, it's hard to think that such a majestic creature could be heading towards its end.
Possibly, just possibly, we journalists can help prevent this. We now have a different story to tell. Whites don't target people deliberately and, all things considered, would probably be mortified to know we hold them up in such fear. As Joseph Conrad said: "The belief in a supernatural source of evil is not necessary; [humans] alone are quite capable of every wickedness."
Even so, as a journalist entering the shark-infested waters off Dyer Island, near Gansbaai at the south-eastern point of Walker Bay (close to where the Birkenhead went down), I was particularly anxious. If there's one group of people sharks should be peeved at, it's us. No other group has spread more falsehoods and hyperbole than the media ... with the possible exception of Hollywood directors that is. If sharks were Americans, they'd sue … and if I were a movie director I'd be safely ensconced somewhere high and dry in the Sahara.
Anxiety soon fled, however, as Brian McFarlane helped me and underwater photographer Geoff Spiby into the metal cage bobbing on the surface next to Predator II, the 12-metre catamaran he uses to take tourists shark-cage diving. He asked us to leave the scuba rigs on board and breathe using only our snorkels, as the mechanical sounds made by demand valves tend to scare the sharks - that's right, I said scare the sharks.
Unfortunately it was summer, not the best season for cage diving, but as we slipped into the cage the signs we'd have a good encounter were promising - a five-and-a-half metre female was mooching around. Let me say it again in case you glossed over that statistic… FIVE-AND-A-HALF METRES - bigger and heavier than a long-wheelbase bakkie.
As we submerged, peeping out from the bars and holding our breaths, the shark appeared out of the gloom. Passing within touching distance, she glided by effortlessly, propelled by imperceptible movements of her tail. It looked almost artificial... as if she were a model toy driven by a little engine. The eyes were not those of a puppet, however. They were alive, assessing us, unfamiliar visitors to her aquatic realm.
Rice cake or rump steak?
Sharks are attracted to dive boats by chum: the evil-smelling concoction of fish blood and oil that Brian had been ladling into the water since we anchored. This forms an oily slick behind the boat. Supreme opportunists that they are, whites follow the feint trail, hoping for a windfall-a dead whale, seal or big fish. All they find at these boats, however, is a tuna head tied to a rope. And, what's more, the operators usually drag this toward the boats preventing the shark from getting it.
This chumming and baiting has concerned other coastal users since cage-diving operations began. It's banned in the USA and many people in South Mrica would feel happier if this were the case here too.
"There is no clear evidence that shark-cage operators are responsible for the perceived increase in shark activity and shark attacks in recent years," affirmed shark expert Dr Len Compagno. I caught up with him in his cluttered office - festooned with remnants of old wetsuit, pictures and other shark paraphernalia - at the South African Museum where he is curator of fishes.
"Chumming is not a new activity - fishers have disposed of fish guts and blood into the water round their boats since fishing began, so to suddenly get hot under the collar about 10 or so licensed operators using chum, is unfortunate."
Not surprisingly, the shark-diving operators agree. "It's ridiculous," said JP Botha, co-owner of Marine Dynamics, one of the licensed operators working out of Gansbaai.
"We've been blamed for attacks that happened over a thousand kilometres away, involving different species of sharks. Luckily, with the scarcity of evidence, all the hoo-ha is beginning to subside."
Chumming for sharks isn't the Lotto. Certain areas tend to be good for sharks - Dyer Island off-shore of Gansbaai is arguably the best place to dive with white sharks anywhere in the world. But if you drop chum into the water at random, you could wait a really long rime before any whites pop by for a visit.
Of course that's not to say whites have a limited distribution. They occur in temperate coastal waters worldwide, yet have a penchant for turning up where they're not expected. Debbie Smith, who runs the Rocktail Bay Dive Centre in Maputaland, has seen two whites while out with dive groups: one in Ponta do Ouro in Mozambique, the other off Rocktail Bay, south of Kosi Bay.
"I had drifted over the reef to check on a hole where we normally find turtles and came face to face with a three-metre female white shark. Keeping the group close, we watched as she circled us serenely. She then passed roughly a metre from us, before disappearing into the deep blue. It was magic, she was not aggressive at all, probably just curious."
Unfortunately, this curiosity is probably the root cause of most negative interactions between sharks and humans. Let's not call them attacks, because that has sinister connotations.
"White sharks are curious, intelligent, apex predators," said Len Compagno. "They actively investigate new items in their surroundings and it isn't uncommon for them to investigate floating objects. Some of these behaviours, and I am hesitant to say this, may even be playful. We've seen sharks pick up floating planks and toss them, once twice and more - without a rational explanation. It's kinda like they're bored and kicking a can about.
"But, and herein lies the problem with their human interactions, their major manipulatory organ is their mouth. So when they investigate you in the water, they can do excessive damage, even if to the shark it was only gently mouthing you to see what you are. To be sure, if it was a full-blown predatory attack they'd easily cut you in half - big sharks have been known to slice 200-kilogram bull-seals in two."
Apex predators are those at the very top of the food web - very simply: eat everything and fear nothing. Yet they face the same problems all predators do - every predatory interaction has to be seen as a cost benefit decision involving the amount of effort exerted in the 'chase,' for the amount of energy returned by eating the prey item. Basically, do you chow the stationary rice cake or the galloping rump steak? In this scenario humans are, luckily for us, rice cakes.
Sharks make split-second decisions on the energy content of a prey item as soon as they bite into it. If they bite you they immediately assess you as something not worth eating and so are unlikely to finish you off. If you were a seal with a high percentage of energy-rich blubber, however....
There have, of course, been instances of sharks eating people; such as the white captured in the Mediterranean with the bodies of two adults and a child in it. But these are relatively rare and probably have lots to do with the nutritional state of the shark in question. If the shark is half starved, then rice cakes make a welcome snack until something blubberier comes along.
Back off - that girl's mine!
Scientists are also beginning to understand more about the behavioural interactions between white sharks. However, research in this direction is slow and frustrating according to Ryan Jordan, a PhD student from the University of Pretoria currently studying white shark biology.
"There are just so many unknowns - we are really just discovering aspects of the very complex lifestyles these animals lead. A little bit here, a little bit there."
Some of the interesting trends scientists such as Ryan are beginning to notice, however, is sharks definitely interact with each other and communicate using body language. For instance, stiff, arched bodies and gaping mouths (underwater) seem to be threat displays, warning off other sharks.
These same behaviours interest Andre Hartman, another co-owner of Marine Dynamics. Andre, it must be said, is God's gift to the media - a real old man of the sea and seemingly fearless shark man. He has been featured in numerous documentaries and was one of the central characters in the National Geographic cover story of April 2000. He has lived and worked with whites his whole life and now regularly dives with white sharks outside of protective cages.
In this very high-risk activity, understanding what the whites are trying to communicate is the difference between a nice dive and Davey Jones's locker.
Andre was also the first person known to have placed his hand on a white shark's snout, by accident originally, and notice that the shark went into a kind of trance. With his hand on their snouts, sharks stand on their tails in the water between the engines of his boat, head out, motionless. Why and how this works no-one is quite sure. But possibly it has something to do with the over-stimulation of the organs of Lorenzini - or the complex sensory array in their snouts capable of detecting miniscule electoral pulses, which aid the shark in hunting. Whatever the reason, it's still dramatic to see two-and-a-half tons tamed by this Daniel of the ocean.
In summer, however, Andre has noticed the sharks are much more skittish and weary. "Everybody down there seems to get a little stressed out and so I tend to be far more cautious. Even the snout trick doesn't usually work," he told me.
I asked Len Compagno about this, who said he wasn't sure of the exact causes, but did mention that many sharks have a definite mating season. During this time males assert their dominance. This is especially true when receptive females are in the vicinity. For ragged-tooth sharks at least, this seems to happen in the southern summer.
Is this also a factor in white shark behaviour? It's hard to tell as mating white sharks have never been documented. However, the pattern fits. What this means of course, is white sharks kicking round Southern Africa during the summer holiday are not only more likely to encounter people, but could be feeling a little aggro when they do.
Could this explain the recent spate of interactions between surf-skiers in the Western Cape and great whites? No-one can say for sure, but think of it this way: surf-skis are six-odd-metre intruders. If there were females in the 'vicinity, males could easily be saying: "Hey dude back off, that girl's mine."
This aggressive, dominance behaviour could also help explain the attack on Craig Bovim off Scarborough on the Cape Peninsula, Christmas eve.
He was in the water diving for lobsters, when he noticed a four-metre shark, initially thought to be a raggie but more likely a great white. The shark did not attack immediately but hung around - possibly issuing threats Craig didn't understand. Keeping it in sight, he tried to head into the relative safety of the kelp, but too late. The shark 'investigated' him and in the process, unfortunately, Craig stuffed his arms down the shark's throat.
He pummelled it with his knees and the shark, realising its error, released him and departed. His arms, however, were already badly lacerated and he was losing blood fast. Craig headed for the beach, from where he was rushed to hospital by air ambulance. I am glad to report that Craig is recovering.
The rapid response of medical-rescue services has been the number one factor in decreasing the percentage of fatal interactions - attacks if you must - between sharks and humans. "The best way to deal with the shark issue is to remain calm and emotionless. It is far too easy to shout: bring in shark nets or kill all sharks - both of which amount to an environmental disaster," according to Compagno. "The reality is, we are in their world and in some ways we have to accept the consequences. That doesn't mean we should stand idle. Rescue services should be trained and prepared to deal with the trauma of shark 'attacks'."
Sharks are not killers but, rather, they have killed. And therein lies a subtle difference. Killer implies ruthless, cold-blooded and malicious. None of which apply to whites. They kill to survive, as do we.
Worldwide shark populations are in alarming decline. White sharks, in particular, seem to be threatened, even though they are protected in large parts of their range. This is due to the price on their heads. Shark-fin soup made from white's fins fetches top-dollar; a set of jaws could bring in a couple of thousand dollars. With that sort of reward an active black-market exists.
As Ryan Jordan pointed out: "That is only the direct mortality. It's hard to quantify the effects of over-fishing, which reduces available prey and by-catch, or sharks caught incidentally while fishing for other species. These are probably even more detrimental to population numbers."
That there should be any doubt of the survival of white sharks is a tragedy. After my experiences diving in the shark cages, it's hard to think that such a majestic creature could be heading towards its end.
Possibly, just possibly, we journalists can help prevent this. We now have a different story to tell. Whites don't target people deliberately and, all things considered, would probably be mortified to know we hold them up in such fear. As Joseph Conrad said: "The belief in a supernatural source of evil is not necessary; [humans] alone are quite capable of every wickedness."
A Green Light for Greener Fuels in South Africa?
Oil supplies are under threat. Environmentalists are clamouring for reductions in emissions. Vehicle owners want cheaper fuel. Can renewable biofuels appease all these parties and still make a profit?
“They’ll never let it happen.” The chemical engineer with whom I was discussing recent developments in the biofuel business was adamant. She also insisted on remaining anonymous – big oil companies don’t like engineers with their own opinions it would seem.
“Do you really think big oil companies are going to stand by and allow these new technologies to grow to their full potential,“ she continued eyeing me intently.
And yet, despite these sentiments and widespread concern regarding the influences of ‘oil’ on our future – leaving conspiracy theorists aside, many people believe oil was the real force behind the US-led incursion into Iraq – it is hard to deny the money flowing into alternate fuel technologies these days. In particular biofuel technologies (that is fuels that originate from biological sources such as biodiesel and bioethanol) have received tremendous political and financial support recently.
The most popular source materials for biofuel production are maize and sugarcane which are converted into bioethanol – a popular addition to petrol. In addition, vegetable oils such as canola, sunflower, soya and jatropha (a type of tree) together with animal oils such as catfish oil are refined through a process of transesterification to form biodiesel – a diesel equivalent that can be used in modern diesel engines without requiring any modifications.
Biofuel technology is not new and few people realise that the first diesel engine, created by German engineer Rudolf Diesel in 1893, was powered by peanut oil (although technically this was not refined so was not a biodiesel by any modern definition). Diesel’s vision was a world of engines driven by renewable energy sources – biofuels.
Large petroleum companies, however, were able to stifle development offering their oil-based products to the market at significantly lower prices. But Diesel was adamant and in a visionary speech given in 1912, he insisted that the time would come when oil reserves would falter and humans would be forced to revert to renewable alternatives such as biodiesel and so on. With recent instability in the Middle East and no significant new oil reserve discoveries in recent years, it seems Diesel’s prescient observations have been vindicated.
Ethanol as a Fuel Additive
Fuelling souped-up hot rods with pure ethanol has long been a popular pastime for backcounty rednecks in the US not to mention racing enthusiast’s worldwide. These days however, ethanol is increasingly finding a legitimate place in mainstream automobile fuels. Many countries, and in this Brazil is a world leader, already use ethanol derived from maize and sugarcane as an additive in their petrol. Percentages of ethanol commonly range from 10% to 25%, although percentages as high as 85% are available in certain states in the US. These mixes are generally referred to as E10, E25 and so on depending on the percentage of ethanol; E100 is pure ethanol.
The advantages of ethanol are multiple. It reduces the cost per litre of fuel, reduces harmful emissions including those involved in global warming, helps increase the octane of unleaded petrol reducing the dependence of alternates which are generally less environmentally-friendly, and probably most significantly, reduces the reliance on non-renewable fossil-fuels such as oil and coal.
South Africa currently does not utilise any biologically produced fuel additives, although pundits predict this will soon change when the long awaited government policy on biofuels is published (expected October 2006). The government is expected to announce a mandatory 10% ethanol addition to all petrol sold in the country alongside significant biodiesel additions.
Strategically this makes sense and will help reduce South Africa’s reliance on foreign oil supplies, while benefiting the environment and the economies of rural farming communities. The current head of the Southern Africa Biofuels Association (Saba), Erhard Seiler, believes that locally produced biofuels have the potential to meet 10% of local demand by 2010. Considering the volumes required (currently SA utilises some 11-billion litres of petrol and 8-billion litres of diesel per year), it is hardly surprising that a new venture, Ethanol Africa, has recently began construction of a R700-million bioethanol plant in Bothaville in the Free State. Ethanol Africa plans to develop eight such bioethanol facilities round the country and is adamant that biofuels are the way of the future.
The Bothaville plant will process 1 125 tons of yellow maize daily, producing 473 000 litres of ethanol and 63 000 litres of biodiesel a day. The maize will be sourced from surrounding farms – probably on a contracted out production basis, significantly improving the economics of local farming communities. In addition, it is expected to greatly increase the viability of small-scale farming in the area and it is hoped that a significant percentage of the maize requirements will be sourced from small-scale operations.
Significant Job opportunities will also be created by the plant, with quoted figures predicting the creation of as many as 10 000 jobs including both direct and indirect opportunities. Although this number is probably inflated, the location of the opportunities is important in terms of developing rural communities. A significant proportion of the opportunities will be in rural farming areas and this will not only uplift depressed rural areas of the country but will help ease the drain into urban areas.
Not everyone is happy with the recent developments in the biofuel industry, however.
Biofuels: Panacea or Pariah
Biofuels are not universally accepted as the panacea of world energy problems and deep rumblings have sounded from various quarters.
Uncertainty surrounds the economic viability of biofuels, although this is not the major concern of many experts, who are worried by the impacts of biofuels on land use (for farming) and indeed food prices.
One such critic is Unilever, a company which produces a significant proportion of the world’s food. Their concern is that food prices will soar with concomitant shortages of staple foods. These sentiments were echoed in a recent editorial published in the Washington Post entitled “Starving the people to feed the cars”. In this, author Lester R. Brown, president of the Earth Policy Institute, hints at food shortages – especially in developing countries – as crops increase in value through their use as fuel. If oil prices continue to rise out of control, even marginal oil-bearing crops could be turned into fuel, thereby increasing food costs resulting in increased food shortages and starvation.
Evidence to back these concerns is readily available. Brazil, which produces more than half the world’s sugar, now converts roughly half its crop into bioethanol for fuel. This has caused a near doubling of world sugar prices over the last couple of years. Similarly, livestock farmers in the US have raised concerns about the price of feed for their animals as more and more bioethanol facilities come online in maize producing areas of the country.
Ethanol Africa, maintains that South Africans need not be concerned by these developments. In a statement, the company has responded to critics explaining they plan to use only yellow corn, which is not used currently as a major food source.
Be that as it may, many energy experts maintain that to pursue biofuels will further delay a shift to more efficient, renewable vehicles; such as solar-powered, highly efficient gas-electric hybrid or pure electric vehicles. Brown maintains in his Washington Post article that if wind power was to be harnessed effectively, electric vehicles could run primarily off wind-generated electricity at a petrol price equivalent of roughly R3.00 a litre.
Make Your Own Biodiesel
A growing number of enthusiasts have begun making their own biodiesel, utilising a variety of vegetable oils including old cooking oil. The process is relatively simple requiring basic chemicals found in your average hardware store or chemist – methanol, sodium hydroxide or caustic soda – a blender, thermometer, an accurate scale and a plastic drum or two. I won’t go into details here but if you have access to the internet various detailed recipes are available (for starters check out www.wikipedia.com or www.journeytoforever.org).
And it’s not only weirdoes that are busy playing Doctor Strange in the garage. Environmentalists are excited by the potential of these micro-scale refineries to reuse old, waste oils in communally driven recycling efforts. Most importantly, with high oil prices the current indications are that these micro-refineries could operate profitably making waste-oil recycling into a viable small business and it is likely we will begin to see more and more small-scale recycling/biodiesel plants developing in our communities.
The Future of Biofuels
There is little doubt that biofuel technology will continue to improve in the years ahead. Although many manufacturers are experimenting with alternate fuels such as hydrogen, these suffer from the fact that engines need to be re-designed to accommodate these fuels. Not so with biofuels such as bioethanol and biodiesel that can both be used in current vehicle engine configurations. That is not to say, we will see a radical change to biofuels in the near future; far more likely is a slow increase in their use as additives.
Eventually, if technology develops to the point where these biofuels can be produced more efficiently we may eventually reach a point where all vehicles run off biofuels. To make this a reality however, a tremendous amount of research is required. In particular, investigations into the use of non-essential crops or crop residues (known as cellulosic biomass) including various species of grass, cornhusks, wood chips and other agricultural waste is required. Recent surveys in the United States suggest that as much as 30 percent of American fuel requirements could be derived from such sources.
Also underway is research into a species of algae that is grown hyponically and which therefore does not compete for prime agricultural lands; whether this will prove a viable feedstock for biofuel production remains to be seen.
One thing is certain, however; oil will not last forever. As it dwindles energy costs will increase dramatically and political instability will ensue. In the end, biofuels may well turn out to be the new ‘oil.’ We can only hope they’ll be better at calming troubled waters….
Biofuels and Your Vehicle
Possibly the greatest factor that will contribute to the success of biofuels is that your vehicle will not need significant modifications – if it needs any modifications at all – to enable it to run on biofuels. Although Mitsubishi has not released any research on the specific effects of biodiesel and ethanol on its vehicles, its parent company Daimler Chrysler has already begun to embrace biofuel technology and is working together with its competitor Volkswagen and German-based fuel developer Choren Industries to create biodiesel fuels that can be used in any diesel engine without modification. It is not clear at this stage how vehicle performance will be influenced by biofuels.
“They’ll never let it happen.” The chemical engineer with whom I was discussing recent developments in the biofuel business was adamant. She also insisted on remaining anonymous – big oil companies don’t like engineers with their own opinions it would seem.
“Do you really think big oil companies are going to stand by and allow these new technologies to grow to their full potential,“ she continued eyeing me intently.
And yet, despite these sentiments and widespread concern regarding the influences of ‘oil’ on our future – leaving conspiracy theorists aside, many people believe oil was the real force behind the US-led incursion into Iraq – it is hard to deny the money flowing into alternate fuel technologies these days. In particular biofuel technologies (that is fuels that originate from biological sources such as biodiesel and bioethanol) have received tremendous political and financial support recently.
The most popular source materials for biofuel production are maize and sugarcane which are converted into bioethanol – a popular addition to petrol. In addition, vegetable oils such as canola, sunflower, soya and jatropha (a type of tree) together with animal oils such as catfish oil are refined through a process of transesterification to form biodiesel – a diesel equivalent that can be used in modern diesel engines without requiring any modifications.
Biofuel technology is not new and few people realise that the first diesel engine, created by German engineer Rudolf Diesel in 1893, was powered by peanut oil (although technically this was not refined so was not a biodiesel by any modern definition). Diesel’s vision was a world of engines driven by renewable energy sources – biofuels.
Large petroleum companies, however, were able to stifle development offering their oil-based products to the market at significantly lower prices. But Diesel was adamant and in a visionary speech given in 1912, he insisted that the time would come when oil reserves would falter and humans would be forced to revert to renewable alternatives such as biodiesel and so on. With recent instability in the Middle East and no significant new oil reserve discoveries in recent years, it seems Diesel’s prescient observations have been vindicated.
Ethanol as a Fuel Additive
Fuelling souped-up hot rods with pure ethanol has long been a popular pastime for backcounty rednecks in the US not to mention racing enthusiast’s worldwide. These days however, ethanol is increasingly finding a legitimate place in mainstream automobile fuels. Many countries, and in this Brazil is a world leader, already use ethanol derived from maize and sugarcane as an additive in their petrol. Percentages of ethanol commonly range from 10% to 25%, although percentages as high as 85% are available in certain states in the US. These mixes are generally referred to as E10, E25 and so on depending on the percentage of ethanol; E100 is pure ethanol.
The advantages of ethanol are multiple. It reduces the cost per litre of fuel, reduces harmful emissions including those involved in global warming, helps increase the octane of unleaded petrol reducing the dependence of alternates which are generally less environmentally-friendly, and probably most significantly, reduces the reliance on non-renewable fossil-fuels such as oil and coal.
South Africa currently does not utilise any biologically produced fuel additives, although pundits predict this will soon change when the long awaited government policy on biofuels is published (expected October 2006). The government is expected to announce a mandatory 10% ethanol addition to all petrol sold in the country alongside significant biodiesel additions.
Strategically this makes sense and will help reduce South Africa’s reliance on foreign oil supplies, while benefiting the environment and the economies of rural farming communities. The current head of the Southern Africa Biofuels Association (Saba), Erhard Seiler, believes that locally produced biofuels have the potential to meet 10% of local demand by 2010. Considering the volumes required (currently SA utilises some 11-billion litres of petrol and 8-billion litres of diesel per year), it is hardly surprising that a new venture, Ethanol Africa, has recently began construction of a R700-million bioethanol plant in Bothaville in the Free State. Ethanol Africa plans to develop eight such bioethanol facilities round the country and is adamant that biofuels are the way of the future.
The Bothaville plant will process 1 125 tons of yellow maize daily, producing 473 000 litres of ethanol and 63 000 litres of biodiesel a day. The maize will be sourced from surrounding farms – probably on a contracted out production basis, significantly improving the economics of local farming communities. In addition, it is expected to greatly increase the viability of small-scale farming in the area and it is hoped that a significant percentage of the maize requirements will be sourced from small-scale operations.
Significant Job opportunities will also be created by the plant, with quoted figures predicting the creation of as many as 10 000 jobs including both direct and indirect opportunities. Although this number is probably inflated, the location of the opportunities is important in terms of developing rural communities. A significant proportion of the opportunities will be in rural farming areas and this will not only uplift depressed rural areas of the country but will help ease the drain into urban areas.
Not everyone is happy with the recent developments in the biofuel industry, however.
Biofuels: Panacea or Pariah
Biofuels are not universally accepted as the panacea of world energy problems and deep rumblings have sounded from various quarters.
Uncertainty surrounds the economic viability of biofuels, although this is not the major concern of many experts, who are worried by the impacts of biofuels on land use (for farming) and indeed food prices.
One such critic is Unilever, a company which produces a significant proportion of the world’s food. Their concern is that food prices will soar with concomitant shortages of staple foods. These sentiments were echoed in a recent editorial published in the Washington Post entitled “Starving the people to feed the cars”. In this, author Lester R. Brown, president of the Earth Policy Institute, hints at food shortages – especially in developing countries – as crops increase in value through their use as fuel. If oil prices continue to rise out of control, even marginal oil-bearing crops could be turned into fuel, thereby increasing food costs resulting in increased food shortages and starvation.
Evidence to back these concerns is readily available. Brazil, which produces more than half the world’s sugar, now converts roughly half its crop into bioethanol for fuel. This has caused a near doubling of world sugar prices over the last couple of years. Similarly, livestock farmers in the US have raised concerns about the price of feed for their animals as more and more bioethanol facilities come online in maize producing areas of the country.
Ethanol Africa, maintains that South Africans need not be concerned by these developments. In a statement, the company has responded to critics explaining they plan to use only yellow corn, which is not used currently as a major food source.
Be that as it may, many energy experts maintain that to pursue biofuels will further delay a shift to more efficient, renewable vehicles; such as solar-powered, highly efficient gas-electric hybrid or pure electric vehicles. Brown maintains in his Washington Post article that if wind power was to be harnessed effectively, electric vehicles could run primarily off wind-generated electricity at a petrol price equivalent of roughly R3.00 a litre.
Make Your Own Biodiesel
A growing number of enthusiasts have begun making their own biodiesel, utilising a variety of vegetable oils including old cooking oil. The process is relatively simple requiring basic chemicals found in your average hardware store or chemist – methanol, sodium hydroxide or caustic soda – a blender, thermometer, an accurate scale and a plastic drum or two. I won’t go into details here but if you have access to the internet various detailed recipes are available (for starters check out www.wikipedia.com or www.journeytoforever.org).
And it’s not only weirdoes that are busy playing Doctor Strange in the garage. Environmentalists are excited by the potential of these micro-scale refineries to reuse old, waste oils in communally driven recycling efforts. Most importantly, with high oil prices the current indications are that these micro-refineries could operate profitably making waste-oil recycling into a viable small business and it is likely we will begin to see more and more small-scale recycling/biodiesel plants developing in our communities.
The Future of Biofuels
There is little doubt that biofuel technology will continue to improve in the years ahead. Although many manufacturers are experimenting with alternate fuels such as hydrogen, these suffer from the fact that engines need to be re-designed to accommodate these fuels. Not so with biofuels such as bioethanol and biodiesel that can both be used in current vehicle engine configurations. That is not to say, we will see a radical change to biofuels in the near future; far more likely is a slow increase in their use as additives.
Eventually, if technology develops to the point where these biofuels can be produced more efficiently we may eventually reach a point where all vehicles run off biofuels. To make this a reality however, a tremendous amount of research is required. In particular, investigations into the use of non-essential crops or crop residues (known as cellulosic biomass) including various species of grass, cornhusks, wood chips and other agricultural waste is required. Recent surveys in the United States suggest that as much as 30 percent of American fuel requirements could be derived from such sources.
Also underway is research into a species of algae that is grown hyponically and which therefore does not compete for prime agricultural lands; whether this will prove a viable feedstock for biofuel production remains to be seen.
One thing is certain, however; oil will not last forever. As it dwindles energy costs will increase dramatically and political instability will ensue. In the end, biofuels may well turn out to be the new ‘oil.’ We can only hope they’ll be better at calming troubled waters….
Biofuels and Your Vehicle
Possibly the greatest factor that will contribute to the success of biofuels is that your vehicle will not need significant modifications – if it needs any modifications at all – to enable it to run on biofuels. Although Mitsubishi has not released any research on the specific effects of biodiesel and ethanol on its vehicles, its parent company Daimler Chrysler has already begun to embrace biofuel technology and is working together with its competitor Volkswagen and German-based fuel developer Choren Industries to create biodiesel fuels that can be used in any diesel engine without modification. It is not clear at this stage how vehicle performance will be influenced by biofuels.
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