Wednesday, 15 July 2015

Video By Shark Expert Ila France Porcher, Author Of ~The SHARK SESSIONS~ Available For Shark Week 2015





The Shark Sessions” relates the story of sharks who were Porcher's companions for many years in Tahiti. When they were finned and massacred by a company from Singapore, she wrote down their story so that the world would find out : what they were like, and what had happened to them. Her powerful mini-documentary is now available.

[Wilmington, NC July 15, 2015] Shark expert Ila France Porcher has announced the release of a new video mini-documentary to coincide with Shark Week 2015. Porcher is the author of 'The Shark Sessions: My Sunset Rendezvous'. The book presents the story of her long-term ethological study of reef sharks in Tahiti, and the resulting findings, against the background of the uneasy society surrounding it. Intelligence in wild animals in general, and sharks in particular, is the major theme.

"In 2004, I was interviewed by the BBC for Discovery's 'Shark Week' regarding the evidence for thinking in sharks that I had found during my underwater study of their behaviour," Porcher stated. "For years, I had been keeping track of more than 600 sharks who passed through the area, and could recognize 300 on sight. 
 
With the certainty that comes with repeatedly verified, first hand knowledge of their behaviour, I had learned that individual sharks could be easily distinguished, not only by their appearance, but because they each had distinctive ways of behaving. I was able to report that: 
 
•    each shark is a unique individual.
•    behaviour patterns that had been considered automatic and purely instinctive, such as roaming, reactions to sudden events, and their responses to other sharks and to me, were actually flexible and varied at different times.
•    they showed a range of emotional states including fear, rage, curiosity, excitement, and happiness.
•    they treated people, and other sharks, as individuals.

ila_porcher_cover "From my long association with with the resident sharks who accompanied me during my observation sessions, I learned that sharks can develop companionships with people if the person approaches them with patience and calmness so that they can let go of their fear.

But Shark Week  left out my urgent message that those sharks were actually being finned and were in need of protection, and omitted my findings. The presenter stated, 'Ila claims that these sharks have personalities, but the jury's still out on that.'

"But the jury was not out. Cognitive thought in fish was beginning to be recognized, and my findings that sharks were capable of it too, had already been presented at a scientific conference by then. Since that time, more and more discoveries have been made about the sentience of a wide variety of oceanic life.

The discovery that sharks are intelligently aware, and are pursuing lives of meaning to themselves, has startling implications. It changes our perception of them, and of their place in  nature, as well as ours. Yet, these scientific facts are being ignored, and many to continue to present sharks as brutal  man-eating killers.”

So she created a mini-documentary to complement the Shark Week entertainment this year, which shows actual footage of the sharks she studied, and some surprising shark behaviour.

Ila France Porcher is available for media interviews and can be reached by email at ilafranceporcher@gmail.com. Her mini documentary is available on Youtube at https://www.youtube.com/watch?v=hryPvS5cmqM
More information is available at her website at http://ilafranceporcher.wix.com/author.

About  Ila France Porcher:

Ila France Porcher is a self-taught, published ethologist. She grew up in British Columbia, Canada, and at an early age became fascinated by watching and drawing wild animals. As a result, she naturally became a wildlife artist, and in time began documenting the behaviour of the animals she painted, being especially intrigued by actions suggesting intelligence and cognition.

In Tahiti she found sharks to be the first wild animals who came to her instead of fleeing. They were so intriguing that she launched an intensive study of them, systematically observing and recording their behaviour. Following the precepts of the field of cognitive ethology, and later with the guidance of world class marine ethologist Dr. Arthur A. Myrberg Jr., University of Miami, she learned to interpret their behaviour. Part of her study was subsequently published in the peer-reviewed journal Marine Biology, and some of her observations are considered to be the first documented cases of cognition in sharks. She is credited with the discovery of a way to study these much maligned predators that does not involve killing them, and was dubbed “the Jane Goodall of Sharks,” for her investigation of their intelligent behaviour in the wild, while giving a presentation about them at the University of Miami.

- See more at:
http://www.freepublicitygroup.com/news/release_ila_porcher_shark_week_jul115/#sthash.RcrOyrtd.dpuf


By Shark Expert Ila France Porcher, Author Of 'The Shark Sessions', Available For Shark Week 2015

“The Shark Sessions” relates the story of sharks who were Porcher's companions for many years in Tahiti. When they were finned and massacred by a company from Singapore, she wrote down their story so that the world would find out : what they were like, and what had happened to them. Her powerful mini-documentary is now available.



Author Ila France Porcher[Wilmington, NC July 15, 2015] Shark expert Ila France Porcher has announced the release of a new video mini-documentary to coincide with Shark Week 2015. Porcher is the author of 'The Shark Sessions: My Sunset Rendezvous'. The book presents the story of her long-term ethological study of reef sharks in Tahiti, and the resulting findings, against the background of the uneasy society surrounding it. Intelligence in wild animals in general, and sharks in particular, is the major theme.
"In 2004, I was interviewed by the BBC for Discovery's 'Shark Week' regarding the evidence for thinking in sharks that I had found during my underwater study of their behaviour," Porcher stated. "For years, I had been keeping track of more than 600 sharks who passed through the area, and could recognize 300 on sight.
“With the certainty that comes with repeatedly verified, first hand knowledge of their behaviour, I had learned that individual sharks could be easily distinguished, not only by their appearance, but because they each had distinctive ways of behaving. I was able to report that:
•    each shark is a unique individual.
•    behaviour patterns that had been considered automatic and purely instinctive, such as roaming, reactions to sudden events, and their responses to other sharks and to me, were actually flexible and varied at different times.
•    they showed a range of emotional states including fear, rage, curiosity, excitement, and happiness.
•    they treated people, and other sharks, as individuals.

ila_porcher_cover"From my long association with with the resident sharks who accompanied me during my observation sessions, I learned that sharks can develop companionships with people if the person approaches them with patience and calmness so that they can let go of their fear.
But Shark Week  left out my urgent message that those sharks were actually being finned and were in need of protection, and omitted my findings. The presenter stated, 'Ila claims that these sharks have personalities, but the jury's still out on that.'
"But the jury was not out. Cognitive thought in fish was beginning to be recognized, and my findings that sharks were capable of it too, had already been presented at a scientific conference by then. Since that time, more and more discoveries have been made about the sentience of a wide variety of oceanic life.
“The discovery that sharks are intelligently aware, and are pursuing lives of meaning to themselves, has startling implications. It changes our perception of them, and of their place in  nature, as well as ours. Yet, these scientific facts are being ignored, and many to continue to present sharks as brutal  man-eating killers.”
So she created a mini-documentary to complement the Shark Week entertainment this year, which shows actual footage of the sharks she studied, and some surprising shark behaviour.
Ila France Porcher is available for media interviews and can be reached by email at ilafranceporcher@gmail.com. Her mini documentary is available on Youtube at https://www.youtube.com/watch?v=hryPvS5cmqM. More information is available at her website at http://ilafranceporcher.wix.com/author.
About  Ila France Porcher:
Ila France Porcher is a self-taught, published ethologist. She grew up in British Columbia, Canada, and at an early age became fascinated by watching and drawing wild animals. As a result, she naturally became a wildlife artist, and in time began documenting the behaviour of the animals she painted, being especially intrigued by actions suggesting intelligence and cognition.
In Tahiti she found sharks to be the first wild animals who came to her instead of fleeing. They were so intriguing that she launched an intensive study of them, systematically observing and recording their behaviour. Following the precepts of the field of cognitive ethology, and later with the guidance of world class marine ethologist Dr. Arthur A. Myrberg Jr., University of Miami, she learned to interpret their behaviour. Part of her study was subsequently published in the peer-reviewed journal Marine Biology, and some of her observations are considered to be the first documented cases of cognition in sharks. She is credited with the discovery of a way to study these much maligned predators that does not involve killing them, and was dubbed “the Jane Goodall of Sharks,” for her investigation of their intelligent behaviour in the wild, while giving a presentation about them at the University of Miami.

- See more at: http://www.freepublicitygroup.com/news/release_ila_porcher_shark_week_jul115/#sthash.RcrOyrtd.dpuf

Thursday, 9 July 2015

About the Bite Reflex in Sharks



I had many opportunities to observe sharks under circumstances in which I expected them to bite, as a dog or other mammal would tend to do. Yet they did not. Further, while the sharks had preferred companions, I never saw them fighting with each other. They appeared to have friends, but no enemies.

All other species, wild and tame, with whom I had the intimacy I shared with sharks, had bitten me sooner or later, either by accident or in a fit of pique. Even my pet dog sometimes grabbed my hand in her teeth along with the offered cookie.

For years people had told me, and I half believed myself, that one day I would be bitten and would bleed to death, or faint and drown. Since I was alone far from shore as night was falling, I could expect no one to save me. These circumstances enhanced what appeared to be an instinctive tendency to react with darkening consciousness and soaring terror to certain visual cues. So I had long acquaintance with the phenomenon of fear. Often it took all my psychological force to compose my mind in order to overcome it.

When things went wrong, I would find myself in tossing waters opaque with blood and excited sharks, in a situation for which I was unprepared. Yet, no matter what happened, no shark bit me, time after time.

Why had none of those hundreds of sharks of four different species, some many times my size, ever bitten me? I would watch Martha, my favourite, coil through the sea in front of my face, snapping up the treats I was freeing for her while ignoring my hands and the little plastic bag I had brought them in, and be convinced that it could not be a random coincidence.

There had to be a reason.

One night I accidentally kicked a shark with all my force, not realizing that the six foot animal was between my legs as I finned upward to reach into my kayak. Expecting her to turn and slash, I peered underwater to scrutinize the situation, but there was no change in either her speed nor trajectory as she curved around to lazily circle me.

It was then that I realized that I was expecting a reaction from a shark that was based on my experiences with mammals. As mammals, we share the automatic biting reflex displayed by dogs, cats, primates, rats, and others. Anyone who has been seriously assaulted knows that the instinct to bite in self defence is very thinly veiled beneath our civilized daily lives. It is an automatic reflex that we take for granted.

But that night, I realized that these requiem sharks must not share this strong bite reflex.

Perhaps our fear of sharks is based on the intrinsic knowledge that we, and animals like us, instinctively bite in aggression or fear. We just naturally assume that sharks will too.

But they don't.

Separated from us evolutionarily by a gulf of time spanning half a billion years, the bite reflex in sharks seems much weaker than ours. With their big mouths and shocking sets of teeth, our imaginations are undone as we consider them opening to bite us. But in fact, with only rare exceptions, mostly found between great white sharks, they bite while eating, but not to injure another animal in the environment.

On the contrary, they seem to have an inborn inhibition against biting companion animals. They don't regard us as prey, so they apparently view us as other animals who share their ecological community.

Even the great white shark has been shown by Dr. Peter Klimley to ritualize conflict when ownership of a seal prey comes into question. The shark who can splash water farthest with its tail wins the seal, so a physical battle, which would gravely harm both sharks, given their dentition, is avoided.

Ila France Porcher 

 THE SHARK SESSIONS

Monday, 6 July 2015

Sharks Enjoy Divers as Divers Enjoy Sharks!

Sharks are interested in others, and their spontaneous gestures toward divers show their curiosity toward other members of their submarine community, including divers who show interest in them. The interest is returned.

Thus it is possible through photos to capture the eye to eye gaze of these mysterious creatures of the deep, when for just few moments of their day, they meet us.
Recognition of others as individuals has long been established in fish and sharks, as in other social species. As well as knowing others, sharks demonstrate by their actions that they recognize themselves as being separate from others and observable. To this degree they are self aware.

The photo shows one of my shark companions coming to greet me when she found me in the lagoon. She looks at me with first one eye and then the other as she approaches with her gently undulating movement.


She nearly touches my face with hers, then turns to swim away at an angle over my shoulder.
I gave her a treat after she had followed me for a long time, and snapped a photo as she accelerated away shaking her scrap. If you look closely, you can see her right eye looking back at me. Sharks, like horses, can look straight behind them as well as in front due to their serpentine motion. 

This tiger shark had come over to look at me and when she left, she turned and glanced at me behind her, with one eye after another.
Here a tiger shark had come to see me, then swam away and suddenly turned back..
 She swam straight back to me

and came to look at me again. 

This curiosity seemed to be associated with the shark's interest in the other large animals in the region. Her focus on my eyes is typical of all of the close approaches of this sort by sharks that I have witnessed.

I have often come across statements by people, especially fishermen, who were approached by a shark in this way, who claimed that the shark was "attacking," or "would have attacked" had the shark not been shot or blown up with a power head, or something like that. But the real reason for these close approaches is the natural, social curiosity of this intelligent animal.

Bull sharks will come for a friendly look, too.

So will Caribbean reef sharks.
And lemon sharks.
If so many different species of shark will do this, the behaviour pattern is likely wide-spread among them. Curiosity that is not based on a biological need is a sign of intelligence, and in this case is apparently linked to a wish to socialize.

A communication passes through a shared gaze in eye contact, and it seems important to sharks,  given this common behaviour with divers, as well as to us mammals.
The book I wrote about my studies, The Shark Sessions, describes the natural behaviour of sharks in detail.
(c) Ila France Porcher 2015




Saturday, 4 July 2015

Sad Memorial to a Finned Shark

 
Its been a long time since I wrote and posted this tribute to Madonna, my number one shark, when she was finned. It is she with whom I was swimming in this illustration on the cover of my book, The Shark Sessions.

So here it is again.

Ode to Madonna

"In just the last couple of months, waiting for the law to be passed to protect the sharks, the last of the older, mature females I first met some years ago have vanished from my part of the lagoon. This includes my number one shark, Madonna.

Madonna was the first shark to meet my kayak when I arrived in the lagoon in the mornings. She was nearly six feet long, steel grey, and heavily built. When I dove down and swam to her, she would come to me and look into my mask.

Meeting her by chance in the lagoon, she would swim to me when I called her, and circle, spiralling toward me til she was within arms' reach. But she did not like me to swim with her. She would set off on a sinuous path, and when I followed, she would come back, often turn sideways, accelerate and stop, or just vanish into the blue, but usually not before we had gone to meet up with one or two of her friends. Never could I detect the slightest sign between them as they passed, but I didn't think it could be chance that we had met up with them, knowing that they were her friends.

Beautiful Madonna was not one of our brightest lights. When I brought a treat for her, as I always did when she returned to her home range after breeding or birthing, I would sometimes have to throw it for her time after time before she could locate it, and often one of her friends would coil through the water to snatch it the moment it left my hand, a trick poor Madonna could never manage. Once I spent 45 minutes in terrible current just trying to get her treat to her.

Nevertheless, she would hopefully come to me for a bite. When I had nothing, and was actually promenading in the lagoon with her friend Martha, she would come charging in. I would fin backward, till we were swimming nose to nose, me on my back and her on top of me, while Martha circled us, watching. Madonna would finally give up when she realized I had nothing with me, and me and Martha would go on alone.

Madonna did this once when it was almost too dark to see, having arrived with a group of rather macho males from the ocean. She behaved as if she were starving to death, having just had her babies. When she soared up to my face all her companions did too, and while I could guide her around me with my hand, I didn't have enough hands to push away half a dozen sharks at once, and didn't want to be rammed by the strangers or have my mask knocked off in the dark.

Feeling sorry for my poor shark, who did look awfully emaciated after birthing, I returned as soon as conditions permitted, and trailed scent through her home range, followed by a tiny juvenile who always followed me, just out of sight, at that time. Finally, Madonna glided in, the juvenile now flitting excitedly at her side, apparently more confident in the presence of the big shark.

As she circled, I tossed the food so it fell to the side of her swimway, and saw her target it, but she slowed, allowing the excited juvenile to get it first. Luckily I had brought enough for both. 

I spent so much time with Madonna, I can remember every gesture, every movement she would make in different moods.

We all read all the time about thousands of sharks being finned all over the world, but when the sharks meeting this shocking end are ones you have come to know, and with whom you have spent time for many years, sharks of whom you have grown fond, the psychological effect is more intense.

Just as it is disturbing to read in the paper that some dogs elsewhere were poisoned -- but if it is your dogs who were poisoned and died, you reel."
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You can form a companionship with a shark just as you can with a dog, and they are just as intelligent and sensitive. They should not be fished; they should not be finned. They are peaceful creatures and there is no need to fear them.

(c) Ila France Porcher



Saturday, 2 May 2015

Samuel H. 'doc' Gruber: Shark Science Pioneer


Doc Gruber began studying sharks in 1961, perhaps before any other scientist had done full-time research on a living shark. During his long career, he founded the Bimini Biological Field Station (Shark Lab), the Shark Specialist Group of the International Union for the Conservation of Nature, (IUCN), a United Nations organization based in Switzerland, and the American Elasmobranch Society. He has published over 200 scientific papers, and his research is still ongoing today. 

His decision to study sharks was as unplanned as it was final.

Doc in 1957 with black grouper
As a young man growing up in Florida, he loved to dive, and often went off for weekends of scuba diving and spear fishing on a 30 metre schooner called the Blue Goose. The ship had belonged to Hermann Göring, commander-in-chief of the German Luftwaffe (Air Force) under the Nazis, and it had found its way to Miami when it was liberated at the end of World War II. A weekend of diving fun on the Blue Goose cost only seven dollars, and at that time, there were still big fish!

On one of these outings in 1958, Gruber had speared a grouper hiding in a submarine cave, and was emerging with it into open water when he saw a hammerhead shark approaching. It was the largest shark he had ever seen, and as it glided towards him, it seemed to be the size of a submarine! Sure that he was about to die, he plunged back into the cave with his fish, and found himself in the same position that the grouper had just been in, as he looked out. Watching in awe as the momentous shark passed him, he was seized with the desire to know what sort of an animal it was.

When he returned to the university, he asked his professor what was known about sharks, and found that no one knew much at all. So he decided then and there to become a marine biologist and study them.


His research begins


With the idea of becoming a medical doctor, Gruber was attending Emory University at the time, and was majoring in pre-medical studies. He had been especially intrigued by the study of comparative anatomy in which he had dissected a shark, a giant salamander, and a cat. That summer he was taking courses at the University of Miami, and had asked if he could assist the comparative anatomy laboratory dissecting the animals.

Now, inspired by his riveting meeting with the hammerhead shark, he transferred to the University of Miami, earned his under-graduate degree in zoology and chemistry, and applied to graduate school to study sharks.

Gruber in 1963 studying sharks' eyes
In 1960, the University of Miami’s Marine School had hired Dr. Warren Wisby as professor and researcher in marine animal behaviour, with an emphasis on sharks. As a student of the famous professor Arthur Davis Hasler, Wisby was best known for having discovered the actual mechanism of homing in salmon. By marking hatchling salmon, and going back to their streams when they returned to spawn, Wisby had found that they came back to the exact stream in which they had hatched.

So Gruber’s timing was perfect. He was given a research assistantship, and didn’t have to pay for tuition. In fact he was paid the huge sum of 103 dollars a month as a graduate student there!

Wisby told him that the Navy had given them a grant to study shark senses. When aircraft went down at sea, it happened at times that sharks attacked the flyers in the water. In those days flyers wore two types of suits—high visibility suits called International Orange, and the standard khaki flying suits. According to a Navy report, the flyers wearing International Orange suits were attacked to a man, while the ones wearing khaki suits were left alone.

As a result, the Navy had started calling those orange suits yum yum yellow.

Wisby directed Gruber to look at the literature and report back on the possibility that sharks have colour vision. So he examined all the old reports. They were mostly in German, and they concluded that sharks could not see colours because they lacked the cone-shaped photoreceptors in the eye’s retina that permit colour vision in humans and other animals.

Gruber and Wisby collecting shark eyes to study at a fishing tournament
The Duplexity Theory of vision was introduced in the 1860s by a German scientist named Max Schultze, and states that rods and cones in the retinas of an animal that possesses both, have two functions. Rods are used in night vision when there is little light, while the cones take over during the day, providing the ability to see colours, fine details, and to discern rapidly flashing lights.

Some animals, such as squirrels and iguanas, that are active in daytime, have no rods in their eyes, and nocturnal animals or those adapted to the darkness of caves or the deep sea, have no cones. Therefore, the lack of cones found by early researchers in the retinas of sharks, suggested that they were unable to distinguish colours.

But Wisby questioned the old conclusions. He asked Gruber to go out and actually collect sharks’ eyes, and see what he could find.

Collecting eyes at a shark tournament
So Gruber went to shark tournaments and collected the eyes of every species of large shark caught off the of the eastern seaboard of the US. He put a catheter into their hearts while they were still beating—the animals were brain-dead—and perfused gluteraldehyde, a preservative chemical, through their arteries, to fix their eyes for future study under the electron microscope.
On one occasion, he was notified that a young great white shark was caught and was being held for him. This was the chance of a lifetime for the young graduate student, as white sharks were very rare. He ran out in a boat to where the fisherman was waiting with a barely living 54 lb. specimen, successfully perfused the shark, and collected the eyes.

Can sharks see colour?


Year after year, Gruber worked in a histology lab comparing the retinas of the many species of sharks to see whether they had both rods and cones. And, amazingly, every species he studied had them. Some species seemed to have better retinas than others, but they all had rods and cones. The great white shark had five rods to one cone, which was an especially high ratio.

It seemed that the earlier scientists had studied the cold-water, bottom-loving sharks of the northern seas off Europe, and those species had very few cone cells because they were adapted to dark conditions. Those inaccurate early findings had resulted in many false ideas about sharks taking root. The idea that they had an excellent sense of smell had spread because they came quickly to a scent, and so the concept of a shark as a swimming nose, with poor eyesight, was born a century ago.

The forebrain of a shark, called the telencephalon, is considered one of the most important parts of the brain, like our cerebral hemispheres. And in the shark, the telencephalon was thought to be the centre that analysed scents, because that was how it looked to the early researchers. They did not know how the forebrain worked, and they had never looked at how sharks really behaved, or tried to do neural examinations, yet their primitive ideas about sharks had persisted.

diagram of the brain of a shark, showing the telencephalon
Wisby was pleased with Gruber’s discovery, but pointed out that just because the sharks had cone cells, didn’t mean that they could see colours. “What do the rods and cones mean for sharks?” Wisby asked, and directed Gruber to experiment to learn whether sharks see colours, and investigate their other visual capabilities.

As the eyes of a human or animal adapt to darkness, rods take over the function of vision, providing high sensitivity to light, but no colour. The switching over between the cones and rods is something that can be measured, and it was this line of research that Gruber began to pursue in 1962 for his master, and later his doctorate degrees.

He used the lemon shark as a model, and chose three methods to test the Duplexity Theory of vision in sharks.

Image of the rods and cones in a shark's retina
To assess the rod and cone activity in the retina, he put contact lens electrodes on anaesthetized lemon sharks, and recorded the electrical responses of the retina when illuminated. He used electrophysiology to record electroretinograms, which are similar to the electrocardiogram of doctors, in order to examine the electrical activity of the associated neurons.

His second method involved a behavioural study, following the Pavlovian method of testing called classical or respondent conditioning, and the third was the Skinnerian method, which is called operant conditioning.

Gruber’s results were unambiguous. The three methods gave the same results—there was no doubt that sharks could see colour. The rods functioned as expected in the dark, and the cones were most active in the light-adapted state. He found that as sharks adjusted to darkness, the sensitivity of their eyes became greater and greater, and reached the maximum dark-adaptation after about an hour, achieving a million-fold increase in sensitivity!

They adapted better than humans because unlike us, they possess the tapetum lucidum. This is the mirror-like membrane at the back of the eye which produces eye-shine in some animals. Light entering the eye passes through the retina, and is reflected, as if by a mirror, back from this membrane, potentially doubling the eye’s sensitivity.

eye-shine

The learning rate of a shark


Another interesting finding that emerged from Gruber’s research during his doctoral studies was the speed at which sharks learn.

He was working on Pavlovian training conditioning, doing an experiment in which a shark would see a flash of light, and then receive a mild electric shock. After a certain number of trials, when the shark saw the light, it would have learned to anticipate the shock, and have a reaction. This is called a conditioned response.

The reaction that Gruber planned to use for the experiment was the pause in the shark’s heart-rate resulting from the fear of the coming shock. Fear causes the heart to skip a beat, then accelerate, so at the moment that the shark realized that it was about to receive another shock, its heart paused, and this reaction could be measured. The number of trials it took for the animal to learn the association between the light and the shock, gave a measure of its ability to learn.

While Gruber was flashing the light, and giving the shock, he was looking at the readout on the oscilloscope, rather than at the shark, which was trussed up underwater, with an electrode in its cardiac chamber, looking out into the room through a big Plexiglas bubble.

Then one day, he happened to look at the shark at the moment in which it anticipated the shock, and saw that it winked—the nictitating membrane of the shark’s eye closed. This provided another conditioned response to the light, which meant that there was no need for the heart monitoring—all Gruber had to do was observe. Due to the need for the heart monitoring, the sharks had been unable to survive long enough for him to get them trained, so his discovery was crucial to the success of this important experiment.
The nictitating membrane can be seen here as the lemon shark in the experiment winks.

Now Gruber used a World War II infra-red sniper scope to observe the shark in total darkness, and found that after about ten trials, or repetitions, the shark would wink in expectation of the shock. It was a conditioned response that he got from a shark in only about three minutes!

One session consisted of 10 sets of 10 trials, and after about 80 trials, the shark was responding 100 percent of the time. The next day it took only 3 or 4 trials to get the shark to respond, and it responded 100% of the time after 40 trials. On the third day, it had a 100% response from the start. So it took only about 10 trials for the first response, 80 trials to get the 100% response, and only three days to the state in which the shark was conditioned long term.

By chance, psychologists had been studying Pavlovian conditioning in cats and rabbits using the same paradigm. They used the flash of light as the initial stimulus, and followed it with a puff of air onto the cornea, instead of an electric shock. As in Gruber's experiment, the conditioned response was the movement of the nictitating membrane, so the experiment was a terrestrial version of precisely what Gruber had been doing with sharks.

What was surprising was that the sharks had learned the relationship between the light and the shock ten times faster than the cats and rabbits! These had taken about 800 trials to achieve 100% conditioning, while the sharks had taken only 80 trials!

Gruber working on the experiment in 1966
Further, the sharks remembered what they had learned for over a year, which was far longer than anyone had expected.

Gruber discovered many more interesting things in the course of his research. He found that sharks have different “IQs” and different personalities, and that some are left-handed and some are right-handed. He also found that they have an occlusable tapetum, a further refinement of their vision, as well as a mobile pupil in a variety of shapes, which only sharks and rays, and no other fish, have.

Published


Arthur A. Myrberg, the youngest full professor at the University, took Wisby’s place in 1964, and mentored Gruber during the last years of his master and doctorate degrees. While Gruber and his student, Joel Cohen, were studying shark vision, Myrberg and his students worked on their hearing, and others (not at the University of Miami), were working on olfaction, taste, and electoreception.
In 1976, the Navy asked for a summary of all of the work it had funded about the sensory systems of sharks, and they put their findings together in a major book, which was published in the government printing offices. Gruber’s discoveries about shark vision filled a large chapter.

Ethology


With his findings published, Gruber no longer wanted to work in a dark and damp laboratory, and longed to understand the role sharks play in the marine environment. He dreamed of studying their behaviour in a similar, systematic way, in the wild, and decided that he would find a way to do it, using the lemon shark he had come to know so well, and wanted to understand more deeply.

By then he had become an assistant professor at the University of Miami Rosenstiel School of Marine and Atmospheric Sciences, teaching advanced courses in animal behaviour, tropical marine biology, and the physiology and behaviour of marine organisms.

He had done a post-doctoral study in 1971-72, at the Max-Planck Institute in Germany, under Nobel laureate Konrad Lorenz, the famous Austrian ethologist, just as Myrberg had done a decade before. Both men were interested in pursuing their interest in ethology, and as a side project, they had put together an observational study on a captive colony of bonnethead sharks, which was published in the journal Copeia in 1974. It remains the only ethogram, which is an inventory of the repertoire of behaviour patterns displayed by a species, that was ever published for sharks.

Then in 1976, they gathered together all of their information on shark behaviour for a symposium in New Orleans, and it was published in the journal American Zoologist.

Gruber and Myrberg developed a close personal friendship that was to last all their lives. They travelled together as they pursued their research in Europe and the Middle East. They dove with Cousteau in Monaco, travelled through Europe visiting friends and colleagues, and studied sharks in the Florida Keys and the Caribbean. And when Gruber got engaged, it was at Myrberg’s home.

Gruber left Navy research in 1976, and in 1977 he proposed a study to the National Science Foundation, on the role lemon sharks in the tropical marine environment. His goal was to do an autecological study designed to examine many aspect of this species’ biology, with an emphasis on behavior and ecology. It was funded in 1978 and is still continuing today in 2014.

At last he was fulfilling his dream, of discovering what a shark is, and what it does in its life in the wild.

A watercolour portrait of a tiger shark (by the writer)

Bio-energetics


Gruber chose bio-energetics as way of understanding the biology of the lemon shark. Bio-energetics gives the researcher a mathematical method to describe the workings of a living system. Like all things in nature, a shark conforms to the laws of thermodynamics, that decree that in a system, the energy that comes out, no matter how it is channeled or converted, has to equal the energy that has gone in.

In other words, the energy that goes into a shark as food, will come out through growth, metabolism, waste, other biological products. The processes of metabolism—the nerves, digestion, muscles, respiration, and other biological processes—will likely burn half of the calories, and such materials as mucus, urine, and faeces can be burned up in a calorimeter to find how many calories were lost that way. The calories consumed must be partitioned within the body into only four unknowns, and the process can be analysed.

As an example, the common practice of dieting and exercising to reduce one’s weight, utilizes the principle of bioenergetics to achieve a goal. By decreasing the energy going into the body in the form of food, we can force it to use stored fat to make up the deficit, and thus lose weight.

Gruber described it this way, “It is possible to make an equation that balances in four unknowns. It is a simple thing to do mathematically and it reveals a great deal about the animal. It shows how they make their living, what they require for food, their metabolic needs, what they need to digest food, how much of what they eat is assimilated, how much is lost in waste products, how quickly they grow, and how much food it takes them to grow.

“That’s what you can tell about a shark’s life and what it takes to grow a shark in the environment and that’s what we did. It took us over ten years.”

Through a combination of laboratory research and studies in the field, Gruber and his colleagues and students focused so much research on the lemon shark that they discovered much about its life history characteristics, its population dynamics, its growth, reproduction, and genetics. He was determined to make sure that their experiments were realistic by always comparing laboratory results to what could be learned from sharks in the marine environment.

Fieldwork


Initially Gruber studied lemon sharks in Coupon Bight in the Florida Keys. Using nets, he and his colleagues would reliably catch 100 to 120 juvenile lemon sharks there, each summer season, which they would work up and release. But in the early eighties, their numbers began to fall, and in three years he could not catch one shark there. All of the work he had done during all of those years was wasted.

He found out that it was due to overfishing. Fishermen had been catching the little baby sharks in the nursery for crab traps and had fished them all out. The mothers that were supposed to be coming back to the place they were born to give birth had been fished too, so the entire local population of sharks had disappeared.

Gruber knew that the sharks were in trouble again, because this had already happened to him in Florida. So he began doing his research at a small island in the Bahamas at the place where he would later establish the Bimini Biological Field Station. Four times a year, he went there for his field research using National Science Foundation research vessels which were at his disposal from the University of Miami.

Later, when he had the Bimini field station set up, they could do permanent work there without the need to go back and forth to Florida, which allowed them to expand their research.

The research

The Bimini Shark Lab that Gruber founded in the Bahamas

The main thrust of Gruber’s research was trophic ecology or autecology, the ecology of one species.

Bimini’s lagoon was like a marine lake, where the juvenile lemon sharks were obliged to remain, and each shark could be looked at year after year for six or seven years before it left the area. The location was ideal. There were two to three hundred sharks divided between three to four nursery areas, and he tagged nearly all of them, and focused hard on learning all about their lives as he tried to unravel the ecology of the lemon shark. How many sharks were there? How many lived? How many died? How many grew up to maturity? How fast did they grow? What would it take to grow a lemon shark up from a pup to an adult of 80 kg?

Each spring, when the lemon shark pups were born, Gruber and the students did a comprehensive tagging study. They built a large pen, which could hold up to 150 sharks. Then they caught the sharks in nets, tagged them with an electronic micro-tag, took a genetic sample, weighed them, measured them, sexed them, and put them in the giant pen. Every year they would catch, tag, and work up between 180 and 230 sharks. The sharks were released, and then the next year the same sharks that survived, could be caught and measured again. The year 2014 was their 20th year.

The shark pens are visible in the foreground
After more than a decade of research, they balanced the bio-energetic equation for a young, fast-growing, 2 kg lemon shark at 25 degrees centigrade, and discovered that the little shark was an energy conserver, and ate only about seven times its body weight in a year. By comparison, many fish, such as tuna, blow a lot of energy and have to eat a lot of food. And humans, in comparison with lemon sharks, eat an enormous amount.

With the sharks living free in a place where they could be watched from year to year, many experiments were possible. For example, they were able to study their movements, their relationship to temperatures, their food, their place in the ecological system, and their social networks. The nursery was a region of mangroves, and certain little snails called Batillaria were low on the food chain and were the keystone species. The next level was crabs, then fish, then sharks—sharks were on the fifth level.

The countless studies took years and years, doctoral dissertations, and masters theses, and thousands of students all coming to Bimini to study sharks. Gruber taught a University of Miami course there for 22 years, sometimes twice a year; now he teaches five university courses at the station. He had graduate students, built big holding pens at his research facility, and kept dozens of lemon sharks.

And as time passed and he learned of its abilities and capacities, the lemon shark became an animal of complete fascination. To Gruber, the lemon shark had gone from a predatory fish with fins and teeth to being more like a family member.

He said,

“As I went through my early career and I got married and we had children, then we got a house and we got cars, I realized that the lemon shark had provided a living for me in the human world, whereby I could become a functional and useful citizen and have a family. It was all because of the lemon shark. That’s why I get so nervous when I think that they are having problems underwater, not only with being overfished, but also with us handling them.

So I have not been able to remain objective in my feelings for them, although I have tried to remain objective in my research of them.”

Doc Gruber loves lemon sharks

(c) Ila France Porcher

Illustrations courtesy of Dr. Gruber, except where indicated.

This first of three parts, was originally published in Shark Tales in X-ray Dive Magazine, issue 64. See Part two next!