I have been a “Pink Floyd” fan ever since my childhood friend’s brother tortured us both with a continuous -high volume- session of the Album “The Wall”. At first we were scared (Faustino’s intentions were to expel us out of the room), but then we became addicted to the music. The scheme did not work for him, but worked nicely for us. One of the albums I came to enjoy in the early 1980’s was “A Nice Pair”…and when you see these giant pearls you’ll have to agree it is a good name for this blog entry.
This summer presented itself with many challenges and opportunities, but also with unique experiences. We had a chance to visit a certain pearl collector, who had recently acquired two incredible natural Gulf of California pearls: one being a huge “Black Lip Oyster” (Pinctada mazatlanica) white pearl, and the other a large drop-shaped “Rainbow Lip Oyster” (Pteria sterna) pearl. As I’ve stated before: both were NATURAL PEARLS. In two decades of working with pearls we had never seen any like these, so we had to share this experience with all of you.
Pearl #1: The Big Yaqui
I gave this pearl this nick-name for a couple of reasons: 1) we were told that the person that obtained the pearl is from a Yaqui community in the southern part of Sonora, and 2) it is BIG!
This silvery-white baroque pearl was produced from a large, probably very old, “Black Lipped Pearl Oyster” that was fished out of the northern part of the coast of Sonora. When we saw this pearl, it had some brown colored protein deposits on the surface (they can be easily removed) and one of those spots even had the shape of a tiny “rainbow lip oyster” baby (spat)! The pearl was examined under long wave UV light to check for fluorescence and it had the typical blue glow of most pearls: just as expected from a Pinctada pearl.
The pearl weighed in at 106 Carats (21.2 grams)…a true solid beauty!…well, once you peel off some of the brown colored protein.
Pearl #2: The Mermen’s Teardrop
Now, as most of you already know (if you’ve been a loyal follower of this blog) the “Rainbow Lipped Pearl Oyster” is not considered to be a large sized oyster, but more of a medium sized animal so it cannot produce a pearl as Huge as the first one…but this pearl was still quite a find! It was fished out by a local diver.
This beautiful baroque drop-shaped pearl (its actual shape is that of a squished drop) weighed in at 15 carats (3 grams), and it was also inspected under long wave UV: it shone with a beautiful dark red color, typical of pearls produced by Pteria sterna.
Final Remarks
Well, we have a new addition to our “Pearl Museum”: an incredible “Rainbow Lip Oyster” shell with a bubbly-looking blister pearl. It is not the blister pearl that makes the shell so special but its size: it measures 12 cm in diameter, and weighs in at 165 grams (just one valve). The largest previous shell we had collected measured 14 cm and has a weight of a mere 44 grams.
What does this mean? That the “heavy” shell is comes from an long-lived animal: the shells of this species thicken (and become heavy) with age. We believe that this species can live to be –at the most- 8 years old, but the vast majority of individuals will die at an age between 5 to 6 years old. So this shell in particular is our “Metuselah” specimen: the oldest “Rainbow Lipped Oyster” we have been able to find (so far).
You may see this –and other shells- in our small museum display that we have next to our jewelry store, featuring many varieties of pearly shells from the world’s oceans, but if you want to see it now just take a look at the following photo:
To the left you see the Pteria sterna shell, and to the right, a big (but not too old) Pinctada mazatlanica shell (measuring 15 cm).
And here I am back, with a strong desire to revisit the series of posts about the legendary pearl diver knows as "El Mechudo", and on this instance we will cover the most grim and tragic event from the history of this legend: the death of this blasphemous Yaqui pearl diver.
The last time we dealt with this subject was back in January 6th with the entry of “Who was ‘El Mechudo’?”, and on that occasion we detailed the possible site from where the pearl oysters where being fished and where this legendary diver is said to have drowned. Now comes the time to analyze and dissect the manner of his tragic death by reviewing several versions of this legend:
“One of the many Yaqui indians -before he slid into the watery embrace to find the pearl that belonged to the Virgin- said “I am claiming the pearl for the Devil”… Chronicles tell us that the unfortunate man never came out of the sea and that all his companions fled in terror and commenting on the outcome of that terrible blasphemy.” (Author and Date unknown)
Another version of the event, cited by Fernando Jordan (1967) even mentions that: Satan took the fisherman’s word, and the fisherman did not reappear and the waters did not return his body. The place is now taboo and no one goes there to fish for pearls. Those who have seen -at the bottom- the ghost of the blasphemous diver, who has grown long haired and beard. He seems alive and in his hand he holds a huge Black-lip pearl oyster shell. Or even this version, that I personally heard –totally devoid of the supernatural-in La Paz about 10 years ago, and which I have adapted as follows: ‘El Mechudo’ went once more into the salty embrace of those turquoise waters…never coming out again. But there was no time to find out what had happened to him…bad weather just made it impossible. The next morning the fishing armada made it to the same spot and the divers plunged into the waters. A certain diver screamed out "I found him! I found him!" and every single diver moved into that spot. What they saw was a spectral image: the lifeless body of "El Mechudo" still clutching the giant oyster that had caught his hand in self-defense… his long hair had come loose and flowed all around him. The very obvious cause of death of the legendary diver is by drowning, and this could have occurred due to many causes: fatigue, vascular problems, he could have become "entangled" in some way or have suffered the attack of an animal. The legend somehow suggests that the pearl oyster might have had something to do with his death: that the diver’s hand had been captured by the oyster, preventing him from surfacing. But in addition, we understand that there is a permanence of the drowned diver on the site, his body being found there later… and this in turn ends the legend with a “haunted pearl bed”, an accursed ghost that scares off all other divers. So, the death of “El Mechudo” leads us to the myth of the “killer clam”, the basic premise being a clam -or pearl oyster- that is big and heavy enough to keep a diver from surfacing…just long enough for him to drown. And in this case the oyster is also able of keeping the captured hand (alongside the rest of the body) clutched down a sufficient amount of time (at least over 24 hours) for the other divers to find his a body in the same spot. This would give rise to the myth of the “Murderous Oyster” (to give it a quirky adjective). Is this possible at all? Can an oyster keep a man trapped that long? Let us find out… 
The "Mortal Clamp"
Pearl oysters are bivalve mollusks that have a strong adductor muscle which is used to achieve the closure of its two shells, this is used in order for the oyster to protect itself and avoid being eaten by predators; a bivalve’s life is partially dependent on its ability to close and keep its shells closed. If we introduce our fingers into an oyster it will certainly close its valves and it will clamp our hand… and what happens if we cannot release from its hold? In a few minutes we will drown.
Now, even if the oyster closes its shell with our hand in it, what prevents us from simply coming up with the oyster to the surface? Well, oysters are strongly attached to their living place (usually on rocks, corals and other shells) by means of a myriad of thin, elastic fibers referred to as "byssal threads" which are secreted by the byssal gland. These fibers look a bit like plastic, are somewhat elastic and very resistant, but will it be able to securely anchor the oyster when a person is desperately fighting for dear life? To answer both questions, I conducted the following “experiment”: I went “pearl diving” securing several Black lip pearl oysters (Pinctada mazatlanica), and intentionally placing my fingers inside them to simulate the “mortal clamp” and then it was a matter of coming out with my life. The result of this simple experiment can be seen in this short video:
Results:
The first fishing event –described as “Capture #1” in the video- shows the usual living place for black-lips in Guaymas: attached to rocky reefs at depths ranging from almost surface level and down to some 10 meters in depth (20 feet). The oysters are now –once again- seen forming small clusters, and several of these make up for a pearl bed. I dislodged oysters quite easily…in just seconds and with no effort.
Fishing event "Capture # 2", was carried out at a depth of 4 meters (13 feet), on sandy bottom (but littered with pebbles and shell bits of various bivalves). On this substrate, pearl oysters usually attach to shells and on the video it is clearly visible how the oyster is easily released and comes up with a fragment of a “pen shell”. The oyster measured 10 cm (4 inches) in diameter and had another -smaller- pearl oyster “piggy-backing” on its shell.
In the third fishing event (capture #3), at a depth of only 3 meters (9.8 feet), we had an area of overlapping environments: mainly sandy bottom, but with the presence of encrusting corals and a small rocky reef nearby. I located a small group of black-lips and it was extremely easy to release a group of three oysters simultaneously.
And finally, I introduced my fingers several times inside different black-lip oysters and every time I obtained the same result: the oysters quickly closed their shells on my fingers and they held me as hard as it was possible for them, yet it was very easy to release my fingers in just seconds, thus my life was never in any danger. Just in case my mother or my wife ever read this blog entry: these experiments were performed at a depth of just a mere 1.50 meters (4.9 feet), so I was never under any duress nor undue risk. 
Discussion
How did the myth of the "Mortal Clamp" or of the "Killer Clam" (or whatever name you want to give it) emerge? Well, there are other varieties of bivalves in the World’s oceans, some being HUGE in size and of very HEAVY weight, which are quite capable of keeping a man stuck long enough to drown him. In fact, a there exists a particular animal known as the "giant clam" (Tridacna gigas), that is sometimes referred of as a “killer clam” (perfect title for a future Hollywood film), which inhabits the Indo-Pacific ocean, and which is perfectly suited to become a nightmare for any pearl diver. Just look at this cute photograph (taken from this page):
Wikipedia’s website even mentions that a U.S. Navy diver’s manual includes a technique that can be used by divers to rid themselves of the deadly clamp of this species of clam, and refers to the death of a Phillipino pearl diver which drew the gigantic “Pearl of Lao Tzu”, a huge calcareous concretion (or non-nacreous pearl) that was obtained from one of these giant clams.
Conclusion
- It’s really not all that difficult to fish for pearl oysters, given that there is sufficient abundance of them; the hardest thing about “pearl diving” will be the depth you have to dive down to in order to extract them and this only if you are using your lung capacity.
- There is no real danger of drowning once you are “captured” by a black-lip’s valves: its “claw of death” lacks the necessary strength to maintain an unbreakable grip. Furthermore: it is not difficult to remove them from their attachment point in the unlikely case they do.
Until next time…
After a short absence due to our many obligations at the pearl farm and also at the Gem Show in Tucson, Arizona, we continue to share our experiences in the pearl production. And for us, an important part of our aquaculture process is based on Environmental Sustainability: the production of pearls with full-respect for Bacochibampo Bay’s ecosystems.
An It is because of this reason that -through the years- we have carried out an active process of re-stocking of several native species, whose populations have become endangered because of the fishing activities carried out by the locals. Among these species we can list the following: the “Black-lip pearl oyster”, the “Lion’s Paw Scallop”, the “Pen Shells” and the “Sea Cucumbers”.
However, our efforts have not been effectively transmitted to the general public because we basically have a one-man PR department (me!) and that I do spend most of my time working (as expected!) either in the production of pearl oysters and their pearls OR in the process of selling pearls and pearl jewelry; and the little time left from these occupations does not allow us to carry out an effective social communication effort although we do have our website up-&-running, as well as this blog (in two languages), a Facebook page and a Tweeter account.
But this year we have the fortune of having two young, bright and hardworking students helping us out at the farm. These students of the Guaymas Campus of ITSON (a local Public University) are about to graduate as Bachelor’s in Tourism. Thanks to an academic program of this important local institution, this young pair will help us in two very important areas: Sales and Research.
In the Sales area we have the invaluable assistance of Miss Veronica Machado and in the production area we have the strong support of Jesus Antonio Mendoza. Jesus Antonio -known by his nickname “El Tigre”- is helping in data collection and analyzing the important biological information for several small projects, including the “Sea Cucumbers Project” and the bio-cleaning of pearl-cages.
I have asked Jesus “El Tigre” Mendoza to write a bit about his experiences of working in our pearl farm, as their training focuses mainly on tourism and he has a very different way of viewing our pearl farming activities: this is an entirely “alien concept”. And this is his first contribution to the Blogosphere. I hope you will be able to see things through the eyes of this young man:
From a very young age I have had great admiration and respect for nature, especially for all the natural resources that exist in the region where I live; I have always admired the contrasting combination found between the mountains, the desert and the sea. Despite of living in a place where the climate is extreme and where there is almost no rain, I’m always surprised how plants and animals have adapting to survive in these arid lands, and how our people have learned to survive.
I live in a very popular city located in northwestern Mexico: the famous port of Guaymas, located in the state of Sonora, which is situated on the shores of the Sea of Cortez (aka Gulf of California). This port’s economy is largely dependent on fishing, although in recent years has all fisheries have declined, due to over-exploitation, and thus this activity -in turn- came to be partially replaced by the maquiladora industry, but these do not provide the same quality of life –as fishing did- to our community.
It is until now that I have come to understand the great importance of the Sea of Cortez, not only for Guaymas but for the whole world: this sea has a unique biodiversity of marine species, all which are part of a large marine ecosystem on which we all depend for our survival. Species such as the vaquita marina, and the native species that are found at the pearl farm, such as the sea cucumbers, the many starfishes, the Cortez Angelfish, among others are just a part of a long list of flora and fauna that live in our waters.
The Gulf of California is also breeding place for beauty and rarity, the home of a Gem which is produced by a rarely-known pearl oyster species: the “Rainbow Lip Oyster”, an animal that produces pearls of intense and diverse colors: red, purple, blue, green and rainbow-like. Here at the farm they become high-end jewelry items, used primarily by women that visit this farm.
Soon –and thanks to the help of Veronica & Jesus- we will be finalizing details of our next “El Mechudo” video and we will have additional presentations from Jesus and Veronica.
A recurring image I have had in my mind for the last couple of months is that of a drowned man floating in the sea. Grim dream, to say the least. And in connection with this dream, just a few weeks ago I was looking for information on the Smithsonian Museum (will tell the reason in aun upcoming entry) and there I found this photo of a sculpture of one Benjamin Paul Akers, called "The Dead Pearl Diver" and I felt like it was time to talk about the pearl fisheries in Mexico’s Northwestern region and give my try at the legends of the Yaqui pearl divers, including the famous legend of "El Mechudo" (or “The Long Haired One”), which I once wrote about in our official website.
But before touching the subject of legends and myths, let us first talk about facts.
The pearl fisheries in Baja California Sur and Sonora
The Pearl fisheries in Northwestern Mexico depended mainly on the use of Yaqui pearl divers, a native nation of Sonora. At the time when the legend of "El Mechudo" appears into history, many Yaqui were had rebelled against the governments of Sonora and Mexico. The President of Mexico, General Porfirio Diaz – ordered the arrest of all rebellious Yaquis and had them sent off to work at the haciendas of the far off State of Yucatan … and hence comes the name of this sector within the City of Guaymas, Sonora, known as "la Yucatan": this was once a “prisoner camp”, from which the yaqui were sent to Yucatan. This dark period of our regional and national history is known as the "Guerra del Yaqui". Many Yaquis were sent to work for the owners of the pearl fishing fleets of Sonora and Baja California Sur. We are therefore in the period that marks the end of the 19th century and the beginning of 20th.
In those years, the pearl fishery was an important part of the economy of Baja California Sur but was somewhat less for Sonora (which was already had a more diversified economy), but most of the revenue ended up benefiting a few families: that of the shipowners. The divers obtained work, a roof in a barrack and a few meals, and a very dangerous work environment.
In this situation, it is easy to understand the great enmity that existed between these two groups of Mexicans: the "white" or "Yoris" and the Yaquis . This created for a tense working releationship: how could the men in charge of the fishing crews (usually a “Yori”) give his men (Yaqui) knives for the extraction of the pearl oysters? The knives could easily have been used to cut their hearts out!
But, how could the Yaqui divers protect themselves from the attack of the fearsome sharks?!?! Some sources mention that divers were armed with a sort of "wooden stick" (a stave, which could have also been used to kill a person in true Van Helsing fashion); other authors state that the death of divers due to shark attacks was overrated, so it is very likely that in many occassions divers did not employ any defensive device, altough Vicente Calvo mentions several of the dangers afflicting the pearl divers of Sonora in the 1840′s:
… But the Manta-rays, would quickly throw themselves over them (the divers), and would compress them against the bottom and then they would drown within minutes.
Being truthful: I do not think the latter is possible. I have never seen or heard of a Manta-ray performing this type of maneuver; but if a diver actually believed that his death could happen if attacked by one of these fish, then he might go into a "panic attack" and end up drowning due to his own fears.
Pearl Fishing was carried out from a "mothership" from which descended several small boats, each with 2 to 4 men, and thus they managed to cover most of a fishing area of a "pearl bed”. Divers dressed only with a loincloth, and would throw themselves from the boat, some helped with primitive weigh-stones to help them quickly reach the bottom. We can watch this activity when watching the classic Mexican film "La Perla", if you don’t have access to the movie you can also watch this short video that contains a few segments of the movie (watch the action at around 1 minute & 25 seconds):
The divers descended to depths between 2 and 26 meters ( 6-86 feet) to find their catch of pearl oysters. Sometimes the physical exhaustion caused by continuous fishing (they dived for up to 6 hours daily) and lack of drinking water and food (did you perhaps believe that divers received an adequate nutrition?) caused some to lose consciousness and drown.
Again we have the description of Vicente Calvo on the pearl fishery of Sonora (and I place emphasis here, as many people believe still that only Baja California had a major pearl fishery):
Fishing starts in June and ends in October, using two or three boats from 40 to 60 tons each. In early November, these boats begin to arrive at the Port of Guaymas… the average time spent by the diver underwater is of one and a half minutes, but in such a short dive-time each divers collects many oysters.
Pearl fishing in the Sonoran coast began when the waters warmed enough and stopped when it is cooled off. The Gulf of California is a sub-tropical sea, so we have ample temperature differences between summer (with 32/90 degrees Celsius/Fahrenheit on the surface) and during winter we have recorded up to 12/53 degrees Celsius/Fahrenheit here in Bacochibampo Bay). Unfortunately, this pearl fishing period also coincided with the breeding season of the "Panamic Black-lip Pearl Oyster" (Pinctada mazatlanica), so that the effects of fishing were doubly harmful to the populations of this particular pearl oyster.
Another interesting description of Vicente Calvo states that:
All divers feel -at the beginning of each task- how blood flows from their noses, and they see this as a good sign, and will continue –happier- with their work, which lasts no more than six hours.
And this brings us to another reference to the hardships associated with fishing for pearls, but this time by an British Lieutenant by the name Robert William Hale Hardy, who in the 1820’s visited various spots within the of Sea of Cortez -including Guaymas- and he even dived for pearls at the bay of Mulege, and so he states about this occassion:
…I felt myself gliding through the slippery water, which, from its density, gave one the idea of swimming through a thick jelly; again I experienced the same change of temperature in the water as I descended; and again the agonizing sensation in my ears and eyes made me waver. But now, reason and resolution urged me on, although every instant the pain increased as I descended; and at the depth of six or seven fathoms, I felt a sensation in my ears like that produced by the explosion of a gun; at the same moment l lost all sense of pain, and afterwards reached the bottom, which I explored with a facility which I had thought unattainable.
…I no sooner found myself on the surface than I became sensible of what had happened to my ears, eyes, and mouth; I was literally bleeding from each of these, though wholly unconscious of it. But now was the greatest danger in diving, as the sharks, mantas, and tintereros, have an astonishingly quick scent for blood.
R.W.H. Hardy. Travels into the Interior of Mexico in 1825,1826,1827 and 1828.
This was really a risky profession in many ways, and divers would find their lives shortened and their health compromised… in the above cases we can see that the diver’s body is subject to a bleeding nose and the bursting of their eardrums…or even being drowned or devoured.
The Legend of "El Mechudo"
This is probably one of my favorite stories or legends which references to the pearl fisheries in our area, and it’s a very Mexican –and Sonoran and Lower Californian- legend. This story has been described in several other sources, including the blog of my friend Benjamin Arredondo, author of one of my favorite blogs "El Bable". However, I think there are things that should be reconsidered within this legend and then reinterpreted so that it has more shades of reality… and what do I mean by this? There are certain details that make the story quite unrealistic at some points, but by re-focusing these it can turned into a real story.
Well, so far I’ve written a lot about the fisheries… and nothing of the legend. So, this is waht author Fernando Jordan mentions about a site near La Paz known as "Punta El Mechudo" (“Long-Haired One Point”):
Southwest of San Jose Island and 12 km from ‘Amortajada bay’ and at the end of last century (19th) there existed a pearl bed that was a good producer of pearls, and on which hundreds of divers gathered every year. At the end of each season, before the cold north winds made diving impossible, the fishermen would prepare to take one last dive to offer a pearl to the Virgin’. On one occasion a diver was preparing to jump into the sea for the last time, when someone warned him from attempting it, he shouted:
‘No more do you need to dive. We already have the pearl of the Virgin’
The fisherman, made a gesture of disdain, and replied scornfully:
‘I am not going after the pearl of the Virgin, I’ll get one for the devil.
And he jumped into the water.
Satan took him to the sea-floor, and the fisherman did not reappear nor did the sea return his body. This place is now taboo, and no one goes there to look for pearls. Those who have, state that they found -at the very bottom- the blaspheming diver’s ghost, who has grown long hair and a huge beard and a long tongue. It seems alive, and in his hands it holds a huge mother-of-pearl shell. It is the ‘pearl of the devil’ they say, and because of the long-haired ghost the place has been given the name ‘El Mechudo’.
Fernando Jordan “El Otro México”, 1967
This is –if it can be called this way- the “official version” of the legend, and as you’ve read, it is also known as the "Legend of the Devil’s Pearl". In the next blog entries I will begin to “break down” this legend, and will hopefully come up with an alternative ending for the legend, but the next entry deals with this issue of the “Virgin’s Pearl”.
Until next time!
Continuing with the subject of “pearl culture and the environment”, we will now talk about some of the reasons why a farmer will not want to culture his pearls for a longer period of time, and also of how a pearl farm can affect the environment: but remembering that this can be in either a positive or negative way.
Behind every great Pearl there is a Great Pearl Oyster…
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By “growing” or raising young pearl oysters (usually known as “spats”)
- By means of the Fishing of Wild Fully-Grown Pearl Oysters (adults)
The Pearl Cultivation Period
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Water pollution: oil spills, water runoffs with fertilizers/pesticides, etc.
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Environmental disruption: that can be as dramatic as a tropical storm (hurricane) or a tsunami, or even something as subtle changes in ocean currents or extensive climate changes (such as those caused by a “El Niño” or “La Niña” year), which can range from the partial destruction of a farm (see our series of posts on “Pearls and hurricanes”) to massive pearl oyster mortalities, or that prevents their development, the growth of pearls or their lack of beauty.
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Accidents: at times – and we do know of this – a commercial fishing boat may simply decide to fish on your farm, and become entangled with your aquaculture gear; this –of course- only happens if the ship’s Captain decides that he does not want to respect a no-fishing zone and does so at night, when there is no visibility. This has happened to us.
The “Right Time”: No more & No less
Thus, if a farmer has to produce pearls for 4 years – as we do – the risks simply accumulate, day by day. On the other hand, if the producer is dedicated to extract wild oysters and subsequently produces pearls with a short cultivation period (4-10 months) then his risks are minimal. The issue here is to find the correct thing to do: have the right time to grow good quality pearls and have a TOLERABLE risk. But, I have yet to mention to another “party” or 3rd-person involved in the industry: the environment.- Do some species disappear or some (new ones) appear?
- Are there are any changes in the ocean’s floor (smell, color, grain size)?
- Are there any physical and chemical changes (salinity, pH, dissolved oxygen) in seawater?
- Are your oysters healthy?
- By using “spat” or pearl oyster juveniles: this can be done by either collecting juveniles from the environment or through the purchase of “Lab raised spat”, produced in highly specialized production centers;
- Fishing for “Wild Grown (adult) oysters”: these animals are usually obtained by fishermen that will sell the wild-raised pearl oyster to a farmer (at a price that ranges from cents to some $15 US dollars per oyster, pricing depending on multiple conditions) or by pearl-divers that are employed by the farmer. The preferred oyster sizes range between 10 and 16 cm (4-6 inches) in diameter, which will allow you to grow larger pearls.
On December, 2010, we had an unexpected visitor to our farm: Richard D. Fisher, author of some of my favorite books about Mexico’s Copper Canyon and the Sea of Cortez, such as: “National Parks of Northwest Mexico”, and his latest “Copper Canyon: Chihuahua, Mexico”. Not only is the information on the books interesting and quite accurate, but they also have valuable historical, geological and ethnographic information and EXCELLENT PHOTOS. So, you may imagine my surprise when I met Richard in a Bus Tour group from our friends at “A Closer Look Tours”…I was honored to take the whole group to a complete tour of our pearl farm and –as usual- answer our visitor’s questions regarding the subject of pearls (one of these days I will write a Blog-post with the most common and interesting questions we’ve been asked), and guess who asked one of the “best questions” we’ve been asked over the years? Yes, it was Richard D. Fisher indeed, and the question was: “Did the Japanese really Poison the Sea of Cortez’s Pearl Beds in the 1940’s???”
Let us ponder on this story, so let us go back to the early years of the 20th Century…
From 1900 to 1920:
In those days, the Mexican Pearl Fisheries were still quite active throughout the Gulf of California, but mainly around the Southern tip of the Lower California peninsula (Baja California Sur), with La Paz acting as the main pearl trade-hub. Skin divers were still very much active in the fisheries, but after several hundreds of years of “pearling”, the pearl beds had become less plentiful, thus a new breed of diver was needed: the Helmeted Diver. And these were few in numbers but could work for hours and could go deeper than the typical skin diver, thus it was possible to find larger –older- oysters in deeper waters and fetch some larger pearls.
At the same moment, Dr. Gastón Vivés had his farm up and running quite successfully until 1914 when it was destroyed by the “Constitutionalist Army” during the Mexican Revolution. And from this moment on, the only pearls that could be obtained from these waters were the 100% natural pearls from wild-caught oysters (as opposed to the natural pearls from farm-raised oysters from Dr. Vivés’ black lip farm). And you may imagine that during a civil war people become even more impoverished and will have to resort to sacking their most valuable natural resources in order to obtain funds to sustain them…and this is what probably happened to the pearl beds in the area once the “Pearling Companies” (mostly Mexican, but some even from Great Britain and other parts of Europe) stopped their operations during and after the Revolution.
From 1921 to 1940:
This is a particularly bleak period for the pearl fisheries. The beds on the Baja California side had become commercially exhausted (meaning: no sense in fishing them anymore), but had time to “revive” on the mainland side (mainly in Sonora and Sinaloa). A couple of areas were particularly good “placeres” (name given to places were a given resource is abundant): the waters in front of Caborca and those around “Isla Tiburón”, were the fishery was conducted by the Seri Indian Nation. But in any case, the pearls were on the brink of becoming a legend…then, complete disaster struck the area: in 1939 a “mysterious disease” was traveling from the northern part of the Gulf of California, moving southwards and killing every single black lipped pearl oyster, leaving just empty shells which were identified by the local fishermen due to their silvery shine…
By 1940 the few remaining pearl beds in the Gulf had been decimated and the Cortez Pearl became the newest addition to the vast collection of Mexican fables, stories, myths and legends.
The Japanese Conspiracy Theory
In the late 1930’s most Mexican people were not really thinking of the future “space race” nor with “little green men” and had little interest in such “conspiracy theories”…but this does not mean that our fishermen lacked from imagination nor ideas. They actually began to wonder what some boats with “rising sun” flags and men from a different language and race were doing inside their Gulf…and these men seemed quite suspicious: they anchored here and dropped little devices into the water, retrieved them and then moved to another spot and repeated the process and, yet, they never seemed to fish anything! Also, instead of the friendly exchange of products (cigars, gas, bait, etc.) that they seemed to enjoy with other fishermen –regardless of nationality- these guys were overly serious and would not trade a thing!!! They must be up to some mischief indeed!!!
Back in 1939, many Mexican fishermen still remembered the importance of their pearl fisheries and considered the local pearl oysters as a useful food & shell resource that might reward them with a very valuable gem…if they were truly lucky. Some people had heard that the Japanese had begun producing cultured pearls and that they seemed to be unparalleled in their ability to produce them; still, many believed that cultured pearls were no match to the “real thing” (the natural pearl) and that Mexico would once again become a major league player in the World’s pearl markets.
So, add ingredient #1 (the presence of “tricksy” Japanese in the Gulf) and ingredient #2 (the Return of the Mexican Pearl) and you basically have created a plot, a Japanese conspiracy to POISON the Sea of Cortez and destroy any possible rival for the Japanese Cultured Pearl: the Japanese vessels were dropping poison into the pearl beds to kill their opponent before it had a chance to get back on its feet. And you wouldn’t believe how many people heard of this plot, and how many talk about it as a certifiable truth: people from Guaymas, from La Paz, from Hermosillo, from Mexico City…everyone!
Now, is there any truth in this plot? Could the Japanese have really killed off the pearl beds?
The Facts and the Myths
It is a fact that many Japanese vessels with Japanese men were in the Sea of Cortez in the late 1930’s, and they were definitively up to something, but it is highly unlikely they were sent on a mission to kill pearl oysters. Why? Because with the technology available in those days it is very unlikely they could have possessed a toxin or poison made specially to kill pearl oysters…any other poison must have killed other creatures as well: all sorts of clams, snails and maybe even fish that the fishermen would have noticed. But no it did not. Even today (2011) I am not aware of a toxin that will only kill pearl oysters…and I hope it is never invented!
So, what were the Japanese doing here if not killing oysters?!?! Well, check your timeline and you will notice that the “Pacific War” officially begun in December 17th, 1941 and Japan went into war with the United States of America, Mexico’s northern neighbor. So, could it be possible that the Japanese were taking depth measurements of areas in the Sea of Cortez??? Could they possibly have planned an attack into U.S. soil from Mexico in order to avoid the heavily defended California coast??? It does sound as a possibility…doesn’t it? Unfourtunately I don’t have any information on this subject…so let us hope that Wikileaks will produce these in a couple of years.
What caused the Mass Mortalities???
This is also an interesting subject. The “official” explanation given by the Mexican Government was that it had been caused by an unknown epidemic (epizootic disease), but they never gave any scientific proof to the fact or they just wanted an easy explanation to what seemed to be a lost cause, because from that moment on (1939) the Pearl Fishery was considered officially closed and a fishing ban was imposed on the capture or fishery of the Mexican Black Lipped Pearl Oyster (Pinctada mazatlanica).
But there were other interesting things happening at the same time, such as…the operation of the United States’ great “Hoover Dam”. Let me place a quote from Wikipedia’s here to further explain:
Environmental impact
The changes in water use caused by Hoover Dam’s construction has had a large impact on the Colorado River Delta. The construction of the dam has been credited as causing the decline of this estuarine ecosystem.[98] For six years, after the construction of the dam and while Lake Mead filled, virtually no water reached the mouth of the river.[99] The delta’s estuary, which once had a freshwater-saltwater mixing zone stretching 40 miles (64 km) south of the river’s mouth, was turned into an inverse estuary where the level of salinity was higher close to the river’s mouth.[100]
The Colorado River had experienced natural flooding before the construction of the Hoover Dam. The dam eliminated the natural flooding, which imperiled many species adapted to the flooding, including both plants and animals.[101] The construction of the dam decimated the populations of native fish in the river downstream from the dam.[102] Four species of fish native to the Colorado River, the Bonytail chub, Colorado pikeminnow, Humpback chub, and Razorback sucker, are currently listed as endangered.[103][104]
If “Hoover Dam” began operating in 1936 and it is known that 6 years later (1942) there was no more fresh-water flowing unto the Gulf of California, then we can begin to imagine the environmental consequences. The “Colorado River” had its waters discharging into the Gulf for millions of years and then…kaput! No more water for you! So, what are the possible consequences: the impact was felt almost immediately on the Gulf’s northern region and its wetlands, but the effect had to creep down as the lack of freshwater made the Gulf of California “saltier” (the “average” salinity of the world’s ocean is 3.5%, with that of the Sea of Cortez being almost 3.6%) and a higher salinity level usually means less dissolved oxygen (which marine animals will use to breathe from the water). Besides this fact we can imagine that many other substances came with the river’s waters, including silt and many minerals…all these possibly very important to sustain a variety of marine plants and microscopic algae, creatures that are considered the basis of most marine ecosystems.
You may say “but the river’s water stopped flowing in 1942 and the oysters died in 1939!!!”, and yes…that is a fact, but the fact remains that there was less water available each year since the dam’s inauguration and by 1939 this was already causing havoc on our local ecosystems.
Conclusion
Have we finally pinpointed the truth to this dire plot or conspiracy theory? Not at all. I believe that there is still much to be done to reach this point, but a possibility would be that we could have indeed had a negative effect from “Hoover Dam” and this combined with the overfishing of the pearl beds and maybe we even had an epidemic or –just to make matters worse- an unknown environmental change. In any case: the Japanese are not to blame. They did not poison the Sea of Cortez to kill off a potential commercial threat.
I would also like to point out that I am in no way now blaming the American people for this disaster (we played our own part in this tragedy), and in those days (1930’s) few people knew or cared or understood how significant something like this truly was. Even now, few Nations are willing to consider Nature as a “User” of a given natural resource. In the meantime, we might speculate that our pearl oysters have had time to adapt to their “new” environment and –if given the opportunity- they will be able to repopulate our waters once more.
Here we are back again with this topic that I find increasingly interesting, due in part because I have used it as a form of catharsis, allowing me to remember one of the reasons why we started a Pearl Aquaculture project -some 17 years ago- when we were still students at the Guaymas Campus of the Tec de Monterrey. In those days, we first wanted to understand the reasons or logic surrounding the origin of natural pearls and how they are created within the pearl oysters and -of course- there was this previous “knowledge” about the origin of pearls: the mystical, magical, whimsical and musical “grain of sand theory“, which is really just another “pearl myth”.
Another Myth that Afflicts Humanity
It seems that regardless of the time period or place, this sand-grain-to-pearl myth has become very popular: it can be heard almost in any country and language. In my case my grandmother told me, when I was just a child, that pearls grew in an oyster as a result of an irritation caused by a grain of sand, so that there was no better choice for the little animal than to coat the painful and offensive particle with soft layers of nacre. I, of course, assimilated this important information and used it wherever there was an opportunity –and there were not many I must admit- until it came time to put this theory to the test.
Previous Experiments
From Left to Right: Manue, Enrique & Douglas
Back in 1991, our select group of friends – including Mauricio Atl Tahuilan, Carlos Navarro Serment and Jesús Gutiérrez – had helped us to collect some 70 Pearl oysters to start off our studies on Pearl oyster reproduction and culture. Most of the oysters collected were “Black Lips” (Pinctada mazatlanica) and only a few specimens were “Rainbow Lips” (Pteria sterna), so we use some of these few animals for a very simple experiment: use sand to produce natural pearls. And the result was simply disappointing: we did not obtain a single Pearl. Zero. Zilch. Nothing. Nada. And there arose the question of why didn’t it work? Because we all know that a grain of sand will induce the production of a pearl…thus, a thousand grains of sand should be capable of allowing for the production of a thousand pearls and a million grains of sand …well, a million pearls!!! It was just so obvious and foolproof.
But it was not. As much sand as we used, we could not produce pearls. Not a single one. On the other hand, when we took a peek inside our oysters we noticed that the oysters were perfectly clean, without a trace of sand. We could not know -for real- what really happened in those days because we simply did not have the time to sit there -in front of an oyster- for some 24 straight hours. Can you imagine yourself sitting, just watching an animal that -for some people- is as interesting as a rock??? Therefore, we came up with conjectures and hypotheses, but we never quite knew what was truly happening; anyway, we were “satisfied” with our guesses. Many years have passed now since those days, and the technology to help us is now available –and is also inexpensive- to perform these small experiments…and, of course, for the “birth” of this Blog to have the motivation to write and document the experiments.
Experimenting with sand: the Present
We used a small fish tank with clean seawater to introduce two “Rainbow Lipped oysters” into which we had –previously- introduce one and a half tablespoons of sand. We placed a small video camera to take a time-lapse video for the next 18 hours to record what happens to an oyster which has sand inside. The results did not astonish us, and lived up to our expectations.
The Results
After 3 hours in the tank, oysters would quickly open and close their valves, in a movement and launched a “cloud” of sand out of their bodies. This action removed a great proportion of sand from their bodies, but for the next 8 hours the oysters continued to, slowly, releases small “sand packets”. These “sand packets” consist of a sticky mucus that the oyster secretes in order to “bind” or adhere the sand, and thus it is more easy for them to remove the annoying particles. By next morning, the oysters were almost perfectly clean.
While – at first view – the oysters seemed to be clean from sand (we could see the most of the sand laying at the bottom of the tank) an oyster was sacrificed in order to inspect its body thoroughly, and we still managed to find a very small amount of sand inside. Under natural conditions, the oyster would have managed to remove all remaining sand in some additional hours, but here it was necessary to see the “mucus in action”: our video displays how the Oyster uses its mucus to catch some sand particles and helps to eliminate them.
Conclusions
Pearl oysters are perfectly adapted to their natural environment – the ocean – which has an inexhaustible source of sand. Because of this perfect adaptation, these lowly creatures can – very easily – remove every single annoying grain of sand from their bodies; thus, we can discard sand as being able to help produce natural pearls. In my opinion this is highly unlikely.
Thus, we hope that with the information generated by this test and the proofs on video we will help –once and for all- eliminate the false myth of the “grain of sand”. We hope that this myth will not become resurrected –a zombie of its former self- and come back to haunt us in the future… I swear that if I have to listen –once more- the question of “Is it not a grain of sand that makes the pearl?” something very, very bad, will happen …. I’m just joking: I have already been seared in the flesh –and mind and soul- with this question for years and years, so I am certain I will be able to sustain it longer (but try not to put me to the test, please).
A Blister Pearl!
While inspecting the oyster that was sacrificed for the “grain of sand experiment” I found a worm-like mud-blister pearl. Since our last blog-episode was about these pearls, and I already had the camera rigged it was just natural to make this information available for you all. So, I simply used a scalpel to break the mother-of-pearl layer on this “small tunnel” and found a small orange colored worm. It was clearly a drill-worm (genus Polydora). This discovery can be seen in the video as well.
Coming soon
This Blog will continue to have more information of interest to you, but probably this information will become a little more “spaced” in time, since our farming activities become intensified during the winter season and we usually spend more time at the farm than at the office (where I write the Blog).
So please do not despair, I promise more posts in the near future and do continue to visit our Blog and send your comments and suggestions.
Here we are once more with the intention of sharing information about these beautiful marine gems. On this occasion will continue with the subject of natural pearls and specifically about how these gems are created in nature.
During the era scientific enlightenment in the late 1800′s, scientists from all over the world were searching to understand how pearl oysters were able of producing pearls, and their discoveries were fascinating. But some of the first things they discovered at to do with the internal structure of the pearl, since in order to obtain the truth it was necessary to cut open pearls and inspect their core. And what they found is that pearls are very much like onions, at least structurally.
When an onion is cut in half what we see inside are numerous concentric layers, each stacked on the previous one, and in a similar manner pearls are produced: the original seed that caused the pearl to originate will be found at its core, surrounded by millions of micron thin layers of Aragonite. Perhaps this is a reason why the ancient Greeks gave the name “Margarita” to the pearl, since this is also the word for “onion” (hence the name “Margaritifera” that was given in early times to many pearl producing mollusks, meaning “pearl bearer”) in that language.
The Inner structure of an Onion (left) and a Natural Pearl (right).
In the above images of an onion and a natural pearl (both cut-in-half) we can see their internal resemblance, and going further into the deeper core we can also appreciate how their core is not round, but with each additional coating of nacre (in the case of the pearl) the shape becomes rounder, softer, although most natural pearls I have personally seen are rarely 100% round, most being baroque and a good proportion of them being semi-baroque in shape (mainly in the shape of buttons, bullets and drops).
But of course we do have several types of natural pearls. Many don’t look like the image that we have in our brains as being a pearl, but they are nonetheless pearls. We basically have two major groups of natural pearls: blisters and loose pearls. Of these two groups we would have subgroups as well. Let us begin with the pearls that could be considered the most common.
Blister pearls
Perhaps some of the most common natural pearls are those usually referred as blister pearls in English, “ampollas” in Spanish or as “ampulles” in French, and we could even say that these laid the foundation for the eventual production of mabé pearls (also known as blister or half pearls). These pearls are commonly found formed on the pearl oyster’s shell, as a response from a very active “Bio-terrorist” (usually an animal that actively drills through the oyster’s shell). The reasons for this active attack on the oyster’s shell are varied and depend on the species that attacks the oyster, blister pearls being the result of the oyster’s defense mechanism against these intruders.
The varieties of organisms that “attack” the oyster’s shell are huge and include animals such as sponges, polychaete worms and drill mussels. Many of these creatures are not really after the oysters flesh, meaning there not there to actually eat the oyster but that they are actually just looking for a “home” and have been known as “domiciliares” because they usually make their homes inside the oyster’s shell and -unfortunately for the pearl oyster-these actually weaken the shell, making it really brittle and easy to break. Of course, these “Bioterrorists” will also come in direct contact with the oyster’s flesh and this interaction will almost certainly produce blister pearls.
There’s a variety of sponge known as, usually colored with a bright orange red or yellow with a sticky consistency, which grows on a large variety of shellfish here in the Sea of Cortez, and it seems to have a preference for the black-lipped pearl oyster (Pinctada mazatlanica). It can cause small lump like blisters, but I have never seen any pretty specimen of pearl caused by this sponge.
Another creature capable of causing blister pearls is the infamous drill mussel or pholids. These creatures –and here I also have to include the Cliona sponge- are actually filter feeders just like pearl oysters are, so we can be sure that they don’t attack the shell to eat the oyster’s flesh, but they have brittle shells so they need the protection of a hard substance around them. These little creatures can actually bore stone, wood as well as sea shells. We have seen numerous blister pearls formed by the attack of these agents, as well as in one loose pearl. These creatures also have a preference for black-lipped pearl oysters, but may occasionally attack older individuals of the rainbow lipped pearl oyster variety (Pteria sterna).
The group of organisms which we find more interesting in the case of pearl formation of the polychaete worms, mainly those of genus Polydora: slender worms usually with a bright red coloration. These worms have the capacity to infest pearl oysters to the point of weakening them and causing their death and in the process making the oyster produce numerous “mud blisters”, which may eventually become coated with nacre.
Shell Damage caused by Drill worms and Drill Mussels
Mud Blisters
We have examined several varieties of the so-called mud blisters and in most instances where we have found are the remains of dead drill worms, as well as good quantities of very organic mud. It would be difficult to fully identify what causes this variety of blister pearl, but I believe that it is safe to say that it is a combination of the worm´s drilling activity and the entrance of mud due to the disappearance of the drill worm. What caused the drill worm to disappear? Well, we have also seen large numbers of predatory polychaete worms on the oyster’s shell and these may very well go after the drill worms and kill them, leaving their home vacated.
When removing a mud blister and cutting it in half we usually find a protective coating of protein secreted by the pearl oyster that that helps to coat the organic mud and that is in turn coated with nacre.
Unusual blister pearls
Some very unusual specimens have been found that include other varieties of animals as the cause, these include fish and crustaceans. Perhaps the most interesting specimen is that of a small fish that was found in the shell of a Mexican black lip pearl oyster that was fished in Baja California during the last days of the 19th century (this specimen is still kept in the American museum of natural history in New York). The fish was identified as a “pearl fish” (family Carapidae), which are usually associated with many species of clams and oysters and sea cucumbers (please use this link if you want to see an animated diagram of a pearl fish, if you’re a proctologist you will enjoy this). And although we have seen these fish inside oysters we have never had the fantastic opportunity of finding a “fish pearl”.
Pearl fish are not parasitic but instead they find shelter within the oyster’s shells. I believe most oysters would not be offended by the presence of this little fish, but in this particular case may be the little fish died and the oyster preceded to rapidly coat it with pearl or nacre, I don’t believe this could’ve ever happen with a live fish.
Other possible sources for blister pearls
Other organisms that could be turned into pearls -but that I have never seen turned into pearls- are the little shrimp and crabs that are found inside pearl oysters. The little translucent “pearl shrimp” are also found in many other species of clams, such as pen shells, and are typically found within the large Pinctada oysters. The species we find in the Sea of Cortez is Pontonia margarita, and we can usually find two individuals within an oyster (one male and one female, the male usually being the smaller of the two), this species does not seem to affect the pearl oyster.
Another type of crustacean we have seen inhabiting the oyster’s body is the “pea crab”; these little crabs are somewhat soft and quite clumsy, no wonder they need the protection they find inside an oyster’s shell. These little crabs have only been reported as found living inside the Australian silver lip pearl oyster (Pinctada maxima), but the Sea of Cortez has a variety that is only found within the rainbow lipped pearl oyster (Pteria sterna) and this will be the first time this will be reported in writing. The name of this species is still unknown (Pinnotheres sp.) and we usually only find one inside an oyster. We have seen some crabs causing a disturbance within the oyster that could eventually lead to the production of blister pearls, but we have yet to find a “crab pearl”.
So, what do you think about all the life-forms that depend or use a pearl oyster -in a way or another- for their survival? Life is indeed a web, and if you can save one species you will be offering an “umbrella” of protection for many others…
In our next chapter will continue talking about natural pearls and their possible origins, in the meantime I will continue hunting for additional facts and -of course- searching for more mythical pearls: I can clearly see myself wearing a pea crab pearl pendant.
Once more we are here, sharing our thoughts and hearts with you…hoping you will allow us to guide you into the history of the Gulf of California Pearl. I hope you find the story of Dr. Gastón Vivés feats as enthralling as we did when we first learned of his existence in 1991. So this week we continue with the most important area of the “CCCyP” or “Pearl Farm”: the “Raceways” or aquaculture channels.
When flying over Isla Espíritu Santo you will easily be able to distinguish the little bay and estuary where this famous pearl farm once stood, this because you can clearly distinguish the man-made shape of the culture station. This part of Dr. Vivés’ operation was a special as all others, but this one is the one most people can see, touch and easily comprehend in its operation. After almost 100 years of abandonment, harsh weather and even hurricanes, this area is still in good condition but slowly being overtaken by the mangrove forest.
This little “ensenada” or harbor has a small mangrove forest growing in typical estuarine fashion: you have a little inland lagoon with its sides all covered with mangrove trees. Gastón Vivés must have “cleared” some of the mangrove forest in order to improve the pearl culture environment, because pearl oysters are not commonly found inside these lagoons. The problems you usually have when you work in an estuary such as this one are the following:
- Increased salinity levels during summer months
- Decreased salinity levels after the rainy season
- Higher/Lower temperatures than those in the ocean
- Reduced oxygen levels.
- Lots and lots of mosquitoes and some terrible little -almost invisible- bugs we call “jejenes” (No-see-ems???)
But on the other hand you also have important benefits such as:
- Higher than average productivity levels (food)
- Easier handling of animals in shallower water
- Secluded area, easier to protect
So, it is obvious Dr. Vives decided to remove a portion of the mangrove forest and use it to grow his black-lipped pearl oysters (Pinctada mazatlanica) instead. It is hard to know if they dredged the bottom of the lagoon in order to remove the usually black-muck (highly organic mud) that is commonly associated with these forests. It could have been, but maybe they just closed the communication between the ocean and the lagoon…then they cut the trees, allowed the bottom to dry and have workers remove the anoxic muck and then prepare the bottom with more adequate conditions such as “tepetate” rock. This also gave them time to work with the masonry.
Pearl Culture Raceways at Isla Espíritu Santo
I can imagine this was a very intense workload for those involved. Why? Let us go back to 1890 and imagine that the World was different: sailboats on the remotest part of Mexico, a desert island with little or no food and fresh-water available, high temperatures of 45 Celsius (over 120 Fahrenheit) during midday, poisonous snakes and arthropods, mosquitoes, no medical help…you can keep adding it up. So, you not only needed workers, but logistics that are similar to those needed to fight battles and win wars: those that cannot supply their armies are the ones that will loose. And it was an army that Gastón Vivés had to take care of: at the height of the farm’s operation it is said it had over 1,200 men working on the Island.
So, among all the things he had to do is have his workers build barracks and other areas needed to establish and serve a large contingent of people. The docking area would have been important as well, because you need constant transportation of people and goods from La Paz to Espíritu Santo, and drinking water would have been a problem (although several fresh -and some briny- water springs are identified on the island). In order to obtain meat, goats were introduced and allowed to forage the desert shrubbery…something that nowadays is considered an “ecological nightmare” (but in those days the notion of “ecology” was non-existent). Once the whole site was constructed it would no longer be the peaceful island but a noisy bustling place of activity (heck! we’ve got towns in the “sierra” that have only some 88 people… and this place had hundreds of workers!): cooks cooking, iron-smiths bashing iron, carpenters nailing planks, divers, packagers…everything but plumbers and electricians.
The Nursery System
About the Masonry work: marvelous. He had great stone-smiths (for a lack of a better word) that -in my opinion- were serious artists and cared about quality. They used dark/red volcanic rocks to form the canals. Their amazing masonry work looks quite sturdy in most places, but the roots of the mangrove are slowly destroying them…
Inside the canals or water-channels it was possible to see some fish darting in and out (usually the common “Lisa” or “Mullet”), as well as an aggressive little Blue-Crab (Callinectes bellicosus). The water is mainly murky-green: thick and rich with nutrients. The water is shallow and has very little movement, the bottom seems more sandy instead of the black pudding-like muck you find at other estuaries (maybe I just needed to stand there until I sank…but did not have much time).
This place would have looked somewhat different some 100 years ago, because this part of the farm was entirely covered: it had a great “palapa” roof made with palm fronds (I did not see a single palm tree here, so the fronds would have been transported from the mainland as with most other things such as wood) and wood beams (very much like the palapa we employ at our Guaymas pearl farm today).
The reason for these roofs is simple: the sun is strong at this latitude and it warms the water; warmer water usually holds less oxygen and some creatures can suffocate… so, just add some shade and the water’s temperature will be cooler. Smart man. In winter you would have the opposite problem (cold water) so you can remove the palm covering and the water will warm up.
This raceway or canal system was very important because it was the “nursery system”, the place were the delicate little juvenile black-lips would be kept under constant surveillance. Why? Well, he did choose a lagoon…and these are well stocked with blue-crabs and these just adore little oysters for their “botana” (tastier than nachos). So, guards were places on top of the canals, armed with fork-like lancers and ready to defend the little pearl oysters. But many other creatures could have wanted to enjoy a free lunch as well: but mainly the octopus, snails and starfish.
The canals had wooden planks to allow the guards to move easily from one place to another and chase the intruders. Also, when the water from the canals was taken out (during the low tide) people would be able to jump inside and work with the animals, perform close inspection and even remove some predators that could have escaped from the guard’s watchful gaze.
The bottom was “conditioned” as I mentioned before, but the little juveniles were not left on the bottom just sitting. Nope. This was all worked out in detail. The little oysters were introduced inside small metal mesh cages, shaped like rectangles. We found the remains of several of these cages at the island…all oxidized, but of course plastic was unavailable in those days.
These juvenile oysters were obtained using special “spat collectors” (of a special design, and we will talk of these in the near future), and the little creatures must have measured some 3 cm (about 1 inch) when caught.
At this stage, the oysters are quite delicate because their shells are not hard enough to protect them and they have a special “anchoring” system (the bissus) they employ to grab a hold of a rock or coral and it is quite delicate: you should never pull them. Also, their small body size does not give the oyster enough protection from sudden temperature changes (they can heat easily under sunlight, and if placed rapidly in cold water the shock can kill them)… so it seems very likely Dr. Gastón Vivés’ medical training might have given him a very sound foundation to understand the oysters and give them the best possible conditions to improve their growth and survival.
By means of the mesh cages, it was easy to handle many oysters at once and protect them from most predators and he would have been able to reduce mortality rates to very tolerable levels (5-20%) at an age when -if you don’t do the right things- you can have a mortality rate of up to 80%.
Truly a revolutionary man and way ahead of his time… let us continue with this account in the coming weeks. In the meantime, you can watch a small video about our visit to this historical site. The video has titles in Spanish only, but if you read this entry you will be able to grasp the meaning…I will add sub-titles to the video in the future.