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Pearls & the Environment, Part 3

Obtaining the “Seeds” for your Farm

In order to “fatten” or grow your pearl oysters from a “juvenile” stage, what many refer to as “seed” or “spat” (oysters measuring between 2 and 8 mm), you either buy your litle oysters from specialized bivalve producing lab-facility, or you must establish a “wild spat collection” program. “Lab-raised spat” can be a very good option, but it may have a few disadvantages that are solvable. Let us first consider the advantages and then the disadvantages of Laboratory produced Juveniles:


  • You may have your spat at the desired schedule for your operation.
  • You can have all the spat you need for your farm.
  • Juveniles will have a very similar size (homogeneous) and growth rate.
  • The “Lab” may not produce spat for you due to a lack of demand (important if you use native or endemic species).
  • The quality of the spat may be very low (=high mortality and or lower growth).
  • The spat may have low genetic variability, since they come from a small group of “parents”. 


    The advantages of obtaining “spat” from wild-collectors are many, but it also has its disadvantages:


    • The seed is inexpensive (almost free!)
    • The spat has undergone a “natural selection” process, where only the “stronger” (or “luckiest”) survived.
    • There is much genetic variability within the group, which makes them less likely to die from some environmental change or a disease.


    However, in regard to the disadvantages we have:


    • You fully depend on the environment to capture your baby-pearl oysters, and it is becoming increasingly more difficult to predict the exact time for spat-collection (due to environmental changes) and
    • It is almost impossible to predict the amount of seed that you are going to obtain and, in addition
    • Your Juveniles will have variable sizes (heterogeneous) and you simply
    • Do not know the group’s their “genetic make-up”: you could end up with “oyster-duds”.


    Therefore, it is necessary to carry out, for months or even years, proper tests to find the most suitable areas for spat collection and understand in detail the reproductive behavior of the pearl oysters within the area of cultivation. Still, it’s easy to mess-up and obtain fewer than the desired amount of spat, so a mixed strategy can be more profitable: use both laboratory and wild–caught spat.

  • At our farm in Guaymas, we have been blessed with good seed collection areas that have allowed us to rely 100% on wild-caught spat since 1994, but we have experienced environmental disruptive phenomena (such as an “El Niño” or a “La Niña Year) that have caused us major problems in this area. However, seed production laboratories in the region do not sell pearl oyster spat… due to a lack of customers.

    So far we have only seen this strategy –the use of spat or “seed”- to start your pearl farm, but in a future post we’ll also discuss the other strategy: gathering large, wild-bred pearl oysters… but even before we compare all these strategies: how do you think these strategies can affect the environment? Surely the answer will surprise you (unless you already know something about this topic)…


    What can happen if I use “Lab-Raised Spat”?

    If this strategy is used properly, your farm can enjoy an uninterrupted supply of juvenile oysters, without ever having to depend on the environment’s natural supply. But, as with so many other things in which Humans get their hands-in, it can also lead to at a least pair of “unfourtunate” environmental problems. Among these we have “Genetic Pollution” and also the world-wide ocurrences of “massive pearl oyster mortalities”. Here’s why:

    Setting: Japan, in the early 1960’s when the pearl aquaculture industry began a period of growth that seemed inexhaustible… thousands of pearl farms with their hundreds of rafts and thousands of culture cages, all inside the crowded bays of this island nation. With millions of “Akoya-gai” pearl oysters in culture there simply there were no more “wild-bred” pearl oysters available (most of these had been fished out to supply the pearl aquaculture industry) and there was not enough wild spat for the farmers. Since the Japanese people have been using research to advance their aquaculture technology, they generated enough knowledge to be able to rear laboratory-produced juveniles of all types of mollusks. Under this production system all that is needed is to procure a couple of oysters, an “Adam and Eve” if you will; from this couple you will be able to obtain millions of baby oysters (a female oyster can produce -depending on the species and other conditions- between 100,000 and 1 million eggs in a single “egg discharge”) or “spat”.

    The problem that may be generated under this system is that all your oysters are descendants of this single pair of oysters (your “studs”), thus they are all siblings, and genetically speaking: these oysters are very similar (but not identical, remember that there is a genetic effect known as “Genetic Recombination” which makes it possible for an increase in genetic differences). This makes them more likely to react similarly to environmental change or disease: if one of them becomes sick… most likely all others will too. This problem can be avoided using a larger number of parent oysters or “studs” and we will gain a much greater genetic variability among our pearl oysters. Unfourtunately, once producers have used this productive system, they will imediately begin with the selection of “strains” or “Breeds” of genetically improved oyster stock, in which the parents are selected solely based on characteristics that are considered as desirable, such as:

    • A faster growth rate
    • Better Shell-Shape and/or
    • Better Shell color (=color of the pearl)


    And this is where a vicious cycle can begin, having no end in sight until its consequences become catastrophic, yet very few seem to care about this problem. Originally, pearl oysters are selected with the characteristics of faster growth rate and shell color, and from these you get a first generation (F1) of oysters that may be larger, grow better and produce pearls with a more similar color. Initially, this is something very good for the producer, since he’ll have the ability to introduce just the “right product” for the mass market: most pearls will be very similar and you can produce tens of thousands of identical pieces.

    However, if the the farmer re-runs the selection of broodstock (from the F1 or first generation) he will be able to further refine these characteristics: the pearl oysters will grow even faster and will have a better color selection. And so, the process is repeated for several generations… until his organisms (let us say, in their F10) become “genetically depressed” in a process known as inbreeding.

    I ask the question again: What does the Environment think of this? How can we affect the Environment? Well, let us gather some information from the Wikipedia on this topic:


    Inbreeding is the reproduction from the mating of two genetically related parents, which can increase the chances of offspring being affected by recessive or deleterious traits. This generally leads to a decreased fitness of a population, which is called inbreeding depression. Deleterious alleles causing inbreeding depression can subsequently be removed through culling, which is also known as genetic purging.

    Thus, growers should avoid the phenomenon of “genetic depression” through a less stringent selection or by introducing “new blood” -originating from wild oysters- so as to avoid this  negative phenomenon.


    Negative Environmental Impact from using Lab-raised Spat

    Although I would like to say that there is absolutely no negative impact, I must declare just the opposite. There is evidence that the use of lab-raised organisms can have an effect known as “genetic pollution” upon the wild-bred populations. This is something that is believed –by some- to have had affected the Japanese populations of Akoya-gai (Pinctada imbricata) oysters and could have helped cause the already known mass mortalities of pearl oysters. How so? Because of the production of sexually-infertile chromosome-altered oysters know as polyploids. These oysters are supposed to be infertile, thus the energy an oyster devotes to reproduction is instead spent on growth…a great thing for any pearl farmer, but as with all good ideas some are not that good. So, some of these unfertile polyploids began reproducing, their altereded gametes giving rise to some “Franken-Oysters” that settled in Japan’s bays, becoming part of the Akoya-gai’s “gene pool”.

But why do these things happen??? Because we cannot put a leash on Nature, because we just lack the Humility to accept that sometimes we just have a great tendency to wreck things up, and very specially when it comes to the environment.

This aspect is similar to the “Wild Corn vs GMO Corn” controversy: pearl oysters are key species in many ecosystems and they also have cultural-value in many lands, why not just take care of the critters and raise decent cultured pearls and doing it in the best possible way? Well, there is always someone who goes the extra-mile to get an extra penny…seems this is what Life is all about after all.

 The Solution

Our solution to this problem is simple: AVOID using inbred organisms, by always introducing “new blood” (wild-organisms from your locality to prevent any damage) into your selected “breed” and to always avoid using chromosomic-freaks. Mexico –among many others- is a Megadiverse country, and deserves the protection of its remaining natural resources: these belong not only to us, but to our children and all future generations, and as many have stated before: the Environment knows nothing about borders, languages or Human culture, so in essence it belongs to whole of Humanity and for all other Living beings with which we share this beautiful blue planet.

Let us learn from the mistakes of others, and avoid falling into the habit of continuously using “damage control” techiques. In the next post I will discuss the “collection of wild spat”. Until next time!


Pearl Culture & the Environment- Part 1

Just a couple of days ago a friend of mine –he is a retired Canadian farmer- and I were discussing the way the North American “Meat Industry” (beef, poultry, pork, etc.) had become misguided by the constant search of higher volumes of production (which, somehow, equal MONEY), but this was being done at the expense of both the animals and the consumers (all of us). Kurt began by telling me about his experience when dealing with local Animal Sanitation officers, about the indiscriminate use of antibiotics on cattle and the plain lack of “common sense” on the part of those involved in the industry. He told me: “I did not inject my animals with antibiotics, but instead I offered them land on which to forage, clean straw-bedding and care. My animals never developed the infections I was told they would suffer and they fattened better than those under the strain of antibiotics”. He cared for his animals and treated them with respect. Some in the industry seem to have noticed the same thing and have reverted to “the Old way”.

Just a couple of days later we were reading an “old” article written by Shigeru Akamatsu, a person with much influence in the Pearl Industry (being Counselor of the “Japan Pearl Promotion Society”, and he started as a pearl culture researcher under Kokichi Mikimoto’s leadership) and I felt this article tied in perfectly with the talk I had with Kurt, and thus this entry got its start.

The Reasons Behind the Changes

The article “Pearl Culture and the Biological Environment” (published in “Ship & Ocean Newsletter”#8G March 5, 2004) which can be downloaded in PDF format is quite interesting because it finally approaches the decline of the Japanese Pearling Industry in a way that is finally understood: the industry as a whole has to admit its guilt. No longer is guilt being laid upon the “wrath of Nature” in the way of red tides or mysterious diseases. And although Mr. Akamatsu does not mention it this way, I could read the word “greed” on certain paragraphs…but he never mentions this sin, rather handling it in a more political way by using a term like “in the pursuit of economic efficiency”.

Mr. Akamatsu states in this article’s first paragraph:

Japan dominated the world’s cultured pearl industry for many years, but in recent times that state of affairs is changing rapidly. Though the rapid globalization of the pearl industry can be considered as one of the reasons, the primary cause is the deterioration of pearl farms caused by the occurrence of harmful red tides and the massive mortality of Akoya pearl oysters due to an infectious disease. Such phenomena relate not only to pearl culture, but also to BSE, carp herpes, avian influenza, etc., and may be the price paid for not treating animals as living creatures, in the pursuit of economic efficiency, as well as for incessantly changing the natural environment for the expansion of production.”

Akoya Pearl Farm in Japan

When pearl culture began in the early 20th Century, the overall idea was to produce a natural pearl substitute but that would keep the attributes of the pearl: beauty and durability. Initially, pearl culturing periods were long (2-5 years) but many in the industry noticed that pearls with shorter culture periods still looked nice (1-2 years) but then they saw that most people could not tell the difference between “instant pearls” (4-8 months) and those with a longer culture periods, thus shorter pearl-growth periods became more common…and profits increased. Why would profits increase? This is something that every pearl farmer understands, but let me explain it shortly: each pearl oyster in your farm costs you money, every day.

In order to cope with mounting costs (labor, equipment & fuel) pearl farmers can use many strategies, such as:

  1. Increase stocking density: you grow more oysters in the space you already have.
  2. Decrease your Work-force: substituting manpower with machinery and equipment.
  3. Decrease your Pearl Culture Period: you grow your pearls in less time.

Let us talk about the implications of each of these strategies.


Stocking Density

Growing more oysters in the same space you had may sound efficient: If you can fit 10 books in a box that once only held 7 books –thanks to a more clever way of arranging your books- then you have done this in a more efficient manner. But it is not necessarily the same with living organisms: animals –even plants- will thrive under adequate conditions, but overstocking/over-crowding will yield unhappy critters…and this brings about stress.

Imagine you live in a 10 x 10 meter room (sounds like a prison-cell, doesn’t it?) and all of your basic needs are fulfilled in this space that has a toilet, lavatory, book-case, table and chairs, bed and TV set. Now imagine you have a new guest, it may become uncomfortable but livable, but now: crowd the cell with 8 more “guests” for a total of 10 people…1 per square meter. Life becomes unbearable for all: can’t eat, can’t use the toilet nor watch TV nor reach for a book, then there’s the lack of food, stress, the smell and finally disease. Not a nice option…would it be nice for an oyster? Our mollusks don’t have brains nor conscience so they will not suffer any psychological damage, but their bodies will indeed react to overcrowding by displaying less growth (become stunted), will be less healthy and will become sick (ultimately they will die) and their pearls will lack beauty.

We can actually tell when an animal did not enjoy a healthy life when we see its shell and pearl: unhealthy oysters will have dull shells, without intense colors (the trade-mark of our “Rainbow-Lipped Oysters”) and their pearls will have dull luster and light colors. But overcrowding oysters is not the only factor that will affect their health: the environment (pollution, climate change, hurricanes) and disease (caused by parasites), but these are not under the control of a farmer. It is up to the farmer to have healthier pearl oysters by means of adequate stocking densities.

Infections are a major headache for producers: infected oysters may quickly infect their sisters & brothers under crowded conditions, and since overcrowding makes oysters weak –due to a combination of lack of food and oxygen- and parasites can easily “jump” from an oyster to many others if the distance is short.

In our case we hold our “Rainbow Lipped Oysters” under more than adequate conditions inside Bacochibampo Bay: we use less than 1% of the bay’s entire area and there are no other mollusk farms in the vicinity (the closest one is an edible oyster farm in Kino Bay, some 180 Km/112 miles away). We are making sure that our fledgling venture will not follow the same course as others, but let us see what has happened in other pearl producing countries:

The Cook Islands: here we’ll cite information about pearl-farming mortalities caused by overstocking (you can read the whole article by downloading the PDF file from the link):

“In Manihiki Lagoon, one potential stressor which may have been related to the onset of mortalities was the high stocking density. Prior to the disease outbreak the number of oysters cultured in Manihiki Lagoon was reportedly at an all-time high. In conclusion, our data suggest that an unprecedented disease outbreak in P. margaritifera [the Black-Lipped Pearl Oyster] in Manihiki lagoon in November 2000 was associated with vibriosis caused by V. harveyi [a species of Vibrio virus] and other opportunistic vibrios.”

Japan: When we began our experimental pearl farm in 1994 we heard about a “mysterious disease” that was killing the Akoya Pearl Oyster and that nothing could be done about this “viral outbreak”. The blame was laid entirely upon an “unknown virus” and you can read some of the thoughts of the time (taken from “NOVA: the Perfect Pearl”) on the following paragraph:

“Experts attribute the initial oyster deaths in 1994 to “red tide,” a bloom of microscopic, toxin-producing animals in the ocean that proved deadly to the oysters. Even after several years of scientific investigation, the specific cause of the disease remains a mystery. The illness first makes itself known when the abductor muscle, which holds the two parts of the oyster shell together, turns a reddish-brown. Ultimately, eight out of ten affected oysters die from the affliction, which so far has only affected akoya oysters. Others feel the oyster farmers themselves might be to blame. “The Japanese have always tended to place too many oysters too close together” wrote Andy Müller in the December 1996/January 1997 issue of Pearl World.


So, in both instances we’ve seen that over-crowding –both your cages and your bays- leads to severe problems in pearl production. Why do it at all? Many reasons there are, but they are one and the same: the COST of floats, equipment (pearl culture cages), more workers (salaries), of paying for more “sea-rights”, the costs of moving away from densely packed areas into remote areas (devoid of many necessary services), but in the end they are all translated into the cost of producing pearls. If pearls kept a high value you would not need to grow billions of pearls, thus by producing more pearls the industry shot itself in the foot and a vicious cycle began to turn and churn.


Labor Costs

Adrian Amarillas holding a pocket net with Black-Lips

Many people believe this is a major solution to a company’s problems, but we believe this is really a big mistake. Companies are nothing if they don’t have people: they are made of people and one of the purposes of any company should be the production of well-paid jobs. Making money is not bad and should be a goal of every company, but it should not be the sole goal: there is a particular pride to producing pearls and the people that help you achieve this… become your trusted allies.

Farm-wise: without workers a pearl farm would just die. Pearl farming is a work intensive operation, involving divers, aquaculture technicians, farm-workers, mechanics, surveillance guards and many other people. Loose one link and the rest will follow. And pearl farmers usually work under very specific time constraints such as: the seeding season, the spat collecting season, harvest season, etc. This means that if you DO NOT finish a certain activity ON TIME you WILL NOT BE ABLE TO FINISH IT AT ALL and will have to move to the next one, ultimately this means it is highly unproductive and foolish.

And something I really want to stress here is that pearl farming is very artisanal in Mexico: very little machinery is employed. And we want to keep it that way for several reasons which many may approve and others will disprove, and it may be one of the reasons why we ended up with the Fair Trade Gems seal of approval (the only pearl –so far- in this list is the “Cortez Pearl”): we have very few jobs in Mexico. Our economy just doesn’t work because it is fueled by our exports (mainly raw-goods such as oil, agriculture goods and metals) and our cheap labor-force (which is also “exported” to other countries) in manufacturing for offshore companies. If we purchased machinery that would allow us to avoid hiring additional workers we would be a part of the problem, not a solution…so, even if this costs us more and makes us less efficient we will continue on this path.

In a future post we’ll explain a little more about our labor strategies.


Pearl Culture Period

The longer the pearl resides inside its “mother” or “host” oyster, the bigger it becomes and the more “pearl” (nacre) it will have…but this also means you must continue to grow your pearl oysters for longer time periods. Many sources state that the pearl culturing period in Japan took between 2 to 4 years to complete, the Akoya pearl ending up with a very good coating of 0.95 mm (Ward, 1995). This good nacre coating made it possible for the pearl to look beautiful, lustrous and have the endurance –basically, to pass the test of time- that all gems should have.


Cortez Pearls in Half

But many in the pearl-industry noticed that most consumers would not be able to tell the difference between a thickly-coated pearl and one with a thin-nacre coating. Thus, a bad practice was initiated in the industry and pearl culturing periods fell to –in some cases- down to less than 6 months (with a coating of less than 0.2 mm, once again Ward, 1995 is the source). This saved farmers a lot of money in wages & cages…but, was it really worth it?

This issue was addressed quite some time ago by many in the pearl industry, but a particularly strong voice was that of the late Australian Pearl Farmer & Consultant C. Denis George, who in 1971 stated:

“The Japanese technicians are insisting that this thin cultivation [of the pearl] does not make any difference in the appearance of the pearl, but in my opinion this is beside the point and does make a lot of difference in the principles involved and their material value in dollars paid by the customer in the belief she is acquiring a pearl of value… This resulted in many losing their trust in pearls, other withdrawing from the industry or going bankrupt; and many scores of thousands of women all over the world…became bitterly disappointed when their treasure faded.” (Excerpt from “The Black Pearls: History and Development”. 1971. Lapidary Journal).

Akoya Pearl Quality Compared

Comparing Nacre Thickness of Akoya Pearls


From a farmer’s perspective, there are many situations that will make you consider against having longer pearl culture periods, such as:

  1. Global Warming & Hurricanes
  2. Pollution
  3. Disease
  4. Age of your Pearl Oysters

But regardless of these situations, a pearl farmer should have set his farm’s goal for nacre thickness and stick to it as much as possible. For instance, our pearl culturing period ranges from 18 to 24 months (after the moment the pearl oyster is operated), and this allows us to harvest pearls with an excellent nacre coating of 1.5 mm around the nucleus, although many pearls will grow over 2.0 mm of nacre, some will grow less than the 0.8 mm minimum acceptable standard. You really have to stick to this minimum culture period because you simply cannot accept anything below the 0.8 mm thickness mark…if the pearl falls below this number it has got to go down the drain (pearly gehenna: the pearls must be cast to the deep waters of the Sea of Cortez, where bacteria will recycle their materials).

Compare this to the Tahitian Pearl Ministry’s quality check for Tahitian black pearls in the year 2001:

“…the minimum nacre thickness requirement for all exported Tahitian pearls at 0.6 mm went into effect on Sept.1. The assembly voted to bump that minimum up to 0.8 mm beginning July 2002.” (“Tahitian Government to Improve Pearl Exports” by Victoria Gomelsky in Gemstone News. National Jeweler. September 2001 page 28).

This actually means that many in the pearl industry are –or were- producing pearls with a nacre thickness that is simply not adequate, and this affects those producers that are interested in keeping a high quality standard in their pearls, because –in the end- all pearls are considered as equals by many customers. Not so.


Final Thoughts

  • Pearl Oysters are an important species in their local ecosystems, but too much of a good thing can ruin things for all so it is really important that you do not disrupt your environment’s carrying capacity by overwhelming it with billions of pearl oysters: healthy oysters will produce exceptional pearls.
  • Keep your Local Jobs: If we were all able of making our companies thrive, then let us keep our local jobs truly local, by offering good wages and good working conditions; we might lose money by NOT having workers in other countries do the work we could on our own, but we would fuel OUR economy. If we all did our part our economy would grow and we would not have people leaving this Country for the one up north.
  • Keep your Pearl Quality High: Good pearls are the first to go! Pearl buyers are always looking for the pearl of a lifetime…the pearl that will make them gasp in awe! Low quality pearls are good for trinkets or for feeding your local bacteria. Would like to finish this subject with a mention from the Bible:

Matthew 13:45-46

45 “Again, the kingdom of heaven is like a merchant looking for fine pearls. 46 When he found one of great value, he went away and sold everything he had and bought it.”

So, what do you think about this subject? Should producers consider the Environment as their Ally or as a “bloody nuisance”? What should you -as a pearl buyer- consider as a good trade-off? Please let me know your thoughts…in the comments area.

On our next post we’ll detail some of the reasons for not growing pearls for longer periods of time and some of the ways how pearl farming can affect the environment…both in a positive and a negative manner.