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Sustaining Life with Pearl Farming

The Sustainability Corner – Introduction

Writer / Publisher : CortezPearls 

Back in 1990 I began dreaming of a humane method for growing pearls. I had just begun my master’s degree in Conservation Management and Sustainable Development, and my focus was on creating a system that would be able to grow pearl oysters but without damaging the environment, disrupting the local communities and finally, that could offer a product that would make you feel good in every way. Why was this the focus? Back in the 1980’s and 1990’s the most successful aquaculture ventures were those revolving around shrimp farming, and I had visited several of these and -to my dismay- I saw how these were usually established in mangrove forest lagoons, destroying these important ecosystems to build the shrimp ponds, but most of these ventures also established a work system that had dozens of badly-paid workers living in barracks and away from their families for prolonged periods, and some of these farms were responsible for introducing several Asian-shrimp virus strains that not only were responsible for the near destruction of this aquaculture industry, but that also introduced these to the wild-grown shrimp populations and caused a triple-whammy effect. When a farm was vacated, we ended up with dead-salty plots of land, devoid of life except for some desert bushes and “sea-monkey”-like crustaceans.

And this was NOT what I wanted as the basis for a new aquafarming industry. The more that my research group and I learned about pearl farming, the greater credibility we developed that a pearling venture would be able to attain the proverbial Environmental Shangri-La. But what about working conditions? That had to be addressed as well, we wanted loyal workers not slaves that would “rise against their masters”. Even back in those days, pearl farmers all over the world understood the clear relationship between pearls oysters and their environment and this led to the phrase “Beautiful pearls can only be grown in a Healthy Environment”, but as time passed and we ended up working with more farm employees that I saw another factor in the equation: pearl oysters will only be properly taken care of by people that love and are satisfied with jobs, thus giving us a final reveal: “Beautiful Pearls are Grown in Healthy Pearl Oysters that are Taken Care by People that Love Them”, this gives us a full circle on the connection between the Environment, the Mollusks, the People and the Gem.

This column will hopefully tackle these issues in a way that will allow pearl connoisseurs to understand how pearl farming offers the best in class in Sustainability within the Wide World of Gems.

Sustaining Life with Pearl Farming

One of the most important aspects of pearl farming is its inherent ability to protect and create more life than the one that was available previously. And what do I mean by this? When you start a pearl farm in a location, you begin with a resource that has already been “pillaged & plundered”, probably for hundreds, if not thousands, of years. As an example, we have the pearl fisheries of the Persian Gulf -whose pearls were adorning the ancient rulers of Egypt, Persia, and Rome- or the most recent Gulf of California pearl fisheries that began an intense fishery in the 1600s: what we see today is just a shadow of what used to be before the fisheries commenced, some 420 years ago.

When you start a pearl farm then, you will commence on a previously fished and impacted environment, where pearl oysters are usually not abundant. This was very much the scenario I encountered back in 1992: a mollusk census in Bacochibampo Bay, Guaymas, Sonora, Mexico, revealed that in an area of 400 hectares (988 acres) we just had less than 150 live pearl oysters. This means that we just had 0.355 oysters per square meter (/m2), and the thing here is…why should we care about this at all? Well, you see, pearl oysters are sessile, and they do not move about to go out on dates with others so they need to be found living in clusters or “pearl beds” or they will not be able to breed successfully. According to studies, you need at least 10 oysters per square meter to ensure successful reproduction: the chances of the microscopically small sexual cells finding each other diminishes dramatically with fewer oysters.

So, in the above example, pearl oysters were on the brink of a local extinction event, just about ready to disappear; but along came a small research group to put a stop on this by gathering as many of the wild oysters we could and then we placed them all together in a protective cage in the bay, and then they started breeding in captivity…but their descendants were free to head out to the sea. At 150 oysters per sq meter they were at least 14 times more successful than the minimum number required, and many times more successful than dispersed all over the bay. And then, slowly, “biological magic” began to happen…

Pearls in the Web of Life

Pearls are not only a product of a living being -a mollusk- but their “mother mollusk” is also a host for dozens of other life-forms! When we think about other animals that we use in our lives (as a food source or as a luxury good, such as furs) we can rarely imagine these creatures being a part of something larger or co-existing with other animals from different species. We may picture a henhouse bursting with chickens, or a pen full of cows, but we find it hard to imagine these caged animals as being a “part of something greater”, but with pearl oysters it is quite the opposite and quite fascinating.

In Nature, pearl oysters are usually found attached to rocks or hard corals, thus they are surrounded by other life forms and their rock-like shells make them extremely attractive to many species of plants and animals that will call a pearl oyster “Home”. I once handled pearl oysters that were literally covered with Life: it had about five species of algae, six species of polychaetae and flat worms, eight species of crabs and crustaceans, four of “snails” (conchs, limpets, and chitons) and seven species of other mollusks (drill mussels, geoducks, mussels, scallops and other pearl oysters). And these were the ones I could see just by using my eyes.

In a sense, pearl oysters resemble a “small ecosystem” of their own, a self-contained biome where a tug of war ensues and leads to eventual stability. But why would this be important? We still have two more articles to explore this subject, but it is important to say that sometimes we focus on the “large” item on the picture and totally miss out on all the other important images. One of my teachers once told us: “we were at a gray whale symposium and the speaker mentioned the importance of saving gray whales, when another man asked his voice to be heard and explained that without gray whales, we would also lose a unique species of barnacle”.

We rarely see the whole picture.

In a sense, pearl oysters might be a “small ecosystem” of their own, a self-contained biome where a tug of war ensues and leads to eventual stability. But why does this happen? And does it hurt the mollusk? One of my Marine Biology teachers -Dr Fernando Manrique, a friend of Jacques Cousteau- once told us that the Ocean was teeming with Life, and that the hardest thing for many lifeforms to find was an “available apartment”, a place to settle and that would help them avoid being tossed around by waves and water currents. Rocks are the best “condos” in this aquatic world, but oyster shells are a good second place. And because of this, a pearl oyster’s life become that of a patient renter, never asking much and sometimes suffering from being too lenient with its established guests.

Pearl oysters can become so attractive to other lifeforms that they may become completely covered by these “epibionts” (from the Greek “Epi”, which means “On top” and “Bio” for “Life”) and the mollusks may weaken due to lack of oxygen and food, and this is the main reason why pearl farmers must clean their oysters several times a year, sometimes even on a monthly basis. The traditional cleaning method involves manual labor; thus, oysters are individually scrapped free of these creatures. This is a time consuming and costly operation, and it may stress the oysters just a bit (but much better than leaving them to slowly suffocate).

In Nature, there are other creatures that clean the oysters and there are more natural strategies to clean them. For instance, Australian pearl farmers may lay their flat-panel baskets, with their valuable pearl-bearing oysters, right on top of the sandy bottom, where these epibionts will suffocate and die; in another pearl farm in Ahe, Tahiti, the oysters will be hanging from ropes and are placed in a reef area, teeming with colorful fishes that will eat-away all the plants and invertebrates off the shells. Both are simple, all-natural and effective methods to clean your oysters and promote their health and growth, to help them produce beautiful pearls.

In our last entry, where we learned that the outside of pearl oysters acts as a small ecosystem in itself, but now we will “dive deeper” into the oysters themselves to find that this pattern repeats itself -in a kind of Hermetic understanding of the “As is Above, is Below” law- but with different actors involved. And, if you ever had the opportunity to stare into a live and open pearl oyster, you would begin experiencing a calmness that emanates from these animals…as if staring into an encased, fleshy orchid, a peaceful womb. And it is this protective environment that some unusual creatures are searching for.

Many pearl oysters received the name of “Mother of Pearl Oysters” since they would “give birth” to pearls themselves, but many small and frail creatures would probably pronounce this same name to describe these mollusks just as many people call our planet “Mother Earth”. Who are the dwellers of this small, motherly environment? Well, there are just a few and each variety of pearl oyster will be able to house its own unique species in a unique biological association known as commensalism: species that live on another one, without causing damage to their host.

One of the most bizarre of these is the “Pearl Fish” (Carapus), serpentine-shaped and almost translucent fishes that love living inside pearl oysters of genus Pinctada. These slow and frail creatures require a place to hide from predators, and pearl oysters offer them quite a large and luxurious nacreous apartment. Little is known of these reclusive fishes, which are easily identified due to their unusual dwelling habits, including starfishes, other bivalves and -quite oddly- inside the anus of sea cucumbers. It is easy to imagine why they would prefer pearl oysters, isn’t it?

Well, these fishes will ultimately find an oyster, find a mate, produce their offspring and live their “pearl dream”, but it happens that they also end up dying and their tiny corpses will soon start decaying, most of them becoming expelled from their host pearl oyster; but in exceptional occasions something truly special happens: the pearl oyster will cover them with mother-of-pearl, thus they become “nacreous mummies” or one of the most striking natural blister pearls you have ever laid eyes on.

These small nacreous coffins become an enduring testament to the lives of these rare inhabitants of our seas: all Life is important to keep an adequate Balance, and pearl oysters -as you have been able to ascertain with these last entries- are a key player in many marine environments, not only due to their main biological function but also to protect and nurture so many other minor players.

Black Lipped oysters (Pinctada mazatlanica) have been found to contain -quite rarely!- these unique natural blister pearls with the dead remains of a “pearl fish” (Carapus dubius). The photo of the shell on the left can be seen on display at the Mineral Museum in Zacatecas, México, and the one on the right was photographed from NYC’s Natural History Museum’s collection.