Here you will get to know most of the operations performed in a Pearl Farm, so grab your favorite sandals, put on your sunglasses and prepare to immerse yourself inside Mexico's Premiere Pearl Farm.
This pearl farm is currently owned by a group of Mexican Investors that include the three founders of the original research project. The farm's installations are still based at the Guaymas Campus of the I.T.E.S.M. (popularly known as the "Tec de Monterrey").
This Campus has been around since 1968, specializing in courses related to Aquaculture, Marine Biology, Food Processing, and Conservation Management. Many important advances in aquaculture took place here since then, applied research has been an important part of this Institute. Unfortunately, it has closed down all of its Educational & Research operations until notice.
The Pearl Farm resides inside one of Guaymas' most beautiful bays: Bacochibampo Bay (meaning "Bay of Sea-Snakes" in the Yaqui Indian language).
The pearl farm itself evolved -back in 1991- as a spin-off from a Research Project ("Aquaculture of Native Bivalve Species") that had begun back in 1985. Pearl Farm Tours started -quite accidentally- back in 1997, but since then we have received tens of thousands of visitors from all over the World.
The project grew both in size and importance, until in 1996 it was declared as a high-priority project under the name of "ITESM/Perlas de Guaymas", then renamed as "Perlas del Mar de Cortés S.A. de C.V.", when it reached its commercial period in the year 2000 and now it has finally changed hands to become the property of "Granja de Perlas del Mar de Cortez S.A. de C.V." and this is the trade-name we are known for: Perlas del Mar de Cortez or Cortez Pearls in English.
You are now at the dock, the first step taken into the fascinating world of pearl culture. From here, you can watch the ceaseless activities revolving around pearl culture: spat collection, cleaning of the oysters, seeding them into their cages and even harvests.
Here you can also get an excellent view of our suspended culture farm, from these "long-lines" we "hang" the culture cages in which the pearl oysters grow. Presently we are culturing some 250,000 native pearl oysters within our aquaculture facilities. This is -without a doubt- the largest single concentration of native pearl oysters on this side of the Pacific Ocean.
A pearl farm is not only a way to obtain pearls, but it can also act as a "breeding station" helping to replenish the Gulf with these -once very abundant- valuable species. Our unique pearl oysters are known as the "Rainbow-Lipped Pearl Oyster" (Pteria sterna) and the "Black-Lipped Pearl Oyster" (Pinctada mazatlanica).
The Pearl Oysters
Pearl Oysters are mollusks, primitive soft-bodied invertebrates with a hard protective shell. There are many kinds of mollusks: bivalves (clams, scallops, mussels, and pearl oysters), gastropods (abalone, slugs, and snails) and cephalopods (squid and octopus). Of these animals, only pearl oysters (family Pteriidae), freshwater mussels (family Unionidae) and Abalone (Family Haliotidae) are capable of producing nacreous pearls.
And of these three groups of mollusks, Pearl Oysters (family Pteriidae) produce the most beautiful pearls of all. Most of the world's cultured pearls (known as freshwater pearls or FWP) are produced by freshwater mussels (Unionids); followed by Saltwater pearls, produced mainly by about three different species of pearl oysters of the Genus Pinctada: the "Akoya" pearl oyster (Pinctada imbricata=fucata), the "White/Gold Lipped Oyster" (Pinctada maxima) and the "Black-Lipped Oyster" (Pinctada margaritifera). The "mabe-gai" or "Penguin Winged Pearl Oyster" (Pteria penguin) is used solely for the production of the "mabe" pearl (also known as a "half-pearl").
Then, every kind of saltwater pearl -be it "Akoya", "South Sea" or "Tahitian Black"- are produced within Pinctada type pearl oysters. The only pearl farm that utilizes a Pteria type pearl oyster for the production of loose cultured pearls in the World is ours, located in Guaymas, Sonora, Mexico.
We produce both loose cultured pearls and mabes (half-pearls), mainly from the "Rainbow-Lipped Pearl Oyster" (Pteria sterna), a unique species native to the Gulf of California. We also grow some pearls on the local "Black-Lipped Pearl Oyster" (Pinctada mazatlanica).
Our unique Rainbow Lipped Pearl Oyster is capable of producing pearls of unique colors: black, rainbows, blue, pistachio, golden and purple. We also harvest pearls in light and dark gray colors, but always with a beautiful sheen of blue, green and/or lavender. These pearls might as well be considered the World's rarest cultured pearls... since all come from this single farm, and so few are produced: only 5 kilos per year (do compare our production with any other pearl producing country).
Spat Collection: gathering the seeds
Before one can start growing pearls, you have to start by growing the oysters themselves. This process first starts with a procedure called "spat collection".
At a certain time of the year, usually in spring or fall, just when the water temperature changes from cold to warm or vice versa, adult pearl oysters (from both the natural populations and those grown at the pearl farm) will spawn into the rich, nutrient-laden waters of the Sea of Cortez.
The sperm will fertilize the egg...and nature's cycle will proceed: billions of microscopic pearl oyster larvae will become a part of the zooplankton, feeding upon even smaller phytoplankton (microscopic one-celled algae/bacteria), until they are ready to settle and begin an "oyster-like" life...basically attached to a rock or coral.
At just the appropriate moment, hundreds of "spat collectors" are thrown into the waters of the bay. These will stay in the water column for up to two full months, collecting the "spat" or "baby pearl oysters". How can this happen?
The spat collectors consist of lines of plastic mesh bags (like the ones used to pack oranges in) filled up with discarded fishing net (to offer them volume). Why are these so attractive to the baby oysters? Here in the Gulf of California, pearl oysters used to find certain species of fan corals (family Gorgonidae) on which they loved to settle. The structure of a mesh bag and that of a fan coral are very similar... thus we can easily fool the baby oysters into thinking they are attaching to a "Giant Fan Coral". Our technique is so effective, that we can catch well over 10 thousand baby oysters per bag. That's a World Record!
Anyway, this is not over yet. We have to allow the "spat" to grow to a size visible to the naked eye (it takes anywhere from 1 to 3 months for this to happen), then we retrieve the spat collectors. Each bag is then meticulously hand and eye inspected for baby oysters as small as 3 mm. At the end of the day, all the little oysters are counted and put inside special rearing cages.
And now, finally, the aquaculture operation can begin...
Growing Oysters in a Farm
The first time an oyster is placed inside a protective culture cage, it will be in a structure known as a "Pearl Net". These are small, pyramid shaped mesh cages. These need to have a small mesh size: in order to keep the tiny oysters inside and keep the predators outside!
Studies have shown that out of every million pearl oysters born, only from one to ten will survive to adulthood. Thanks to the protection of the growth cages, some 90-95% of the oysters collected will reach adulthood and will breed successfully several times in their lifetime of over 4 years.
Thus protected, the baby oysters will start growing very fast, feeding on the nutrient-rich waters of Bacochibampo bay. At the end of a six to eight month period, the oysters will be considered "juveniles" and will be ready to be transferred to the next type of culture cage: the "Lantern Net".
Lantern nets are cylindrical in shape, with five layers, and have a wider mesh size. This is done to improve the water flow within the cage, thus allowing the oysters to feed properly. Thanks to this scheme the oysters can grow faster and healthier. The process is repeated several times in an oyster's lifetime.
A juvenile pearl oyster will measure some 4 to 5 cm (about 2 inches) and will be kept inside this net until they have become young adults (at an age of twelve to eighteen months) finally attaining a size of 7 to 8 cm (4-5 inches). The oysters have grown to the minimum size needed to start growing a cultured pearl. The "pearl seeding" operation can now commence.