The Sustainability Corner – Issue 2

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…

Stay tuned to learn what happened next in the next issue!
Pteria sterna on a coral fan