It is no secret what two and three year old children want. They tell you NOW. However, have you asked your local oysters what they want? The Few Oyster Charitable Trusts don’t do surveys about this. You might be clueless…as was I in my paleolithic era.
My own observations are that oysters only have a limited set of communication tool:
-Closed up tight means they are scared or out of the water, but still living.
-Living and slightly cracked open under water means they are eating.
-Open and dead whether in or out of the water means they are were once alive, but are now dead.
What do you know or learn about oysters in this picture?
It seems pretty basic to assume that a successful oyster life is one where the oyster (in the free floating form as a larvae) chooses wisely and attaches itself, permanently, to a place where it can live out its natural life, about 5-8 years. During that time, it spawns, it fights neighbors for space and food, let’s progeny attach to its outer shell…and come that Day We All Face, it let’s go and its hinged shell falls off…down…to expose new shell to the next generation. No science has yet definitively determined how newly spawned larvae utilize their limited freedom of choice (in the vagaries of tide and wave and wind and bathymetry) to find shell, but sniffing or feeling or 7th sensing their way, they prefer to attach to Mom and Dad or Grandparent’s shell. Not given that choice, they settle somewhere else or die.
Of course, in the course of deciding where to settle, comb or walnut jellyfish (except they are not jellyfish at all!) vacuum in the larvae by the millions. Stinging jellyfish harvest this jelly. And so it goes with all the fauna and flora in the sea, giving and getting from its cohabitant species.
The moment comes that determines ultimate fate: strike on a piece of driftwood, on granite riprap, on a mussel perched in a marsh face, on a blade of marsh grass, a piling, a shell on the mudflat, whatever, or the ultimate, an oyster reef?
Do you see the four oyster spats on this shell?
So, let’s take the forensic approach on what fate has in store.
-Driftwood: seems hard, above the bottom and in the flow of life giving tide, but wood rots and the perch disintegrates. These oysters thrive for a bit, 2-3 years, then down into killing mud.
Can you see the stick these guys call Mom? They will not survive the next winter, just leaving Youth.
-RipRap a possibility: permanent and as hard as 7 on Moh’s Mineralogy Scale. Observe the density, however, some oysters, some of the time, not usually of any large sized….hmmm. The perch is not porous so the grip tenuous, the rock heats excessively, subject to waves and ice…still only temporarily okay. Only the good die young.
-Cousin striped mussel, fellow filter feeder, is adept at grabbing hold of marsh grass root at its edge with the sea (toe). Many a larvae latch onto this shell and grow gangbusters. However (and there is always a but), the oyster genes have predetermined it to be the King of the Sessile (attached, not like clam or scallop) Shellfish. The King grows large, and brothers stack upon its Yertle the Turtle. Wave hits, blue crab attacks the mussel base, scour undercuts…so down into the muck goes the emerging oyster adult.
-Tall and heron-like blade of grass can resist incoming waves, but not when encumbered by a growing spat. It breaks, and down into the muck goes our hero spat.
-But Oh the inviting bottom! Largely featureless, there are a few dead shells just barely above the saturated, oozing mud. There the Spat sides astride its support base. It grows into a virtual sail reaching up into the water column for the tidal flow of food. Size and success breed failure, as wave or soft underpinnings give way under the weight of thriving oyster mass. Hello killing mud.
Oysters on the reef, but not so much in the surroundings.
But what of the lucky larvae that strikes on a firm, habitable base, up above the mud with its diseases, predators, low oxygen, toxic deposits, and low flow. Here we have a formula for a long successful life, like generations over millions of years before.
We call this haven an oyster reef.
Remember that mud flat with a few oysters? Next to it, now you see the choice for settlement that the larvae will have this summer at this newly installed reef.
Just look around at your waterfront. What do you see? Successful habitat, or just a killing zone for oyster spat?