Oysters and Oyster Shells

6 Amazing Things You Probably Don’t Know About Oysters & Their Shells

As I’ve started painting oyster shells and turning them into beautiful jewelry pieces, keychains, trinket holders, and more, the quest for knowledge about these fascinating shells has been pushing me to learn everything I can about them (with the exception of eating them. Ew.) Here are a few bits of information that surprised and fascinated me. Here’s hoping you will learn something new like I did!

*Oysters are nature’s water filtration system!

  • One adult oyster has the capability of filtering 25-50 gallons of water a day as it feeds off the phytoplankton in the water!
  • Oysters can maintain the balance of a marine ecosystem by reducing excess algae and sediment that can lead to low oxygen levels, which causes other marine life to die.
  • Watch this time lapse video of these incredible filter-feeders, produced by the Marine Biological Laboratory in Woods Hole, Massachusetts. A 5-gallon aquarium filled with algae-water and a couple dozen oysters is filtered and cleaned in only four hours!
  • Oysters are being used to restore and improve the quality of the water in the New York Harbor through the Billion Oysters Project and in the Hudson River Fund’s Oyster Research Restoration Project.

*Oyster Shells can be used to restore reefs in harbors and bays. Don’t throw them in the trash or they will end up in a landfill instead!

  • 85% of oyster reefs have been lost worldwide mainly due to their sensitivity to the pollution in waters.
  • As oysters are harvested from the bays for us to suck and swallow, their habitats are reduced. Many restaurants and wholesale distributors are working with oyster recycling programs to help minimize this loss.
  • Young oyster larva utilize the recycled oysters for attachment and growth. They prefer it to any other hard substrate.
  • This film, “Sink Your Shucks,” explains the oyster shell recycling process in a clear and humorous manner and was selected as the Best Conservation Film at the 40th Annual Benthic Ecology Meeting held in Mobile, Alabama in March, 2011.

*A “baby” oyster is called a spat. 

  • In only 6-8 hours, a new larvae has already produced a small part of its shell and cilia. It swims around for 2-3 weeks. This is the only time the oyster isn’t stationary.
  • A larvae that attaches itself to a hard substrate (such as an oyster shell) is then called a spat. It turns into a sub-adult at the size of 25 mm (1 inch).
  • As the oyster grows, it forms around the surface it attaches to as well as the other oysters around it.
  • It takes 3 months for it to reach the size of

*About those pearls…..

  • Pearl oysters are from a different family of oysters than the edible ones. Don’t expect to crunch down on a pearl while eating dinner.
  • Pearls are produced when a foreign irritation becomes lodged inside the shell. The oyster responds by coating it with nacre, which is the same substance that makes up the (gorgeous) inside of the shell. Nacre is made of calcium and protein.
  • The foreign substance is not a grain of sand. The oyster is capable of ridding itself of that on its own. Actually (gross spoiler alert), the substance is often a parasite, such as a sea-worm or bug, that latches on and can’t be expelled. Eeewwww!
  • Most pearls today, however, are cultured, which means that a tiny sphere of mother-of-pearl is inserted by hand in order to produce the pearls that are beaded onto your necklace. Only about 1 in 10,000 wild oysters will actually produce a pearl.
  • Pearls can only be produced in unpolluted, pristine waters. This is the reason most pearl farms are located on remote, distant islands.
  • As oysters age, they produce better and better pearls. Pearl farmers take great care when extracting the pearl so as not to harm the oyster. It can continue to grow more pearls as it ages!
  • While the surface of a genuine pearl looks lustrous and gleaming, it is actually formed from millions of tiny crystals and will have a “gritty” feel due to the imperfections. Try rubbing your necklace pearls on your teeth to see if they are the real thing!

*Oysters have been eaten by man for over 6,000 years!

*25% of New York Harbor used to be oyster beds.

  • Manhattan’s oldest street was named Pearl Street because it was covered with crushed oyster shells by the Danish in the 1700’s.
  • Most oysters can live 20 years in captivity.
  • The reason people think oysters are a natural aphrodisiac is due to the high amount of zinc. It is true that a zinc-deficient diet can cause impotence.
  • Crushed oyster shells in your garden reduces the acidity in the soil, helps with drainage and an even release of calcium throughout the growing season.
  • The earliest oyster species predates man!

*Many common myths abound about the oyster!

*Oysters are meatier in months that have an “r” in them. This is why you may hear them pronounced “arsters.” This myth probably begain back in the day before refrigeration allowed them to be cooled during transport. Today, oysters can be enjoyed 12 months out of the year.

*Aphrodite, the Goddess of Love, is believed to have emerged from the sea in an oyster shell.




Ode to Oysters (or, Happy National Oyster Day!)

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