Oysters Are 'Functionally Extinct'

02/04/2011 04:21 pm ET | Updated May 25, 2011

Oysters aren't disappearing from the dining table anytime soon, but they may be disappearing from our oceans.

A recent study published in BioScience has shown that the mollusks, declared "functionally extinct," are disappearing quickly as 85 percent of their reefs have been destroyed through disease or over-harvesting, according to the AFP. 75 percent of the remaining wild oysters can be found in 5 locations in North America.

So what does "functionally extinct" mean?

Oysters no longer play almost any significant role in their ecosystems.

From the AFP:

"Oyster reefs are at less than 10 percent of their prior abundance in most bays (70 percent) and ecoregions (63 percent)," said the study.

"They are functionally extinct -- in that they lack any significant ecosystem role and remain at less than one percent of prior abundances in many bays (37 percent) and ecoregions (28 percent) -- particularly in North America, Australia and Europe."

While the study didn't include parts of South Africa, China, Japan, North Korea, and South Korea, other studies suggest that there's been a significant decrease in oysters in these regions as well, according to the authors.

However, according to the AFP, native oyster catches are highest in the Gulf of Mexico. The world's 5 top sites for oyster catches were in North America.