Oysters are saltwater bivalve mollusks that live in marine or brackish (a mix of saline and fresh) waters.

A single oyster can filter over 3.7 liters of water in just one hour.

In the 1800s, the oyster population in the Atlantic Ocean's Chesapeake Bay was able to filter water from the entire estuary in just three to four days.

Today, that same filtration process takes about a year, due to the dramatically reduced number of habitant oysters.

The global oyster population is a mere 1 percent of what it was 200 years ago due to over-harvesting, habitat loss, and disease.

The Hudson River was once home to over 890 square kilometers of oyster reef, making its current population functionally extinct by contrast.

Oyster shell piles found in New York's Dobbs Ferry from 6950 B.C. are the oldest evidence of human life found in the Hudson Valley.

A healthy oyster population signifies a healthy body of water.

Due to their high sensitivity to environmental stressors, oysters are often regarded as a metaphorical "canary in a coal mine" for their inhabitant bodies of water.

Oysters are very sensitive to sound, relying on sonic waves and currents to regulate their circadian rhythms. Detecting weather events such as rain may even induce spawning.

Low-frequency underwater noise pollution from cargo ships, pile drivers, and explosions causes oysters to close their shells.

Oysters are able to change their gender based on environmental, nutritional, and physiological stresses, and sometimes on an annual basis. They mature as males but may change to female later on in their adult life, sometimes switching back again.

Oyster reefs provide protective habitats for many cohabitant species and are natural storm barriers, dramatically minimizing the impact of tidal waves by as much as 76 to 93 percent of the wave's energy.

There are more than 80 restoration projects underway in the United States, resulting in as much as 212 percent increases in oyster growth and 850 percent increases in other marine life on the reefs.

Organizations such as the Billion Oyster Project (B.O.P.) in New York, the Chesapeake Bay Foundation in Maryland, and the Florida Oceanographic Oyster Restoration (FL.O.O.R.) are working to restore local oyster reefs, collecting discarded oyster shells from restaurants to create ideal substrates for oyster larvae to latch on to.

While other oyster shells are the ideal substrate for fledgeling oysters to latch onto, anecdotal evidence suggests that golf balls will do in a pinch.

When oysters are harvested the correct way, they are among the most sustainable sources of seafood, resulting in no bycatch (other species unintentionally caught).

The shell of an oyster is comprised of 259 distinct proteins, currently making them too complex to recreate in a laboratory.

Pearl oysters (family Aviculidae) are entirely separate species from food oysters (family Ostreidae), which are also known as "true oysters."

Pearls are the only gemstone that is produced by a living organism.

Almost all shell-bearing mollusks have the ability to develop pearls, though they are not considered as valuable as those that are oyster-borne.

The largest pearl oyster is the Pinctada maxima, which are roughly the size of a dinner plate and are found around the Philippines, Indonesia, Australia, and Fiji.

When harvested in the wild, only about three or four oysters in a two metric ton haul will contain commercially viable pearls, making them extremely valuable.

In 1916, a British biologist in Japan named William Saville-Kent developed the process of "perliculture" alongside his Japanese colleagues Tatsuhei Mise and Tokichi Nishikawa, allowing pearls to be farmed instead of harvested.

Despite looking exactly the same as natural pearls, farmed pearls are much less valuable.

Pearls are created when an irritant such as sand enters a mollusk's chamber. The mollusk coats that object with a substance called nacre, or mother of pearl.

It takes between three and seven years for an oyster to produce a pearl.

One serving (approximately six oysters) contains over 250 percent of the recommended daily dose of vitamin B-12, which is essential for the proper development and maintenance of the human brain, nervous system, and blood cells.

Six oysters will also provide a substantial daily dose of zinc, copper, iodine, iron, magnesium, manganese, and phosphorus.

Crushed oyster shells are beneficial to garden beds, neutralizing soil acidity and releasing calcium throughout the growing season.

Despite popular belief, there is little scientific evidence backing up the oyster as an aphrodisiac.

It is still widely rumored, however, that the famed Venetian copulator Casanova would eat 50 raw oysters for breakfast.

True aficionados of the edible oyster chew two or three times, and drink the briny liquor, savoring as much of the flavor as possible.

An oyster's flavor is largely dictated by its waters, making it one of the most expressive examples of locavore eating — the same type of oyster will taste different depending on where it was raised.

There is an oyster variety from Maryland called the “Sweet Jesus” oyster.

The American food writer M.F.K. Fisher, who John Updike once referred to as a “poet of the appetites,” dedicated an entire book to the humble mollusk, titled Consider the Oyster in 1941. The book introduced many American readers into their “strange, cold succulence” and delved deep into their “dreadful but exciting” lives.

An excerpt from Consider the Oyster reads: “American oysters differ as much as American people, so that the Atlantic Coast inhabitants spend their childhood and adolescence floating free and unprotected with the tides, conceived far from their mothers and their fathers too by milt let loose in the water near the eggs, while the Western oysters lie within special brooding chambers of the maternal shell, inseminated and secure, until they are some two weeks old. The Easterners seem more daring.”