1Oysters are a versatile shellfish.
2You can bake them, boil them, smoke them, or eat them raw right from the shell.
3Over the years, wild oyster stocks have declined due to overfishing and pollution.
4So today, 95% of the oysters we consume come from oyster farms.
5Oysters are filter feeders, meaning they draw seawater over their gills
6to trap and eat the phytoplankton (microscopic aquatic organisms).
7An adult oyster can filter more than five quarts of seawater per hour.
8Oyster farms are located in or by the sea
9because the oysters need to feed off seawater to survive.
10The hatchery keeps the oysters in upwellers (mesh bottom buckets sitting in seawater).
11Oysters can reproduce once they're six months old.
12However, the ideal breeding age is between 2 and 10 years.
13At breeding time, workers put the oysters into breeding trays,
14oscillating the temperature between 68 and 86 degrees to stimulate spawning.
15The females squirt out eggs, the males squirt out semen,
16and 16 hours later, the fertilized eggs hatch larvae.
17Right from birth, the oysters feed on a blend of the phytoplankton they'd eat in the wild.
18The hatchery dilutes this plankton mix in seawater
19and pumps it to the oyster containers.
20Marine biologists manage the ponds in which the hatchery grows its phytoplankton supply.
21The larvae are so tiny, you can't see them in the water.
22They're visible only under a microscope.
23Right from the time they hatch, they already have a shell and can swim.
24By about the 2-week mark, they've grown to the size of a speck,
25about 1/64 of an inch long.
26However, now they act like miniature adults and stay put.
27The hatchery keeps them in suspension in circulating water,
28so they have an ample supply of food and oxygen.
29As they grow, they're transferred to progressively larger bottles.
30By the time they're four to six weeks old, they're ready to leave the hatchery and move to the oyster farm.
31The farm floats in a harbor.
32The baby oysters arriving are a tiny fraction of an inch long.
33They go into upwellers.
34Pipes circulate seawater, and the babies filter feed on the natural phytoplankton.
35Over the next six weeks or so,
36they quadruple in size to about 2/10 of an inch in length.
37Workers then pack them in plastic mesh bags,
38stack the bags on metal racks, and suspend the racks in the sea.
39The oysters live like that for three months,
40getting transferred into progressively larger mesh bags as they grow.
41Halfway into it, the oysters are this big, about 8/10 of an inch long.
42By the end of three months, they're double this size,
43grown up enough to leave home and venture out into the real world.
44Workers lay them on the sea floor and leave them for six months to reach harvest size,
45which is determined not by length anymore, but by weight, just under three ounces.
46To finally harvest the oysters,
47they lower a custom-built machine that's part dredger, part conveyor.
48It generates jets of water that blow the oysters off the seabed onto the conveyor.
49They travel up out of the water into the boat.
50That conveyor dumps the oysters onto another conveyor that leads to the picking station.
51There, workers select the correct size oysters and put them into baskets.
52Whatever they leave on the conveyor, smaller oysters, rocks and such,
53continues to the end and drops back into the water.
54Of course, the harvesting machine misses some 3-ounce oysters.
55Those remain on the seabed, sometimes for years,
56growing larger like this guy, weighing about 2.2 pounds.
57Prior to sale, the harvested oysters go through a cleaning process called depuration.
58For 42 hours, they sit in tanks filled with seawater, sterilized by ultraviolet light.
59The oysters draw this clean water through their gills.
60This flushes out all the bacteria.
61Thanks to this depuration process, it's safe to eat raw oysters.
62It's taken a good 18 months to grow from microscopic organism to dining delicacy,
63which has a refrigerated shelf life of about a week.