Raising Oysters
[size=3][color=#29384e][font=Times New Roman]In the oysters were raised in much the same way as dirt farmers raised tomatoes- by transplanting them. First[/font][font=宋体]，[/font][font=Times New Roman] farmers selected the oyster bed[/font][font=宋体]，[/font][font=Times New Roman] cleared the bottom of old shells and other debris[/font][font=宋体]，[/font][font=Times New Roman] then scattered clean shells about. Next[/font][font=宋体]，[/font][font=Times New Roman] they[/font][font=宋体]“[/font][font=Times New Roman]planted[/font][font=宋体]”[/font][font=Times New Roman]fertilized oyster eggs[/font][font=宋体]，[/font][font=Times New Roman] which within two or three weeks hatched into larvae. The larvae drifted until they attached themselves to the clean shells on the bottom. There they remained and in time grew into baby oysters called seed or spat. The spat grew larger by drawing in seawater from which they derived microscopic particles of food. Before long[/font][font=宋体]，[/font][font=Times New Roman] farmers gathered the baby oysters[/font][font=宋体]，[/font][font=Times New Roman] transplanted them once more into another body of water to fatten them up.[/font][/color][/size][size=3][color=#29384e][font=Times New Roman] [/font][/color][/size]
[size=3][color=#29384e][font=宋体] [/font][font=Times New Roman]Until recently the supply of wild oysters and those crudely farmed were more than enough to satisfy people[/font][font=宋体]‘[/font][font=Times New Roman]s needs. But today the delectable seafood is no longer available in abundance. The problem has become so serious that some oyster beds have vanished entirely.[/font][/color][/size]
[size=3][color=#29384e][font=Times New Roman] [/font][/color][/size]
[size=3][color=#29384e][font=宋体] [/font][font=Times New Roman]Fortunately[/font][font=宋体]，[/font][font=Times New Roman] as far back as the early 1900[/font][font=宋体]‘[/font][font=Times New Roman]s marine biologists realized that if new measures were not taken[/font][font=宋体]，[/font][font=Times New Roman] oysters would become extinct or at best a luxury food. So they set up well-equipped hatcheries and went to work. But they did not have the proper equipment or the skill to handle the eggs. They did not know when[/font][font=宋体]，[/font][font=Times New Roman] what[/font][font=宋体]，[/font][font=Times New Roman] and how to feed the larvae. And they knew little about the predators that attack and eat baby oysters by the millions. They failed[/font][font=宋体]，[/font][font=Times New Roman] but they doggedly kept at it. Finally[/font][font=宋体]，[/font][font=Times New Roman] in the 1940[/font][font=宋体]’[/font][font=Times New Roman]s a significant breakthrough was made.[/font][/color][/size]
[size=3][color=#29384e][font=Times New Roman] [/font][/color][/size]
[color=#29384e][font=宋体][size=10.5pt] [/size][/font][size=10.5pt]The marine biologists discovered that by raising the temperature of the water[/size][font=宋体][size=10.5pt]，[/size][/font][size=10.5pt] they could induce oysters to spawn not only in the summer but also in the fall[/size][font=宋体][size=10.5pt]，[/size][/font][size=10.5pt] winter[/size][font=宋体][size=10.5pt]，[/size][/font][size=10.5pt] and spring. Later they developed a technique for feeding the larvae and rearing them to spat. Going still further[/size][font=宋体][size=10.5pt]，[/size][/font][size=10.5pt] they succeeded in breeding new strains that were resistant to diseases[/size][font=宋体][size=10.5pt]，[/size][/font][size=10.5pt] grew faster and larger[/size][font=宋体][size=10.5pt]，[/size][/font][size=10.5pt] and flourished in water of different salinities and temperatures. In addition[/size][font=宋体][size=10.5pt]，[/size][/font][size=10.5pt] the cultivated oysters tasted better[/size][font=宋体][size=10.5pt]！[/size][/font][/color]
页:
[1]