Note:
(a) "德国唯一的牡蛎养殖场面积约30公顷，位于叙尔特岛（Sylt）沿岸的潮间带上，专产 '皇家'（Royal）牡蛎。每年，蒂特迈尔牡蛎公司（Dittmeyer's Austern-Compagnie）"
(i) Sylt https://en.wikipedia.org/wiki/Sylt
(an island in the state of Schleswig-Holstein; belongs to the North Frisian Islands and is the largest island in North Frisia; In 1141, Sylt is recorded as an island [name meaning unknown])
(ii) About Us. Dittmeyer's Frucht-Plantagen, undated www.dittmeyer.com/3-1-About-us.html
("1986 start of oyster farm ,Dittmeyer's Austern-Compagnie' on the isle of Sylt; 1997 formation of ,Dittmeyer's Frucht-Plantagen' as a holding company in Hamburg")
(iii) German English dictionary:
* Frucht (noun feminine): "fruit" https://en.wiktionary.org/wiki/Frucht
* Plantage (noun feminine; plural Plantagen): "plantation" https://en.wiktionary.org/wiki/Plantage
* Auster (noun feminine; plural Austern): "oyster" https://en.wiktionary.org/wiki/Auster
((b) "一到冬季，牡蛎会用储罐运到岛上，以免它们被瓦登海上的冰层压扁。为每年的转运，专门铺设了可装满15个储罐的两条管道。流入新鲜北海水的每一条管道可容纳3万只牡蛎。而在最后一次上路、成为全国各地餐馆的盘中餐前，牡蛎们要在那些储罐内作中途停留。"
(i) Wadden Sea https://en.wikipedia.org/wiki/Wadden_Sea
(ii)
(A) 储罐 storage tank
(B) But oysters do not use the cylinder-like storage tank for LNG (liquified natural gas) or petroleum. Instead oysters use wet storage system. Search images.google.com with (wet storage system oyster) and you can see it yourself.
(iii) PRODUCTS > Oyster. Dittmeyer's Frucht-Plantagen, undated www.dittmeyer.com/11-1-Oysters.html
three consecutive paragraphs:
"In 1986 we decided it was time to revive the Sylter oyster tradition after a 50-year break in its long history. Oyster fishery on the North Frisian Islands has a tradition extending back over 1000 years. Our ancestors used sailing boats to drag nets across the mudflats to collect the oysters.
"Our Sylter Royal oysters are raised by our staff of four using the rack and bag method. With this method iron trestles about 50cm high are set up in the tidal shallows. Attached to these are mesh sacks in which the oysters grow. At high tide they are covered with seawater and during low tide fall dry. Breeding on trestles prevent the oysters becoming sandy and also protect them from predators living on the seabed.
"The mesh sacks are shaken and turned over regularly so that the oysters do not grow together or get misshapen. They also have to be constantly freed from algae growth.
"Different approaches can be taken in bed preparation, seeding, grow-out, and harvesting depending upon the target market, substrate characteristics, predator population, and environmental conditions. For instance, bag, rack-and-bag, and suspended culture methods are typically employed to grow single oysters for the half-shell market. Oysters for the shucked-meat market can be grown in clusters * * * Suspended cultures, such as long-line and stake culture, are primarily used in areas that are not suitable for bottom culture.
"Oyster Bottom Culture: This method is used to grow oysters directly on the bottom. It has been used for more than a century and is the most widespread form of shellfish cultivation still used at the present time.
"Harvested clams are generally left in net bags in wet storage, either in marine waters or upland tanks filled with seawater, to purge sand for at least 24 hours.
"Increases in nutrient levels above natural levels can result in excessive plant and algae growth, a process called eutrophication [which 'causes a dense growth of plant life and death of animal life from lack of oxygen']. Grays Harbor and Willapa Bay have a low to moderate risk of eutrophication (PSAT 2007, as cited in USFWS, March 24, 2009). This is due, in part, to the high tidal flushing of both estuaries.
(iv)
(A) Cambria Bold, How Oysters Are Grown; A Visit to Island Creek Oysters [name of oyster farm] in Duxbury, Massachusetts. Kitchn, July 26, 2013 http://www.thekitchn.com/island-creek-oysters-grower-tour-192689
("When oysters grow in the wild in oyster reefs, they typically attach to old oyster shells (for the calcium carbonate — see above). Because of this they tend to grow in clusters and one on top of the other. This is also why wild oysters typically have "gnarly shapes," says Chris, instead of the nice round shape and deep cup you associate with farmed oysters")
(B) Amber Kuehn, Oyster Farming. The Breeze (a magazine), January 2016 www.bluffton.com/oyster-farming/
("The oyster farmers check on the oysters periodically and disrupt the cages to discourage wild spat from attaching to farmed oyster shell, preventing the cluster")