STRANDE — Just north of Strande, along northern Germany's Kiel Fjord, stands the Bülk lighthouse, built in 1865 and still functioning. Around it are rocky beaches, a favorite spot for surfers because of the strong winds that kick up waves coming in from the Baltic Sea.
Just to the west, a less scenic view: a sewage facility, a modern plant with low buildings, lumpy towers and large, round pools that attract flocks of raucous sea gulls. Strangely enough, this is also home to shrimp. The crustaceans are raised by an aquaculture company called Förde-Garnelen (Fjord-Prawn), which set up shop right next to the waste treatment plant. The choice may sound counter-intuitive: Sewage and shrimp aren't exactly the most mouth-watering combination. But the facility's location is actually a stroke of genius.
As is often the case, it's best not to judge a book by its cover. The sewage plant, it turns out, is a fantastic source of clean water, It is also an ideal place to dispose of shrimp excretions, which can simultaneously be used to generate heat that the little critters need to thrive. The conditions, in other words, are nearly perfect.
Seafood lovers might be disappointed to find they can't actually buy any shrimp at the Bülk facilty. For now, Förde-Garnelen is still experimenting with rather than selling its product: Litopenaeus vannamei, also known as whiteleg shrimp or Pacific white shrimp.
Outside, the facility is encircled by cold winds. But inside, its halls are a hot and steamy 30° Celsius (86°F), with a humidity index of 90%. Treated water drawn from the fjord is saturated with sea salt and aerated with oxygen. The shrimp are separated by size: they are initially grown upstairs, then allowed to migrate to the lower pools via pipes when they have reached a certain size.
Company general managers Stefan Paasch and Bert Wecker explain that this system allows them to avoid manually transfering the shrimp with fishing nets. On the lower floor the pools are draped with nets "to prevent the prawns from jumping out," Wecker explains. With 10 foot-like pods, the creatures have extremely powerful back fins and are able to propel themselves out of the warm water.
Stefan Paasch scoops shrimp from the treated sewage water — Screenshot Arte
Some pools contain several lattices arranged horizontally above one another. These serve as "bedrooms" for the shrimp. "Prawns have quite strong urges to rest at times and that is when they retreat to the lattices," says Wecker. “In the wild they simply lie down on the ocean floor. But in an aquaculture facility, there simply isn't enough space for all the prawns to rest on the floor of the pools. The lattices allow for the pools to be used at their full capacity."
Wecker, who hails from Plauen in Saxony, is a marine biologist. Paasch, from Groß Wittensee near Eckernförde, is the builder. The two met at an aquaculture conference. Wecker knew about the sewage treatment plant because of work he did there as researcher with the Kiel University. Paasch, worked for a company that worked in tandem with the university. After they met, the two decided to pool their knowledge and utilize the treatment facility for their budding industry.
More than 90% of the 65 million tons of seafood consumed in Germany annually is imported from abroad, mostly from China, Vietnam and Indonesia. The frozen seafood can last for about 6-7 months, but its production often takes a toll on the environment. Increasing demand in Europe, Japan and the United States for shrimp is leading to water pollution and the deforestation in mangrove forests, where the crustaceans tend to be raised.
There are a number of reasons, therefore, why local aquaculture production makes sense, especially given the availability of EU subsidies. Another company, York Dyckerhoff, has established a shrimp farm in Mecklenburg-West Pomerania.
Still, raising prawns is no easy endeavor. In the case of Förde-Garnelen, Paasch is responsible for the technical aspects of the plant and is constantly striving to optimize its usage. Wecker looks after the animals, which arrive as babies in consignments of 500,000. They are transported by plane from Florida, arriving in plastic bags complete with water and oxygen.
"We work with seedlings seeing as it would be too expensive and difficult to produce the larvae ourselves," says Wecker. Between half and 80% of the seedlings survive, he says. "But we believe we can increase the rate."
The 5-mm long animals — all eyes at that stage — are nursed with special food consisting of tiny sardine crustaceans and soy protein. Over the course of six months, the shrimp grow from an initial weight of approximately 0.03 grams to 30-35 grams. That's when a tiny electrical shock and some very cold water are used to kill the prawns.
The very first gourmets are enjoying the fruit of the Bülk sewage plant, as local restaurants participating in a network called “Feinheimisch” (Fine Local) have, on occasion, been able to serve the tasty seafood treats. Other would-be customers are now lining up.
"The prawns aren't frozen," says Wecker. "We send them in thermal boxes that will enable them to be delivered fresh to any customer within the country within 24 hours."