“Offshore, Open Ocean, Far Out”—currently unknown or seldom used terms
among the German public, have become since the mid-1990s common
“catch-phrases” in Asia and the USA. In an effort to cover the immense demand for
seafood products, new regions beneath the coastal waters were sought. However, at
that time only a few world-wide Open Ocean Aquaculture businesses are in
operation and are still a new method of aquaculture internationally. Main research
efforts in an international perspective were placed in the provision of sturdy offshore technology, which resist the extreme environmental conditions and warrants
safe utilisation of the installation. However, so far, little operational implementation
of the results of extensive research has been undertaken.
Several types of cultivation in combination with the foundations of offshore
wind turbines were suggested: (1) Predominately longline constructions for the
cultivation of seaweed and mussels, by which submersible ropes provide the habitat
on which the candidates can settle (Fig. 11.2a). (2) Other techniques, such as ring
and cage constructions (Fig. 11.2b, c), which can be placed on the water surface
and under water, as well as the construction SOSSEC (Submersible Offshore
Shellfish and Seaweed Cage) (Fig. 11.2d) can be operated, too.
The advantage of submersible culture constructions is the avoidance of the
impact of harsh weather conditions and strong wave mechanics. Thus, a combination of these techniques with the main pillar of the wind turbine installation
dispenses the need for a sophisticated mooring of the aquaculture system, which
would impact strongly on the benthic ecosystem. Due to the solid construction of
the wind turbine, such systems would be very safe.
The feasibility study suggested a variety of candidates, which can be cultivated
under such hydrodynamic and environmental conditions within the North Sea, and
hold large potentials on the German market. Additionally, the study pointed to the
technical challenges and the importance of the socio-economic drivers. All users
have to be addressed at the beginning of a new project in order to find an overarching consensus of all parties thereto.
As predominately, already existing data sets were used in the feasibility study of
offshore aquaculture potentials within the areas of wind farms in the German North
Sea, this study was theoretical in nature. In order to determine the feasibility of
JFig. 11.2 a–d First drawings to show the multi-use concept combining aquaculture with wind
farms. a Top a birds-eye view of longline constructions. Special pylon anchorages ensure access
and maintenance of the wind energy plants by ship; down Side view of a submerged mussel and
seaweed longline culture. The wind energy plant pylon is used as the anchorage for one end of the
longline. The line can reach a length of 100–300 m. Longer lines may be mounted to the next
pylon; b Top A bird’s-eye view of a ring construction. The combined rings are fixed around the
pylon as well as a pylon with a single offshore ring construction using two anchorages; down Side
view of a pylon with offshore ring construction used for cultivation of algae and mussels. An
anchor stone is placed at the outermost point of the ring construction; c Side view of a pylon
combined with an ‘on bottom’ cage for oyster culture and oyster trays fixed to a longline as well as
a rotating oyster cage (drum); d SOSSEC design (Submersible Offshore Shellfish and Seaweed
Cage), which is during culture in a submerged mode and can be lifted to the surface for harvest.
Modified after Buck (2000, 2001); Images AWI/Prof. Dr. Bela H. Buck
11 The German Case Study: Pioneer Projects of Aquaculture …
259
among the German public, have become since the mid-1990s common
“catch-phrases” in Asia and the USA. In an effort to cover the immense demand for
seafood products, new regions beneath the coastal waters were sought. However, at
that time only a few world-wide Open Ocean Aquaculture businesses are in
operation and are still a new method of aquaculture internationally. Main research
efforts in an international perspective were placed in the provision of sturdy offshore technology, which resist the extreme environmental conditions and warrants
safe utilisation of the installation. However, so far, little operational implementation
of the results of extensive research has been undertaken.
Several types of cultivation in combination with the foundations of offshore
wind turbines were suggested: (1) Predominately longline constructions for the
cultivation of seaweed and mussels, by which submersible ropes provide the habitat
on which the candidates can settle (Fig. 11.2a). (2) Other techniques, such as ring
and cage constructions (Fig. 11.2b, c), which can be placed on the water surface
and under water, as well as the construction SOSSEC (Submersible Offshore
Shellfish and Seaweed Cage) (Fig. 11.2d) can be operated, too.
The advantage of submersible culture constructions is the avoidance of the
impact of harsh weather conditions and strong wave mechanics. Thus, a combination of these techniques with the main pillar of the wind turbine installation
dispenses the need for a sophisticated mooring of the aquaculture system, which
would impact strongly on the benthic ecosystem. Due to the solid construction of
the wind turbine, such systems would be very safe.
The feasibility study suggested a variety of candidates, which can be cultivated
under such hydrodynamic and environmental conditions within the North Sea, and
hold large potentials on the German market. Additionally, the study pointed to the
technical challenges and the importance of the socio-economic drivers. All users
have to be addressed at the beginning of a new project in order to find an overarching consensus of all parties thereto.
As predominately, already existing data sets were used in the feasibility study of
offshore aquaculture potentials within the areas of wind farms in the German North
Sea, this study was theoretical in nature. In order to determine the feasibility of
JFig. 11.2 a–d First drawings to show the multi-use concept combining aquaculture with wind
farms. a Top a birds-eye view of longline constructions. Special pylon anchorages ensure access
and maintenance of the wind energy plants by ship; down Side view of a submerged mussel and
seaweed longline culture. The wind energy plant pylon is used as the anchorage for one end of the
longline. The line can reach a length of 100–300 m. Longer lines may be mounted to the next
pylon; b Top A bird’s-eye view of a ring construction. The combined rings are fixed around the
pylon as well as a pylon with a single offshore ring construction using two anchorages; down Side
view of a pylon with offshore ring construction used for cultivation of algae and mussels. An
anchor stone is placed at the outermost point of the ring construction; c Side view of a pylon
combined with an ‘on bottom’ cage for oyster culture and oyster trays fixed to a longline as well as
a rotating oyster cage (drum); d SOSSEC design (Submersible Offshore Shellfish and Seaweed
Cage), which is during culture in a submerged mode and can be lifted to the surface for harvest.
Modified after Buck (2000, 2001); Images AWI/Prof. Dr. Bela H. Buck
11 The German Case Study: Pioneer Projects of Aquaculture …
259