turbines in the Borkum Riffgat offshore wind farm 70 km off the German-Dutch
coast. Researchers will survey the ecological habitat and how many of the juveniles
settle successfully in the stone fields (Krone et al. 2013).
The shown foundation has climbing aids in the form of guide profiles, which are
fastened in some sections to the offshore construction in a vertical, horizontal,
and/or diagonal direction (Fig. 11.17a–c). These profiles are designed as rib-shaped
flat or round profiles as well as structured by flat transverse profiles, which are also
used for making breeding places (Krone et al. 2012). The pyramid-like structure
(polyhedral form) relates to an artificial habitat to crustaceans on soft bottoms
(Fig. 11.17d; Krone 2012b). Lobsters and other crustaceans as basically hard
substrate animals also settle on soft soils when suitable habitats are available. This
device can be placed next to wind turbine foundations. Another device is a scavenging carriage including a basic unit and a running unit that is configured to
detachably couple the scavenging carriage with a rail device to be movable. The
scavenging carriage is configured to detachably couple with the habitat carriage and
the lifting device (Fig. 11.17e; Krone and Krämer (2011). Finally, one more device
was invented to be used to establish and harvest a colony of benthic animals, in
particular crabs. The device is hoisted and lowered in the folded form, and is laid
out in the folded or fully open form. Tubular components improve drift and are
particularly attractive as a habitat for crabs. This device can be used as an artificial
reef to establish a colony and as a trap for effectively harvesting crabs in the
immediate surroundings of wind turbines in offshore areas (Fig. 11.17f; Krone and
Krämer (2012).
11.3.3.2 Candidate: Cancer pagurus
The edible crab or brown crab is a potential candidate for multi-use by passive gear
fishery within offshore wind farms (OWF). As this species covers fairly the same
niche as the European lobster and is also a high value seafood product on the
market, it is another promising candidate that should be examined. Passive fishery
on brown crab is very common along Northern European coasts and also in several
offshore areas of the German Bight and reduces the ecological pressure on the
endangered lobster population. Clear positive effects on the potential of OWFs to
function as refuge for fish and marine animals were observed for crustacean species
such as brown crab (Cancer pagurus) due to increased opportunities for shelter and
food availability (Stelzenmüller et al. 2016).
11.3.4 Fish Species
Fish as a candidate for offshore multi-use concepts is new. Most of the studies on
aquaculture in offshore wind farms concentrated on invertebrates and algae. In
recent years, interest in offshore fish cultivation is increasing (Buck and Krause
11 The German Case Study: Pioneer Projects of Aquaculture …
281
coast. Researchers will survey the ecological habitat and how many of the juveniles
settle successfully in the stone fields (Krone et al. 2013).
The shown foundation has climbing aids in the form of guide profiles, which are
fastened in some sections to the offshore construction in a vertical, horizontal,
and/or diagonal direction (Fig. 11.17a–c). These profiles are designed as rib-shaped
flat or round profiles as well as structured by flat transverse profiles, which are also
used for making breeding places (Krone et al. 2012). The pyramid-like structure
(polyhedral form) relates to an artificial habitat to crustaceans on soft bottoms
(Fig. 11.17d; Krone 2012b). Lobsters and other crustaceans as basically hard
substrate animals also settle on soft soils when suitable habitats are available. This
device can be placed next to wind turbine foundations. Another device is a scavenging carriage including a basic unit and a running unit that is configured to
detachably couple the scavenging carriage with a rail device to be movable. The
scavenging carriage is configured to detachably couple with the habitat carriage and
the lifting device (Fig. 11.17e; Krone and Krämer (2011). Finally, one more device
was invented to be used to establish and harvest a colony of benthic animals, in
particular crabs. The device is hoisted and lowered in the folded form, and is laid
out in the folded or fully open form. Tubular components improve drift and are
particularly attractive as a habitat for crabs. This device can be used as an artificial
reef to establish a colony and as a trap for effectively harvesting crabs in the
immediate surroundings of wind turbines in offshore areas (Fig. 11.17f; Krone and
Krämer (2012).
11.3.3.2 Candidate: Cancer pagurus
The edible crab or brown crab is a potential candidate for multi-use by passive gear
fishery within offshore wind farms (OWF). As this species covers fairly the same
niche as the European lobster and is also a high value seafood product on the
market, it is another promising candidate that should be examined. Passive fishery
on brown crab is very common along Northern European coasts and also in several
offshore areas of the German Bight and reduces the ecological pressure on the
endangered lobster population. Clear positive effects on the potential of OWFs to
function as refuge for fish and marine animals were observed for crustacean species
such as brown crab (Cancer pagurus) due to increased opportunities for shelter and
food availability (Stelzenmüller et al. 2016).
11.3.4 Fish Species
Fish as a candidate for offshore multi-use concepts is new. Most of the studies on
aquaculture in offshore wind farms concentrated on invertebrates and algae. In
recent years, interest in offshore fish cultivation is increasing (Buck and Krause
11 The German Case Study: Pioneer Projects of Aquaculture …
281