Conwy Bay north of the Menai Straits is exposed to a high wave regime combined
with a high tidal level accompanied with strong current velocities. The second
longline was moored north of Oban (Argyll) Lynn of Lorne at Port a Bhuiltin.
Mussel bottom culture (Deepdock Ltd.) was tested in the windmill park of North
Hoyle OWF (Wales) in 2010. The windmill park contains 30 monopiles and the
depth was 10 m at low tide. The mussels grew well, but unexplainable mortality
occurred at harvest. To our knowledge, no offshore mytiliculture is going on at the
moment.
The Kentish Flats offshore wind farm about 10 km off the coast of Kent provides
a permit to the fishing community to access the wind farm area for trawling of
bivalves as well as for passive fishing strategies (Brown and May 2016). Studies
had been undertaking with regard to various potential impacts on commercial
fishing including the impacts of loss of fishing area resulting from offshore wind
farm installations for environmental impact assessments supporting planning
applications, compensation modelling and preparation of safety strategies. Mussels
were caught at spat size and used for on-bottom cultivation. Other wind farms, such
as Gwynt y Môr, North Hoyle, Lynn and Inner Dowsing wind farms were used for
natural stock relay and ranching projects (CEFAS 2014). No commercial enterprise
is running to this day.
2.6.8 Italy
Offshore long line mussel production has been in place in the Adriatic for some
years and plays an increasingly significant part of production (Danioux et al.
(2000). Experiments were carried out in the central part of the Adriatic sea (Conero
Promotory, Ancona province) in Italy to assess the potential to produce mussels (M.
galloprovincialis) and oysters (Crassostrea gigas) in submerged structures in
combination with artificial reefs in locations where traditional shellfish farming in
not possible (Bombace et al. 2000; Fabi and Spagnolo 2001) (Fig. 2.10). The base
units of the reef consist of concrete blocks of 8 m
3 with holes of different diameters.
The blocks are piled up into pyramids of 2 or 3 layers and layed down at depths of
10–20 m. The distance between the pyramids is 15–50 m. The units at the top are
connected to each other with cables that support nets to collect the mussel seed or
longlines systems. Concrete shellfish cages with dropper lines are placed between
the pyramids.
The structures are seeded naturally with wild mussel seed and an average of
20–55 kg/m
2 /year is produced by the cages and the blocks. A reef of 116 pyramids
and 48 cages produces 260 t of mussels yearly on average. Based on this, the costs
of a reef are paid back after 5 years. Thanks to the dynamic environment, the
environmental impact is reduced to a minimum (Fabi et al. 2009).
2 Offshore and Multi-Use Aquaculture with Extractive Species…
47
with a high tidal level accompanied with strong current velocities. The second
longline was moored north of Oban (Argyll) Lynn of Lorne at Port a Bhuiltin.
Mussel bottom culture (Deepdock Ltd.) was tested in the windmill park of North
Hoyle OWF (Wales) in 2010. The windmill park contains 30 monopiles and the
depth was 10 m at low tide. The mussels grew well, but unexplainable mortality
occurred at harvest. To our knowledge, no offshore mytiliculture is going on at the
moment.
The Kentish Flats offshore wind farm about 10 km off the coast of Kent provides
a permit to the fishing community to access the wind farm area for trawling of
bivalves as well as for passive fishing strategies (Brown and May 2016). Studies
had been undertaking with regard to various potential impacts on commercial
fishing including the impacts of loss of fishing area resulting from offshore wind
farm installations for environmental impact assessments supporting planning
applications, compensation modelling and preparation of safety strategies. Mussels
were caught at spat size and used for on-bottom cultivation. Other wind farms, such
as Gwynt y Môr, North Hoyle, Lynn and Inner Dowsing wind farms were used for
natural stock relay and ranching projects (CEFAS 2014). No commercial enterprise
is running to this day.
2.6.8 Italy
Offshore long line mussel production has been in place in the Adriatic for some
years and plays an increasingly significant part of production (Danioux et al.
(2000). Experiments were carried out in the central part of the Adriatic sea (Conero
Promotory, Ancona province) in Italy to assess the potential to produce mussels (M.
galloprovincialis) and oysters (Crassostrea gigas) in submerged structures in
combination with artificial reefs in locations where traditional shellfish farming in
not possible (Bombace et al. 2000; Fabi and Spagnolo 2001) (Fig. 2.10). The base
units of the reef consist of concrete blocks of 8 m
3 with holes of different diameters.
The blocks are piled up into pyramids of 2 or 3 layers and layed down at depths of
10–20 m. The distance between the pyramids is 15–50 m. The units at the top are
connected to each other with cables that support nets to collect the mussel seed or
longlines systems. Concrete shellfish cages with dropper lines are placed between
the pyramids.
The structures are seeded naturally with wild mussel seed and an average of
20–55 kg/m
2 /year is produced by the cages and the blocks. A reef of 116 pyramids
and 48 cages produces 260 t of mussels yearly on average. Based on this, the costs
of a reef are paid back after 5 years. Thanks to the dynamic environment, the
environmental impact is reduced to a minimum (Fabi et al. 2009).
2 Offshore and Multi-Use Aquaculture with Extractive Species…
47