This contribution presents recent technological advances and innovative
approaches towards aquaculture production in harsher oceanic conditions on the
basis of three case studies involving the idea of multi-use. The recent advancements
of tools and methods to study the response of aquaculture technology to environmental loading such as winds, waves, currents and other mechanical impacts
describe above serve as the basis for the presented studies. Technological challenges and existing obstacles due to the high-energetic environment are discussed at
the end. Within the first two case studies, currently available potential and challenges of aquaculture is discussed in light of its applicability towards harsher
environments and high-energy impacts from winds and waves. Then, we extend our
analysis and the conclusions drawn from those first two case studies and present a
unique third case study. Therein, existing aquaculture cage technology is thoroughly tested as it is innovatively attached to a commonly used offshore wind
energy converter foundation, called a tripile foundation. For the first time, such a
multi-use concept was tested under laboratory conditions with valuable conclusions
and inter-comparisons between existing and anticipated offshore technologies being
reported in the discussion and conclusion chapter.
3.2 Case Study on Long Lines
3.2.1 Mussel Farming Development in NZ
Mussels (the Greenshell™ mussel, Perna canaliculus) are the main shellfish in both
mass and value to be farmed in New Zealand. They have been farmed in sheltered
and semi-sheltered areas since the industry started in 1979. The current production
has fluctuated between 86,000 and 101,000 ton per annum between 2011 and 2014.
Mussels are farmed using the New Zealand longline system, the general structure of
which is discussed below. There are variations to this theme depending on location
and farmer preference.
In 2003 consents for the offshore aquaculture space were lodged and the process
of obtaining this space started. There were numerous reasons for the departure from
the sheltered waters including user conflict and a desire to increase farm size. The
proposed farms were in waters ranging from 6 to 20 km off the coast in water
depths ranging from 35 to 80 m.
In 2005, the first experimental ropes were installed into the open ocean waters of
Hawkes Bay. The first open ocean structure was based on the traditional mussel
backbone but it was influenced by the systems used in the Coromandel in the North
Eastern corner of New Zealand North Island. The Coromandel generally has higher
energy than that of other culture sites such as the Marlborough Sounds.
A traditional inshore New Zealand mussel longline consists of: a mooring;
chain; warp; bridal; backbone; bridal; warp; chain and mooring (Fig. 3.1). The early
moorings were Danforth type anchors. These were overtaken in preference by
3 Technological Approaches to Longline- and Cage-Based …
75
approaches towards aquaculture production in harsher oceanic conditions on the
basis of three case studies involving the idea of multi-use. The recent advancements
of tools and methods to study the response of aquaculture technology to environmental loading such as winds, waves, currents and other mechanical impacts
describe above serve as the basis for the presented studies. Technological challenges and existing obstacles due to the high-energetic environment are discussed at
the end. Within the first two case studies, currently available potential and challenges of aquaculture is discussed in light of its applicability towards harsher
environments and high-energy impacts from winds and waves. Then, we extend our
analysis and the conclusions drawn from those first two case studies and present a
unique third case study. Therein, existing aquaculture cage technology is thoroughly tested as it is innovatively attached to a commonly used offshore wind
energy converter foundation, called a tripile foundation. For the first time, such a
multi-use concept was tested under laboratory conditions with valuable conclusions
and inter-comparisons between existing and anticipated offshore technologies being
reported in the discussion and conclusion chapter.
3.2 Case Study on Long Lines
3.2.1 Mussel Farming Development in NZ
Mussels (the Greenshell™ mussel, Perna canaliculus) are the main shellfish in both
mass and value to be farmed in New Zealand. They have been farmed in sheltered
and semi-sheltered areas since the industry started in 1979. The current production
has fluctuated between 86,000 and 101,000 ton per annum between 2011 and 2014.
Mussels are farmed using the New Zealand longline system, the general structure of
which is discussed below. There are variations to this theme depending on location
and farmer preference.
In 2003 consents for the offshore aquaculture space were lodged and the process
of obtaining this space started. There were numerous reasons for the departure from
the sheltered waters including user conflict and a desire to increase farm size. The
proposed farms were in waters ranging from 6 to 20 km off the coast in water
depths ranging from 35 to 80 m.
In 2005, the first experimental ropes were installed into the open ocean waters of
Hawkes Bay. The first open ocean structure was based on the traditional mussel
backbone but it was influenced by the systems used in the Coromandel in the North
Eastern corner of New Zealand North Island. The Coromandel generally has higher
energy than that of other culture sites such as the Marlborough Sounds.
A traditional inshore New Zealand mussel longline consists of: a mooring;
chain; warp; bridal; backbone; bridal; warp; chain and mooring (Fig. 3.1). The early
moorings were Danforth type anchors. These were overtaken in preference by
3 Technological Approaches to Longline- and Cage-Based …
75