describes the recent development of longline farming in offshore waters of New
Zealand. New Zealand has designated over 10,000 ha of permitted open ocean
water space for shellfish farming. The farms range from 8 to 20 km out to sea and a
depth of 35–80 m of water. Research has been ongoing for the last 10 years and the
first commercial efforts are now developing in the Bay of Plenty. New methods are
being developed which should increase efficiency and reduce maintenance with a
particular focus on Greenshell mussel (Perna canaliculus) and the Pacific Oyster
(Crassostrea gigas), Flat Oyster (Tiostrea chilensis) and various seaweeds. The
second case study involves a long-term, open ocean aquaculture (OOA) research
project conducted by the University of New Hampshire. During the course of
approximately 10 years, the technological aspects of OOA farming were conducted
with submersible cages and longlines, surface feeding systems and real time
environmental telemetry. The grow-out potential of multiple marine species such as
cod (Gadus morhua), haddock (Melanogrammus aeglefinus), halibut (Hippoglossus
hippoglossus), blue mussel (Mytilus edulis), sea scallop (Placopecten magellanicus)
and steelhead trout (Oncorhynchus mykiss) were investigated at a site 12 km from
shore. The last study presents a multi-use aspect of aquaculture for an open ocean
site with fish cages attached to existing offshore wind energy foundations.
Technological components such as mounting forces and scour tendencies of two
different cage structures (cylindrical and spherical) were investigated by means of
hydraulic scale modeling. The cages were pre-designed on the basis of linear theory
and existing standards and subsequently exposed to some realistic offshore wave
conditions. The wind farm “Veja Mate” in German waters with 80 planned 5 MW
turbines anchored to the ground by tripiles is taken as the basis for the tested wave
conditions. Based on findings stemming from the three example approaches conclusions are drawn and future research demand is reported.
3.1 Introduction
As the worldwide exploitation rate of capture fisheries continues, the development
of sustainable aquaculture practices is increasing to meet the seafood needs of the
growing world population. The demand for aquatic products was historically satisfied firstly by an effort to expand wild catch and secondly by increasing
land-based and near-shore aquaculture. However, stagnation in wild catch as well
as environmental and societal challenges of land-based and near-shore aquaculture
have greatly promoted efforts to development farming offshore technologies for
harsh, high energetic environments. As a consequence, ocean domestication is of
key importance to maintain the ocean as a sustainable source of food, both economically and ecologically (Marra 2005).
While the annual growth rate of aquaculture production has been 6.3%, total
aquaculture production grew from 34.6 million tons in 2001 to 59.9 million tons in
2010; thus it depicts the second important sector to supply the continued global
demand for marine proteins (FAO 2012). In 2010, world marine farming production
72
N. Goseberg et al.
Zealand. New Zealand has designated over 10,000 ha of permitted open ocean
water space for shellfish farming. The farms range from 8 to 20 km out to sea and a
depth of 35–80 m of water. Research has been ongoing for the last 10 years and the
first commercial efforts are now developing in the Bay of Plenty. New methods are
being developed which should increase efficiency and reduce maintenance with a
particular focus on Greenshell mussel (Perna canaliculus) and the Pacific Oyster
(Crassostrea gigas), Flat Oyster (Tiostrea chilensis) and various seaweeds. The
second case study involves a long-term, open ocean aquaculture (OOA) research
project conducted by the University of New Hampshire. During the course of
approximately 10 years, the technological aspects of OOA farming were conducted
with submersible cages and longlines, surface feeding systems and real time
environmental telemetry. The grow-out potential of multiple marine species such as
cod (Gadus morhua), haddock (Melanogrammus aeglefinus), halibut (Hippoglossus
hippoglossus), blue mussel (Mytilus edulis), sea scallop (Placopecten magellanicus)
and steelhead trout (Oncorhynchus mykiss) were investigated at a site 12 km from
shore. The last study presents a multi-use aspect of aquaculture for an open ocean
site with fish cages attached to existing offshore wind energy foundations.
Technological components such as mounting forces and scour tendencies of two
different cage structures (cylindrical and spherical) were investigated by means of
hydraulic scale modeling. The cages were pre-designed on the basis of linear theory
and existing standards and subsequently exposed to some realistic offshore wave
conditions. The wind farm “Veja Mate” in German waters with 80 planned 5 MW
turbines anchored to the ground by tripiles is taken as the basis for the tested wave
conditions. Based on findings stemming from the three example approaches conclusions are drawn and future research demand is reported.
3.1 Introduction
As the worldwide exploitation rate of capture fisheries continues, the development
of sustainable aquaculture practices is increasing to meet the seafood needs of the
growing world population. The demand for aquatic products was historically satisfied firstly by an effort to expand wild catch and secondly by increasing
land-based and near-shore aquaculture. However, stagnation in wild catch as well
as environmental and societal challenges of land-based and near-shore aquaculture
have greatly promoted efforts to development farming offshore technologies for
harsh, high energetic environments. As a consequence, ocean domestication is of
key importance to maintain the ocean as a sustainable source of food, both economically and ecologically (Marra 2005).
While the annual growth rate of aquaculture production has been 6.3%, total
aquaculture production grew from 34.6 million tons in 2001 to 59.9 million tons in
2010; thus it depicts the second important sector to supply the continued global
demand for marine proteins (FAO 2012). In 2010, world marine farming production
72
N. Goseberg et al.