Technological Approaches to Longline- and Cage-Based Aquaculture in Open Ocean Environments

verfasst von

Nils Goseberg, Michael D. Chambers, Kevin Heasman, David Fredriksson, Arne Fredheim, Torsten Schlurmann

Abstract

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. This contribution thus highlights recent technological approaches based on three sample sites which reach out from sheltered near-shore aquaculture sites to sites with harsh wave/current conditions. It compares and evaluates existing technological approaches based on a broad literature review; on this basis, we then strongly advocate for presently available aquaculture technologies to merge with future offshore structures and platforms and to unveil its added value through synergetic multi-use concepts. The first example 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.

Organisationseinheit(en)

Ludwig-Franzius-Institut für Wasserbau, Ästuar- und Küsteningenieurwesen

Externe Organisation(en)

University of New Hampshire
United States Naval Academy
SINTEF Fisheries and Aquaculture
Cawthron Institute

Typ

Beitrag in Buch/Sammelwerk

Seiten

71-95

Anzahl der Seiten

25

Publikationsdatum

07.04.2017

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Allgemeine Agrar- und Biowissenschaften, Allgemeiner Maschinenbau, Volkswirtschaftslehre, Ökonometrie und Finanzen (insg.), Allgemeine Unternehmensführung und Buchhaltung, Allgemeine Sozialwissenschaften, Allgemeine Umweltwissenschaft

Ziele für nachhaltige Entwicklung

SDG 14 – Lebensraum Wasser

Elektronische Version(en)

https://doi.org/10.1007/978-3-319-51159-7_3 (Zugang: Offen)
https://doi.org/10.1007/978-3-319-51159-7_3 (Zugang: Unbekannt)
https://www.scopus.com/inward/record.uri?eid=2-s2.0-85028823530&doi=10.1007%2f978-3-319-51159-7_3&partnerID=40&md5=a2fe9652ed31db029e9e28f96afd05e3 (Zugang: Unbekannt)