Hydrodynamics of bivalve offshore aquaculture

verfasst von

Jannis Landmann

betreut von

Arndt Hildebrandt

Abstract

Without sustainable offshore aquaculture it is impossible to achieve food security for coastal communities. Growing populations in coastal zones, amounting to approximately 40% of the entire human population, exert high pressure on coastal ecosystems and natural resources, and furthermore increase the need for additional food sources. In coastal zones, marine-based nutrients offer great potential to meet this demand. With sustainability in mind, extractive species like mussels and oysters, which require no additional food, are becoming increasingly more important. Therefore, researchers, industry representatives, and policymakers alike are seeking to utilize offshore areas for shellfish aquaculture. To successfully grow shellfish in offshore areas, it is vital to understand the complex interaction of offshore aquaculture systems with waves and currents. Modelling these interactions facilitates the development of aquaculture structures that can withstand these high-energy environments. Therefore, the aim of this thesis is to increase the understanding of the complex flow around offshore shellfish aquaculture systems and their interaction with waves and currents. The literature review reports on the hydromechanic drivers with a focus on the forces, motion, and wave-structure interaction of bivalve aquaculture systems to lay a sound basis for the analysis and interpretation of the results. From there, a lack of information regarding the motions and forces of bivalve aquaculture components in steady and oscillatory flow as well as a lack of guidance as to how the complex surface of mussel dropper lines should be modelled is identified. To address these gaps of knowledge, physical experiments with live blue mussels (Mytilus edulis), substitute surrogate models, a newly designed aquaculture system, and naturally floating islands were conducted. The results of these experiments, published in four journal manuscripts, provide insights regarding the hydrodynamic coefficients for mussel dropper lines and its influencing parameters. Furthermore, the procedural design and creation as well as the hydrodynamic fit of a surrogate structure are shown. Wave and current tests with the novel aquaculture system and the comprehensive analysis of the hydrodynamic interaction of waves and floating natural islands in a large-scale facility provide insights regarding the motion and forces. Combined, the results enhance the understanding of the hydrodynamic processes around bivalve offshore aquaculture structures.

Organisationseinheit(en)

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

Typ

Dissertation

Anzahl der Seiten

110

Publikationsdatum

2023

Publikationsstatus

Veröffentlicht

Ziele für nachhaltige Entwicklung

SDG 2 – Kein Hunger, SDG 14 – Lebensraum Wasser

Elektronische Version(en)

https://doi.org/10.15488/13574 (Zugang: Offen)