Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Abstract
This work attempts to define metrics for hydrodynamic exposure, using known oceanographic variables to provide a universal site assessment method for mariculture structures. Understanding environmental conditions driving open-ocean mariculture siting is crucial in establishing consistent ocean governance, minimizing adverse environmental impacts, and facilitating economically sustainable farm operations. To provide a metric of oceanic conditions and associated requirements for structural design and operation of aquaculture systems, six Exposure Indices (EI) are proposed that consider physical energy levels related to hydrodynamic forces at a site. Four of the proposed indices consider only environmental conditions, while the other two also consider the dimensions of the gear that is exposed to the external loads. These indices are: Exposure Velocity (EV), Exposure Velocity at Reference Depth (EVRD), Specific Exposure Energy (SEE), Depth-integrated Energy Flux (DEF), Structure-centered Depth-integrated Energy (SDE), and a Structure-centered Drag-to-Buoyancy Ratio (SDBR). While these indices are derived with a focus on aquaculture structures, they may also have applications for estimating biological stressors and operational challenges. The proposed exposure indices were evaluated for a range of known aquaculture sites around the world. A sensitivity analysis was conducted that quantified the relationship between the exposure indices and storm event return period. At a regional scale, hindcast numerical data for the German Bight combined with calculations of 50-year extreme values were used to calculate and map each proposed index spatially. Resulting maps showed that exposure is not simply a function of distance from shore. The six indices show plausible performance regarding the objective assessment of aquaculture sites. The authors herein present the indices to the aquaculture and ocean engineering communities for discussion, application, and potential adoption of one or more of the proposed indices.
Department
Mechanical Engineering
Publication Date
10-18-2024
Journal Title
Frontiers in Aquaculture
Publisher
Frontiers Media SA
Digital Object Identifier (DOI)
Document Type
Article
Recommended Citation
Lojek O, Goseberg N, Føre HM, Dewhurst T, Bölker T, Heasman KG, Buck BH, Fredriksson DW and Rickerich S (2024) Hydrodynamic exposure – on the quest to deriving quantitative metrics for mariculture sites. Front. Aquac. 3:1388280. doi: 10.3389/faquc.2024.1388280
Rights
© 2024 Lojek, Goseberg, Føre, Dewhurst, Bölker, Heasman, Buck, Fredriksson and Rickerich.
Comments
This is an open access article published by Frontiers Media SA in Frontiers in Aquaculture in 2024, available online: https://dx.doi.org/10.3389/faquc.2024.1388280