Large-scale laboratory experiments on mussel dropper lines in ocean surface waves

authored by: Rebekka Gieschen, Christian Schwartpaul, Jannis Landmann, Lukas Fröhling, Arndt Hildebrandt, Nils Goseberg
Abstract: The rapid growth of marine aquaculture around the world accentuates issues of sustainabil-ity and environmental impacts of large-scale farming systems. One potential mitigation strategy is to relocate to more energetic offshore locations. However, research regarding the forces which waves and currents impose on aquaculture structures in such conditions is still scarce. The present study aimed at extending the knowledge related to live blue mussels (Mytilus edulis), cultivated on dropper lines, by unique, large-scale laboratory experiments in the Large Wave Flume of the Coastal Research Center in Hannover, Germany. Nine-months-old live dropper lines and a surrogate of 2.0 m length each are exposed to regular waves with wave heights between 0.2 and 1.0 m and periods between 1.5 and 8.0 s. Force time histories are recorded to investigate the inertia and drag characteristics of live mussel and surrogate dropper lines. The surrogate dropper line was developed from 3D scans of blue mussel dropper lines, using the surface descriptor Abbott–Firestone Curve as quality parameter. Pull-off tests of individual mussels are conducted that reveal maximum attachment strength ranges of 0.48 to 10.55 N for mussels that had medium 3.04 cm length, 1.60 cm height and 1.25 cm width. Mean drag coefficients of C_D = 3.9 were found for live blue mussel lines and C_D = 3.4 for the surrogate model, for conditions of Keulegan–Carpenter number (KC) 10 to 380, using regular wave tests.
Organisation(s): Ludwig-Franzius-Institute of Hydraulics, Estuarine and Coastal Engineering
External Organisation(s): Technische Universität Braunschweig
Type: Article
Journal: Journal of Marine Science and Engineering
Volume: 9
Pages: 1-20
No. of pages: 20
Publication date: 30.12.2020
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Civil and Structural Engineering, Water Science and Technology, Ocean Engineering
Sustainable Development Goals: SDG 14 - Life Below Water
Electronic version(s): https://doi.org/10.3390/jmse9010029 (Access: Open)
http://publikationsserver.tu-braunschweig.de/get/69251 (Access: Open)