TY - JOUR

T1 - Large-scale laboratory experiments on mussel dropper lines in ocean surface waves

AU - Gieschen, Rebekka

AU - Schwartpaul, Christian

AU - Landmann, Jannis

AU - Fröhling, Lukas

AU - Hildebrandt, Arndt

AU - Goseberg, Nils

N1 - Funding Information: Acknowledgments: This research was supported with funding from the New Zealand Ministry of Business, Innovation and Employment through the Cawthron Institute project CAWX1607. Furthermore, the authors gratefully thank Tim Staufenberger from Kieler Meeresfarm for providing the mussel specimen, as well as Dirk and Daniela Haase from Meerwasseraquaristik Haase for providing cooling and aeration equipment for mussel storage. We acknowledge support by the German Research Foundation and the Open Access Publication Funds of Technische Universität Braunschweig.

PY - 2020/12/30

Y1 - 2020/12/30

N2 - 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 CD = 3.9 were found for live blue mussel lines and CD = 3.4 for the surrogate model, for conditions of Keulegan–Carpenter number (KC) 10 to 380, using regular wave tests.

AB - 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 CD = 3.9 were found for live blue mussel lines and CD = 3.4 for the surrogate model, for conditions of Keulegan–Carpenter number (KC) 10 to 380, using regular wave tests.

KW - Aquaculture

KW - Bivalves

KW - Large Wave Flume

KW - Physical model tests

KW - Waves

UR - http://www.scopus.com/inward/record.url?scp=85099569115&partnerID=8YFLogxK

U2 - 10.3390/jmse9010029

DO - 10.3390/jmse9010029

M3 - Article

AN - SCOPUS:85099569115

VL - 9

SP - 1

EP - 20

JO - Journal of Marine Science and Engineering

JF - Journal of Marine Science and Engineering

IS - 1

M1 - 29

ER -